72 results on '"Armah GE"'
Search Results
2. Pattern of Breast Diseases in Accra: Review of Mammography Reports
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Brakohiapa, EK, Armah, GE, Clegg-Lamptey, JNA, and Brakohiapa, WO
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Mammography, sonography, screening study, diagnostic study, ductal carcinoma in situ, invasive ductal carcinoma - Abstract
Objectives: To document the mammographic patterns in females seeking medical attention in Accra.Design: An analytic retrospective study was conducted using data extracted from mammography request forms and corresponding radiological reports of 180 females. Setting: The radiology departments of Korle-Bu Teaching Hospital, the Trust Hospital and Medical Imaging Ghana, all located in Accra.Results: One hundred and eighty radiologic request forms for mammographic evaluations and their corresponding reports from the study period were reviewed. The mean age of the study population was 48.7 years (SD=10.0), and the median age group was the 41–50 group. There were more screening mammography evaluations (115 examinations) than diagnostic mammography evaluations (65 examinations). Most of the cases diagnosed as breast cancer were in the age group 41–50 years. Benign lesions were commoner than cancer (55 and 16 cases respectively). The commonest presenting complaint was of pain.Conclusion: The larger number of screening mammographic evaluations conducted for asymptomatic females during the study period, as compared to diagnostic mammographic evaluations for symptomatic females, suggests that educational programs on early breast cancer detection are having a positive impact on the target population. The observation that 22.8% of lesions had features suggestive of breast cancer in the study is significantly high to also warrant intensification of the existing awareness programs. As non-specific masses were the most common radiographically observed lesions, hospitals equipped with sonography and biopsy facilities that compliment their mammography are better suited for thorough breast disease evaluation.Keywords: Mammography, sonography, screening study, diagnostic study, ductal carcinoma in situ, invasive ductal carcinoma.
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- 2014
3. The African Vaccine-Preventable Diseases Network: a vaccine advocacy initiative
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Wiysonge, CS, primary, Armah, GE, additional, Madhi, SA, additional, Were, F, additional, Kitaka, SB, additional, Akoua-Koffi, C, additional, Gresenguet, G, additional, Gatheru, Z, additional, Maranga, PW, additional, Dicko, A, additional, Falade, AG, additional, Boula, AYC, additional, Kuit, SB, additional, Odusanya, OO, additional, Sow, PS, additional, Lakhani, N, additional, Mpabalwani, EM, additional, Tamfum, JJM, additional, and Hussey, GD, additional
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- 2011
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4. Clinical Features and Outcome of Children Admitted with Rotavirus Diarrhoea at a Tertiary Health Facility in the Gambia
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Ideh, RC, primary, Rodrigues, OP, additional, Armah, GE, additional, Lloyd-Evans, N, additional, and Enweronu-Laryea, CC, additional
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- 2011
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5. Adverse effects of mosquito coil smoke on lung, liver and certain drug metabilishing enzymes in male wistar albino rats
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Okine, LKN, primary, Nyarko, AK, additional, Armah, GE, additional, Awumbila, B, additional, Owusu, K, additional, Set-Soafia, S, additional, and Ofosuhene, M, additional
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- 2006
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6. Tumours and tumour-like lesions of the lower face at Korle Bu Teaching Hospital, Ghana – an eight year study
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Ampofo Patrick, Armah George, and Parkins Grace EA
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Surgery ,RD1-811 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Abstract Background The oro-facial region including the jawbones, the maxilla and mandible and related tissues can be the site of a multitude of neoplastic conditions. These tumours have a predilection for the entire facial region; however, odontogenic tumours tend to affect the mandible more than the maxilla, especially, in West African children. We report results from a retrospective study spanning eight years on the frequency, clinical presentation, sites and character of lower face tumours seen in the main referral hospital in Ghana. Patients and methods Records of consecutive patients of all age and sex seen by the first author's team at the Department of Oral and Maxillofacial Surgery, Korle-Bu Teaching Hospital with tumours affecting the lower part of the face from January 1996 to December 2003 were retrieved, coded and entered into a database. The data were then analyzed by age, sex, presenting signs and symptoms, site of lesion, and their histology. Results A total of 394 patients with oro-facial swellings were retrieved from the registry out of which 210 had lower face tumour and tumour-like lesions. The complete data set was obtained for 171 patients, comprising 99 (58%) males and 72 (42%) females. The most common clinical presenting features were mandibular facial swelling (63%), intra-oral swelling (55%), pain (41%) and ulceration (29%). The tumours were predominantly found in the right (43%), anterior (19%) and left (18%) aspects of the lower face. The remainder making up 20% were found in the floor of the mouth, tongue and lips. Seventy eight (45.6%) of the patients presented with lesions that were classified as malignant of which 54 (62%) were diagnosed as squamous cell carcinoma (SCC). Sixty-two (36.3%) had benign odontogenic tumours and thirty-one (18.1%) had non-odontogenic tumour-like lesions. Fifty-four (62%) of malignant tumours were squamous cell carcinoma; 58 (93.6%) of the benign odontogenic tumours were classified as ameloblastoma. The mean age at presentation of all lesions was 40.4 years with over 50% of benign lesions in patients aged between 11 and 30 years. Malignant tumours were more commonly detected in patients between 41 and 70 years (63%). Conclusion Tumours and tumour-like lesions of the lower face comprising the mandible, tongue and adjacent structures are a diverse group of neoplasm and are seen commonly in practice of Maxillofacial surgery. Both malignant and benign tumours are seen in the Ghanaian population. In the present study, SCC and ameloblastoma were the commonest malignant and benign odontogenic tumours seen respectively; the two representing more than 65% of all tumours.
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- 2007
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7. Impact of dosing schedules on performance of rotavirus vaccines in Ghana.
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Asare EO, Al-Mamun MA, Armah GE, Lopman BA, and Pitzer VE
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Background: Available live-oral rotavirus vaccines are associated with low to moderate performance in low- and middle-income settings. There is limited evidence relating to how the vaccine dosing schedule might be adjusted to improve vaccine performance in these settings., Methods: We used mathematical models fitted to rotavirus surveillance data for children <5 years of age from three different hospitals in Ghana (Korle-Bu Teaching Hospital in Accra, Komfo Anokye Teaching Hospital in Kumasi and War Memorial Hospital in Navrongo) to project the impact of rotavirus vaccination over a 10-year period (April 2012-March 2022). We quantified and compared the impact of the previous vaccination program in Ghana to the model-predicted impact for other vaccine dosing schedules across the three hospitals and the entire country, under different assumptions about vaccine protection. To project the rotavirus vaccine impact over Ghana, we sampled from the range of model parameters for Accra and Navrongo, assuming that these two settings represent the "extremes" of rotavirus epidemiology within Ghana., Results: For the previously implemented 6/10-week monovalent Rotarix vaccine (RV1) schedule, the model-estimated average annual incidence of moderate-to-severe rotavirus-associated gastroenteritis (RVGE) ranged between 1,151 and 3,002 per 100,000 people per year over the 10-year period for the three sites. Compared to no vaccination, the model-estimated median percentage reductions in RVGE ranged from 28-85% and 12-71% among children <1 year and <5 years of age respectively, with the highest and lowest percentage reductions predicted using model parameters estimated for Accra and Navrongo, respectively. The median predicted reductions in RVGE for the whole country ranged from 57-66% and 35-45% among children <1 year and <5 years of age, respectively. The 1/6/10- and 6/10/14-week schedules provided the best and comparable reductions in RVGE compared to the original 6/10-week schedule, whereas there was no improvement in impact for the 10/14-week schedule., Conclusions: We found that administering an additional dose of RV1 might be an effective strategy to improve rotavirus vaccine impact, particularly in settings with low vaccine effectiveness. The results could be extrapolated to other countries using a 2-dose vaccine schedule with low to moderate vaccine performance., Competing Interests: Conflict of interest VEP is a member of the WHO Immunization and Vaccine-related Implementation Research Advisory Committee (IVIR-AC).
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- 2024
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8. Emergence of Intergenogroup Reassortant G9P[4] Strains Following Rotavirus Vaccine Introduction in Ghana.
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Doan YH, Dennis FE, Takemae N, Haga K, Shimizu H, Appiah MG, Lartey BL, Damanka SA, Hayashi T, Suzuki T, Kageyama T, Armah GE, and Katayama K
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- Child, Humans, Ghana epidemiology, Genome, Viral, Reassortant Viruses genetics, Phylogeny, Genotype, Rotavirus Infections epidemiology, Rotavirus Infections prevention & control, Rotavirus Infections genetics, Rotavirus Vaccines, Rotavirus genetics
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Rotavirus (RVA) is a leading cause of childhood gastroenteritis. RVA vaccines have reduced the global disease burden; however, the emergence of intergenogroup reassortant strains is a growing concern. During surveillance in Ghana, we observed the emergence of G9P[4] RVA strains in the fourth year after RVA vaccine introduction. To investigate whether Ghanaian G9P[4] strains also exhibited the DS-1-like backbone, as seen in reassortant G1/G3/G8/G9 strains found in other countries in recent years, this study determined the whole genome sequences of fifteen G9P[4] and two G2P[4] RVA strains detected during 2015-2016. The results reveal that the Ghanaian G9P[4] strains exhibited a double-reassortant genotype, with G9-VP7 and E6-NSP4 genes on a DS-1-like backbone (G9-P[4]-I2-R2-C2-M2-A2-N2-T2-E6-H2). Although they shared a common ancestor with G9P[4] DS-1-like strains from other countries, further intra-reassortment events were observed among the original G9P[4] and co-circulating strains in Ghana. In the post-vaccine era, there were significant changes in the distribution of RVA genotype constellations, with unique strains emerging, indicating an impact beyond natural cyclical fluctuations. However, reassortant strains may exhibit instability and have a limited duration of appearance. Current vaccines have shown efficacy against DS-1-like strains; however, ongoing surveillance in fully vaccinated children is crucial for addressing concerns about long-term effectiveness.
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- 2023
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9. The Full Impact of Rotavirus Vaccines in Africa Has Yet to Be Realized.
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Steele AD, Armah GE, Mwenda JM, and Kirkwood CD
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- Humans, Infant, Diarrhea epidemiology, Diarrhea prevention & control, Africa epidemiology, Vaccination, Rotavirus Vaccines, Rotavirus Infections epidemiology, Rotavirus Infections prevention & control, Rotavirus
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Africa bears the brunt of diarrheal mortality globally. Rotavirus vaccination rates are high across the continent and demonstrate impact on diarrheal disease reduction. Nevertheless, there is room for significant improvement in managing rotavirus vaccine coverage, in access to recognized public services such as appropriate medical care, including oral rehydration therapy and improved water and sanitation., Competing Interests: Potential conflicts of interest . The authors report no conflicts of interest. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)
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- 2023
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10. Maintaining Momentum for Rotavirus Immunization in Africa during the COVID-19 Era: Report of the 13th African Rotavirus Symposium.
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Were FN, Jere KC, Armah GE, Mphahlele MJ, Mwenda JM, and Steele AD
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The 13th African Rotavirus Symposium was held as a virtual event hosted by the University of Nairobi, Kenya and The Kenya Paediatric Association on 3rd and 4th November 2021. This biennial event organized under the auspices of the African Rotavirus Network shapes the agenda for rotavirus research and prevention on the continent, attracting key international and regional opinion leaders, researchers, and public health scientists. The African Rotavirus Network is a regional network of institutions initially established in 1999, and now encompassing much of the diarrheal disease and rotavirus related research in Africa, in collaboration with the World Health Organization African Regional Office (WHO-AFRO), Ministries of Health, and other partners. Surges in SARS-CoV2 variants and concomitant travel restrictions limited the meeting to a webinar platform with invited scientific presentations and scientific presentations from selected abstracts. The scientific program covered updates on burden of diarrheal diseases including rotavirus, the genomic characterization of rotavirus strains pre- and post-rotavirus vaccine introduction, and data from clinical evaluation of new rotavirus vaccines in Africa. Finally, 42 of the 54 African countries have fully introduced rotavirus vaccination at the time of the meeting, including the two recently WHO pre-qualified vaccines from India. Nonetheless, the full benefit of rotavirus vaccination is yet to be realized in Africa where approximately 80% of the global burden of rotavirus mortality exists.
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- 2022
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11. Estimating the cost of COVID-19 vaccine deployment and introduction in Ghana using the CVIC tool.
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Nonvignon J, Owusu R, Asare B, Adjagba A, Aun YW, Yeung KHT, Azeez JNK, Gyansa-Lutterodt M, Gulbi G, Amponsa-Achiano K, Dadzie F, Armah GE, Brenzel L, Hutubessy R, and Resch SC
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- Ghana epidemiology, Humans, Immunization Programs, SARS-CoV-2, COVID-19 prevention & control, COVID-19 Vaccines
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Background: This study estimated cost of COVID-19 vaccine introduction and deployment in Ghana., Methods: Using the WHO-UNICEF COVID-19 Vaccine Introduction and deployment Costing (CVIC) tool Ghana's Ministry of Health Technical Working Group for Health Technology Assessment (TWG-HTA) in collaboration with School of Public Health, University of Ghana, organized an initial two-day workshop that brought together partners to deliberate and agree on input parameters to populate the CVIC tool. A further 2-3 days validation with the Expanded Program of Immunization (EPI) and other partners to finalize the analysis was done. Three scenarios, with different combinations of vaccine products and delivery modalities, as well as time period were analyzed. The scenarios included AstraZeneca (40%), Johnson & Johnson (J&J) (30%), Moderna, Pfizer, and Sputnik V at 10% each; with primary schedule completed by second half of 2021 (Scenario 1); AstraZeneca (30%), J&J (40%), Moderna, Pfizer, and Sputnik V at 10% each with primary schedule completed by first half of 2022 (Scenario 2); and equal distribution (20%) among AstraZeneca, J&J, Moderna, Pfizer, and Sputnik V with primary schedule completed by second half of 2022 (Scenario 3)., Results: The estimated total cost of COVID-19 vaccination ranges between $348.7 and $436.1 million for the target population of 17.5 million. These translate into per person completed primary schedule cost of $20.9-$26.2 and per dose (including vaccine cost) of $10.5-$13.1. Again, per person completed primary schedule excluding vaccine cost was $4.5 and $4.6, thus per dose excluding vaccine also ranged from $2.2 - $2.3. The main cost driver was vaccine doses, including shipping, which accounts for between 78% and 83% of total cost. Further, an estimated 8,437-10,247 vaccinators (non-FTEs) would be required during 2021-2022 to vaccinate using a mix of delivery strategies, accounting for 8-10% of total cost., Conclusion: These findings provide the estimates to inform resource mobilization efforts by government and other partners., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Justice Nonvignon reports administrative support was provided by Ghana Ministry of Health. Stephen C. Resch reports article publishing charges was provided by Bill & Melinda Gates Foundation., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
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- 2022
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12. Detection of Enterotoxigenic Escherichia coli in Rotavirus-Infected Ghanaian Children Diagnosed with Acute Gastroenteritis.
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Dzudzor B, Amenyedor A, Amarh V, and Armah GE
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- Acute Disease, Child, Preschool, Diarrhea epidemiology, Diarrhea etiology, Diarrhea microbiology, Diarrhea virology, Escherichia coli Infections epidemiology, Escherichia coli Infections microbiology, Female, Gastroenteritis epidemiology, Gastroenteritis etiology, Gastroenteritis microbiology, Ghana epidemiology, Humans, Infant, Infant, Newborn, Male, Rotavirus Infections epidemiology, Enterotoxigenic Escherichia coli isolation & purification, Escherichia coli Infections complications, Gastroenteritis diagnosis, Rotavirus Infections complications
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Diarrhea is a notable global health problem in several developing countries, especially in children. Prior to the introduction of the rotavirus vaccination program in Ghana, a surveillance study was conducted to investigate the prevalence of the disease caused by rotavirus in children. In this report, we re-used archival stool samples from the pre-vaccine surveillance study to provide information on prevalence of enterotoxigenic Escherichia coli in Ghanaian children. Re-analysis of the stool samples revealed co-infection of enterotoxigenic E. coli and rotavirus in 2% of the children whose samples were selected for this study. As Ghana is approaching 10 years post-implementation of the rotavirus vaccination program, the preliminary data presented in this report are a vital reference for subsequent studies aimed at ascertaining the effect of the vaccine on both rotavirus and enterotoxigenic E. coli.
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- 2021
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13. Understanding Pediatric Norovirus Epidemiology: A Decade of Study among Ghanaian Children.
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Lartey BL, Quaye O, Damanka SA, Agbemabiese CA, Armachie J, Dennis FE, Enweronu-Laryea C, and Armah GE
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- Caliciviridae Infections diagnosis, Child, Preschool, Feces virology, Female, Gastroenteritis virology, Genetic Variation, Ghana epidemiology, Humans, Infant, Infant, Newborn, Male, Norovirus classification, Phylogeny, Prevalence, Sequence Analysis, DNA, Virus Shedding, Caliciviridae Infections epidemiology, Gastroenteritis epidemiology, Genotype, Norovirus genetics
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Understanding the epidemiology of human norovirus infection in children within Ghana and the entire sub-Saharan African region, where future norovirus vaccines would have the greatest impact, is essential. We analyzed 1337 diarrheic stool samples collected from children <5 years from January 2008 to December 2017 and found 485 (36.2%) shedding the virus. GII.4 (54.1%), GII.3 (7.7%), GII.6 (5.3%), GII.17 (4.7%), and GII.5 (4.7%) were the most common norovirus genotypes. Although norovirus GII.4 remained the predominant capsid genotype throughout the study period, an increase in GII.6 and GII.3 capsid genotypes was observed in 2013 and 2014, respectively. The severity of clinical illness in children infected with GII.4 norovirus strains was similar to illness caused by non-GII.4 strains. Since the epidemiology of norovirus changes rapidly, establishment of systematic surveillance within sentinel sites across the country would enhance the monitoring of circulating norovirus strains and allow continuous understanding of norovirus infection in Ghana.
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- 2020
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14. Modeling of rotavirus transmission dynamics and impact of vaccination in Ghana.
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Asare EO, Al-Mamun MA, Armah GE, Lopman BA, Parashar UD, Binka F, and Pitzer VE
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- Child, Child, Preschool, Ghana epidemiology, Humans, Infant, Vaccination, Rotavirus, Rotavirus Infections epidemiology, Rotavirus Infections prevention & control, Rotavirus Vaccines
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Background: Rotavirus incidence remains relatively high in low-income countries (LICs) compared to high-income countries (HICs) after vaccine introduction. Ghana introduced monovalent rotavirus vaccine in April 2012 and despite the high coverage, vaccine performance has been modest compared to developed countries. The predictors of low vaccine effectiveness in LICs are poorly understood, and the drivers of subnational heterogeneity in rotavirus vaccine impact are unknown., Methods: We used mathematical models to investigate variations in rotavirus incidence in children <5 years old in Ghana. We fit models to surveillance and case-control data from three different hospitals: Korle-Bu Teaching Hospital in Accra, Komfo Anokye Teaching Hospital in Kumasi, and War Memorial Hospital in Navrongo. The models were fitted to both pre- and post-vaccine data to estimate parameters describing the transmission rate, waning of maternal immunity, and vaccine response rate., Results: The seasonal pattern and age distribution of rotavirus cases varied among the three study sites in Ghana. Our model was able to capture the spatio-temporal variations in rotavirus incidence across the three sites and showed good agreement with the age distribution of observed cases. The rotavirus transmission rate was highest in Accra and lowest in Navrongo, while the estimated duration of maternal immunity was longer (~5 months) in Accra and Kumasi and shorter (~3 months) in Navrongo. The proportion of infants who responded to the vaccine was estimated to be high in Accra and Kumasi and low in Navrongo., Conclusions: Rotavirus vaccine impact varies within Ghana. A low vaccine response rate was estimated for Navrongo, where rotavirus is highly seasonal and incidence limited to a few months of the year. Our findings highlight the need to further explore the relationship between rotavirus seasonality, maternal immunity, and vaccine response rate to determine how they influence vaccine effectiveness and to develop strategies to improve vaccine impact., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)
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- 2020
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15. Next-generation sequencing of a human-animal reassortant G6P[14] rotavirus A strain from a child hospitalized with diarrhoea.
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Damanka SA, Dennis FE, Lartey BL, Nyarko KM, Agbemabiese CA, and Armah GE
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- Animals, Diarrhea therapy, Feces virology, Genome, Viral, Ghana, Goats, High-Throughput Nucleotide Sequencing, Hospitalization, Humans, Infant, Phylogeny, Reassortant Viruses classification, Reassortant Viruses genetics, Rotavirus classification, Rotavirus genetics, Rotavirus Infections therapy, Sheep, Diarrhea virology, Goat Diseases virology, Reassortant Viruses isolation & purification, Rotavirus isolation & purification, Rotavirus Infections veterinary, Rotavirus Infections virology, Sheep Diseases virology
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We previously reported the VP4 and the VP7 genotypes of the first G6P[14] rotavirus strain (RVA/Human-wt/GHA/M0084/2010/G6P[14]) from the stool of an infant with diarrhoea in Ghana. In the current study, we obtained the complete genome sequences using Illumina MiSeq next-generation sequencing to enable us to determine the host species origin of the genes by phylogenetic analysis. The genotype constellation was G6-P[14]-I2-R2-C2-M2-A11-N2-T6-E2-H3. Phylogenetic analysis showed that M0084 was a reassortant strain from RVAs of both artiodactyl and human host species origin. The level of sequence identity of the individual genes of M0084 to other sequences in the GenBank ranged from 95.2 to 99.5%; however, there was no single strain from the GenBank database with a complete genome sequence that was highly similar to that of M0084. To help trace the source of such unique gene pools being introduced into human RVAs, it will be useful to examine RVA sequences from potential reservoirs such as sheep and goats, which are common domestic animals in this locality.
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- 2020
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16. Distribution of rotavirus genotypes in the postvaccine introduction era in Ashaiman, Greater Accra Region, Ghana, 2014-2016.
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Letsa V, Damanka S, Dennis F, Lartey B, Armah GE, Betrapally N, Gautam R, Esona MD, Bowen MD, and Quaye O
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- Animals, Child, Preschool, Gastroenteritis epidemiology, Ghana epidemiology, Humans, Infant, Phylogeny, Prevalence, RNA, Viral genetics, Rotavirus Infections transmission, Rotavirus Infections virology, Sequence Analysis, DNA, Zoonoses epidemiology, Zoonoses virology, Feces virology, Gastroenteritis virology, Genotype, Rotavirus genetics, Rotavirus Infections epidemiology
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Group A Rotaviruses (RVAs) are the most important etiological agents of acute gastroenteritis (AGE) in children less than 5 years of age. Mortality resulting from RVA gastroenteritis is higher in developing countries than in developed ones, causing a huge public health burden in global regions like Africa and South-East Asia. This study reports RVA genotypes detected in Ashaiman, Greater Accra Region, Ghana, in the postvaccine introduction era for the period 2014-2016. Stool samples were collected from children less than 5 years of age who visited Ashaiman Polyclinic with AGE from November 2014 to May 2015 and from December 2015 to June 2016. The samples were tested by enzyme immunoassay (EIA), and one-step multiplex reverse transcription polymerase chain reaction was performed on the EIA positive samples for gel-based binomial genotyping. Of the 369 stool samples collected from children with AGE, 145 (39%) tested positive by EIA. Five VP7 (G1, G3, G9, G10, and G12) and three VP4 (P[4], P[6] and P[8]) genotypes were detected. Eight G/P combinations were identified of which, G3P[6], G12P[8], G1P[8], and G9P[4] were the most prevalent and responsible for 93 (68%) of the AGE cases, and seven mixed-types were detected which represented 8% of the RVA cases. High prevalence, diversity, and mixed-types of RVAs were detected from Ashaiman with the emergence of unusual genotypes., (© 2019 Wiley Periodicals, Inc.)
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- 2019
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17. Genetic analysis of Ghanaian G1P[8] and G9P[8] rotavirus A strains reveals the impact of P[8] VP4 gene polymorphism on P-genotyping.
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Damanka SA, Agbemabiese CA, Dennis FE, Lartey BL, Adiku TK, Enweronu-Laryea CC, and Armah GE
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- Antigens, Viral genetics, Child, Preschool, Genotype, Ghana epidemiology, Humans, Infant, Molecular Epidemiology, Phylogeny, Polymorphism, Genetic, RNA, Viral genetics, Rotavirus classification, Rotavirus Infections epidemiology, Capsid Proteins genetics, Rotavirus genetics, Rotavirus Infections virology
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The World Health Organisation rotavirus surveillance networks have documented and shown eclectic geographic and temporal diversity in circulating G- and P- genotypes identified in children <5 years of age. To effectively monitor vaccine performance and effectiveness, robust molecular and phylogenetic techniques are essential to detect novel strain variants that might emerge due to vaccine pressure. This study inferred the phylogenetic history of the VP7 and VP4 genes of previously non-typeable strains and provided insight into the diversity of P[8] VP4 sequences which impacted the outcome of our routine VP4 genotyping method. Near-full-length VP7 gene and the VP8* fragment of the VP4 gene were obtained by Sanger sequencing and genotypes were determined using RotaC v2.0 web-based genotyping tool. The genotypes of the 57 rotavirus-positive samples with sufficient stool was determined. Forty-eight of the 57 (84.2%) had the P[8] specificity, of which 43 (89.6%) were characterized as P[8]a subtype and 5 (10.4%) as the rare OP354-like subtype. The VP7 gene of 27 samples were successfully sequenced and their G-genotypes confirmed as G1 (18/27) and G9 (9/27). Phylogenetic analysis of the P[8]a sequences placed them in subcluster IIIc within lineage III together with contemporary G1P[8], G3P[8], G8P[8], and G9P[8] strains detected globally from 2006-2016. The G1 VP7 sequences of the study strains formed a monophyletic cluster with African G1P[8] strains, previously detected in Ghana and Mali during the RotaTeq vaccine trial as well as Togo. The G9 VP7 sequences of the study strains formed a monophyletic cluster with contemporary African G9 sequences from neighbouring Burkina Faso within the major sub-cluster of lineage III. Mutations identified in the primer binding region of the VP8* sequence of the Ghanaian P[8]a strains may have resulted in the genotyping failure since the newly designed primer successfully genotyped the previously non-typeable P[8] strains. In summary, the G1, G9, and P[8]a sequences were highly similar to contemporary African strains at the lineage level. The study also resolved the methodological challenges of the standard genotyping techniques and highlighted the need for regular evaluation of the multiplex PCR-typing method especially in the post-vaccination era. The study further highlights the need for regions to start using sequencing data from local rotavirus strains to design and update genotyping primers., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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18. Whole genome characterization and evolutionary analysis of OP354-like P[8] Rotavirus A strains isolated from Ghanaian children with diarrhoea.
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Damanka SA, Kwofie S, Dennis FE, Lartey BL, Agbemabiese CA, Doan YH, Adiku TK, Katayama K, Enweronu-Laryea CC, and Armah GE
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- Genetic Variation, Genotype, Ghana, Humans, Phylogeny, Rotavirus isolation & purification, Whole Genome Sequencing, Diarrhea virology, Evolution, Molecular, Genome, Viral, Genomics methods, Rotavirus classification, Rotavirus genetics, Rotavirus Infections virology
- Abstract
In 2010, the rare OP354-like P[8]b rotavirus subtype was detected in children less than 2 years old in Ghana. In this follow-up study, to provide insight into the evolutionary history of the genome of Ghanaian P[8]b strains RVA/Human-wt/GHA/GHDC949/2010/G9P[8] and RVA/Human-wt/GHA/GHM0094/2010/G9P[8] detected in an infant and a 7-month old child hospitalised for acute gastroenteritis, we sequenced the complete genome using both Sanger sequencing and Illumina MiSeq technology followed by phylogenetic analysis of the near-full length sequences. Both strains possessed the Wa-like/genotype 1 constellation G9P[8]b-I1-R1-C1-M1-A1-N1-T1-E1-H1. Sequence comparison and phylogenetic inference showed that both strains were identical at the lineage level throughout the 11 genome segments. Their VP7 sequences belonged to the major sub-lineage of the G9-lineage III whereas their VP4 sequences belonged to P[8]b cluster I. The VP7 and VP4 genes of the study strains were closely related to a Senegalese G9P[8]b strain detected in 2009. In the remaining nine genome segments, both strains consistently clustered together with Wa-like RVA strains possessing either P[8]a or P[8]b mostly of African RVA origin. The introduction of a P[8]b subtype VP4 gene into the stable Wa-like strain backbone may result in strains that might propagate easily in the human population, with a potential to become an important public health concern, especially because it is not certain if the monovalent rotavirus vaccine (Rotarix) used in Ghana will be efficacious against such strains. Our analysis of the full genomes of GHM0094 and GHDC949 adds to knowledge of the genetic make-up and evolutionary dynamics of P[8]b rotavirus strains., Competing Interests: The authors have declared that no competing interests exist.
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- 2019
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19. Sub-genotype phylogeny of the non-G, non-P genes of genotype 2 Rotavirus A strains.
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Agbemabiese CA, Nakagomi T, Damanka SA, Dennis FE, Lartey BL, Armah GE, and Nakagomi O
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- Animals, Base Sequence genetics, Genotype, Humans, Phylogeny, Rotavirus Infections veterinary, Evolution, Molecular, Genes, Viral genetics, RNA, Viral genetics, Rotavirus genetics, Rotavirus Infections virology
- Abstract
Recent increase in the detection of unusual G1P[8], G3P[8], G8P[8], and G9P[4] Rotavirus A (RVA) strains bearing the DS-1-like constellation of the non-G, non-P genes (hereafter referred to as the genotype 2 backbone) requires better understanding of their evolutionary relationship. However, within a genotype, there is lack of a consensus lineage designation framework and a set of common sequences that can serve as references. Phylogenetic analyses were carried out on over 8,500 RVA genotype 2 genes systematically retrieved from the rotavirus database within the NCBI Virus Variation Resource. In line with previous designations, using pairwise comparison of cogent nucleotide sequences and stringent bootstrap support, reference lineages were defined. This study proposes a lineage framework and provides a dataset ranging from 34 to 145 sequences for each genotype 2 gene for orderly lineage designation of global genotype 2 genes of RVAs detected in human and animals. The framework identified five to 31 lineages depending on the gene. The least number of lineages (five to seven) were observed in genotypes A2 (NSP1), T2 (NSP3) and H2 (NSP5) which are limited to human RVA whereas the most number of lineages (31) was observed in genotype E2 (NSP4). Sharing of the same lineage constellations of the genotype 2 backbone genes between recently-emerging, unusual G1P[8], G3P[8], G8P[8] and G9P[4] reassortants and many contemporary G2P[4] strains provided strong support to the hypothesis that unusual genotype 2 strains originated primarily from reassortment events in the recent past involving contemporary G2P[4] strains as one parent and ordinary genotype 1 strains or animal RVA strains as the other. The lineage framework with selected reference sequences will help researchers to identify the lineage to which a given genotype 2 strain belongs, and trace the evolutionary history of common and unusual genotype 2 strains in circulation., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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20. Rotavirus Vaccine Take in Infants Is Associated With Secretor Status.
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Armah GE, Cortese MM, Dennis FE, Yu Y, Morrow AL, McNeal MM, Lewis KDC, Awuni DA, Armachie J, and Parashar UD
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- Child, Preschool, Female, Genotype, Ghana, Humans, Infant, Male, Rotavirus Vaccines administration & dosage, Saliva chemistry, Histocompatibility Antigens analysis, Rotavirus immunology, Rotavirus Infections prevention & control, Rotavirus Vaccines immunology, Seroconversion
- Abstract
Rotaviruses bind to enterocytes in a genotype-specific manner via histo-blood group antigens (HBGAs), which are also detectable in saliva. We evaluated antirotavirus immunoglobulin A seroconversion ('vaccine take") among 166 Ghanaian infants after 2-3 doses of G1P[8] rotavirus vaccine during a vaccine trial, by HBGA status from saliva collected at age 4.1 years. Only secretor status was associated with seroconversion: 41% seroconversion for secretors vs 13% for nonsecretors; relative risk, 3.2 (95% confidence interval, 1.2-8.1; P = .016). Neither Lewis antigen nor salivary antigen blood type was associated with seroconversion. Likelihood of "take" for any particular rotavirus vaccine may differ across populations based on HBGAs., (Published by Oxford University Press for the Infectious Diseases Society of America 2018.)
- Published
- 2019
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21. Rotavirus strain distribution in Ghana pre- and post- rotavirus vaccine introduction.
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Lartey BL, Damanka S, Dennis FE, Enweronu-Laryea CC, Addo-Yobo E, Ansong D, Kwarteng-Owusu S, Sagoe KW, Mwenda JM, Diamenu SK, Narh C, Binka F, Parashar U, Lopman B, and Armah GE
- Subjects
- Antigens, Viral genetics, Capsid Proteins genetics, Child, Preschool, Feces virology, Gastroenteritis epidemiology, Gastroenteritis prevention & control, Gastroenteritis virology, Ghana epidemiology, Humans, Immunoenzyme Techniques, Infant, Phylogeny, Prevalence, RNA, Viral genetics, Rotavirus isolation & purification, Rotavirus Infections prevention & control, Sequence Analysis, DNA, Vaccination Coverage, Vaccines, Attenuated therapeutic use, Genotype, Immunization Programs, Rotavirus genetics, Rotavirus Infections epidemiology, Rotavirus Vaccines therapeutic use
- Abstract
Background: Ghana introduced the monovalent rotavirus vaccine (Rotarix) into its national paediatric vaccination programme in May2012. Vaccine introduction was initiated nationwide and achieved >85% coverage within a few months. Rotavirus strain distribution pre- and post-RV vaccine introduction is reported., Methods: Stool samples were collected from diarrhoeic children <5 years of age hospitalized between 2009 and 2016 at sentinel sites across Ghana and analyzed for the presence of group A rotavirus by enzyme immunoassay. Rotavirus strains were characterized by RT-PCR and sequencing., Results: A total of 1363 rotavirus EIA-positive samples were subjected to molecular characterization. These were made up of 823 (60.4%) and 540 (39.6%) samples from the pre- and post-vaccine periods respectively. Rotavirus VP7 genotypes G1, G2 and G3, and VP4 genotypes P[6] and P[8] constituted more than 65% of circulating G and P types in the pre-vaccine period. The common strains detected were G1P[8] (20%), G3P[6] (9.2%) and G2P[6] (4.9%). During the post-vaccine period, G12, G1 and G10 genotypes, constituted more than 65% of the VP7 genotypes whilst P[6] and P[8] made up more than 75% of the VP4 genotypes. The predominant circulating strains were G12P[8] (26%), G10P[6] (10%) G3P[6] (8.1%) and G1P[8] (8.0%). We also observed the emergence of the unusual rotavirus strain G9P[4] during this period., Conclusion: Rotavirus G1P[8], the major strain in circulation during the pre-vaccination era, was replaced by G12P[8] as the most predominant strain after vaccine introduction. This strain replacement could be temporary and unrelated to vaccine introduction since an increase in G12 was observed in countries yet to introduce the rotavirus vaccine in West Africa. A continuous surveillance programme in the post-vaccine era is necessary for the monitoring of circulating rotavirus strains and the detection of unusual/emerging genotypes., (Copyright © 2018 Elsevier Ltd. All rights reserved.)
- Published
- 2018
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22. Identification of Amino Acid Substitutions Within the VP7 Genes of G2 Rotavirus Strains in Ghana.
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Damanka SA, Agbemabiese CA, Lartey BL, Dennis FE, Asamoah FK, Adiku TK, Enweronu-Laryea CC, Sagoe KW, Ofori MF, and Armah GE
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- Feces virology, Gastroenteritis virology, Genotype, Ghana, Humans, Phylogeny, Polymerase Chain Reaction, RNA, Viral genetics, Rotavirus Infections, Sequence Analysis, DNA, Amino Acid Substitution, Antigens, Viral genetics, Capsid Proteins genetics, Rotavirus genetics
- Abstract
We used the dideoxynucleotide chain termination method to determine the strains of nine non-typeable rotavirus enzyme immunoassay-positive samples, which were identified as G2. We detected nucleotide changes in the primer-binding region and amino acid substitutions within the VP7 protein of the G2 rotavirus strains. Genotyping primers need to be updated regularly.
- Published
- 2018
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23. Detection of Dengue Virus among Children with Suspected Malaria, Accra, Ghana.
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Amoako N, Duodu S, Dennis FE, Bonney JHK, Asante KP, Ameh J, Mosi L, Hayashi T, Agbosu EE, Pratt D, Operario DJ, Fields B, Liu J, Houpt ER, Armah GE, Stoler J, and Awandare GA
- Subjects
- Adolescent, Child, Child, Preschool, Coinfection, Cross-Sectional Studies, Dengue virology, Dengue Virus classification, Dengue Virus isolation & purification, Female, Ghana epidemiology, Humans, Infant, Infant, Newborn, Malaria parasitology, Male, Plasmodium classification, Plasmodium isolation & purification, Real-Time Polymerase Chain Reaction, Serogroup, DNA, Protozoan genetics, Dengue epidemiology, Dengue Virus genetics, Malaria epidemiology, Plasmodium genetics, RNA, Viral genetics
- Abstract
We report new molecular evidence of locally acquired dengue virus infections in Ghana. We detected dengue viral RNA among children with suspected malaria by using a multipathogen real-time PCR. Subsequent sequence analysis revealed a close relationship with dengue virus serotype 2, which was implicated in a 2016 outbreak in Burkina Faso.
- Published
- 2018
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24. Urban sanitation coverage and environmental fecal contamination: Links between the household and public environments of Accra, Ghana.
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Berendes DM, Kirby AE, Clennon JA, Agbemabiese C, Ampofo JA, Armah GE, Baker KK, Liu P, Reese HE, Robb KA, Wellington N, Yakubu H, and Moe CL
- Subjects
- Adenoviridae isolation & purification, Cluster Analysis, Escherichia coli isolation & purification, Feces microbiology, Feces virology, Ghana, Humans, Norovirus isolation & purification, Population Density, Poverty statistics & numerical data, Residence Characteristics, Waste Disposal, Fluid economics, Waste Disposal, Fluid methods, Environmental Monitoring, Environmental Pollution analysis, Sanitation statistics & numerical data, Sewage analysis
- Abstract
Exposure to fecal contamination in public areas, especially in dense, urban environments, may significantly contribute to enteric infection risk. This study examined associations between sanitation and fecal contamination in public environments in four low-income neighborhoods in Accra, Ghana. Soil (n = 72) and open drain (n = 90) samples were tested for E. coli, adenovirus, and norovirus. Sanitation facilities in surveyed households (n = 793) were categorized by onsite fecal sludge containment ("contained" vs. "uncontained") using previous Joint Monitoring Program infrastructure guidelines. Most sanitation facilities were shared by multiple households. Associations between spatial clustering of household sanitation coverage and fecal contamination were examined, controlling for neighborhood and population density (measured as enumeration areas in the 2010 census and spatially matched to sample locations). E. coli concentrations in drains within 50m of clusters of contained household sanitation were more than 3 log-units lower than those outside of clusters. Further, although results were not always statistically significant, E. coli concentrations in drains showed consistent trends with household sanitation coverage clusters: concentrations were lower in or near clusters of high coverage of household sanitation facilities-especially contained facilities-and vice versa. Virus detection in drains and E. coli concentrations in soil were not significantly associated with clustering of any type of household sanitation and did not exhibit consistent trends. Population density alone was not significantly associated with any of the fecal contamination outcomes by itself and was a significant, yet inconsistent, effect modifier of the association between sanitation clusters and E. coli concentrations. These findings suggest clustering of contained household sanitation, even when shared, may be associated with lower levels of fecal contamination within drains in the immediate public domain. Further research is needed to better quantify these relationships and examine impacts on health., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2018
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25. Epidemiological Survey of Rotaviruses Responsible for Infantile Diarrhea by the Immunomolecular Technique in Cotonou (Benin, West Africa).
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Agbla JMM, Capo-Chichi A, Agbankpé AJ, Dougnon TV, Yadouleton AWM, Houngbégnon O, Glele-Kakai C, Armah GE, and Bankolé H
- Abstract
Rotavirus remains the main causative agent of gastroenteritis in young children, in countries that have not yet introduced the vaccine. Benin, in order to implement the WHO recommendations, projects to introduce the rotavirus vaccine in 2018 as part of its Expanded Program on Immunization. But before the introduction of this vaccine, epidemiological data on rotavirus infections and rotavirus genotypes circulating in Benin should be available. The aim of this study is to generate epidemiological data on infantile rotavirus diarrhea in Benin. In order to determine the epidemiological characteristics and electrophoretypes of rotavirus responsible for gastroenteritis in diarrheic children aged 0 to 5 years, 186 stool samples were collected according to the WHO Rotavirus Laboratory Manual from March 2014 to February 2015 at Suru-Lere University Hospital Center. Detection of rotavirus antigen was performed by the ELISA test, followed by molecular characterization using polyacrylamide gel electrophoresis. 186 stool samples were analyzed for rotavirus, and seventy-three (39.2%) were found to be positive for rotavirus antigen by ELISA. Children aged 3 to 24 months were the most affected by rotavirus diarrhea in this study. Of the seventy-three children affected with rotavirus diarrhea, 27 (37%) had vomiting accompanied by dehydration and fever. Results based on electrophoresis showed that, among the 73 samples tested, 38 yielded typical rotavirus electrophoretic migration profiles.
- Published
- 2018
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26. Reaching every child with rotavirus vaccine: Report from the 10th African rotavirus symposium held in Bamako, Mali.
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Sow SO, Steele AD, Mwenda JM, Armah GE, and Neuzil KM
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- Child, Humans, Immunization Programs methods, Intussusception immunology, Mali, Vaccination methods, World Health Organization, Rotavirus immunology, Rotavirus Infections immunology, Rotavirus Infections prevention & control, Rotavirus Vaccines immunology
- Abstract
The Center for Vaccine Development - Mali (CVD - Mali), the World Health Organization's regional office in Africa (WHO/AFRO), and the CVD at the University of Maryland School of Medicine hosted the 10th African Rotavirus Symposium in Bamako, Mali on 1-2 June 2016. The symposium is coordinated by WHO/AFRO, the Regional Rotavirus Reference Laboratories, and the African Rotavirus Network (ARN), with support from the Bill & Melinda Gates Foundation. The event brings together leading rotavirus researchers, scientists, and policy-makers from across Africa and the world. Over 150 participants, from 31 countries, including 27 in Africa, joined forces to address the theme "Reaching Every Child in Africa with Rotavirus Vaccines." This symposium, the first in francophone Africa, occurred at an unprecedented time when 33 African countries had introduced rotavirus vaccines into their national immunization programs. The symposium concluded with a Call to Action to introduce rotavirus vaccines in the 21 remaining African countries, to increase access in countries with existing vaccination programs, and to continue surveillance and research on rotavirus and other diarrheal diseases., (Copyright © 2017.)
- Published
- 2017
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27. Detection of the first G6P[14] human rotavirus strain in an infant with diarrhoea in Ghana.
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Damanka S, Lartey B, Agbemabiese C, Dennis FE, Adiku T, Nyarko K, Ofori M, and Armah GE
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- Animals, Cluster Analysis, Computational Biology, Feces virology, Ghana, Humans, Infant, RNA, Viral genetics, RNA, Viral isolation & purification, Reverse Transcriptase Polymerase Chain Reaction, Rotavirus genetics, Sequence Analysis, DNA, Diarrhea virology, Genotype, Rotavirus classification, Rotavirus isolation & purification, Rotavirus Infections virology
- Abstract
Background: Rotaviruses with G6P[14] specificity are mostly isolated in cattle and have been established as a rare cause of gastroenteritis in humans. This study reports the first detection of G6P[14] rotavirus strain in Ghana from the stool of an infant during a hospital-based rotavirus surveillance study in 2010., Methods: Viral RNA was extracted and rotavirus VP7 and VP4 genes amplified by one step RT-PCR using gene-specific primers. The DNA was purified, sequenced and genotypes determined using BLAST and RotaC v2.0. Phylogenetic tree was constructed using maximum likelihood method in MEGA v6.06 software and statistically supported by bootstrapping with 1000 replicates. Phylogenetic distances were calculated using the Kimura-2 parameter model., Results: The study strain, GHA-M0084/2010 was characterised as G6P[14]. The VP7 gene of the Ghanaian strain clustered in G6 lineage-III together with artiodactyl and human rotavirus (HRV) strains. It exhibited the highest nucleotide (88.1 %) and amino acid (86.9 %) sequence identity with Belgian HRV strain, B10925. The VP8* fragment of the VP4 gene was closely related to HRV strains detected in France, Italy, Spain and Belgium. It exhibited the strongest nucleotide sequence identity (87.9 %) with HRV strains, PA169 and PR/1300 (Italy) and the strongest amino acid sequence identity (89.3 %) with HRV strain R2775/FRA/07 (France)., Conclusion: The study reports the first detection of G6P[14] HRV strain in an infant in Ghana. The detection of G6P[14], an unusual strain pre-vaccine introduction in Ghana, suggests a potential compromise of vaccine effectiveness and indicates the necessity for continuous surveillance in the post vaccine era.
- Published
- 2016
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28. Genomic constellation and evolution of Ghanaian G2P[4] rotavirus strains from a global perspective.
- Author
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Agbemabiese CA, Nakagomi T, Doan YH, Do LP, Damanka S, Armah GE, and Nakagomi O
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- Child, Preschool, Evolution, Molecular, Ghana epidemiology, Humans, Infant, Infant, Newborn, Molecular Epidemiology, Phylogeny, Reassortant Viruses classification, Reassortant Viruses genetics, Rotavirus classification, Rotavirus Infections epidemiology, Viral Proteins genetics, Genome, Viral genetics, Rotavirus genetics, Rotavirus Infections virology
- Abstract
Understanding of the genetic diversity and evolution of Rotavirus A (RVA) strains, a common cause of severe diarrhoea in children, needs to be based on the analysis at the whole genome level in the vaccine era. This study sequenced the whole genomes of six representative G2P[4] strains detected in Ghana from 2008 to 2013, and analysed them phylogenetically with a global collection of G2P[4] strains and African non-G2P[4] DS-1-like strains. The genotype constellation of the study strains was G2-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2. Strains from the same season were highly identical across the whole genome while strains from different seasons were more divergent from each other. The VP7, VP4, VP2, NSP1, and NSP5 genes belonged to lineage IVa; the VP6, VP1, NSP2, and NSP3 genes belonged to lineage V, and all these genes evolved in the same fashion as the global strains. In the NSP4 gene, lineages V (2008) and X (2009) were replaced by VI (2012/2013) whereas in the VP3 gene, lineage V (2008/2009) was replaced by VII (2012/2013) and these replacements coincided with the vaccine introduction period (2012). The evolutionary rate of the NSP4 gene was 1.2×10
-3 substitutions/site/year and was rather comparable to that of the remaining 10 genes. The multiple NSP4 lineages were explained by intra-genotype reassortment with co-circulating African human DS-1-like strains bearing G2[6], G3P[6], G6[6] and G8. There was no explicit evidence of the contribution of animal RVA strains to the genome of the Ghanaian G2P[4] strains. In summary, this study revealed the dynamic evolution of the G2P[4] strains through intra-genotype reassortment events leading to African specific lineages such IX and X in the NSP4 gene. So far, there was no evidence of a recent direct involvement of animal RVA genes in the genome diversity of African G2P[4] strains., (Copyright © 2016 Elsevier B.V. All rights reserved.)- Published
- 2016
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29. Rotavirus Infection in Children with Diarrhea at Korle-Bu Teaching Hospital, Ghana.
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Damanka S, Adiku TK, Armah GE, Rodrigues O, Donkor ES, Nortey D, and Asmah R
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- Capsid Proteins genetics, Child, Preschool, Diarrhea diagnosis, Diarrhea mortality, Diarrhea virology, Feces virology, Female, Gastroenteritis diagnosis, Gastroenteritis mortality, Gastroenteritis virology, Ghana epidemiology, Hospitalization statistics & numerical data, Hospitals, Teaching, Humans, Infant, Male, Phylogeny, Prevalence, Reverse Transcriptase Polymerase Chain Reaction, Rotavirus classification, Rotavirus isolation & purification, Rotavirus Infections diagnosis, Rotavirus Infections mortality, Rotavirus Infections virology, Survival Analysis, Diarrhea epidemiology, Gastroenteritis epidemiology, Genotype, RNA, Viral genetics, Rotavirus genetics, Rotavirus Infections epidemiology
- Abstract
Human rotavirus infection was studied over a 13-month period (January 2004 to January 2005) in children <5 years of age admitted with severe diarrhea at the Korle-Bu Teaching Hospital in Accra, Ghana. During this period, 206 hospitalizations for diarrhea were recorded, with 34.0% (70/206) being positive for rotavirus infection. Infection occurred throughout the year, with peak rotavirus infection occurring during the month of March. Hospitalization associated with rotaviruses was most common in the 6-8 month age group. The case fatality rate of rotavirus infection was 2.9% (2/70) and occurred in children <12 months of age. Four rotavirus VP7 genotypes (G1, G2, G3, and G9) were detected. The predominant genotypes were G2 (22.9%), G1 (17.1%), G9 (17.1%) and G3 (12.9%). Mixed G types were also detected. The predominant VP4 genotypes (P types) were P[6] (38.6%), P[8] (21.4%), P[4] (4.3%) and P[9] (1.4%). The predominant rotavirus strains infecting children in Accra were G9P[6] (10.0%) and G1P[8] (8.6%). Strains with unusual genotypes such as G2P[8] and G(2/3)P[6] were also detected.
- Published
- 2016
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30. Norovirus Epidemiology in Africa: A Review.
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Mans J, Armah GE, Steele AD, and Taylor MB
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- Adult, Africa epidemiology, Caliciviridae Infections virology, Carrier State epidemiology, Carrier State virology, Child, Preschool, Female, Gastroenteritis virology, Genetic Variation, Genotype, Humans, Infant, Infant, Newborn, Male, Molecular Epidemiology, Prevalence, Recombination, Genetic, Seasons, Caliciviridae Infections epidemiology, Gastroenteritis epidemiology, Norovirus genetics
- Abstract
Norovirus (NoV) is recognised as a leading cause of gastroenteritis worldwide across all age groups. The prevalence and diversity of NoVs in many African countries is still unknown, although early sero-prevalence studies indicated widespread early infection. Reports on NoVs in Africa vary widely in terms of study duration, population groups and size, inclusion of asymptomatic controls, as well as genotyping information. This review provides an estimate of NoV prevalence and distribution of genotypes of NoVs in Africa. Inclusion criteria for the review were study duration of at least 6 months, population size of >50 and diagnosis by RT-PCR. As regions used for genotyping varied, or genotyping was not always performed, this was not considered as an inclusion criteria. A literature search containing the terms norovirus+Africa yielded 74 publications. Of these 19 studies from 14 out of the 54 countries in Africa met the inclusion criteria. Data from studies not meeting the inclusion criteria, based on sample size or short duration, were included as discussion points. The majority of studies published focused on children, under five years of age, hospitalised with acute gastroenteritis. The mean overall prevalence was 13.5% (range 0.8-25.5%) in children with gastroenteritis and 9.7% (range 7-31%) in asymptomatic controls, where tested. NoV GII.4 was the predominant genotype identified in most of the studies that presented genotyping data. Other prevalent genotypes detected included GII.3 and GII.6. In conclusion, NoV is a common pathogen in children with diarrhoea in Africa, with considerable carriage in asymptomatic children. There is however, a paucity of data on NoV infection in adults.
- Published
- 2016
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31. Identification of OP354-like human rotavirus strains with subtype P[8]b in Ghanaian children with diarrhoea.
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Damanka S, Dennis FE, Agbemabiese C, Lartey B, Adiku T, Nyarko K, Enweronu-Laryea CC, Sagoe KW, Ofori M, Rodrigues O, and Armah GE
- Subjects
- Child, Preschool, DNA Primers genetics, Ghana, Humans, Infant, Phylogeny, Reverse Transcriptase Polymerase Chain Reaction, Rotavirus genetics, Sequence Analysis, DNA, Diarrhea virology, Genotype, Genotyping Techniques methods, Rotavirus classification, Rotavirus isolation & purification, Rotavirus Infections virology
- Abstract
Background: Rotaviruses with the P[8] genotype have been associated with majority of infections. Recent improvements in molecular diagnostics have delineated the P[8] genotype into P[8]a and P[8]b subtypes. P[8]a is the previously known P[8] genotype which is common whilst P[8]b subtype also known as OP354-like strain is genetically distinct, rarely detected and reported from a few countries. In a previous study, the P-types could not be determined for 80 RVA-positive samples by conventional RT-PCR genotyping methods with the recommended pool of P-genotype specific primers used in the WHO Regional Rotavirus Reference Laboratory in Ghana. The present study employed sequence-dependent cDNA amplification method to genotype previously non-typeable P-types., Methods: Viral RNAs were extracted and rotavirus VP4 genes amplified by one step RT-PCR using gene specific primers. PCR amplicons were purified, sequenced and sequences aligned with cognate gene sequences available in GenBank using the ClustalW algorithm. Phylogenetic analysis was performed using the Neighbour-Joining method in MEGA v6.06 software. Phylogenetic tree was statistically supported by bootstrapping with 1000 replicates, and distances calculated using the Kimura-2 parameter model., Results: Of the 80 RVA-positive samples, 57 were successfully sequenced and characterized. Forty-eight of these were identified as P[8] strains of which 5 were characterized as the rare P[8]b subtype. Phylogenetic analysis of the VP8* fragment of the VP4 genes of these P[8]b strains revealed a close relationship with prototype OP354-like P[8]b strain and P[8]b strains of Russian and South African P[8]b origin., Conclusion: The study highlights the importance of regularly updating the primers employed for molecular typing of rotaviruses.
- Published
- 2016
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32. Immunolocalization of the 29 kDa Schistosoma haematobium species-specific antigen: a potential diagnostic marker for urinary schistosomiasis.
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Markakpo US, Armah GE, Fobil JN, Asmah RH, Anim-Baidoo I, Dodoo AK, Madjitey P, Essuman EE, Kojima S, and Bosompem KM
- Subjects
- Animals, Biomarkers urine, Cross-Sectional Studies, Female, Fluorescent Antibody Technique, Indirect, Ghana epidemiology, Humans, Male, Predictive Value of Tests, Schistosomiasis haematobia epidemiology, Schistosomiasis haematobia urine, Species Specificity, Urinalysis, Antigens, Helminth immunology, Schistosoma haematobium isolation & purification, Schistosomiasis haematobia diagnosis
- Abstract
Background: The 29 kDa Schistosoma haematobium species-specific antigen (ShSSA) is of remarkable interest in the diagnosis of urinary schistosomiasis although it had not been fully characterized., Method: To determine the biological importance of ShSSA in S. haematobium and pathogenesis of the disease, we immunolocalized ShSSA in schistosome eggshells, miracidia and adult worm sections using indirect fluorescent antibody test (IFAT)., Results: ShSSA was strongly immunolocalized in the schistosome eggshells, selective regions of the miracidia body and walls of internal organs such as oviduct, ovary, vitelline duct and gut of the adult worm., Conclusion: The strong immunolocalization of ShSSA in schistosome eggshells and adult worm internal organs suggests that the antigens involved in the pathogenesis of urinary schistosomiasis could have originated from the eggs and adult worms of the parasite. The findings also indicate that ShSSA may play a mechanical protective role in the survival of the parasite.
- Published
- 2015
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33. Sustaining rotavirus vaccination in Africa: measuring vaccine effectiveness.
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Armah GE and Binka FN
- Subjects
- Humans, Male, Diarrhea prevention & control, Hospitalization statistics & numerical data, Rotavirus Infections prevention & control, Rotavirus Vaccines administration & dosage, Rotavirus Vaccines immunology
- Published
- 2014
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34. Identification of novel Ghanaian G8P[6] human-bovine reassortant rotavirus strain by next generation sequencing.
- Author
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Dennis FE, Fujii Y, Haga K, Damanka S, Lartey B, Agbemabiese CA, Ohta N, Armah GE, and Katayama K
- Subjects
- Animals, Base Sequence, Capsid Proteins genetics, Cattle, Child, Gene Library, Genotype, Ghana, High-Throughput Nucleotide Sequencing, Humans, Molecular Sequence Data, Phylogeny, RNA, Viral isolation & purification, RNA, Viral metabolism, Reassortant Viruses classification, Reassortant Viruses isolation & purification, Rotavirus classification, Rotavirus isolation & purification, Rotavirus Infections virology, Sequence Analysis, DNA, Viral Nonstructural Proteins genetics, Reassortant Viruses genetics, Rotavirus genetics
- Abstract
Group A rotaviruses (RVAs) are the most important etiological agent of acute gastroenteritis in children <5 years of age worldwide. The monovalent rotavirus vaccine Rotarix was introduced into the national Expanded Programme on Immunization (EPI) in Ghana in May 2012. However, there is a paucity of genetic and phylogenetic data on the complete genomes of human RVAs in circulation pre-vaccine introduction. The common bovine rotavirus VP7 genotype G8 has been sporadically detected in Ghanaian children, usually in combination with the VP4 genotype P[6]. To investigate the genomic constellations and phylogeny of RVA strains in circulation prior to vaccine introduction, the full genomes of two unusual G8P[6] strains, GH018-08 and GH019-08, detected during burden of disease surveillance, were characterized by Illumina MiSeq sequencing. The Ghanaian isolates, GH018-08 and GH019-08, exhibited the unusual, previously unreported genotype constellation G8-P[6]-I2-R2-C2-M2-A2-N2-T2-E2-H3. Phylogenetic analyses confirmed that 10 out of the 11 genes of GH018-08 and GH019-08 were identical/nearly identical, with significant variation detected only in their VP1 genes, and clearly established the occurrence of multiple independent interspecies transmission and reassortment events between co-circulating bovine/ovine/caprine rotaviruses and human DS-1-like RVA strains. These findings highlight the contribution of reassortment and interspecies transmission events to the high rotavirus diversity in this region of Africa, and justify the need for simultaneous monitoring of animal and human rotavirus strains.
- Published
- 2014
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35. Severe acute rotavirus gastroenteritis in children less than 5 years in southern Ghana: 2006-2011.
- Author
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Enweronu-Laryea CC, Sagoe KW, Mwenda JM, and Armah GE
- Subjects
- Child, Preschool, Feces virology, Female, Gastroenteritis mortality, Gastroenteritis virology, Ghana epidemiology, Hospitalization, Humans, Infant, Male, Prevalence, Prospective Studies, Rotavirus Infections mortality, Rotavirus Infections virology, Seasons, Gastroenteritis epidemiology, Rotavirus Infections epidemiology
- Abstract
Background: Rotavirus is a major cause of acute gastroenteritis (AGE) globally. Local data on disease burden will guide recommendations for rotavirus vaccination and monitoring impact of the intervention., Methods: Prospective surveillance for rotavirus gastroenteritis was conducted in 3 hospitals in southern Ghana during the period August 2006 to December 2011, as part of the African Rotavirus Surveillance Network. Clinical data and stool specimens were collected from children <5 years of age and hospitalized with AGE (defined as 3 or more watery stools for up to 7 days). Stool was tested for rotavirus by enzyme immunoassay and rotavirus genotype identified by reverse-transcriptase polymerase chain reaction., Results: We tested 3044 stool samples from 3939 children. Rotavirus was detected in 45.6%, 51.3% and 48.5% of cases at the primary, secondary and tertiary care hospital, respectively. Both genders were equally affected; 75% (2954/3939) of the cohort were aged 3-18 months. Overall, rotavirus was detected in 49.4% (1504/3044) of cases, caused over 30% of AGE hospitalizations all year round and up to 70% of cases during peak seasons. Peak season occurred during cool dry months in 2008, 2010 and 2011 and the rainy season in 2009. Mortality from AGE occurred in 1.5% (45/3044) of cases and 48.9% (22/45) of these were rotavirus positive., Conclusions: Rotavirus causes significant morbidity and mortality in young Ghanaian children. As Ghana introduced rotavirus vaccination in the national immunization program in 2012, continued surveillance is required to monitor the impact of this intervention.
- Published
- 2014
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36. A chronic toxicity study of the ground root bark of Capparis erythrocarpus (Cappareceae) in male Sprague-Dawley rats.
- Author
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Martey ON, Armah GE, Sittie AA, and Okine LK
- Subjects
- Animals, Biomarkers blood, Biomarkers urine, Blood Coagulation drug effects, Body Weight drug effects, Male, Organ Size drug effects, Phytotherapy, Plant Bark, Plant Roots, Plants, Medicinal, Rats, Rats, Sprague-Dawley, Sleep drug effects, Time Factors, Toxicity Tests, Chronic, Capparis chemistry, Plant Extracts toxicity
- Abstract
The safety evaluation of Capparis erythrocarpus (CE) on chronic administration at 18 and 180 mg kg(-1) body weight for 6 months was investigated in male Sprague-Dawley rats. The effects of CE on certain serum biochemical, haematological, urine and histopathological determinations were used as indices of organ specific toxicity. Also the effects of CE on rat blood clotting time and pentobarbital-induced sleeping time were determined. Results indicate that CE had no effect on urine, haematological and serum biochemical indices at termination of treatment with the exception of serum ALT level which was significantly (p < 0.05) attenuated in a dose-dependent fashion (21-35%). There were also no differences in blood clotting time and pentobarbital-induced sleeping time between CE-treated and control animals. Histopathological studies showed that CE did not adversely affect the morphology of the liver, kidney and heart tissues. However, lungs of CE-treated animals showed slight but insignificant inflammatory response in alveolar areas and Clara cell hyperplasia without the thickening of alveolar septa and bronchiolar epithelial wall. Organ weights were not adversely affected by CE treatment. There were significant (p < 0.05) changes in weight of CE-treated animals with duration of treatment compared to control. These results suggest that there is no organ specific toxicity associated with chronic administration of CE in rats and its ability to reduce body weight may be useful for slimming in obese persons.
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- 2013
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37. Rotavirus genotypes associated with childhood severe acute diarrhoea in southern Ghana: a cross-sectional study.
- Author
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Enweronu-Laryea CC, Sagoe KW, Damanka S, Lartey B, and Armah GE
- Subjects
- Child, Preschool, Cross-Sectional Studies, Electrophoresis, Polyacrylamide Gel, Enzyme-Linked Immunosorbent Assay, Feces virology, Female, Gastroenteritis epidemiology, Genetic Variation, Genotype, Ghana epidemiology, Hospitalization, Humans, Infant, Infant, Newborn, Male, Molecular Epidemiology, Prevalence, RNA, Viral genetics, Reverse Transcriptase Polymerase Chain Reaction, Rotavirus isolation & purification, Rotavirus Infections epidemiology, Gastroenteritis pathology, Gastroenteritis virology, Rotavirus classification, Rotavirus genetics, Rotavirus Infections pathology, Rotavirus Infections virology
- Abstract
Background: Rotavirus immunization has been effective in developed countries where genotype G1P[8] is the predominant rotavirus strain. Knowledge of circulating strains in a population before introduction of rotavirus immunization program will be useful in evaluating the effect of the intervention., Methods: Rotavirus was identified by enzyme immuno-assay (EIA) on stool specimens of children (age 0-59 months) hospitalized with acute gastroenteritis from August 2007 to February 2011 in Accra, Ghana. Rotavirus positive specimens were further characterized by polyacrylamide gel electrophoresis (PAGE) and reverse-transcriptase polymerase chain reaction (RT-PCR)., Results: Of the 2277 acute gastroenteritis hospitalizations 1099 (48.2%) were rotavirus-positive by EIA. Of the 1099 cases 977 (89%) were PAGE positive. All EIA positive specimens were further subjected to RT-PCR and 876 (79.7%) had sufficient material for characterization. Of these 876 cases, 741 (84.6%) were assigned G genotype, 709 (80.9%) P genotype, and 624 (71.2%) both G and P genotypes. We identified 8 G genotypes (G1, G2, G3, G4, G8, G9, G10, G12) and 3 P genotypes (P[4], P[6], P[8]). G1 (50.9%), G2 (18.8%), G3 (12.8%), P[8] (36.1%) and P[6] (30.7%) were the most prevalent. The most prevalent genotype combination was G1P[8] (28%). Mixed G (7.3%) and P (24.2%) genotypes were not uncommon. There was year-by-year and seasonal variations for most genotypes., Conclusion: There is great diversity of rotavirus strains in children with severe gastroenteritis in southern Ghana. Even though cross-protection with vaccine-induced immunity occurs, continued strain surveillance is recommended after the introduction of rotavirus vaccine in the national immunization program.
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- 2013
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38. Human G9P[8] rotavirus strains circulating in Cameroon, 1999-2000: Genetic relationships with other G9 strains and detection of a new G9 subtype.
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Esona MD, Mijatovic-Rustempasic S, Foytich K, Roy S, Banyai K, Armah GE, Steele AD, Volotão EM, Gomez MM, Silva MF, Gautam R, Quaye O, Tam KI, Forbi JC, Seheri M, Page N, Nyangao J, Ndze VN, Aminu M, Bowen MD, and Gentsch JR
- Subjects
- Amino Acid Sequence, Antigens, Viral genetics, Cameroon, Capsid Proteins genetics, Child, Preschool, Genome, Viral, Humans, Infant, Molecular Sequence Data, Phylogeny, Sequence Alignment, Rotavirus classification, Rotavirus genetics, Rotavirus Infections virology
- Abstract
Group A rotaviruses (RV-A) are the leading cause of viral gastroenteritis in children worldwide and genotype G9P[8] is one of the five most common genotypes detected in humans. In order to gain insight into the degree of genetic variability of G9P[8] strains circulating in Cameroon, stool samples were collected during the 1999-2000 rotavirus season in two different geographic regions in Cameroon (Southwest and Western Regions). By RT-PCR, 15 G9P[8] strains (15/89=16.8%) were identified whose genomic configurations was subsequently determined by complete or partial gene sequencing. In general, all Cameroonian G9 strains clustered into current globally-spread sublineages of the VP7 gene and displayed 86.6-100% nucleotide identity amongst themselves and 81.2-99.5% nucleotide identity with global G9 strains. The full genome classification of all Cameroonian strains was G9-P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1 but phylogenetic analysis of each gene revealed that the strains were spread across 4 or more distinct lineages. An unusual strain, RVA/Human-wt/CMR/6788/1999/G9P[8], which shared the genomic constellation of other Cameroonian G9P[8] strains, contained a novel G9 subtype which diverged significantly (18.8% nucleotide and 19% amino acid distance) from previously described G9 strains. Nucleotide and amino acid alignments revealed that the 3' end of this gene is highly divergent from other G9 VP7 genes suggesting that it arose through extensive accumulation of point mutations. The results of this study demonstrate that diverse G9 strains circulated in Cameroon during 1999-2000., (Published by Elsevier B.V.)
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- 2013
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39. Efficacy, immunogenicity, and safety of two doses of a tetravalent rotavirus vaccine RRV-TV in Ghana with the first dose administered during the neonatal period.
- Author
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Armah GE, Kapikian AZ, Vesikari T, Cunliffe N, Jacobson RM, Burlington DB, and Ruiz LP Jr
- Subjects
- Double-Blind Method, Female, Gastroenteritis immunology, Ghana, Humans, Infant, Infant, Newborn, Male, Placebos administration & dosage, Pregnancy, Rotavirus Infections immunology, Rotavirus Vaccines administration & dosage, Gastroenteritis prevention & control, Rotavirus Infections prevention & control, Rotavirus Vaccines adverse effects, Rotavirus Vaccines immunology, Vaccination methods
- Abstract
Background: Oral rhesus/rhesus-human reassortant rotavirus tetravalent vaccine (RRV-TV) was licensed in 1998 but withdrawn in 1999 due to a rare association with intussusception, which occurred disproportionately in infants receiving their first dose at ≥90 days of age. This study examined RRV-TV for the prevention of rotavirus gastroenteritis (RV-GE) in Ghana, West Africa, with infants receiving the first dose during the neonatal period and the second before 60 days of age., Methods: In a double-blinded, randomized, placebo-controlled trial in Navrongo, Ghana, we recruited neonates to receive 2 doses of RRV-TV or placebo and followed them to age 12 months., Results: In the intention-to-treat population of 998 infants, we measured a vaccine efficacy of 63.1% against RV-GE of any severity associated with any of the 4 serotypes represented in the vaccine and 60.7% against RV-GE associated with any rotavirus serotype., Conclusions: RRV-TV in a 2-dose schedule with the first dose during the neonatal period is efficacious in preventing RV-GE in rural Ghana. Neonatal dosing results in early protection and may be the optimum schedule to avoid or significantly reduce intussusception, now reported to be associated in international settings with the 2 most widely marketed, licensed, live virus, oral rotavirus vaccines.
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- 2013
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40. Immunogenicity of the pentavalent rotavirus vaccine in African infants.
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Armah GE, Breiman RF, Tapia MD, Dallas MJ, Neuzil KM, Binka FN, Sow SO, Ojwando J, Ciarlet M, and Steele AD
- Subjects
- Administration, Oral, Antibodies, Neutralizing blood, Antibodies, Viral blood, Double-Blind Method, Female, Gastroenteritis epidemiology, Ghana epidemiology, Humans, Immunoglobulin A blood, Infant, Kenya epidemiology, Male, Mali epidemiology, Placebos administration & dosage, Rotavirus Infections epidemiology, Vaccines, Attenuated administration & dosage, Vaccines, Attenuated immunology, Gastroenteritis prevention & control, Rotavirus Infections prevention & control, Rotavirus Vaccines administration & dosage, Rotavirus Vaccines immunology, Vaccination methods
- Abstract
We recently completed a double-blind, placebo-controlled, multicenter Phase III clinical trial of the pentavalent rotavirus vaccine (PRV) in three African countries, Ghana, Kenya, and Mali, from April 2007 to March 2009. The immunogenicity of PRV in African infants is described. In total, 5468 infants were randomized 1:1 to receive 3 doses of PRV or placebo at approximately 6, 10, and 14 weeks of age. Breastfeeding and concomitant administration of EPI vaccines, including OPV, were allowed, and HIV-infected infants were not excluded. Immunogenicity of PRV was assessed by measuring serum anti-rotavirus IgA responses, as well as serum neutralization antibody (SNA) to the human rotavirus serotypes G1, G2, G3, G4 and P1A[8] in approximately 150 infants per country. Sera were collected pre-dose 1 (pD1) and approximately 14 days post-dose 3 (PD3) for immunological analysis. For the sero-response rates (≥ 3-fold rise from pD1 to PD3), the number of subjects evaluable included those with both pD1 and PD3 data available. PRV was immunogenic in African children and significantly reduced severe RVGE in African children through the first two years of life. The pooled anti-rotavirus IgA sero-response rate was 78.3%, with consistent rates in each of the African sites: 73.8% (Kenya), 78.9% (Ghana), and 82.5% (Mali); but generally lower than that reported in Europe and USA. PD3 GMTs (28.2 dilution-units) were 5-10 times lower than those assessed in subjects in clinical trials in developed countries. SNA responses to human rotavirus serotypes G1-G4 and P1A[8] ranged from 6.3% (G3) to 26.5% (G4). PD3 SNA GMTs to G1 and P1A[8] were 4-fold and 3-fold lower respectively, when compared to the corresponding GMTs in subjects who received PRV in similar studies conducted in developed countries. PRV was immunogenic in African infants, and the anti-rotavirus IgA sero-response rates were similar across all three African sites although lower than those observed in Europe and USA. While immune correlates of protection have not been established for rotavirus, the findings are consistent with lower efficacy rates demonstrated during this trial. Further investigation is needed to understand the reason for the lower immunogenicity observed., (Copyright © 2012. Published by Elsevier Ltd.)
- Published
- 2012
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41. Prevalence of severe acute rotavirus gastroenteritis and intussusceptions in Ghanaian children under 5 years of age.
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Enweronu-Laryea CC, Sagoe KW, Glover-Addy H, Asmah RH, Mingle JA, and Armah GE
- Subjects
- Child, Preschool, Feces virology, Female, Gastroenteritis pathology, Ghana epidemiology, Humans, Immunoenzyme Techniques, Infant, Infant, Newborn, Intussusception pathology, Male, Prevalence, Prospective Studies, Reverse Transcriptase Polymerase Chain Reaction, Rotavirus isolation & purification, Rotavirus Infections pathology, Sequence Analysis, DNA, Gastroenteritis complications, Gastroenteritis epidemiology, Intussusception epidemiology, Rotavirus Infections complications, Rotavirus Infections epidemiology
- Abstract
Introduction: Vaccination is the most effective preventive strategy against rotavirus disease. Regional differences in prevalent rotavirus genotypes may affect vaccine efficacy. Pre-vaccine surveillance for burden of rotavirus disease, prevalent rotavirus genotypes, and association between rotavirus disease and intussusceptions helps in monitoring the impact of vaccination., Methodology: A prospective study was conducted from January 2008 to December 2009 in children younger than five years hospitalized for longer than 24 hours with acute gastroenteritis. Data on confirmed cases of intussusception were collected retrospectively. Stools were tested by enzyme immunoassay, reverse-transcriptase polymerase chain reaction and nucleotide sequencing. , Results: Acute gastroenteritis (AGE) caused 13.1% (2,147/16,348) of hospitalizations among children under five years. Stools were tested for 50.2% (1077/2147) of AGE cases. Of these, 49% (528/1077) were rotavirus positive. Rotavirus gastroenteritis, non-rotavirus gastroenteritis, and intussusceptions were most prevalent in children under 15 months [80.3%, 74% and 91% respectively]. Rotavirus was detected from more than 60% of acute gastroenteritis cases during peak months. The prevalence of intussusception showed no seasonal pattern. The peak ages of six to twelve months for acute gastroenteritis and five to eight months for intussusception overlapped. G1, G2 and mixed G/P genotypes were common in the isolated rotaviruses., Conclusion: Rotavirus gastroenteritis causes significant morbidity in children younger than five years of age in Ghana. Although the peak age of rotavirus gastroenteritis and intussusceptions overlapped, there was no seasonal correlation between them. The high prevalence of mixed G/P genotypes in Ghanaian children may affect the effectiveness of vaccination.
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- 2012
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42. Molecular epidemiology of group A human rotaviruses in North West region, Cameroon.
- Author
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Mbuh FA, Armah GE, Omilabu SA, Ahmad AA, and Umoh JU
- Subjects
- Age Distribution, Antigens, Viral immunology, Cameroon epidemiology, Child, Preschool, Diarrhea virology, Electrophoresis, Polyacrylamide Gel, Enzyme-Linked Immunosorbent Assay, Female, Humans, Infant, Infant, Newborn, Male, Rotavirus Infections mortality, Rotavirus Infections virology, Diarrhea epidemiology, Molecular Epidemiology, Rotavirus isolation & purification, Rotavirus Infections epidemiology
- Abstract
Background: Rotavirus (RV) is the most common cause of severe diarrhea in children <5 years of age worldwide accounting for 527,000 deaths annually. Over 80% of these deaths occur in South Asia and sub-Saharan Africa. RV vaccines have significantly reduced RV-associated morbidity and mortalities in several countries like the United States and Mexico while vaccine trials have proved efficacious in Ghana and other developing countries. However, there is paucity of data on RV infection in Cameroon where diarrhea is a major childhood disease., Methods: A total of 534 stool specimens collected between January 2003 and December 2004 from children with acute gastroenteritis in five health districts in the NWR of Cameroon were screened for group A human rotavirus antigen by ELISA and their electropherotypes determined by Polyacrylamide gel electrophoresis., Results: RV was detected in 153 (28.7%) diarrheic specimens with infection occurring throughout the year, being more common in children under two years of age (P < 0.01) with the highest incidence in the 7-9 months age group (P <0.05). Sub clinical infections (9%) occurred mostly in children aged 0 - 6 months old (P<0.01). Source of drinking water was not associated with RV infection. Eleven electropherotype patterns were detected with predominance of long electropherotypes (92.8%) and mixed electropherotypes were seen only in hospitalized children. Some isolates showed overlapping or merged genome segments 7 and 8 or 9 and presenting with 10 segments of the RV genome., Conclusion: RV is a significant cause of pediatric diarrhea in the NWR affecting mostly children under 2 years of age. Continuous RV surveillance and nationwide surveys are recommended to improve the health of young children in Cameroon. More research is needed to fully characterize the isolated RV strains.
- Published
- 2012
43. Genotype diversity of group A rotavirus strains in children with acute diarrhea in urban Burkina Faso, 2008-2010.
- Author
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Bonkoungou IJ, Damanka S, Sanou I, Tiendrébéogo F, Coulibaly SO, Bon F, Haukka K, Traoré AS, Barro N, and Armah GE
- Subjects
- Burkina Faso epidemiology, Child, Preschool, Feces virology, Female, Genotype, Humans, Infant, Infant, Newborn, Male, Prevalence, RNA, Viral genetics, Reverse Transcriptase Polymerase Chain Reaction, Rotavirus isolation & purification, Diarrhea epidemiology, Diarrhea virology, Genetic Variation, Rotavirus classification, Rotavirus genetics, Rotavirus Infections epidemiology, Rotavirus Infections virology
- Abstract
In this study, the diversity of G and P genotypes of rotavirus strains in Burkinabe children were examined. Between November 2008 and February 2010, 447 stool samples were collected from children <5 years of age with acute diarrhea visiting hospital in Ouagadougou. Group A rotavirus was previously detected in 151/447 (33.8%) of the samples tested by an immunochromatographic test and these samples were now tested further for rotavirus G and P genotypes by RT-PCR. Of these, the rotavirus type genes were amplified by RT-PCR for 140/151 (92.7%) samples and G and P genotypes were successfully determined for 81 (57.9%) and 130 (92.9%) samples, respectively. The most prevalent G genotypes were G1, 34/140 (24.3%), and G9, 21/140 (15%), while the predominant P genotypes were P[6], 56/140 (40%), and P[8], 54/140 (38.6%). Among the single infections, 63/140 (45%), the predominant G/P combinations were: G1P[8] (33%), G9P[8] (29%), and G2P[6] (14%). The unusual strains G1P[9] (3%), G12P[6] (3%), G10P[6] (2%), and G2P[8] (2%) were also detected. In a high number of strains 61/140 (43.6%), the G genotype could not be determined and mixed infections were determined in 17/140 (12.1%) of strains identified. This study highlights the high diversity and presence of unusual rotavirus strains in children in Burkina Faso., (Copyright © 2011 Wiley-Liss, Inc.)
- Published
- 2011
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44. Rotavirus diarrhea among children less than 5 years of age in urban Ghana.
- Author
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Binka E, Vermund SH, and Armah GE
- Subjects
- Child, Preschool, Feces virology, Female, Genotype, Ghana epidemiology, Humans, Infant, Infant, Newborn, Male, Prevalence, Rotavirus classification, Rotavirus genetics, Rotavirus isolation & purification, Diarrhea epidemiology, Diarrhea virology, Gastroenteritis epidemiology, Gastroenteritis virology, Rotavirus Infections epidemiology, Rotavirus Infections virology
- Abstract
We collected clinical and morphologic data from children with diarrhea attending 3 diverse hospitals/clinics in Accra. Stool samples were tested for rotavirus and Cryptosporidium spp. In all, 58% of the children with diarrhea had rotavirus infections, 25% of which were of the G3 sero/genotype. The most common strains were G3P [6] (18.8%) and G2P [6] (12.5%). Cryptosporidium spp. infections were uncommon (3/143, 2.0%).
- Published
- 2011
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45. Genomic characterization of human rotavirus G10 strains from the African Rotavirus Network: relationship to animal rotaviruses.
- Author
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Esona MD, Banyai K, Foytich K, Freeman M, Mijatovic-Rustempasic S, Hull J, Kerin T, Steele AD, Armah GE, Geyer A, Page N, Agbaya VA, Forbi JC, Aminu M, Gautam R, Seheri LM, Nyangao J, Glass R, Bowen MD, and Gentsch JR
- Subjects
- Animals, Humans, Phylogeny, Rotavirus classification, Species Specificity, Genome, Viral, Rotavirus genetics
- Abstract
Global rotavirus surveillance has led to the detection of many unusual human rotavirus (HRV) genotypes. The aim of this study was to elucidate the genetic and evolutionary relationships of short fragments of all 11 gene segments of G10 HRV strains identified in West Africa through the African Rotavirus Network (ARN) system. During 1998-2004 surveillance within the ARN, we identified 5 G10 P[8] HRV strains. Fragments of all 11 gene segments of these G10 strains were sequenced. Phylogenetic and sequence analyses of each gene segment revealed high nucleotide similarities amongst the ARN strains (97-100%) except in the case of the VP1(85-96%) and NSP2 genes (87.8-99.7%) where some strains were divergent. All genes of the ARN strains were classified as Wa-like (genotype 1) with the exception of their VP7 gene of all strains (genotype G10) and the VP6 gene of a single strain, 6755/2002/ARN (DS-1 like, genotype 2). While classified as Wa-like, the NSP2 genes of four of the ARN strains occupied a distinct sub-lineage related to simian strain Tuch, while the NSP2 of strain 6755/2002/ARN and NSP5 genes of all strains were closely related to the cognate genes of both human and animal strains belonging to the Wa-like genogroup. Although these findings help to elucidate the evolution of ARN G10 strains, additional sequence studies of cognate animal rotavirus genes are needed to determine irrefutably the specific origin of those genes relative to both human and animal rotavirus strains., (Copyright © 2010. Published by Elsevier B.V.)
- Published
- 2011
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46. Rotavirus VP4 and VP7 genotypes circulating in Cameroon: Identification of unusual types.
- Author
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Esona MD, Armah GE, and Steele AD
- Subjects
- Age Distribution, Antigens, Viral metabolism, Cameroon epidemiology, Capsid Proteins metabolism, Child, Preschool, Diarrhea epidemiology, Diarrhea virology, Genetic Variation, Genotype, Humans, Infant, Rotavirus classification, Antigens, Viral genetics, Capsid Proteins genetics, Rotavirus genetics, Rotavirus Infections epidemiology, Rotavirus Infections virology
- Abstract
Rotavirus remains a priority candidate for vaccine development, because it is the major cause of viral diarrhea in children worldwide. This study characterized rotavirus strains in 195 stool specimens collected from children <5 years of age with diarrhea, in the Southwest Province and Western Province of Cameroon during 1999-2000. The predominant G type was G1 (detected in 44.9% of specimens) and the most predominant P type was P[8] (in 82.7%). The most common G-P combination detected was G1P[8] (in 37.1% of specimens), followed by G9P[8] (in 14%). Rotavirus strains with unusual G-P combinations, such as G1P[4], G2P[8], G8P[8], G9P[4], G5P[8], and G10P[8], were also observed in significant numbers. Analysis of the age distribution showed that G1P[8] was found circulating in all age groups except in infants <6 months old. Strains G2P[4] and G3P[8] were identified in children >37 months and 19-24 months of age, respectively. Strain G9P[8] was found circulating among children >25 months of age. Unusual strains and mixed infections were found circulating in the different age groups, albeit at lower levels. The high prevalence of mixed infections and diversity of rotavirus strains detected in this first study based on genotyping of Cameroonian strains reinforce the need to continue with surveillance programs in Africa, where a high diversity of strains has been reported.
- Published
- 2010
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47. Burden and epidemiology of rotavirus diarrhea in selected African countries: preliminary results from the African Rotavirus Surveillance Network.
- Author
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Mwenda JM, Ntoto KM, Abebe A, Enweronu-Laryea C, Amina I, Mchomvu J, Kisakye A, Mpabalwani EM, Pazvakavambwa I, Armah GE, Seheri LM, Kiulia NM, Page N, Widdowson MA, and Steele AD
- Subjects
- Africa South of the Sahara epidemiology, Child, Preschool, Diarrhea, Infantile epidemiology, Diarrhea, Infantile virology, Humans, Infant, Population Surveillance, Seasons, Time Factors, Diarrhea epidemiology, Diarrhea virology, Rotavirus Infections epidemiology
- Abstract
Severe rotavirus diarrhea in children <5 years of age is a major public health problem; however, limited regional and country specific data on rotavirus disease burden are available from sub-Saharan Africa. In June 2006, the World Health Organization Regional Office for Africa initiated rotavirus surveillance in selected African countries. With use of standardized methodology developed by the World Health Organization, children <5 years of age who were hospitalized with severe diarrhea were enrolled, and stool specimens were collected for detection of rotavirus strains with use of a commercial enzyme immunoassay. Rotavirus strains were further characterized for G and P types with use of a reverse-transcriptase polymerase chain reaction. From June 2006 through December 2008, rotavirus surveillance was established at 14 sites in 11 African countries. Of 5461 stool samples collected from children enrolled in 8 countries with 1 or 2 complete years of data, 2200 (40%) were positive for rotavirus. Ninety percent of all rotavirus hospitalizations occurred among children aged 3-12 months. Predominant types included G1P[8] (21%), G2P[4] (7%), and P [8] (29%); however, unusual types were also detected, including G8P[6] (5%), G8P[8] (1%), G12P[6] (1%), and G12P[6] (1%). A high percentage of mixed rotavirus infections was also detected. These preliminary results indicate that rotavirus is a major cause of severe diarrheal disease in African children.
- Published
- 2010
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48. Characterization of 2 human genotype G10 rotavirus strains, 3008CM and 1784/CI/1999, isolated in Cameroon and Cote d'Ivoire during the 1999-2000 rotavirus season.
- Author
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Esona MD, Page NA, Akran VA, Armah GE, and Steele AD
- Subjects
- Amino Acid Sequence, Antigens, Viral chemistry, Antigens, Viral genetics, Antigens, Viral metabolism, Base Sequence, Cameroon epidemiology, Child, Preschool, Cote d'Ivoire epidemiology, Feces virology, Genotype, Humans, Infant, Infant, Newborn, Molecular Sequence Data, Phylogeny, Rotavirus classification, Rotavirus immunology, Seasons, Rotavirus genetics, Rotavirus Infections epidemiology, Rotavirus Infections virology
- Abstract
During routine rotavirus surveillance projects in Cameroon and Cote d'Ivoire, 2 fecal samples collected from 2 children <5 years of age who presented with symptoms of gastroenteritis were found to give anomalous G typing results. These specimens were strongly rotavirus positive by enzyme immunoassay, displayed VP6 subgroup II specificity and long RNA electropherotypes, and were typed as rotavirus serotype G2 with monoclonal antibodies. In addition, the strains were typed as rotavirus VP7 genotype G3 and VP4 genotype P[8] by reverse-transcription polymerase chain reaction. Further investigation of the polymerase chain reaction G-typing results with a second set of primers revealed that the specimens were not genotype G3, and both samples were sequenced to elucidate the problem. Both strains were found to be genotype G10 by nucleotide sequence. Comparison of nucleotide and amino acid sequences and phylogenetic analysis of the African G10 strains revealed that these strains are closely related to the human G10 strains that were detected during the 2001-2003 rotavirus season in Ghana. The detection of G10 rotavirus in Africa adds to the global distribution of this strain and strengthens the need to continue strain surveillance in developing countries to understand the extent of strain distribution and diversity.
- Published
- 2010
- Full Text
- View/download PDF
49. Rotavirus in Africa: shifting the focus to disease prevention.
- Author
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Neuzil KM, Armah GE, Parashar UD, and Steele AD
- Subjects
- Africa epidemiology, Child, Preschool, Health Policy, Humans, Immunization Programs, Infant, Population Surveillance, Rotavirus Infections epidemiology, World Health Organization, Rotavirus immunology, Rotavirus Infections prevention & control, Rotavirus Vaccines
- Published
- 2010
- Full Text
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50. The global spread of rotavirus G10 strains: Detection in Ghanaian children hospitalized with diarrhea.
- Author
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Armah GE, Hoshino Y, Santos N, Binka F, Damanka S, Adjei R, Honma S, Tatsumi M, Manful T, and Anto F
- Subjects
- Amino Acid Sequence, Animals, Antigens, Viral chemistry, Antigens, Viral genetics, Capsid Proteins genetics, Child, Preschool, Gene Expression Regulation, Viral, Ghana epidemiology, Hospitalization, Humans, Infant, Molecular Sequence Data, Phylogeny, RNA-Binding Proteins genetics, Rotavirus classification, Rotavirus genetics, Rotavirus immunology, Viral Nonstructural Proteins genetics, Diarrhea epidemiology, Diarrhea virology, Rotavirus isolation & purification, Rotavirus Infections epidemiology, Rotavirus Infections virology
- Abstract
From October 2003 through September 2004, a total of 289 stool samples were collected from children <5 years of age who had severe diarrhea at admission to or when visiting the emergency department at the Navrongo War Memorial Hospital in rural Ghana during a study on rotavirus disease burden. Rotavirus antigen was detected in 115 stool samples (39.8%) tested for rotavirus. Four rotavirus-positive samples were found to bear G10P[6] specificity by reverse-transcription polymerase chain reaction, polymerase chain reaction-enzyme-linked immunosorbent assay, and oligonucleotide microarray hybridization. Two of these strains further exhibited serotype G10 specificity by neutralization and subgroup II specificity by enzyme immunoassay and possessed long electropheretic patterns by polyacrylamide gel electrophoresis. Their VP7 genes shared a much closer nucleotide identity with other African human G10 strains (>97%) than with human G10 strain from Asia or South America (<86%) or animal strains (<85%). The VP8* genes of the Ghanaian G10 strains exhibited >94% identity to that of human P[6] virus strains and belonged to the P[6] lineage 1a. The deduced VP7 amino acid sequence showed that the Ghanaian strains were more closely related to human G10 strains than to animal G10 strains. The possession of the typical human subgroup II specificity and the P[6] specificity (frequently found in Ghana and the rest of Africa) and the marked similarity in the VP7 antigenic sites suggest that these G10 strains may have evolved through genetic reassortment between bovine and human strains.
- Published
- 2010
- Full Text
- View/download PDF
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