Search

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.)

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.

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.

Background: Almost all diarrhea deaths in young children occur in developing countries. Immunization against rotavirus, the leading cause of childhood severe dehydrating acute diarrhea may reduce the burden of severe diarrhea in developing countries. Ghana introduced rotavirus and pneumococcal vaccination in the national expanded program on immunization in May 2012., Methods: Review of all-cause diarrheal hospitalization data for children aged 59 months and younger at 2 pediatric referral hospitals in southern Ghana from 2008 to 2014. The proportion of acute diarrhea (defined as 3 or more watery, non-bloody stools within 24 hours that has lasted for less than 7 days) cases caused by rotavirus was determined. Temporal trend and age group distribution of all-cause diarrhea and rotavirus gastroenteritis before and after introduction of the new vaccines were compared., Results: Of the 5847 children hospitalized with all-cause diarrhea during the 74 months (January 2008 - February 2014), 3963 (67.8%) children were recruited for rotavirus surveillance and stool specimens were tested for rotavirus in 3160/3963 (79.7%). Median monthly hospitalization for all-cause diarrhea reduced from 84 [interquartile range (IQR) 62 - 105] during the 52 months pre-vaccination introduction to 46 (IQR 42 - 57) in the 22 months after implementation of vaccination. Significant decline in all-cause diarrhea hospitalization occurred in children aged 0 - 11 months: 56.3% (2711/4817) vs. 47.2% 486/1030 [p = 0.0001, 95% confidence interval (CI) 0.77 - 0.88] and there was significant reduction of rotavirus gastroenteritis hospitalization: 49.7% (1246/2505) vs. 27.8% (182/655) [p = 0.0001, 95% CI 0.32 - 0.47] before and after vaccine introduction respectively., Conclusions: Implementation of rotavirus vaccination program may have resulted in significant reduction of severe diarrhea hospitalization even though this observational study could not exclude the effect of other confounding factors. Continued surveillance is recommended to monitor the progress of this program.

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.

Abstract Introduction Ghana introduced monovalent rotavirus vaccine in April 2012. We sought to determine the long-term impact of routine rotavirus vaccination on rotavirus gastroenteritis hospitalizations in Ghana during the first 4 years following rotavirus vaccine introduction. Methods Active sentinel surveillance for acute gastroenteritis hospitalizations among children <5 years of age was conducted at two sites from July 2009 through June 2016. Stool specimens were collected from enrolled children and tested by enzyme immunoassay. Changes in the proportion of all-cause gastroenteritis hospitalizations due to rotavirus pre- (July 2009–June 2012) and post-vaccine introduction (July 2012–June 2016) were compared using chi-square test. Results The proportion of acute gastroenteritis hospitalizations due to rotavirus among children <5 years of age significantly declined by 42% from a pre-vaccine median of 50% (343/684) to a post-vaccine median of 29% (118/396) (p < 0.001). The age distribution of rotavirus hospitalizations shifted toward older ages with 64% (759/1197) of rotavirus hospitalizations occurring in children <12 months of age pre-vaccine introduction to 47% (212/453) occurring in children <12 months of age post-vaccine introduction (p < 0.001). Discussion The decline in rotavirus hospitalizations following rotavirus vaccine introduction have been sustained over the first 4 years of the vaccination program in Ghana. Continued vaccination against rotavirus will ensure that this burden remains low. [ABSTRACT FROM AUTHOR]

Background. Ghana was among the first African nations to introduce monovalent rotavirus vaccine (RV1) into its childhood immunization schedule in April 2012. We aimed to assess the impact of vaccine introduction on rotavirus and acute gastroenteritis (AGE) hospitalizations and to estimate vaccine effectiveness (VE). Methods. Using data from 2 teaching hospitals, monthly AGE and rotavirus admissions by age were examined 40 months before and 31 months after RV1 introduction using interrupted time-series analyses. From January 2013, we enrolled children <2 years of age who were eligible for RV1 from a total of 7 sentinel sites across the country. To estimate VE, we fit unconditional logistic regression models to calculate odds ratios of vaccination by rotavirus case-patient status, controlling for potential confounders. Results. Vaccine coverage ranged from 95% to 100% for dose 1 and 93% to 100% for dose 2. In the first 3 years after vaccine introduction, the percentage of hospital admissions positive for rotavirus fell from 48% in the prevaccine period to 28% (49% adjusted rate reduction; 95% confidence interval [CI], 32%–63%) postvaccination among <5-year-olds. With high vaccine coverage, it was not possible to arrive at robust VE estimates; any-dose VE against rotavirus hospitalization was estimated at 60% (95% CI, −2% to 84%; P = .056). Conclusions. Results from the first 3 years following RV1 introduction suggest substantial reductions of pediatric diarrheal disease as a result of vaccination. Our VE estimate is consistent with the observed rotavirus decrease and with efficacy estimates from elsewhere in sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

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 intussusceptions 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 intussusceptions showed no seasonal pattern. The peak ages of six to twelve months for acute gastroenteritis and five to eight months for intussusceptions 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. [ABSTRACT FROM AUTHOR]