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Cholera remains a significant cause of mortality in developing countries. Outbreaks of the disease are associated with poverty, lack of potable water and poor sanitation. The survival and persistence of Vibrio cholerae in water has been shown to depend on physico-chemical factors. We studied water sources in Bepanda, an overcrowded neighbourhood in Douala, Cameroon, with limited access to portable water and very poor sanitary conditions as reservoirs of V. cholerae. We analysed 318 samples from various sources (well, tap, stream) from February to July 2009 using standard microbiological techniques and characterised isolates serologically using the polyvalent O1/O139 antisera. Susceptibility to antibiotics previously used for cholera treatment in Douala was studied using the disk diffusion method. Physico-chemical factors (temperature, pH and salinity) that could maintain the endemicity of the organism were analysed using standard methods. Eighty-seven (27.4%) samples were contaminated, with high isolation rates being obtained from streams (52.4%) and wells (29.8%). The number of isolates was significantly higher (P < 0.05) in the rainy season (35.5%). We detected 23 (24%) O1 serogroup isolates in streams and wells, whilst 64 (66.6%) were non-O1/non-O139. Temperature and salinity correlated positively with the occurrence of the organisms. All isolates were susceptible to fluoroquinolones but high resistance rates to trimethoprim or sulfamethozaxole and tetracycline were observed. Vibrio cholerae is endemic in Bepanda with O1 and non-O1/non-O139 serogroups co-existing in the streams and wells hence the possibility of future outbreaks of cholera if sanitation and drinking water quality are not improved. Temperature and salinity are amongst the factors maintaining the endemicity of the organism.

Abstract Background Weather fluctuation affects the incidence of malaria through a network of causuative pathays. Globally, human activities have ultered weather conditions over time, and consequently the number of malaria cases. This study aimed at determining the influence of humidity, temperature and rainfall on malaria incidence in an inland (Muyuka) and a coastal (Tiko) settings for a period of seven years (2011–2017) as well as predict the number of malaria cases two years after (2018 and 2019). Methods Malaria data for Muyuka Health District (MHD) and Tiko Health District (THD) were obtained from the Regional Delegation of Public Health and Tiko District Health service respectively. Climate data for MHD was obtained from the Regional Delegation of Transport while that of THD was gotten from Cameroon Development Coorporation. Spearman rank correlation was used to investigate the relationship between number of malaria cases and the weather variables and the simple seasonal model was used to forecast the number of malaria cases for 2018 and 2019. Results The mean monthly rainfall, temperature and relative humidity for MHD were 200.38 mm, 27.050C, 82.35% and THD were 207.36 mm, 27.57 °C and 84.32% respectively, with a total number of malaria cases of 56,745 and 40,160. In MHD, mean yearly humidity strongly correlated negatively with number of malaria cases (r = − 0.811, p = 0.027) but in THD, a moderate negative yearly correlation was observed (r = − 0.595, p = 0.159). In THD, the mean seasonal temperature moderately correlated (r = 0.599, p = 0.024) positively with the number of malaria cases, whereas MHD had a very weak negative correlation (r = − 0.174, p = 0.551). Likewise mean seasonal rainfall in THD moderately correlated (r = − 0.559, p = 0.038) negatively with malaria cases, contrary to MHD which showed a very weak positive correlation (r = 0.425, p = 0.130). The simple seasonal model predicted 6,842 malaria cases in Muyuka, for 2018 and same number for 2019, while 3167 cases were observed in 2018 and 2848 in 2019. Also 6,738 cases of malaria were predicted for MHD in 2018 likewise 2019, but 7327 cases were observed in 2018 and 21,735 cases in 2019. Conclusion Humidity is the principal climatic variable that negatively influences malaria cases in MHD, while higher seasonal temperatures and lower seasonal rain fall significantly increase malaria cases in THD.

The study was aimed at determining the prevalent biotypes ofPseudomonas aeruginosain the environment of Buea and the susceptibility of isolates to antibiotics.One hundred and fifty clinical specimens (urine, wound and sputum) collected from patients attending various health institutions in Buea, and 50 environmental swabs from furniture, appliances and surroundings of these institutions were screened forP. aeruginosausing standard microbiological and biochemical methods. Antimicrobial susceptibility of the isolates was determined by the disc diffusion assay.Fifty-one (25.5%) of the 200 specimens were positive for the organism with urine (30%) being the most common source of isolation. Biochemical characterization grouped the isolates into eight biotypes with biotypes B III (25.59%), B II (23.53%) and B I (21.57%) being the most prevalent. Antimicrobial susceptibility results of isolates revealed 13 antibiotype patterns based on resistance to the antimicrobial agents investigated. The resistance pattern, cefotaxime, gentamicin and tetracycline (CTXR GENR TETR) was the most common (21.6%) amongst the isolates. Over 40% of the isolates exhibited multi-drug resistance to five or more antibiotics, especially environmental isolates. However, there was a significant difference (P < 0.05) in the susceptibility of isolates to ciprofloxacin (98%), amikacin (90.2%) and netilmicin (80.4%) compared with other drugs used in the study.A combination of biotyping and antibiogram, which are relatively cheap and routinely available methods in our environment, could be useful for clinical and epidemiological studies particularly in laboratories in the developing world with limited resources. [ABSTRACT FROM AUTHOR]

The study was aimed at determining bacterial agents of the upper respiratory tract and the susceptibility patterns of isolates to antibiotics. In total, 200 throat swabs were obtained from students attending different boarding schools within the Buea Municipality and screened to obtain the prevalence of respiratory pathogens and to understand the antibiotic susceptibility patterns of isolates using standard microbiological procedure and the disc-diffusion test. Of the 200 samples screened, 112 (56%) had positive cultures with the dominant bacterial pathogens being Haemophilus influenzae (20%), followed by Streptococcus pneumoniae (15%), Klebsiella pneumoniae (11%), and Staphylococcus aureus (10%). Although 56% of the isolates were recovered from females compared to 44% from males, the difference was not statistically significant (p>0.05). Sixty-seven percent of the pathogens were isolated from the age-group of 10-13 years, 19.6% from the age-group of 14-17 years, and 12.5% from the age-group of 18-21 years. Antibiotic susceptibility testing revealed that gentamicin (92%) and cefuroxime (88.4%) were the most effective antibiotics against the isolates. Generally, susceptibility ranged from 0% to 92% depending on the antibiotic and the species of microorganism. Penicillin had the highest (100%) resistance to all the isolates. The findings revealed that students living in boarding schools in the Buea Municipality were at risk of acquiring upper respiratory tract infections from their peers since the upper respiratory tract of more than 50% of the students was colonized with respiratory pathogens. Although multidrug-resistant strains of organisms were identified, gentamicin and cefuroxime are recommended as the first-line antibiotics of choice against the pathogens. There is, therefore, a need for surveillance of nasopharyngeal carriage of resistant strains of these organisms, especially H. influenzae in unhealthy school children since the vaccine is yet to be introduced in Cameroon. The findings have clinical and epidemiological significance. [ABSTRACT FROM AUTHOR]

Dialysis is a replacement therapy for patients with End-Stage Renal Disease (ESRD). Patients on dialysis are at high risk of acquiring hepatitis C virus (HCV), which has become a leading cause of morbidity and mortality in this population. There is a wide range of prevalence of HCV in dialysis populations around the world. It is still unknown how prevalent HCV infection is among worldwide dialysis patients (including those undergoing hemodialysis and peritoneal dialysis). A review was conducted to estimate the global epidemiology of hepatitis C in dialysis patients. We searched PubMed, Excerpta Medica Database (Embase), Global Index Medicus and Web of Science until October 2022. A manual search of references from relevant articles was also conducted. Heterogeneity was evaluated by the χ2 test on Cochrane's Q statistic, and the sources of heterogeneity were investigated using subgroup analysis. In order to assess publication bias, funnel plots and Egger tests were conducted, and pooled HCV prevalence estimates were generated using a DerSimonian and Laird meta-analysis model. The study is registered with PROSPERO under CRD42022237789. We included 634 papers involving 392160 participants. The overall HCV case fatality rate was 38.7% (95% CI = 28.9-49). The global prevalence of HCV infection in dialysis population group were 24.3% [95% CI = 22.6-25.9]. As indicated by UNSD region, country, dialysis type, and HCV diagnostic targeted; Eastern Europe had the highest prevalence of 48.6% [95% CI = 35.2-62], Indonesia had 63.6% [95% CI = 42.9-82], hemodialysis patients had 25.5% [95% CI = 23.8-27.3], and anti-HCV were detected in 24.5% [95% CI = 22.8-26.2]. Dialysis patients, particularly those on hemodialysis, have a high prevalence and case fatality rate of HCV infection. Hemodialysis units need to implement strict infection control measures., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Kenfack-Momo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Human immunodeficiency virus (HIV) is a major public health concern, particularly in Africa where HIV rates remain substantial. Pregnant women are at an increased risk of acquiring HIV, which has a significant impact on both maternal and child health., Aim: To review summarizes HIV seroprevalence among pregnant women in Africa. It also identifies regional and clinical characteristics that contribute to study-specific estimates variation., Methods: The study included pregnant women from any African country or region, irrespective of their symptoms, and any study design conducted in any setting. Using electronic literature searches, articles published until February 2023 were reviewed. The quality of the included studies was evaluated. The DerSimonian and Laird random-effects model was applied to determine HIV pooled seroprevalence among pregnant women in Africa. Subgroup and sensitivity analyses were conducted to identify potential sources of heterogeneity. Heterogeneity was assessed with Cochran's Q test and I 2 statistics, and publication bias was assessed with Egger's test., Results: A total of 248 studies conducted between 1984 and 2020 were included in the quantitative synthesis (meta-analysis). Out of the total studies, 146 (58.9%) had a low risk of bias and 102 (41.1%) had a moderate risk of bias. No HIV-positive pregnant women died in the included studies. The overall HIV seroprevalence in pregnant women was estimated to be 9.3% [95% confidence interval (CI): 8.3-10.3]. The subgroup analysis showed statistically significant heterogeneity across subgroups ( P < 0.001), with the highest seroprevalence observed in Southern Africa (29.4%, 95%CI: 26.5-32.4) and the lowest seroprevalence observed in Northern Africa (0.7%, 95%CI: 0.3-1.3)., Conclusion: The review found that HIV seroprevalence among pregnant women in African countries remains significant, particularly in Southern African countries. This review can inform the development of targeted public health interventions to address high HIV seroprevalence in pregnant women in African countries., Competing Interests: Conflict-of-interest statement: The authors deny any conflict of interest., (©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.)

While the SARS-CoV-2 dynamic has been described globally, there is a lack of data from Sub-Saharan Africa. We herein report the dynamics of SARS-CoV-2 lineages from March 2020 to March 2022 in Cameroon. Of the 760 whole-genome sequences successfully generated by the national genomic surveillance network, 74% were viral sub-lineages of origin and non-variants of concern, 15% Delta, 6% Omicron, 3% Alpha and 2% Beta variants. The pandemic was driven by SARS-CoV-2 lineages of origin in wave 1 (16 weeks, 2.3% CFR), the Alpha and Beta variants in wave 2 (21 weeks, 1.6% CFR), Delta variants in wave 3 (11 weeks, 2.0% CFR), and omicron variants in wave 4 (8 weeks, 0.73% CFR), with a declining trend over time (p = 0.01208). Even though SARS-CoV-2 heterogeneity did not seemingly contribute to the breadth of transmission, the viral lineages of origin and especially the Delta variants appeared as drivers of COVID-19 severity in Cameroon., (© 2023. The Author(s).)

Background: Women of childbearing age are commonly affected by bacterial vaginosis (BV). Maternal-fetal outcomes associated with BV during pregnancy can be fatal for both the mother and the newborn., Aim: To identify maternal and fetal outcomes in pregnant women with BV encountered globally, highlight their prevalence, and identify maternal-fetal outcomes associated with BV., Methods: The databases Embase, PubMed, Web of Science and Global Index Medicus were searched from inception until December 2022. No restrictions on time or geographical location were imposed when searching for published articles that examined maternal-fetal outcomes in pregnant women with BV. A random effects model was used to perform the meta-analysis. Sources of heterogeneity were investigated using subgroup analysis, and publication bias was assessed using funnel plots and Egger tests., Findings: In total, 26 of the 8983 articles retrieved from the databases met the inclusion criteria and were included in this study. Twenty-two maternal outcomes and 22 fetal outcomes were recorded among pregnant women with BV worldwide. This study determined the prevalence of maternal-fetal outcomes reported in three or more studies. Among fetal outcomes, preterm birth (PTB) had the highest prevalence [17.9%, 95% confidence interval (CI) 13-23.3%], followed by mechanical ventilation (15.2%, 95% CI 0-45.9%), low birth weight (LBW) (14.2%, 95% CI 9.1-20.1%) and neonatal intensive care unit admission (11.2%, 95% CI 0-53.5%). BV was associated with PTB [odds ratio (OR) 1.76, 95% CI 1.32-2.35], LBW (OR 1.73, 95% CI 1.41-2.12) and birth asphyxia (OR 2.90, 95% CI 1.13-7.46). Among maternal outcomes, premature rupture of membranes (PROM) had the highest prevalence (13.2%, 95% CI 6.1-22.3%). BV was associated with the following maternal outcomes: intrauterine infection (OR 2.26, 95% CI 1.44-3.56), miscarriage (OR 2.34, 95% CI 1.18-4.64) and PROM (OR 2.59, 95% CI 1.39-4.82). Maternal and fetal outcomes were most prevalent in women whose BV was diagnosed using the Amsel criteria (37.2%, 95% CI 23-52.6%) and in the third trimester (29.6%, 95% CI 21.2-38.8%). Although reported in fewer than three studies, some maternal-fetal outcomes are highly prevalent, such as respiratory distress (76.67%, 95% CI 57.72-90.07%), dyspareunia (68.33%, 95% CI 55.04-79.74%) and malodorous discharge (85.00%, 95% CI 73.43-92.90%)., Conclusion: BV has been associated with several adverse maternal-fetal outcomes around the world. While BV is a common vaginal infection, the types of maternal-fetal outcomes from pregnant women with BV vary by country., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Rift Valley fever (RVF) is a severe zoonotic mosquito-borne disease that represents an important threat to human and animal health, with major public health and socioeconomic impacts. This disease is endemic throughout many African countries and the Arabian Peninsula. This systematic review with meta-analysis was conducted to determine the RVF prevalence in humans, mosquitoes and other animal species in Africa. The review also provides contemporary data on RVF case fatality rate (CFR) in humans. In this systematic review with meta-analysis, a comprehensive literature search was conducted on the PubMed, Embase, Web of Science and Global Index Medicus databases from January 2000 to June 2022 to identify relevant studies. Pooled CFR and prevalence estimates were calculated using the random-effects model. Subgroup analysis and sensitivity analysis were performed, and the I 2 -statistic was used to investigate a potential source of heterogeneity. A total of 205 articles were included in the final analysis. The overall RVF CFR in humans was found to be 27.5% [95% CI = 8.0-52.5]. The overall pooled prevalence was 7.8% [95% CI = 6.2-9.6] in humans and 9.3% [95% CI = 8.1-10.6] in animals, respectively. The RVF prevalence in individual mosquitoes ranged from 0.0% to 25%. Subgroup analysis showed substantial heterogeneity with respect to geographical regions and human categories. The study shows that there is a correspondingly similar prevalence of RVF in human and animals; however, human CFR is much higher than the observed prevalence. The lack of a surveillance programme and the fact that this virus has subclinical circulation in animals and humans could explain these observations. The implementation of a One Health approach for RVF surveillance and control would be of great interest for human and animal health., (© 2023 The Authors. Veterinary Medicine and Science published by John Wiley & Sons Ltd.)

When studying the dynamics of a pathogen in a host population, one crucial question is whether it transitioned from an epidemic (i.e., the pathogen population and the number of infected hosts are increasing) to an endemic stable state (i.e., the pathogen population reached an equilibrium). For slow-growing and slow-evolving clonal pathogens such as Mycobacterium bovis , the causative agent of bovine (or animal) and zoonotic tuberculosis, it can be challenging to discriminate between these two states. This is a result of the combination of suboptimal detection tests so that the actual extent of the pathogen prevalence is often unknown, as well as of the low genetic diversity, which can hide the temporal signal provided by the accumulation of mutations in the bacterial DNA. In recent years, the increased availability, efficiency, and reliability of genomic reading techniques, such as whole-genome sequencing (WGS), have significantly increased the amount of information we can use to study infectious diseases, and therefore, it has improved the precision of epidemiological inferences for pathogens such as M. bovis . In this study, we use WGS to gain insights into the epidemiology of M. bovis in Cameroon, a developing country where the pathogen has been reported for decades. A total of 91 high-quality sequences were obtained from tissue samples collected in four abattoirs, 64 of which were with complete metadata. We combined these with environmental, demographic, ecological, and cattle movement data to generate inferences using phylodynamic models. Our findings suggest M. bovis in Cameroon is slowly expanding its epidemiological range over time; therefore, endemic stability is unlikely. This suggests that animal movement plays an important role in transmission. The simultaneous prevalence of M. bovis in co-located cattle and humans highlights the risk of such transmission being zoonotic. Therefore, using genomic tools as part of surveillance would vastly improve our understanding of disease ecology and control strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Rossi, Shih, Egbe, Motta, Duchatel, Kelly, Ndip, Sander, Tanya, Lycett, Bronsvoort and Muwonge.)

Background: Occult hepatitis B (OBI) and C (OCI) infections lead to hepatic crises including cases of liver cirrhosis and even hepatocellular carcinoma (HCC). OBI and OCI also pose a significant problem of their transmissibility. This study aimed to assess the overall prevalence of OBI and OCI in the African continent, a region highly endemic for classical hepatitis B and C viruses., Methods: For this systematic review and meta-analysis, we searched: PubMed, Web of Science, African Journal Online and African Index Medicus for published studies on the prevalence of OBI and OCI in Africa. Study selection and data extraction were performed by at least two independent investigators. Heterogeneity (I²) was assessed using the χ² test on the Cochran Q statistic and H parameters. Sources of heterogeneity were explored by subgroup analyses. This study was registered in PROSPERO, with reference number CRD42021252772., Results: We obtained 157 prevalence data for this meta-analysis, from 134 studies for OBI prevalence; 23 studies on OCI prevalence, and a single study on the OBI case fatality rate. The overall estimate for the prevalence of OBI was 14.8% [95% CI = 12.2-17.7] among 18579 participants. The prevalence of seronegative OBI and seropositive OBI was 7.4% [95% CI = 3.8-11.8] and 20.0% [95% CI = 15.3-25.1] respectively. The overall estimate for the prevalence of OCI was 10.7% [95% CI = 6.6-15.4] among 2865 participants. The pooled prevalence of seronegative OCI was estimated at 10.7% [95%CI = 4.8-18.3] and that of seropositive OCI at 14.4% [95%CI = 5.2-22.1]. In Sub-group analysis, patients with malignancies, chronic hepatitis C, and hemodialysis had a higher OCI prevalence. While those with malignancies, liver disorders, and HIV positive registered highest OBI prevalence., Conclusion: This review shows a high prevalence of OBI and OCI in Africa, with variable prevalence between countries and population groups., Competing Interests: Competing interests None., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

This study aimed to assess the global prevalence of occult hepatitis B in blood donors. We searched PubMed, Web of Science, Global Index Medicus, and Excerpta Medica Database. Study selection and data extraction were performed by at least two independent investigators. Heterogeneity (I2) was assessed using the χ2 test on the Cochran Q statistic and H parameters. Sources of heterogeneity were explored by subgroup analyses. This study is registered with PROSPERO, number CRD42021252787. We included 82 studies in this meta-analysis. The overall prevalence of OBI was 6.2% (95% CI: 5.4-7.1) in HBsAg negative and anti-HBc positive blood donors. Only sporadic cases of OBI were reported in HBsAg negative and anti-HBc negative blood donors. The overall prevalence of OBI was 0.2% (95% CI: 0.1-0.4) in HBsAg negative blood donors. The prevalence of OBI was generally higher in countries with low-income economic status. The results of this study show that despite routine screening of blood donors for hepatitis B, the transmission of HBV by blood remains possible via OBI and/or a seronegative window period; hence there is a need for active surveillance and foremost easier access to molecular tests for the screening of blood donors before transfusion., Competing Interests: The authors have declared that no competing interests exist.

Despite sub-Saharan Africa (SSA) accounting for ~20% of the global cattle population, prevalence estimates and related risk factors of bovine tuberculosis (bTB) are still poorly described. The increased sensitivity of the IFN-γ assay and its practical benefits suggest the test could be useful to investigate bTB epidemiology in SSA. This study used a population-based sample to estimate bTB prevalence, identify risk factors and estimate the effective reproductive rate in Cameroonian cattle populations. A cross-sectional study was conducted in the North West Region (NWR) and the Vina Division (VIN) of Cameroon in 2013. A regional stratified sampling frame of pastoral cattle herds produced a sample of 1,448 cattle from 100 herds. In addition, a smaller cross-sectional study sampled 60 dairy cattle from 46 small-holder co-operative dairy farmers in the NWR. Collected blood samples were stimulated with bovine and avian purified protein derivatives, with extracted plasma screened using the IFN-γ enzyme-linked immunosorbent assay (Prionics Bovigam ® ). Design-adjusted population prevalences were estimated, and multivariable mixed-effects logistic regression models using Bayesian inference techniques identified the risk factors for IFN-γ positivity. Using the IFN-γ assay, the prevalence of bTB in the dairy cattle was 21.7% (95% CI: 11.2-32.2). The design-adjusted prevalence of bTB in cattle kept by pastoralists was 11.4% (95% CI: 7.6-17.0) in the NWR and 8.0% (95% CI: 4.7-13.0) in the VIN. A within-herd prevalence estimate for pastoralist cattle also supported that the NWR had higher prevalence herds than the VIN. Additionally, the estimates of the effective reproductive rate R t were 1.12 for the NWR and 1.06 for the VIN, suggesting different transmission rates within regional cattle populations in Cameroon. For pastoral cattle, an increased risk of IFN-γ assay positivity was associated with being male (OR = 1.89; 95% CI:1.15-3.09), increasing herd size (OR = 1.02; 95% CI:1.01-1.03), exposure to the bovine leucosis virus (OR = 2.45; 95% CI: 1.19-4.84) and paratuberculosis (OR = 9.01; 95% CI: 4.17-20.08). Decreased odds were associated with contacts at grazing, buffalo (OR = 0.20; 95% CI: 0.03-0.97) and increased contact with other herds [1-5 herds: OR = 0.16 (95% CI: 0.04-0.55); 6+ herds: OR = 0.18 (95% CI: 0.05-0.64)]. Few studies have used the IFN-γ assay to describe bTB epidemiology in SSA. This study highlights the endemic situation of bTB in Cameroon and potential public health risks from dairy herds. Further work is needed to understand the IFN-γ assay performance, particularly in the presence of co-infections, and how this information can be used to develop control strategies in the SSA contexts., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kelly, Gonzaléz Gordon, Egbe, Freeman, Mazeri, Ngwa, Tanya, Sander, Ndip, Muwonge, Morgan, Handel and Bronsvoort.)

Yellow fever (YF) has re-emerged in the last two decades causing several outbreaks in endemic countries and spreading to new receptive regions. This changing epidemiology of YF creates new challenges for global public health efforts. Yellow fever is caused by the yellow fever virus (YFV) that circulates between humans, the mosquito vector, and non-human primates (NHP). In this systematic review and meta-analysis, we review and analyse data on the case fatality rate (CFR) and prevalence of YFV in humans, and on the prevalence of YFV in arthropods, and NHP in sub-Saharan Africa (SSA). We performed a comprehensive literature search in PubMed, Web of Science, African Journal Online, and African Index Medicus databases. We included studies reporting data on the CFR and/or prevalence of YFV. Extracted data was verified and analysed using the random effect meta-analysis. We conducted subgroup, sensitivity analysis, and publication bias analyses using the random effect meta-analysis while I2 statistic was employed to determine heterogeneity. This review was registered with PROSPERO under the identification CRD42021242444. The final meta-analysis included 55 studies. The overall case fatality rate due to YFV was 31.1% (18.3-45.4) in humans and pooled prevalence of YFV infection was 9.4% (6.9-12.2) in humans. Only five studies in West and East Africa detected the YFV in mosquito species of the genus Aedes and in Anopheles funestus. In NHP, YFV antibodies were found only in members of the Cercopithecidae family. Our analysis provides evidence on the ongoing circulation of the YFV in humans, Aedes mosquitoes and NHP in SSA. These observations highlight the ongoing transmission of the YFV and its potential to cause large outbreaks in SSA. As such, strategies such as those proposed by the WHO's Eliminate Yellow Fever Epidemics (EYE) initiative are urgently needed to control and prevent yellow fever outbreaks in SSA., Competing Interests: The authors have declared that no competing interests exist.

Background: The association between hospitalization for human respiratory syncytial virus (HRSV) bronchiolitis in early childhood and subsequent asthma is well established. The long-term prognosis for non-bronchiolitis lower respiratory tract infections (LRTI) caused by viruses different from HRSV and rhinovirus, on the other hand, has received less interest., Aim: To investigate the relationship between infant LRTI and later asthma and examine the influence of confounding factors., Methods: The PubMed and Global Index Medicus bibliographic databases were used to search for articles published up to October 2021 for this systematic review. We included cohort studies comparing the incidence of asthma between patients with and without LRTI at ≤ 2 years regardless of the virus responsible. The meta-analysis was performed using the random effects model. Sources of heterogeneity were assessed by stratified analyses., Results: This review included 15 articles (18 unique studies) that met the inclusion criteria. LRTIs at ≤ 2 years were associated with an increased risk of subsequent asthma up to 20 years [odds ratio (OR) = 5.0, 95%CI: 3.3-7.5], with doctor-diagnosed asthma (OR = 5.3, 95%CI: 3.3-8.6), current asthma (OR = 5.4, 95%CI: 2.7-10.6), and current medication for asthma (OR = 1.2, 95%CI: 0.7-3.9). Our overall estimates were not affected by publication bias ( P = 0.671), but there was significant heterogeneity [ I 2 = 58.8% (30.6-75.5)]. Compared to studies with hospitalized controls without LRTI, those with ambulatory controls had a significantly higher strength of association between LRTIs and subsequent asthma. The strength of the association between LRTIs and later asthma varied significantly by country and age at the time of the interview. The sensitivity analyses including only studies with similar proportions of confounding factors (gender, age at LRTI development, age at interview, gestational age, birth weight, weight, height, smoking exposure, crowding, family history of atopy, and family history of asthma) between cases and controls did not alter the overall estimates., Conclusion: Regardless of the causative virus and confounding factors, viral LRTIs in children < 2 years are associated with an increased risk of developing a subsequent asthma. Parents and pediatricians should be informed of this risk., Competing Interests: Conflict-of-interest statement: The authors deny any conflict of interest., (©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.)

The interferon-gamma (IFN-γ) assay and single comparative cervical skin test (SCITT) are used to estimate bovine tuberculosis (bTB) prevalence globally. Prevalence estimates of bTB, caused by Mycobacterium bovis , are poorly quantified in many Sub-Saharan African (SSA) cattle populations. Furthermore, antemortem diagnostic performance can vary at different stages of bTB pathogenesis and in different cattle populations. In this study, we aim to explore the level of agreement and disagreement between the IFN-γ assay and SCITT test, along with the drivers for disagreement, in a naturally infected African cattle population. In, 2013, a pastoral cattle population was sampled using a stratified clustered cross-sectional study in Cameroon. A total of 100 pastoral cattle herds in the North West Region (NWR) and the Vina Division (VIN) were sampled totalling 1,448 cattle. Individual animal data and herd-level data were collected, and animals were screened using both the IFN-γ assay and SCITT. Serological ELISAs were used to detect exposure to immunosuppressing co-infections. Agreement analyses were used to compare the performance between the two bTB diagnostic tests, and multivariable mixed-effects logistic regression models (MLR) were developed to investigate the two forms of IFN-γ assay and SCITT binary disagreement. Best agreement using the Cohen's κ statistic, between the SCITT (>2 mm) and the IFN-γ assay implied a 'fair-moderate' agreement for the NWR [κ = 0.42 (95%CI: 0.31-0.53)] and 'poor-moderate' for the VIN [κ = 0.33 (95% CI: 0.18-0.47)]. The main test disagreement was the animals testing positive on the IFN-γ assay and negative by the SCITT. From MLR modeling, adults (adults OR: 7.57; older adults OR = 7.21), females (OR = 0.50), bovine leucosis (OR = 2.30), and paratuberculosis positivity (OR = 6.54) were associated with IFN-γ-positive/SCITT-negative disagreement. Subsets to investigate diagnostic test disagreement for being SCITT-positive and IFN-γ-negative also identified that adults (adults OR = 15.74; older adults OR = 9.18) were associated with IFN-γ-negative/SCITT-positive disagreement. We demonstrate that individual or combined use of the IFN-γ assay and SCITT can lead to a large variation in bTB prevalence estimates. Considering that animal level factors were associated with disagreement between the IFN-γ assay and SCITT in this study, future work should further investigate their impact on diagnostic test performance to develop the approaches to improve SSA prevalence estimates., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kelly, Gonzaléz Gordon, Egbe, Freeman, Mazeri, Ngwa, Tanya, Sander, Ndip, Muwonge, Morgan, Handel and Bronsvoort.)

Rift Valley fever (RVF) is an important emerging zoonoses causing abortion and neonatal deaths in livestock and hemorrhagic fever in humans. It is typically characterized by acute epidemics with abortion storms often preceding human disease and these events have been associated with the El Niño weather cycles. Outside of areas that experience epidemics, little is known about its epidemiology. Here, we present results from a serological study using biobank samples from a study of cattle conducted in 2013 at two sites in Cameroon. A total of 1,458 cattle from 100 herds were bled and sera screened using a commercially available RVF ELISA. The overall design-adjusted animal-level apparent seroprevalence of RVF exposure for the Northwest Region (NWR) of Cameroon was 6.5% (95% CI: 3.9-11.0) and for the Vina Division (VIN) of the Adamawa Region was 8.2% (95% CI: 6.2-11.0). The age-stratified serological results were also used to estimate the force of infection, and the age-independent estimates were 0.029 for the VIN and 0.024 for the NWR. The effective reproductive number was ~1.08. Increasing age and contact with wild antelope species were associated with an increased risk of seropositivity, while high altitudes and contact with buffalo were associated with a reduced risk of seropositivity. The serological patterns are more consistent with an endemical stability rather than the more typical epidemic patterns seen in East Africa. However, there is little surveillance in livestock for abortion storms or in humans with fevers in Cameroon, and it is, therefore, difficult to interpret these observations. There is an urgent need for an integrated One Health approach to understand the levels of human- and livestock-related clinical and asymptomatic disease and whether there is a need to implement interventions such as vaccination., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Bronsvoort, Kelly, Freeman, Callaby, Bagninbom, Ndip, Handel, Tanya, Morgan, Ngwa, Rossi, Nfon and Mazeri.)

Introduction: Due to their common routes of transmission, human immunodeficiency virus (HIV) coinfection with hepatitis B virus (HBV) and/or hepatitis C virus (HCV) has become a major public health problem worldwide, particularly in Africa, where these viruses are endemic. Few systematic reviews report the epidemiological data of HBV and/or HCV coinfection with HIV in Africa, and none provided data on the case fatality rate (CFR) associated with this coinfection. This study was conducted to investigate the prevalence and case fatality rate of HBV and/or HCV infections among people living with human immunodeficiency virus (PLHIV) in Africa., Methods: We conducted a systematic review of published articles in PubMed, Web of Science, African Journal Online, and African Index Medicus up to January 2022. Manual searches of references from retrieved articles and grey literature were also performed. The meta-analysis was performed using a random-effects model. Sources of heterogeneity were investigated using subgroup analysis, while funnel plots and Egger tests were performed to assess publication bias., Results: Of the 4388 articles retrieved from the databases, 314 studies met all the inclusion criteria. The overall HBV case fatality rate estimate was 4.4% (95% CI; 0.7-10.3). The overall seroprevalences of HBV infection, HCV infection, and HBV/HCV coinfection in PLHIV were 10.5% [95% CI = 9.6-11.3], 5.4% [95% CI = 4.6-6.2], and 0.7% [95% CI = 0.3-1.0], respectively. The pooled seroprevalences of current HBsAg, current HBeAg, and acute HBV infection among PLHIV were 10.7% [95% CI = 9.8-11.6], 7.0% [95% CI = 4.7-9.7], and 3.6% [95% CI = 0.0-11.0], respectively. Based on HBV-DNA and HCV-RNA detection, the seroprevalences of HBV and HCV infection in PLHIV were 17.1% [95% CI = 11.5-23.7] and 2.5% [95% CI = 0.9-4.6], respectively. Subgroup analysis showed substantial heterogeneity., Conclusions: In Africa, the prevalence of hepatotropic viruses, particularly HBV and HCV, is high in PLHIV, which increases the case fatality rate. African public health programs should emphasize the need to apply and comply with WHO guidelines on viral hepatitis screening and treatment in HIV-coinfected patients., Review Registration: PROSPERO, CRD42021237795., Competing Interests: The authors have declared that no competing interests exist.

Background: Occult hepatitis C infection (OCI) is characterized by the presence of hepatitis C virus (HCV) RNA in the liver, peripheral blood mononuclear cells (PBMC) and/or ultracentrifuged serum in the absence of detectable HCV-RNA in serum. OCI has been described in several categories of populations including hemodialysis patients, patients with a sustained virological response, immunocompromised individuals, patients with abnormal hepatic function, and apparently healthy subjects., Aim: To highlight the global prevalence of OCI., Methods: We performed a systematic and comprehensive literature search in the following 4 electronic databases PubMed, EMBASE, Global Index Medicus, and Web of Science up to 6th May 2021 to retrieve relevant studies published in the field. Included studies were unrestricted population categories with known RNA status in serum, PBMC, liver tissue and/or ultracentrifuged serum. Data were extracted independently by each author and the Hoy et al tool was used to assess the quality of the included studies. We used the random-effect meta-analysis model to estimate the proportions of OCI and their 95% confidence intervals (95%CI). The Cochran's Q -test and the I 2 test statistics were used to assess heterogeneity between studies. Funnel plot and Egger test were used to examine publication bias. R software version 4.1.0 was used for all analyses., Results: The electronic search resulted in 3950 articles. We obtained 102 prevalence data from 85 included studies. The pooled prevalence of seronegative OCI was estimated to be 9.61% (95%CI: 6.84-12.73) with substantial heterogeneity [ I ² = 94.7% (95%CI: 93.8%-95.4%), P < 0.0001]. Seropositive OCI prevalence was estimated to be 13.39% (95%CI: 7.85-19.99) with substantial heterogeneity [ I 2 = 93.0% (90.8%-94.7%)]. Higher seronegative OCI prevalence was found in Southern Europe and Northern Africa, and in patients with abnormal liver function, hematological disorders, and kidney diseases. Higher seropositive OCI prevalence was found in Southern Europe, Northern America, and Northern Africa., Conclusion: In conclusion, in the present study, it appears that the burden of OCI is high and variable across the different regions and population categories. Further studies on OCI are needed to assess the transmissibility, clinical significance, long-term outcome, and need for treatment., Competing Interests: Conflict-of-interest statement: The authors deny any conflict of interest., (©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background: Crimean-Congo Haemorrhagic Fever (CCHF) is a tick-borne viral zoonotic disease distributed across several continents and recognized as an ongoing health threat. In humans, the infection can progress to a severe disease with high fatality, raising public health concerns due to the limited prophylactic and therapeutic options available. Animal species, clinically unaffected by the virus, serve as viral reservoirs and amplifier hosts, and can be a valuable tool for surveillance. Little is known about the occurrence and prevalence of Crimean-Congo Haemorrhagic Fever Virus (CCHFV) in Cameroon. Knowledge on CCHFV exposure and the factors associated with its presence in sentinel species are a valuable resource to better understand transmission dynamics and assess local risks for zoonotic disease emergence., Methods and Findings: We conducted a CCHFV serological survey and risk factor analysis for animal level seropositivity in pastoral and dairy cattle in the North West Region (NWR) and the Vina Division (VD) of the Adamawa Region in Cameroon. Seroprevalence estimates were adjusted for sampling design-effects and test performance. In addition, explanatory multivariable logistic regression mixed-effects models were fit to estimate the effect of animal characteristics, husbandry practices, risk contacts and ecological features on the serological status of pastoral cattle. The overall seroprevalence was 56.0% (95% CI 53.5-58.6) and 6.7% (95% CI 2.6-16.1) among pastoral and dairy cattle, respectively. Animals going on transhumance had twice the odds of being seropositive (OR 2.0, 95% CI 1.1-3.8), indicating that animal movements could be implicated in disease expansion. From an ecological perspective, absolute humidity (OR 0.6, 95% CI 0.4-0.9) and shrub density (OR 2.1, 95% CI 1.4-3.2) were associated with seropositivity, which suggests an underlying viral dynamic connecting vertebrate host and ticks in a complex transmission network., Conclusions: This study demonstrated high seroprevalence levels of CCHFV antibodies in cattle in Cameroon indicating a potential risk to human populations. However, current understanding of the underlying dynamics of CCHFV locally and the real risk for human populations is incomplete. Further studies designed using a One Health approach are required to improve local knowledge of the disease, host interactions and environmental risk factors. This information is crucial to better project the risks for human populations located in CCHFV-suitable ecological niches., Competing Interests: The authors have declared that no competing interests exist.

A substantial amount of epidemiological data has been reported on Enterovirus D68 (EV-D68) infections after the 2014 outbreak. Our goal was to map the case fatality rate (CFR) and prevalence of current and past EV-D68 infections. We conducted a systematic review (PROSPERO, CRD42021229255) with published articles on EV-68 infections in PubMed, Embase, Web of Science and Global Index Medicus up to January 2021. We determined prevalences using a model random effect. Of the 4,329 articles retrieved from the databases, 89 studies that met the inclusion criteria were from 39 different countries with apparently healthy individuals and patients with acute respiratory infections, acute flaccid myelitis and asthma-related diseases. The CFR estimate revealed occasional deaths (7/1353) related to EV-D68 infections in patients with severe acute respiratory infections. Analyses showed that the combined prevalence of current and past EV-D68 infections was 4% (95% CI = 3.1-5.0) and 66.3% (95% CI = 40.0-88.2), respectively. The highest prevalences were in hospital outbreaks, developed countries, children under 5, after 2014, and in patients with acute flaccid myelitis and asthma-related diseases. The present study shows sporadic deaths linked to severe respiratory EV-D68 infections. The study also highlights a low prevalence of current EV-D68 infections as opposed to the existence of EV-D68 antibodies in almost all participants of the included studies. These findings therefore highlight the need to implement and/or strengthen continuous surveillance of EV-D68 infections in hospitals and in the community for the anticipation of the response to future epidemics., Competing Interests: The authors have declared that no competing interests exist.

Previous work identified that bacterial zoonoses (Brucella species, Coxiella burnetii and Leptospira hardjo) were present in Cameroonian pastoral cattle. To assess the characteristics of this zoonotic risk, we analyse seroprevalence of each pathogen and the associated management, herd and environmental factors in Cameroonian pastoral and dairy cattle. Cross-sectional samples included pastoralist herds in the Northwest Region (NWR n = 750) and Vina Division (VD n = 748) and small holder dairy herds in the NWR (n = 60). Exposure to Brucella spp., C. burnetii and L. hardjo were screened for using commercial ELISAs and population adjusted estimates made. In addition, individual, herd and ecological metadata were collected and used to identify risk factors associated with animal-level seropositivity. In the pastoral cattle, seroprevalence to Brucella spp. was relatively low but was higher in the NWR (4.2%, CI: 2.5%-7.0%) than the VD (1.1%: CI 0.5%-2.4%), while L. hardjo seroprevalence was much higher though similar in the NWR (30.7%, CI 26.3%-35.5%) and VD (35.9%, CI 31.3%-40.7%). No differences were noted in C. burnetii seroprevalence between the two study sites (NWR: 14.6%, CI 11.8%-18.0%. VD: 12.4%, 9.6%-15.9%). Compared to pastoral, dairy cattle had lower seroprevalences for L. hardjo (1.7%, CI: 0.0%-4.9%), C. burnetii (0.0%, CI 0.0%-6.0%) but similar for Brucella spp. (5.0%, CI 0.0%-10.6%). Increased odds of Brucella spp. seropositivity were associated with owning sheep or rearing sheep and fencing cattle in at night. Adult cattle had increased odds of being seropositive for both C. burnetii and L. hardjo. Additionally, exposure to C. burnetii was associated with local ecological conditions and L. hardjo was negatively associated with cattle undertaking transhumance. This work highlights that exposure to these 3 important production diseases and occupational zoonoses are widespread in Cameroonian cattle. Further work is required to understand transmission dynamics between humans and livestock to inform implementation of effective control measures., (© 2021 The Authors. Zoonoses and Public Health published by Wiley-VCH GmbH.)

Rift Valley Fever is an important zoonotic viral disease of livestock occurring across much of Africa causing acute febrile illness, abortion, and neonatal death in livestock particularly sheep and cattle and a range of disease in humans from mild flu-like symptoms to more severe haemorrhagic fever and death. Understanding the epidemiology requires well-evaluated tools including antibody detection ELISAs. It is well-recognized that tests developed in one population do not necessarily perform as well when used in different populations and it is therefore important to assess tests in the populations in which they are to be used. Here we describe the performance of a commercial RVF ELISA (ID.Vet) and an in-house plaque reduction neutralization test (PRNT 80 ). A Bayesian no gold standard latent class model for two tests and ≥2 populations based on the Hui-Walter model was used to estimate the test parameters using a range of populations based on geographical separation and age to assess consistency of performance across different sub-populations. The ID.Vet ELISA had an estimated diagnostic sensitivity (Se) of 0.854 (0.655-0.991 95%BCI) and specificity (Sp) of 0.986 (0.971-0.998 95%BCI) using all the data and splitting the population by geographical region compared to 0.844 (0.660-0.973 95%BCI) and 0.981 (0.965-0.996 95%BCI) for the PRNT 80 . There was slight variation in the mean Se and Sp in different sub-populations mainly in Se estimates due to small numbers of positives in the sub-populations but the 95% BCI generally overlapped suggesting a very consistent performance across the different geographical areas and ages of animals. This is one of few reports of serological evidence of RVF in Central Africa and strongly suggests the virus is actively circulating in this cattle population. This has important public health implications and RVF should be considered as a differential in both livestock disease cases as well as human febrile cases in West and Central Africa not just East Africa. We also demonstrate that the performance of the commercial ELISA is comparable to the PRNT 80 but has the advantages of speed, lower cost and no containment needs making it a much more useful test for low and middle income settings (LMICs).

Bovine tuberculosis (bTB), caused by Mycobacterium bovis , remains a major livestock and public health problem in both high and low-income countries. With the current absence of an effective vaccine, control in cattle populations is reliant on regular testing and removal of positive animals. However, surveillance and control are hampered by imperfect diagnostic tests that have poorly described properties in naturally infected populations. Recent research in cattle co-infected with the temperate liver fluke, Fasciola hepatica , has raised concerns about the performance of the intradermal skin test in high fluke incidence areas. Further, recent studies of parasitic co-infections have demonstrated their impact on Th1 and Th2 responses, concurrent disease pathology and susceptibility to mycobacterial infections. Here we report for the first time the association of co-infection with the tropical liver fluke, Fasciola gigantica , with the presence of bTB-like lesions and the IFN-γ response in naturally infected African cattle. After adjusting for age and sex we observed a complex interaction between fluke status and breed. Fulani cattle had a higher risk of having bTB-like lesions than the mixed breed group. The risk of bTB-like lesions increased in the mixed breed group if they had concurrent evidence of fluke pathology but was less clear in the coinfected Fulani breed. Further, we observed a slight decline in the IFN-γ levels in fluke infected animals. Finally we explored factors associated with IFN-γ false negative results compared to the presence of bTB-like lesions. Fulani cattle had a higher risk of having a false negative result compared to the mixed breed group. Further, the mixed breed cattle had an increased risk of being false negative if also co-infected with fluke. Interesting, as with the risk of bTB-like lesions, this association was less clear in the Fulani cattle with weak evidence of a slight decrease in risk of having a false negative test result when fluke pathology positive. This interesting interaction where different breeds appear to have different responses to co-infections is intriguing but further work is needed to confirm and understand more clearly the possible confounding effects of different other co-infections not measured here, breed, management or exposure risks.

While gastrointestinal disease is common among HIV infected individuals, the prevalence and distribution of ano-rectal pathology has not been well studied in our setting. The objective of this study therefore was to determine the prevalence and determinants of ano-rectal pathology in HIV infected patients attending the Douala General Hospital HIV treatment centre. A hospital-based cross-sectional study was undertaken. We collected socio-demographic, clinical and laboratory data using a structured questionnaire and patients' files. Each study participant had a full physical and ano-rectal examination. We further studied factors associated with having at least one ano-rectal lesion by logistic regression reporting odds ratios (ORs) and their 95% confidence intervals (CI). We included 390 HIV infected patients. The mean age was 41 (SD: 8) years and 48% were men. Median duration since HIV diagnosis was 3 (interquartile range: 2-5) years and median CD4 cell count was 411 (interquartile range: 234-601) cells/mm 3 . Prevalence of ano-rectal pathology was 22.8% (95% CI: 18.7-27.3). Hemorrhoids and proctitis were most common lesions found; each in 10% of patients. From multivariate logistic regression, factors associated with ano-rectal pathology were CD4 < 350 cells/ml (OR: 2.1, 95% CI: 1.1-4.2), not on highly active antiretroviral therapy (OR: 2.2, 95% CI: 1.1-4.6), inpatient (OR: 2.3, 95% CI: 1.2-4.3), ano-rectal intercourse (OR: 5.0, 95% CI: 1.7-15.1), and more than one sexual partner (OR: 2.4, 95% CI: 1.3-4.2). Ano-rectal pathology is common amongst HIV infected patients. Care givers should actively investigate and treat them as this will improve the quality of life of people living with HIV/AIDS.

Background: Control of bovine tuberculosis (bTB) and zoonotic tuberculosis (zTB) has relied upon surveillance and slaughter of infected cattle, milk pasteurisation and public health education. In Cameroon, like many other sub-Saharan African countries, there is limited understanding of current cattle husbandry or milk processing practices or livestock keepers awareness of bTB. This paper describes husbandry and milk processing practices within different Cameroonian cattle keeping communities and bTB awareness in comparison to other infectious diseases., Study Design: A population based cross-sectional sample of herdsmen and a questionnaire were used to gather data from pastoralists and dairy farmers in the North West Region and Vina Division of Cameroon., Results: Pastoralists were predominately male Fulanis who had kept cattle for over a decade. Dairy farmers were non-Fulani and nearly half were female. Pastoralists went on transhumance with their cattle and came into contact with other herds and potential wildlife reservoirs of bTB. Dairy farmers housed their cattle and had little contact with other herds or wildlife. Pastoralists were aware of bTB and other infectious diseases such as foot-and-mouth disease and fasciolosis. These pastoralists were also able to identify clinical signs of these diseases. A similar proportion of dairy farmers were aware of bTB but fewer were aware of foot-and-mouth and fasciolosis. In general, dairy farmers were unable to identify any clinical signs for any of these diseases. Importantly most pastoralists and dairy farmers were unaware that bTB could be transmitted to people by consuming milk., Conclusions: Current cattle husbandry practices make the control of bTB in cattle challenging especially in mobile pastoralist herds. Routine test and slaughter control in dairy herds would be tractable but would have profound impact on dairy farmer livelihoods. Prevention of transmission in milk offers the best approach for human risk mitigation in Cameroon but requires strategies that improved risk awareness amongst producers and consumers.

Helicobacter pylori has been incriminated in human diseases, such as peptic ulcer, gastritis and gastric malignancy. Although modern triple-drug regimens are usually highly effective in the treatment of H. pylori infection, the emergence of resistance to two of the most used antibiotics, metronidazole (Mtz) and clarithromycin (Cla), is a serious and increasing problem. Truncations in the rdxA and frxA genes of H. pylori are thought to be associated with Mtz resistance whereas mutations in the pathogen's 23S-ribosomal-RNA (23S-rRNA) genes are associated with Cla resistance. In a recent study, PCR and sequence analysis of the rdxA, frxA and 23S-rRNA genes were used to explore the genetic basis of resistance to Mtz and Cla in H. pylori. When 200 isolates of H. pylori from the Eastern Cape province of South Africa were tested for antibiotic susceptibility, almost all (95·5%) were found resistant to Mtz and 20·0% were found resistant to Cla. Only the Mtz-resistant isolates showed rdxA and frxA truncation. Two point mutations were detected in the 23S-rRNA genes of the Cla-resistant isolates. Many significant changes (resulting in 13 amino-acid substitutions in nine loci and truncated proteins in 14 loci) were observed in the rdxA genes of the Mtz-resistant isolates, and it appears that, compared with the rarer changes detected in frxA, such mutations may contribute more significantly to the high prevalence of Mtz resistance. To guide empiric treatment, the genotypes and antibiotic susceptibility of H. pylori in the Eastern Cape province of South Africa need to be monitored regularly.

Training is a key component of building capacity for public health surveillance and response, but has often been difficult to quantify. During fiscal 2009, the Armed Forces Health Surveillance Center, Division of Global Emerging Infections Surveillance and Response System (AFHSC-GEIS) supported 18 partner organizations in conducting 123 training initiatives in 40 countries for 3,130 U.S. military, civilian and host-country personnel. The training assisted with supporting compliance with International Health Regulations, IHR (2005). Training activities in pandemic preparedness, outbreak investigation and response, emerging infectious disease (EID) surveillance and pathogen diagnostic techniques were expanded significantly. By engaging local health and other government officials and civilian institutions, the U.S. military's role as a key stakeholder in global public health has been strengthened and has contributed to EID-related surveillance, research and capacity-building initiatives specified elsewhere in this issue. Public health and emerging infections surveillance training accomplished by AFHSC-GEIS and its Department of Defense (DoD) partners during fiscal 2009 will be tabulated and described.

In the U.S.A., human monocytotropic ehrlichiosis (HME) caused by Ehrlichia chaffeensis is an emerging tick-transmitted zoonosis. In Cameroon, where E. canis, E. chaffeensis and E. ewingii have recently been detected in dogs and/or ticks (Rhipicephalus sanguineus), the potential exists for human infections. Patients from the coastal region of Cameroon who had acute fevers of unknown aetiology were therefore checked for ehrlichial infection, using a real-time PCR that amplifies part of a genus-specific gene (dsb) that codes for a disulphide-bond formation protein. Ehrlichial blood was detected in the peripheral blood from 12 (10%) of the 118 patients investigated by PCR. When the 12 amplicons from the positive cases were sequenced, they were found to be identical to each other and to the corresponding dsb sequence of an Arkansas strain of E. chaffeensis. The 12 patients who were PCR-positive for E. chaffeensis suffered from fever (100%), headache (67%), myalgia (42%), arthralgia (58%), pulmonary involvement (17%) and/or a diffuse rash (17%).

Helicobacter pylori is a Gram-negative, micro-aerophilic, motile, curved rod that inhabits the gastric mucosa of the human stomach. It chronically infects thousands of millions of people world-wide, and is one of the most genetically diverse of bacterial species. Infection with the bacterium leads to chronic gastritis, peptic ulceration, gastric cancers and gastric mucosa-associated lymphoid-tissue (MALT) lymphoma. The prevalence of infection appears to be partly determined by geographical and socio-demographic factors, being higher in Africa than elsewhere. Current treatment, based on potent combinations that each consist of a proton-pump inhibitor and two antibiotics, is successful in 80%-90% of patients. Some undesirable side-effects, poor patient compliance and drug resistance are, however, associated with significant levels of treatment failure and with contra-indications for some patients. Antibiotic resistance in H. pylori is a growing global concern that merits the urgent attention of public-health authorities. Numerous pieces of clinical evidence have revealed that eradication of the organism from a patient results in improvement of gastritis and drastically decreases the frequency of relapse of gastric and duodenal ulcers. Natural products, including medicinal plants and honey, may offer useful alternatives in the treatment of H. pylori-related infections.