Hepatitis B and C virus infections in the three Pygmy groups in Cameroon. J Clin Microbiol. 2011;49:737-740. [PMID: 21106785 DOI: 10.1128/jcm.01475-10]

Anti-hepatitis C antibody carriage and risk of liver impairment in rural-Cameroon: adapting the control of hepatocellular carcinoma for resource-limited settings

BACKGROUND

The Viral hepatitis elimination by 2030 is uncertain in resource-limited settings (RLS), due to high burdens and poor diagnostic coverage. This sounds more challenging for hepatitis C virus (HCV) given that antibody (HCVAb) sero-positivity still lacks wide access to HCV RNA molecular testing. This warrants context-specific strategies for appropriate management of liver impairment in RLS. We herein determine the association between anti-HCV positivity and liver impairment in an African RLS.

METHODS

A facility-based observational study was conducted from July-August 2021 among individuals attending the "St Monique" Health Center at Ottou, a rural community of Yaounde,Cameroon. Following a consecutive sampling, consenting individuals were tested for anti-HCV antibodies, hepatitis B surface antigen (HBsAg) and HIV antibodies (HIVAb) as per the national guidelines. After excluding positive cases for HBsAg and/or HIVAb, liver function tests (ALT/AST) were performed on eligible participants (HBsAg and HIVAb negative) and outcomes were compared according to HCVAb status; with p < 0.05 considered statistically significant.

RESULTS

Out of 306 eligible participants (negative for HBsAg and HIVAb) enrolled, the mean age was 34.35 ± 3.67 years. 252(82.35%) were female and 129 (42.17%) were single. The overall HCVAb sero-positivity was 15.68%(48/306), with 17.86% (45/252) among women vs. 5.55%(3/54) among men [OR (95%CI) = 3.69(2.11-9.29),p = 0.04]. HCVAb Carriage was greater among participants aged > 50 years compared to younger ones [38.46%(15/39) versus 12.36% (33/267) respectively, OR(95%CI) = 4.43(2.11-9.29), p < 0.000] and in multipartnership [26.67%(12/45)vs.13.79%(36/261) monopartnership, OR (95%CI) = 2.27(1.07-4.80),p = 0.03]. The liver impairment rate (abnormal ALT+AST levels) was 30.39%(93/306), with 40.19%(123/306) of abnormal ALT alone. Moreover, the burden of Liver impairment was significantly with aged> 50 versus younger ones [69.23% (27/39) versus 24.72%(66/267) respectively, p < 0.000). Interestingly, the burden of liver impairment (abnormal AST + ALAT) was significantly higher in HCVAb positive (62.5%, 30/48) versus HCVAb negative (24.42%, 63/258) participants, OR: 3.90 [1.96; 7.79], p = 0.0001.

CONCLUSIONS

In this rural health facility, HCVAb is highly endemic and the burden of liver impairment is concerning. Interestingly, HCVAb carriage is associated with abnormal liver levels of enzyme (ALT/AST), especially among the elderly populations. Hence, in the absence of nuclei acid testing, ALT/AST are relevant sentinel markers to screen HCVAb carriers who require monitoring/care for HCV-associated hepatocellular carcinoma in RLS.

Endemicity and genetic diversity of Hepatitis delta virus among Pygmies in Cameroon, Central Africa

OBJECTIVE

A single study conducted about three decades ago on hepatitis D virus (HDV) infection among Baka pygmies in Cameroon reported a very high anti-HDV antibodies prevalence of 46%, but HDV genetic diversity has not been studied in this population. The genetic diversity of strains from endemic ancient populations may help to understand the origin and evolutionary history of viruses. This study aimed to investigate the HDV seroprevalence and the genetic diversity in three remote Cameroonian Pygmies with chronic HBV infection.

RESULTS

An unusually high 69% (36/52) level of HDV infection was found among HBsAg-positive pygmies in Cameroon. HDV RNA was detected and sequenced in 38.8% (14/36). The phylogenetic analysis revealed that 9/14 strains (64.3%) were identified and classified as genotype 1 (HDV-1) and 5/14 (35.6%) as genotype 7 (HDV-7), respectively with a bootstrap value of 100%. The further analysis showed the co-circulation of highly diverse HDV genotypes HDV-1 and HDV-7 in this population. These results highlight the endemicity of HDV infection in Central Africa. The highly diverse HDV-1 and HDV-7 in pygmies suggest an African origin of HDV. However, further studies are needed with larger sample size.

Genotype E: The neglected genotype of hepatitis B virus

Hepatitis B virus (HBV) (sub)genotypes A1, D3 and E circulate in sub-Saharan Africa, the region with one of the highest incidences of HBV-associated hepatocellular carcinoma globally. Although genotype E was identified more than 20 years ago, and is the most widespread genotype in Africa, it has not been extensively studied. The current knowledge status and gaps in its origin and evolution, natural history of infection, disease progression, response to antiviral therapy and vaccination are discussed. Genotype E is an African genotype, with unique molecular characteristics that is found mainly in Western and Central Africa and rarely outside Africa except in individuals of African descent. The low prevalence of this genotype in the African descendant populations in the New World, phylogeographic analyses, the low genetic diversity and evidence of remnants of genotype E in ancient HBV samples suggests the relatively recent re-introduction into the population. There is scarcity of information on the clinical and virological characteristics of genotype E-infected patients, disease progression and outcomes and efficacy of anti-HBV drugs. Individuals infected with genotype E have been characterised with high hepatitis B e antigen-positivity and high viral load with a lower end of treatment response to interferon-alpha. A minority of genotype E-infected participants have been included in studies in which treatment response was monitored. Of concern is that current guidelines do not consider patients infected with genotype E. Thus, there is an urgent need for further large-scale investigations into genotype E, the neglected genotype of HBV.

Case-Control Study of the Immune Status of Humans Infected With Zoonotic Gorilla Simian Foamy Viruses

BACKGROUND

Zoonotic simian foamy viruses (SFVs) establish persistent infections in humans, for whom the long-term consequences for health are poorly described. In this study, we aimed to characterize blood-cell phenotypes and plasma biomarkers associated with gorilla SFV infection in humans.

METHODS

We used a case-control design to compare 15 Cameroonian hunters infected with gorilla SFV (cases) to 15 controls matched for age and ethnicity. A flow cytometry-based phenotypic study and quantification of plasma immune biomarkers were carried out on blood samples from all participants. Wilcoxon signed-rank tests were used to compare cases and controls.

RESULTS

Cases had a significantly higher percentage of CD8 T lymphocytes than controls (median, 17.6% vs 13.7%; P = .03) but similar levels of B, natural killer, and CD4 T lymphocytes. Cases also had a lower proportion of recent CD4 thymic emigrants (10.9% vs 18.6%, P = .05), a higher proportion of programmed death receptor 1 (PD-1) expressing memory CD4 T lymphocytes (31.7% vs 24.7%, P = .01), and higher plasma levels of the soluble CD163 scavenger receptor (0.84 vs .59 µg/mL, P = .003) than controls.

CONCLUSIONS

We show, for the first time, that chronic infection with SFV is associated with T lymphocyte differentiation and monocyte activation.

A polymorphic residue that attenuates the antiviral potential of interferon lambda 4 in hominid lineages

As antimicrobial signalling molecules, type III or lambda interferons (IFNλs) are critical for defence against infection by diverse pathogens, including bacteria, fungi and viruses. Counter-intuitively, expression of one member of the family, IFNλ4, is associated with decreased clearance of hepatitis C virus (HCV) in the human population; by contrast, a natural frameshift mutation that abrogates IFNλ4 production improves HCV clearance. To further understand how genetic variation between and within species affects IFNλ4 function, we screened a panel of all known extant coding variants of human IFNλ4 for their antiviral potential and identify three that substantially affect activity: P70S, L79F and K154E. The most notable variant was K154E, which was found in African Congo rainforest ‘Pygmy’ hunter-gatherers. K154E greatly enhanced in vitro activity in a range of antiviral (HCV, Zika virus, influenza virus and encephalomyocarditis virus) and gene expression assays. Remarkably, E154 is the ancestral residue in mammalian IFNλ4s and is extremely well conserved, yet K154 has been fixed throughout evolution of the hominid genus Homo, including Neanderthals. Compared to chimpanzee IFNλ4, the human orthologue had reduced activity due to amino acid K154. Comparison of published gene expression data from humans and chimpanzees showed that this difference in activity between K154 and E154 in IFNλ4 correlates with differences in antiviral gene expression in vivo during HCV infection. Mechanistically, our data show that the human-specific K154 negatively affects IFNλ4 activity through a novel means by reducing its secretion and potency. We thus demonstrate that attenuated activity of IFNλ4 is conserved among humans and postulate that differences in IFNλ4 activity between species contribute to distinct host-specific responses to—and outcomes of—infection, such as HCV infection. The driver of reduced IFNλ4 antiviral activity in humans remains unknown but likely arose between 6 million and 360,000 years ago in Africa.

Natural genetic variation and its influence on the outcome of viral infection is a topical area given the wealth of genetic data now available. However, understanding how clinical phenotype is affected by genetic variation at the molecular level is often lacking yet critical for any insight into immunity and disease. It is known that variants in the antiviral ‘interferon lambda 4’ (IFNL4) gene significantly influence outcome of hepatitis C virus (HCV) infection in humans. Counter-intuitively, those producing IFNL4 have greater risk of establishing chronic HCV infection, compared to individuals with an inactive variant, although the underlying mechanisms remain poorly understood. From a comprehensive screen of all natural human variants, we show that the most common form of IFNλ4 is less able to protect human cells from pathogenic virus infection than the equivalent protein from our closest living relative the chimpanzee. This is as a result of a single amino acid substitution that impedes its release from cells and reduces antiviral gene expression. Our observed differences in activity correlated with divergent host responses in HCV-infected livers from humans and chimpanzees. We suggest that human IFNL4 evolution places humans at a disadvantage when infected with pathogens such as HCV.

Transmission of Hepatitis B and D Viruses in an African Rural Community

According to the World Health Organization (WHO), an estimated 257 million people worldwide are chronically infected with hepatitis B virus (HBV), with approximately 15 million of them being coinfected with hepatitis D virus (HDV). To investigate the prevalence and transmission of HBV and HDV within the general population of a rural village in Cameroon, we analyzed serum samples from most (401/448) of the villagers. HBV surface antigen (HBsAg) was detected in 54 (13.5%) of the 401 samples, with 15% of them also containing anti-HDV antibodies. Although Cameroon has integrated HBV vaccination into their Expanded Program on Immunization for newborns in 2005, an HBsAg carriage rate of 5% was found in children below the age of 5 years. Of the 54 HBsAg-positive samples, 49 HBV pre-S/S sequences (7 genotype A and 42 genotype E sequences) could be amplified by PCR. In spite of the extreme geographical restriction in the recruitment of study participants, a remarkable genetic diversity within HBV genotypes was observed. Phylogenetic analysis of the sequences obtained from PCR products combined with demographic information revealed that the presence of some genetic variants was restricted to members of one household, indicative of intrafamilial transmission, which appears to take place at least in part perinatally from mother to child. Other genetic variants were more widely distributed, reflecting horizontal interhousehold transmission. Data for two households with more than one HBV-HDV-coinfected individual indicate that the two viruses are not necessarily transmitted together, as family members with identical HBV sequences had different HDV statuses. IMPORTANCE This study revealed that the prevalence of HBV and HDV in a rural area of Cameroon is extremely high, underlining the pressing need for the improvement of control strategies. Systematic serological and phylogenetic analyses of HBV sequences turned out to be useful tools to identify networks of virus transmission within and between households. The high HBsAg carriage rate found among children demonstrates that implementation of the HBV birth dose vaccine and improvement of vaccine coverage will be key elements in preventing both HBV and HDV infections. In addition, the high HBsAg carriage rate in adolescents and adults emphasizes the need for identification of chronically infected individuals and linkage to WHO-recommended treatment to prevent progression to liver cirrhosis and hepatocellular carcinoma.

Serological evidence of rift valley fever Phlebovirus and Crimean-Congo hemorrhagic fever orthonairovirus infections among pygmies in the east region of Cameroon

Background

Rift Valley Fever Phlebovirus (RVFV) and Crimean-Congo Hemorrhagic Fever Orthonairovirus (CCHFV) specific antibodies had been documented among humans in urban settings of the southwestern and northern Cameroon in the late 1980s. Recently, evidence for enzootic circulation of RVFV was reported among livestock in both rural and urban settings in Cameroon. However, current estimates of human exposure to RVFV and CCHFV are still to be documented in Cameroon, especially in rural areas. The aim of this study was to assess the seroprevalence of RVFV and CCHFV in rural settings in the Southeastern rain forest of Cameroon.

Results

Using Enzyme-linked Immunosorbent Assays, the presence of RVFV and CCHFV Immunoglobulin G antibodies was investigated in plasma samples originating from 137 Pygmies from four villages of the East region of Cameroon. The studied population was found to be 12.4% (17/137) and 4.4% (6/137) seropositive for RVFV and CCHFV, respectively. The rates of RVFV IgG were comparable between the age groups and sex. Conversely, the rate of CCHFV IgG was significantly higher among the 41–60 years old participants (p = 0.02).

Conclusions

This study provides a substantial evidence of the circulation of RVFV and CCHFV among rural inhabitants of the East region of Cameroon.

Epidemiology of viral hepatitis in the Republic of Congo: review

Objective

Considered an endemic zone, Republic of Congo has a high seroprevalence rate of hepatitis B and C virus. To know the extent of hepatitis infection as a public health problem, we reviewed published literature and other sources for reports of these viral infections in the country.

Results

High seroprevalence of HBV and HCV carriage in blood donors were observed in studies confirming Congo’s place in the hyperendemic area of HBV and HCV infection. These prevalence were compared by Chi square test. We compared the prevalence of three studies conducted in 1996, 2015 and 2016. The statistical results were very significant. HBV genotype E was most prevalent. Very few studies were done on pregnant women. Difficulties in the care and management of patients were also noted because of the high cost of often unavailable treatments. Difficulties arise, however, when an attempt was made to implement the National Hepatitis Control Program. Despite studies conducted on hepatitis prevalence, health interventions are still needed to care and manage these patients and the need to implement the national hepatitis control is more pressing in the Congo.

Sero-epidemiology of human immunodeficiency virus, hepatitis B virus and hepatitis C virus: a cross-sectional survey in a rural setting of the West region of Cameroon

INTRODUCTION

Human immunodeficiency Virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) are the three most common chronic viral infections worldwide, specifically in sub-Saharan Africa (SSA). This study aimed to determine the sero-epidemiology of HIV, HBV and HCV infections in a rural setting of the West region of Cameroon, a SSA country.

METHODS

We conducted a cross-sectional study from August 2 to 5, 2014 in the three health districts of the Menoua Division, West region of Cameroon. Sixteen villages were randomly selected. Participants were currently living in the Division at the time of the survey, and enrolled after they had provided a signed consent form. HIV screening used the "determine test" followed by Hexagon HIV for positive cases to the first assay. HBV and HCV were detected using DIASpot HBsAg and DIASpot HCV-Ab, respectively.

RESULTS

On the whole, 612 subjects consented to take part in this study, of whom 71.1% were females. Mean age of the study population was 45.3 ± 17.9 years. The seroprevalences of HIV, HBV and HCV infections were 1.0% (6/582), 4.5% (20/443) and 6.3% (23/365), respectively. The 41-50 years age group was the most represented among HIV-positive subjects. HBV prevalence was higher in the 21-30 years age group (13.4%), followed by the 51-60 years age group (7.8%), with a significant difference of prevalences among age groups (p = 0.002). All HCV-positive cases were above 40 years of age with a higher prevalence in the > 70 years age group (33.3%) followed by the 61-70 years age group (14.5%); there was a significant difference between the age groups (p = 0.001).

CONCLUSION

The seroprevalences of HIV, HBV and HCV infections in the Menoua Division of the West region of Cameroon were 1.0%, 4.5% and 6.3%, respectively. Preventive measures against these health threats need to be reinforced in this setting.

Seroprevalence of hepatitis C virus infection in Cameroon: a systematic review and meta-analysis

OBJECTIVE

Better knowledge of hepatitis C virus (HCV) seroprevalence at the national level can help to implement pertinent strategies to address the HCV-related burden. The aim of this paper was to estimate the seroprevalence of HCV infection in Cameroon.

DESIGN

Systematic review and meta-analysis.

PARTICIPANTS

People residing in Cameroon.

DATA SOURCES

Electronic databases including PubMed/MEDLINE, AJOL, WHO-Afro Library, Africa Index Medicus, National Institute of Statistics and National AIDS Control Committee, Cameroon from 1 January 2000 to 15 December 2016 were searched. English and French languages papers were considered. Two independent investigators selected studies. The methodological quality of the studies was assessed using the Newcastle-Ottawa scale.

RESULTS

31 studies including 36 407 individuals were finally considered. There was no national representative study. The overall pooled prevalence was 6.5% (95% CI 4.5% to 8.8%; I²=98.3%). A sensitivity analysis of individuals at low risk of HCV infection showed a pooled prevalence of 3.6% (95% CI 2.3% to 5.2%, I²=97.7%, 18 studies) among 22 860 individuals (general population, blood donors and pregnant women), which was higher than for a high-risk population (healthcare workers and people with other identified comorbidities), 12.2% (95% CI 4.9% to 22.2%; I²=98.3%, 13 studies); p=0.018. The prevalence was higher in the East region, in rural settings, and when using an enzyme immunoassay technique for detecting HCV antibodies. Sex, sites, study period, sample size, timing of data collection and methodological quality of studies were not sources of heterogeneity.

LIMITATION

One-third of studies (29.0%) had a low risk bias in their methodology and most were facility-based (87.1%).

CONCLUSION

The seroprevalence of HCV infection in Cameroon indicates the need for comprehensive and effective strategies to interrupt HCV transmission in the Cameroonian population. Specific attention is needed for the East region of the country, rural settings and high-risk populations. A national representative study is needed to provide better estimates.

Seroprevalence of hepatitis B virus infection in Cameroon: a systematic review and meta-analysis

OBJECTIVE

Better knowledge of hepatitis B virus (HBV) infection prevalence at the national level can help to implement pertinent strategies to address HBV related burden. The aim was to estimate the seroprevalence of HBV infection in Cameroon.

DESIGN

Systematic review and meta-analysis.

PARTICIPANTS

People residing in Cameroon.

DATA SOURCES

Electronic databases including PubMed/MEDLINE, African Journals Online (AJOL), ScienceDirect, WHO-Afro Library, WHO-IRIS, African Index Medicus, National Institute of Statistics and National AIDS Control Committee, Cameroon; regardless of language and from 1 January 2000 to 30 September 2016. This was completed with a manual search of references of relevant papers. Risk of bias in methodology of studies was measured using the Newcastle-Ottawa Scale.

RESULTS

Out of 511 retrieved papers, 44 studies with a total of 105 603 individuals were finally included. The overall pooled seroprevalence was 11.2% (95% CI 9.7% to 12.8%) with high heterogeneity between studies (I²=97.9%). Egger's test showed no publication bias (p=0.167). A sensitivity analysis excluding individuals at high risk of HBV infection and after adjustment using trim and fill method showed a pooled seroprevalence of 10.6% (95% CI 8.6% to 12.6%) among 100 501 individuals (general population, blood donors and pregnant women). Sources of heterogeneity included geographical regions across country and setting (rural 13.3% vs urban 9.0%), and implementation of HBV universal immunisation (born after 9.2% vs born before 0.7%). Sex, site, timing of data collection, HBV screening tools and methodological quality of studies were not sources of heterogeneity.

LIMITATION

Only a third of the studies had low risk of bias in their methodology.

CONCLUSION

The seroprevalence of HBV infection in Cameroon is high. Effective strategies to interrupt the transmission of HBV are urgently required. Specific attention is needed for rural settings, certain regions and people born before the implementation of the HBV universal immunisation programme in Cameroon in 2005.

REGISTRATION

PROSPERO, CRD42016042654.

A prominent role of Hepatitis D Virus in liver cancers documented in Central Africa

Background

Hepatocellular Carcinoma (HCC) is one of the commonest cancers in Central Africa, a region with the unusual peculiarity to be hyperendemic for infections with Hepatitis B, C and D viruses. However, data estimating the respective proportions of HCC cases attributable to these viruses are still limited in this area. The current study was undertaken to determine the role of these viruses in HCC compared to non-HCC Cameroonian patients.

Methods

A case–control study was conducted in the Gastroenterology Unit of Central Hospital of Yaounde in collaboration with Centre Pasteur of Cameroon. Blood samples of all HCC cases (n = 88) and matched control individuals without known liver disease (n = 85) were tested for serological markers of Hepatitis B, C and D viral infections using commercially available enzyme immune-assay kits. Hepatitis B and C viral loads were quantified for positive patients by real-time PCR using commercial kits.

Results

The mean age was 46.0 ± 18 and 42.1 ± 16 years old for HCC-patients and controls, respectively for a 2.3 Male/Female sex ratio. The prevalence of hepatitis B surface antigen, antibody to HCV and antibody to HDV were significantly higher in HCC patients (65.90, 20.26 and 26 % respectively) than in control patients (9.23, 4.62 and 1 %) (P < 2.5 10⁻⁵). The risk factors analysis showed that both HBV and HCV infections were strongly associated with HCC development in Cameroon with crude odds ratios of 15.98 (95 % CI 6.19-41.25) and 7.33 (95 % CI 2.09-25.77), respectively. Furthermore, the risk of developing HCC increased even more significantly in case of HBV and HDV co-infections with the odd ratio of 29.3 (95 % CI, 4.1-1231). HBV-DNA level was significantly higher in HBsAg-positive HCC-patients than in HBsAg-positive controls with (6.3 Log IU/mL and 5.7 Log IU/mL) respectively (P < 0.05).

Conclusion

HBV and HCV infections are the mains factors of HCC development in Cameroon. Our results show that patients co-infected with HDV are at very high risk to develop HCC. An active surveillance program of patients and, foremost, an easier access to antivirals and primary prevention measures are crucial steps to reduce the incidence of HCC in this country. Due to the lack of truly efficient antiviral therapy, the fate of HDV-infected patients remains, however, particularly worrying.

Molecular characterization of hepatitis B virus in blood donors from Burkina Faso: Prevalence of quasi-subgenotype A3, genotype E, and mixed infections

Burkina Faso is a highly endemic area for Hepatitis B virus (HBV) which remains a major challenge for blood safety with >13% of candidate blood donors being chronically infected. However, little is known about the molecular epidemiology of the viral strains currently circulating. In this study, 99 HBV strains from HBsAg positive candidate blood donors in Ougadougou were genetically characterized by sequencing the pre-S/S region of the viral genome. Phylogenetic analyses revealed a 25% prevalence of HBV quasi-subgenotype A3 (A3_QS ) co-circulating with the confirmed dominant HBV genotype E (72%). HBV/A3_QS sequences formed a sub-cluster closely related to West-African sequences previously characterized, and showed a low intra-group genetic diversity (0.75%) suggesting a relatively recent spreading of HBV/A3_QS strains in Burkina Faso. Low genetic diversity of genotype E strains compared to A3_QS was confirmed. Mixed infections with the two genotypes were identified in 3% of the donors tested and contributed to artifacts during PCR amplification of the viral genome leading to erroneous apparent intergenotype recombinant sequences. While the co-circulation of two HBV genotypes in a restricted area may favor the emergence of intergenotype recombinant variants, strictly controlled molecular experimental procedures should be used to accurately characterize HBV circulating recombinant forms. J. Med. Virol. 88:2145-2156, 2016. © 2016 Wiley Periodicals, Inc.

Broad Range of Hepatitis B Virus (HBV) Patterns, Dual Circulation of Quasi-Subgenotype A3 and HBV/E and Heterogeneous HBV Mutations in HIV-Positive Patients in Gabon

Integrated data on hepatitis B virus (HBV) patterns, HBV genotypes and mutations are lacking in human immunodeficiency virus type 1 (HIV-1) co-infected patients from Africa. This survey was conducted in 2010-2013 among 762 HIV-1-positive adults from Gabon who were predominantly treated with 3TC-based antiretroviral treatment. HBV patterns were identified using immunoassays detecting total antibody to hepatitis B core antigen (HBcAb), hepatitis B surface antigen (HBsAg), IgM HBcAb, hepatitis B e antigen (HBeAg), antibody to HBsAg (HBsAb) and an in-house real-time PCR test for HBV DNA quantification. Occult hepatitis B (OBI) was defined by the presence of isolated anti-HBc with detectable serum HBV DNA. HBV genotypes and HBV mutations were analyzed by PCR-direct sequencing method. Seventy-one (9.3%) patients tested positive for HBsAg, including one with acute hepatitis B (0.1%; 95% CI, 0.0%-0.2%), nine with HBeAg-positive chronic hepatitis B (CHB) (1.2%; 95% CI, 0.6%-2.2%), 16 with HBeAg-negative CHB (2.1%; 95% CI, 1.2%-3.3%) and 45 inactive HBV carriers (5.9%; 95% CI, 4.4%-7.8%). Sixty-one (8.0%; 95% CI, 6.2%-10.1%) patients showed OBI. Treated patients showed similar HBV DNA levels to those obtained in untreated patients, regardless of HBV patterns. Around 15.0% of OBI patients showed high (>1,000 UI/mL) viremia. The mutation M204V/I conferring resistance to 3TC was more common in HBV/A (47.4%) than in HBV/E isolates (0%) (P = .04). Our findings encouraged clinicians to promote HBV vaccination in patients with no exposure to HBV and to switch 3TC to universal TDF in those with CHB.

[Prevalence and factors associated with HIV and viral hepatitis B and C in the city of Bafoussam in Cameroon]

Introduction

L'objectif de ce travail était de déterminer la séroprévalence et les facteurs associés au VIH et aux hépatites virales B et C dans la ville de Bafoussam au Cameroun.

Méthodes

Il s'agissait d'une étude descriptive et analytique réalisée de février 2012 à Juin 2012 dans la ville de Bafoussam au Cameroun. Pour cette étude, nous avons obtenu une clairance éthique.

Résultats

Au total, 982 personnes ont été dépistées pour le VIH et les hépatites virales B et C. Les femmes représentaient 56,3% des personnes dépistées. La tranche d’âge la plus représentée était celle des 20 à 24 ans. L’âge médian était de 34,5 ans. Les prévalences du VIH, de l'AgHBs, et de l'Ac anti HCV étaient respectivement de 6,0%, 4,1%, et 0,4%. La prévalence du VIH était 2 fois plus élevée parmi les femmes que les hommes avec 8,1% contre 3,5% (p=0,01). Les prévalences les plus élevées ont été observées chez les personnes de 30 à 34 ans, 40 à 44 ans avec 15,0% et 11,5% (p=0,01), les personnes sans emploi avec 11,1% (p<0,001) et les personnes en union libre avec 17,9% (p=0,000). La prévalence du VIH n’était pas directement liée aux comportements et pratiques sexuels de la population de l’étude. On enregistrait une prévalence élevée de 29,3% chez les individus ayant déclaré avoir au moins une infection sexuellement transmissible (p=0,000).

Conclusion

Il apparait urgent de mettre en place des stratégies de prévention contre le VIH, les hépatites virales et les facteurs associés au Cameroun.

Molecular identification of hepatitis B virus genotypes/subgenotypes: revised classification hurdles and updated resolutions

The clinical course of infections with the hepatitis B virus (HBV) substantially varies between individuals, as a consequence of a complex interplay between viral, host, environmental and other factors. Due to the high genetic variability of HBV, the virus can be categorized into different HBV genotypes and subgenotypes, which considerably differ with respect to geographical distribution, transmission routes, disease progression, responses to antiviral therapy or vaccination, and clinical outcome measures such as cirrhosis or hepatocellular carcinoma. However, HBV (sub)genotyping has caused some controversies in the past due to misclassifications and incorrect interpretations of different genotyping methods. Thus, an accurate, holistic and dynamic classification system is essential. In this review article, we aimed at highlighting potential pitfalls in genetic and phylogenetic analyses of HBV and suggest novel terms for HBV classification. Analyzing full-length genome sequences when classifying genotypes and subgenotypes is the foremost prerequisite of this classification system. Careful attention must be paid to all aspects of phylogenetic analysis, such as bootstrapping values and meeting the necessary thresholds for (sub)genotyping. Quasi-subgenotype refers to subgenotypes that were incorrectly suggested to be novel. As many of these strains were misclassified due to genetic differences resulting from recombination, we propose the term "recombino-subgenotype". Moreover, immigration is an important confounding facet of global HBV distribution and substantially changes the geographic pattern of HBV (sub)genotypes. We therefore suggest the term "immigro-subgenotype" to distinguish exotic (sub)genotypes from native ones. We are strongly convinced that applying these two proposed terms in HBV classification will help harmonize this rapidly progressing field and allow for improved prophylaxis, diagnosis and treatment.

[Evaluation of vaccination status against hepatitis B and HBsAg carriage among medical and paramedical staff of the Yaoundé Central Hospital, Cameroon]

Introduction

L’hépatite virale B est une affection à haut risque pour le personnel de santé. Au Cameroun, la vaccination contre le virus de l’hépatite B n'est pas obligatoire pour le personnel de santé. Le but de l’étude était d'évaluer l’état vaccinal contre l’hépatite virale B et la prévalence de l’Antigène HBs au sein du personnel médical et paramédical de l’Hôpital Central de Yaoundé.

Méthodes

Il s'agissait d'une étude prospective, transversale menée à l’Hôpital Central de Yaoundé du 1er juillet au 31 octobre 2011. Toute personne membre du corps médical et paramédical ayant signée la fiche de consentement éclairé était incluse dans l’étude. Ceux ayant refusé de signer la fiche de consentement éclairé ou dont la fiche d'enquête n'avait pas été complètement remplie étaient exclus de l’étude. Une recherche systématique de l’antigène HBs était effectuée chez chaque personne incluse dans l’étude.

Résultats

Au total 282 personnes ont participé à l’étude sur 760, soit un taux de participation de 37,1%. Les personnes ne connaissant pas leur statut sérologique vis-à-vis du virus de l’hépatite B était au nombre de 221 (85%). Deux cent vingt-cinq (86,5%) personnes n'étaient pas vaccinées contre l’hépatite B. Les personnes ayant reçu moins de 3 doses du vaccin contre l’hépatite virale B étaient au nombre de 23 (8,8%). Douze personnes (4,6%) déclaraient avoir reçu les 3 doses du vaccin contre l’hépatite virale B. La prévalence de l’antigène HBs était de 6,6% (n = 12).

Conclusion

Cette étude montre que la prévalence de l’hépatite virale B reste élevée chez le personnel de l’Hôpital Central de Yaoundé (6,6%). Il ya un besoin de sensibilisation du personnel médical aux risques liés à l’exercice de leur profession.

Hepatitis B virus exposure during childhood in Cameroon, Central African Republic and Senegal after the integration of HBV vaccine in the expanded program on immunization

BACKGROUND

More than 2 billion people worldwide have been exposed to hepatitis B virus (HBV). To prevent these infections, Senegal and Cameroon integrated the HBV vaccine into their Expanded Program on Immunization (EPI) in 2005, as did the Central African Republic (CAR) in 2008. We evaluated the prevalence of HBV exposure and infection after the integration of the HBV vaccine in the EPI.

METHODS

An observational cross-sectional study was conducted among the hospitalized children 3 months to 6 years of age in Cameroon, CAR and Senegal. Plasma was collected for the detection of anti-HBc, anti-HBs and hepatitis B surface antigen in children with anti-HBc and anti-HBs.

RESULTS

Between April 2009 and May 2010, 1783 children were enrolled, 19.4% of whom were anti-HBc positive. The percentage of children with anti-HBc was 44.4% among the children younger than 6 months, decreasing after 6 months to reach 18.8% at 12 months. This decline was followed by a rapid increase in anti-HBc positivity rate in CAR observed as early as 12 months of age compared with Cameroon and Senegal, where the anti-HBc increased between 18 and 36 months of age, respectively. The prevalence of hepatitis B surface antigen-positive children was significantly higher in CAR than that in Cameroon and Senegal (5.1% versus 0.7% and 0.2%; P < 0.001). Socioeconomic level, age and country were factors associated with the presence of anti-HBc.

CONCLUSIONS

Passive transfer of anti-HBc maternal antibodies versus HBV exposure could be differentiated as early as 12 months of age. The low prevalence of anti-HBc and hepatitis B surface antigen among children born after the integration of HBV vaccine in the EPI in Cameroon and Senegal suggests a positive impact of HBV vaccination.

Hepatitis B and C: neglected diseases among health care workers in Cameroon

BACKGROUND

Healthcare workers (HCW) are at risk of acquiring blood-borne viral infections, particularly hepatitis B (HBV), hepatitis C (HCV), and HIV, especially in high endemic regions such as sub-Saharan Africa.

METHODS

Sera from 237 hospital workers in Southwest Cameroon were tested for anti-hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg), anti-hepatitis B surface antigen (anti-HBs), anti-HCV and (on a voluntary basis) for anti-HIV. Information on pre-study testing for HBV, HCV and HIV and pre-study HBV vaccination status was collected from these individuals.

RESULTS

The pre-study testing rate among participating hospital staff for HBV was 23.6% (56/237), for HCV 16% (38/237), and for HIV 91.6% (217/237). The pre-study HBV vaccination rate was 12.3% (29/237). Analysis of anti-HBc revealed that 73.4% (174/237) of the hospital staff had been infected by HBV. Active HBV infection (HBsAg positivity) was detected in 15 participants. Anti-HCV was found in four of 237 participants, HIV antibodies were detected in four of 200 participants tested.

CONCLUSION

HBV and HCV are neglected diseases among HCW in sub-Saharan Africa. The vaccination rate against HBV was very low at 12.3%, and therefore anti-HBc testing should be mandatory to identify HCW requiring HBV vaccination. Testing for HBV and routine HBV vaccination for HBV-negative HCW should be strongly enforced in Cameroon.

High Rates of Hepatitis B and C and HIV Infections among Blood Donors in Cameroon: A Proposed Blood Screening Algorithm for Blood Donors in Resource-Limited Settings

Background. Infections with human immunodeficiency virus (HIV), hepatitis B (HBV), and hepatitis C virus (HCV) are currently major public health problems. Methods. A retrospective study was conducted from January to June 2008 at the Blood Bank of the Central Hospital, Yaoundé (Cameroon). The objective was to study the prevalence of HIV, HBV, and HCV and their coinfections among blood donors. Results. A total of 4650 donors were identified, and the sex ratio (male/female) was 14/1. The median age of donors was 28 years (range: 16 to 69 years). Among blood donors, HBV, HIV, and HCV infection prevalences were 12.14%  (n = 565) , 4.44%  (n = 206), and 1.44%  (n = 67), respectively. Coinfection with HIV and HBV was observed among 0.77% donors, followed by hepatitis B and C co-infection (0.21%) and HIV and HCV coinfection (0.06%). Co-infection with HIV-HBV-HCV was encountered in 2 donors. The HIV, HBV, and HCV infections lead to a destruction of one out of six sets of blood collected. Conclusion. There is a need to review policies for blood collection from donors, by modifying the algorithm of blood donors testing. Pretesting potential donors using rapid tests could help to avoid collection and destruction of (infected) blood.

Low immune response to hepatitis B vaccine among children in Dakar, Senegal

HBV vaccine was introduced into the Expanded Programme on Immunization (EPI) in Senegal and Cameroon in 2005. We conducted a cross-sectional study in both countries to assess the HBV immune protection among children. All consecutive children under 4 years old, hospitalized for any reason between May 2009 and May 2010, with an immunisation card and a complete HBV vaccination, were tested for anti-HBs and anti-HBc. A total of 242 anti-HBc-negative children (128 in Cameroon and 114 in Senegal) were considered in the analysis. The prevalence of children with anti-HBs ≥10 IU/L was higher in Cameroon with 92% (95% CI: 87%–97%) compared to Senegal with 58% (95% CI: 49%–67%), (p<0.001). The response to vaccination in Senegal was lower in 2006–2007 (43%) than in 2008–2009 (65%), (p = 0.028). Our results, although not based on a representative sample of Senegalese or Cameroonian child populations, reveal a significant problem in vaccine response in Senegal. This response problem extends well beyond hepatitis B: the same children who have not developed an immune response to the HBV vaccine are also at risk for diphtheria, tetanus, pertussis (DTwP) and Haemophilus influenzae type b (Hib). Field biological monitoring should be carried out regularly in resource-poor countries to check quality of the vaccine administered.