Increased exposure to hepatitis B virus infection in HIV-positive South African antenatal women

In silico analysis of mutations associated with occult hepatitis B virus (HBV) infection in South Africa

Occult hepatitis B virus (OBI) infection is defined by the presence of viral DNA in the liver and/or serum in absence of hepatitis B surface antigen (HBsAg). While multiple studies have identified mutations that are associated with OBI, only a small portion of these mutations have been functionally characterized in vitro. Using complementary in silico approaches, the effects of OBI-associated amino acid mutations on HBV protein function in HBV/HIV-positive ART-naïve South Africans were evaluated. Two OBI-associated mutations in the PreS1 region, one in the PreS2 region, and seven in the surface region of subgenotype A1 sequences were identified as deleterious. In subgenotype A2 sequences, 11 OBI-associated mutations in the PreS1 region, seven in the PreS2 region, and 31 in the surface region were identified as deleterious. In the polymerase region, 14 OBI-associated mutations in subgenotype A1 and 71 OBI-associated mutations in subgenotype A2 were identified as deleterious. This study utilized in silico approaches to characterize the likely impact of OBI-associated mutations on viral function, thereby identifying and prioritizing candidates and reducing the significant cost associated with functional studies that are essential for mechanistic studies of the OBI phenotype.

Viral hepatitis B and C in HIV-exposed South African infants

Background

Whilst much attention is given to eliminating HIV mother-to-child transmission (MTCT), little has been done to ensure the same for hepatitis B virus (HBV) transmission. The introduction of HBV immunization at six weeks of age has reduced HBV horizontal transmission in South Africa. However, in order to eliminate HBV MTCT, further interventions are needed. The risk of hepatitis C virus (HCV) MTCT in HIV-infected (HIV+) African women is not yet well described. This study aimed to determine the rate of HBV and HCV vertical transmission in HIV-exposed infants in South Africa.

Methods

Serum samples from infants enrolled in an isoniazid prevention study (P1041) were screened for HBV and HCV serology markers; screening was performed on samples collected at approximately 60 weeks of age of the infants. HBV DNA was quantified in HBsAg positive samples and HBV strains characterized through gene sequencing. All HCV antibody samples with inconclusive results underwent molecular testing.

Results

Three of 821 infants were positive for both HBsAg and HBV DNA. All HBV strains belonged to HBV sub-genotype A1. The rtM204I mutation associated with lamivudine resistance was identified in one infant, a second infant harboured the double A1762T/G1764A BCP mutation. Phylogenetic analysis showed clustering between mother and infant viral genomic sequences. Twenty-one of 821 HIV-exposed infants tested had inconclusive HCV antibody results, none were HCV PCR positive.

Conclusions

This study suggests that HBV vertical transmission is likely to be occurring in HIV-exposed infants in South Africa.. A more robust strategy of HBV prevention, including birth dose vaccination, is required to eradicate HBV MTCT. HCV infection was not detected.

Impact of Lamivudine-Based Antiretroviral Treatment on Hepatitis B Viremia in HIV-Coinfected South Africans

This prospective study investigated the impact of lamivudine-containing antiretroviral therapy (ART) on HIV-positive patients in South Africa with baseline hepatitis B virus (HBV) infection. Follow-up samples from 56 HBV/HIV co-infected patients, 25 with occult HBV infection (OBI) and 31 with chronic HBV infection (CHB), were available for analysis. HBV viral loads were quantified at 6, 12, 18, and 24 months post-ART initiation by the COBAS TaqMan HBV Test 48 assay, and the HBV polymerase gene was amplified with an in-house nested polymerase chain reaction assay. During 24 months of lamivudine-based ART, 6 of 8 (75%) OBI and 4 of 6 (67%) CHB patients achieved undetectable levels of HBV DNA, while 2 patients had persistent HBV DNA levels ≥ 2 × 10⁵ despite lamivudine-based ART for 24 months. HIV viremia was undetectable in all patients at 12 months, suggesting high adherence to ART. Several lamivudine-associated HBV resistance mutations, including L180M, A181T, M204I, and M204V, were observed. Sequence analysis also revealed a rare genotype G infection. While resource-limited settings may use lamivudine-based ART because of availability and low cost, antivirals with dual therapy against HBV and HIV (e.g., lamivudine and tenofovir) should always be recommended with the regular monitoring of HBV viremia levels.

Prevalence and burden of HBV co-infection among people living with HIV: A global systematic review and meta-analysis

Globally, in 2017 35 million people were living with HIV (PLHIV) and 257 million had chronic HBV infection (HBsAg positive). The extent of HIV-HBsAg co-infection is unknown. We undertook a systematic review to estimate the global burden of HBsAg co-infection in PLHIV. We searched MEDLINE, Embase and other databases for published studies (2002-2018) measuring prevalence of HBsAg among PLHIV. The review was registered with PROSPERO (#CRD42019123388). Populations were categorized by HIV-exposure category. The global burden of co-infection was estimated by applying regional co-infection prevalence estimates to UNAIDS estimates of PLHIV. We conducted a meta-analysis to estimate the odds of HBsAg among PLHIV compared to HIV-negative individuals. We identified 506 estimates (475 studies) of HIV-HBsAg co-infection prevalence from 80/195 (41.0%) countries. Globally, the prevalence of HIV-HBsAg co-infection is 7.6% (IQR 5.6%-12.1%) in PLHIV, or 2.7 million HIV-HBsAg co-infections (IQR 2.0-4.2). The greatest burden (69% of cases; 1.9 million) is in sub-Saharan Africa. Globally, there was little difference in prevalence of HIV-HBsAg co-infection by population group (approximately 6%-7%), but it was slightly higher among people who inject drugs (11.8% IQR 6.0%-16.9%). Odds of HBsAg infection were 1.4 times higher among PLHIV compared to HIV-negative individuals. There is therefore, a high global burden of HIV-HBsAg co-infection, especially in sub-Saharan Africa. Key prevention strategies include infant HBV vaccination, including a timely birth-dose. Findings also highlight the importance of targeting PLHIV, especially high-risk groups for testing, catch-up HBV vaccination and other preventative interventions. The global scale-up of antiretroviral therapy (ART) for PLHIV using a tenofovir-based ART regimen provides an opportunity to simultaneously treat those with HBV co-infection, and in pregnant women to also reduce mother-to-child transmission of HBV alongside HIV.

Hepatitis B sero-prevalence in children under 15 years of age in South Africa using residual samples from community-based febrile rash surveillance

Introduction and methods

Hepatitis B is a vaccine preventable disease and is notifiable in South Africa. Hepatitis B vaccination was incorporated into the Expanded Programme on Immunisation in South Africa in 1995. We used a convenience sample from community-based febrile rash surveillance in 2013 to estimate hepatitis B sero-prevalence. Of samples serologically negative for acute measles infection, 450 samples spanning nine provinces of South Africa were tested for hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs) and hepatitis B core antibody (anti-HBc).

Results

Two children (2/450; 0.4%) tested positive for HBsAg. Three hundred and three children (67.3%) had evidence of vaccine induced immunity. Vaccine induced immunity was present in 80.2% of 1–5 year olds, but only 60.3% of 10–14 year olds. Natural immunity, indicating exposure to circulating hepatitis B, was present in 13/450 (2.9%) children.

Conclusion

Chronic hepatitis B in South African has decreased in prevalence from highly endemic levels prior to vaccine introduction to approximately 0.4% in this sample, demonstrating impact of a successful vaccination programme 18 years after introduction. Decreased vaccine-induced immunity with increasing age may reflect waning antibody titres over time.

Hepatitis B in sub-Saharan Africa: strategies to achieve the 2030 elimination targets

The WHO global health sector strategy on viral hepatitis, created in May, 2016, aims to achieve a 90% reduction in new cases of chronic hepatitis B and C and a 65% reduction in mortality due to hepatitis B and C by 2030. Hepatitis B virus (HBV) is endemic in sub-Saharan Africa, and despite the introduction of universal hepatitis B vaccination and effective antiviral therapy, the estimated overall seroprevalence of hepatitis B surface antigen remains high at 6·1% (95% uncertainty interval 4·6-8·5). In this Series paper, we have reviewed the literature to examine the epidemiology, burden of liver disease, and elimination strategies of hepatitis B in sub-Saharan Africa. This paper reflects a supranational perspective of sub-Saharan Africa, and recommends several priority elimination strategies that address the need both to prevent new infections and to diagnose and treat chronic infections. The key to achieving these elimination goals in sub-Saharan Africa is the effective prevention of new infections via universal implementation of the HBV birth-dose vaccine, full vaccine coverage, access to affordable diagnostics to identify HBV-infected individuals, and to enable linkage to care and antiviral therapy.

The investment case for hepatitis B and C in South Africa: adaptation and innovation in policy analysis for disease program scale-up

Even though WHO has approved global goals for hepatitis elimination, most countries have yet to establish programs for hepatitis B and C, which account for 320 million infections and over a million deaths annually. One reason for this slow response is the paucity of robust, compelling analyses showing that national HBV/HCV programs could have a significant impact on these epidemics and save lives in a cost-effective, affordable manner. In this context, our team used an investment case approach to develop a national hepatitis action plan for South Africa, grounded in a process of intensive engagement of local stakeholders. Costs were estimated for each activity using an ingredients-based, bottom-up costing tool designed by the authors. The health impact and cost-effectiveness of the Action Plan were assessed by simulating its four priority interventions (HBV birth dose vaccination, PMTCT, HBV treatment and HCV treatment) using previously developed models calibrated to South Africa's demographic and epidemic profile. The Action Plan is estimated to require ZAR3.8 billion (US$294 million) over 2017-2021, about 0.5% of projected government health spending. Treatment scale-up over the initial 5-year period would avert 13 000 HBV-related and 7000 HCV-related deaths. If scale up continues beyond 2021 in line with WHO goals, more than 670 000 new infections, 200 000 HBV-related deaths, and 30 000 HCV-related deaths could be averted. The incremental cost-effectiveness of the Action Plan is estimated at $3310 per DALY averted, less than the benchmark of half of per capita GDP. Our analysis suggests that the proposed scale-up can be accommodated within South Africa's fiscal space and represents good use of scarce resources. Discussions are ongoing in South Africa on the allocation of budget to hepatitis. Our work illustrates the value and feasibility of using an investment case approach to assess the costs and relative priority of scaling up HBV/HCV services.

The status of hepatitis B control in the African region

The World Health Organization (WHO) African Region has approximately 100 million people with chronic hepatitis B virus (HBV) infection. This review describes the status of hepatitis B control in the Region. We present hepatitis B vaccine (HepB) coverage data and from available data in the published literature, the impact of HepB vaccination on hepatitis B surface antigen (HBsAg) prevalence, a marker of chronic infection, among children, HBsAg prevalence in pregnant women, and risk of perinatal transmission. Lastly, we describe challenges with HepB birth dose (HepB-BD) introduction reported in the Region, and propose strategies to increase coverage. In 2015, regional three dose HepB coverage was 76%, and 16(34%) of 47 countries reported ≥ 90% coverage. Overall, 11 countries introduced HepB-BD; only nine provide universal HepB-BD, and of these, five reported ≥ 80% coverage. From non-nationally representative serosurveys among children, HBsAg prevalence was lower among children born after HepB introduction compared to those born before HepB introduction. However, some studies still found HBsAg prevalence to be above 2%. From limited surveys among pregnant women, the median HBsAg prevalence varied by country, ranging from 1.9% (Madagascar) to 16.1% (Niger); hepatitis B e antigen (HBeAg) prevalence among HBsAg-positive women ranged from 3.3% (Zimbabwe) to 28.5% (Nigeria). Studies in three countries indicated that the risk of perinatal HBV transmission was associated with HBeAg expression or high HBV DNA viral load. Major challenges for timely HepB-BD administration were poor knowledge of or lack of national HepB-BD vaccination guidelines, high prevalence of home births, and unreliable vaccine supply. Overall, substantial progress has been made in the region. However, countries need to improve HepB3 coverage and some countries might need to consider introducing the HepB-BD to help achieve the regional hepatitis B control goal of < 2% HBsAg prevalence among children < 5 years old by 2020. To facilitate HepB-BD introduction and improve timely coverage, strategies are needed to reach both facility-based and home births. Strong political commitment, clear policy recommendations and staff training on HepB-BD administration are also required. Furthermore, high quality nationally representative serosurveys among children are needed to inform decision makers about progress towards the regional control goal.

High prevalence of active and occult hepatitis B virus infections in healthcare workers from two provinces of South Africa

BACKGROUND

Hepatitis B (HB) is a vaccine-preventable liver disease caused by infection with the blood-borne hepatitis B virus (HBV). South African healthcare workers (HCWs) may be at high risk of occupational exposure to HBV infection, since previous studies have found suboptimal levels of protection against HBV in HCWs.

METHODS

A descriptive prevalence study based on self-administered questionnaires with data on demographics and HB vaccination status, and stored serum samples collected from 2009 to 2012, from 333 HCWs working or studying in Gauteng and Mpumalanga province hospitals or nursing colleges, was conducted. Samples were tested for HB surface antigen (HBsAg), antibodies to HBsAg (anti-HBs), antibodies to HB core antigen (anti-HBc), and HBV deoxyribonucleic acid (DNA).

RESULTS

The majority of HCWs from whom the serum samples were drawn were black (91.4% [298/326]), female (82.6% [275/333]) and had received at least one dose of HB vaccine (70.9% [236/333]). The average age was 38.8years (range: 19-62). Of the HCWs, 23.2% (73/314) were susceptible (negative for all markers); 9.6% (30/314) were infected (HBsAg and/or DNA positive); 29.0% (91/314) were exposed (positive for either HBsAg, anti-HBc, or DNA); 18.8% (59/314) were immune due to natural infection (anti-HBs and anti-HBc positive only); while 47.8% (150/314) were immune due to vaccination (anti-HBs positive only). Furthermore, HBV DNA was detected in 8.6% (27/314) and occult HBV infection (OBI) (HBV DNA positive but HBsAg negative) was found in 6.7% (21/314) of samples.

DISCUSSION AND CONCLUSION

This study, which is the first to report OBI in South African HCWs, found high rates of active HBV infection and sub-optimal protection against HBV in HCWs. There is a need to strengthen vaccination programmes through a policy that ensures protection for all HCWs and their patients.

The prevalence of hepatitis B virus infection in HIV-positive and HIV-negative infants: KwaZulu-Natal, South Africa

Background

The prevalence of hepatitis B virus (HBV) amongst South African infants and children has been reported in the pre-HIV era. Despite the reported high prevalence of HIV in the general population of South Africa, the rate of HIV/HBV co-infection amongst infants and children remains poorly reported.

Objectives

We describe the prevalence of HBV infection amongst HIV-positive and HIV-negative infants by molecular methods of diagnosis using dried blood spot samples.

Methods

This retrospective cross-sectional study was conducted between July 2011 and December 2011 in an academic referral laboratory offering viral diagnostic services to the entire KwaZulu-Natal province of South Africa. A total of 322 study samples were collected from discarded residual dried blood spot samples following routine infant diagnosis of HIV. Equal proportions of HIV-positive and HIV-negative infant specimens were studied. Statistical differences in the prevalence of HBV between the HIV-positive and HIV-negative samples were calculated using the Pearson chi-square test, and a p-value < 0.05 was considered statistically significant. Further testing for HBV DNA using a nested polymerase chain reaction method was performed.

Results

The overall prevalence of HBV was 10%. In the HIV-positive group, 21 of 161 infants tested positive for HBV compared with 12 of 161 HIV-negative infants who tested positive for HBV. The proportion of infants infected with HBV was marginally higher amongst HIV-positive infants (13.0%; 95% CI 6.8–19.9) compared with HIV-negative infants (7.5%; 95% CI 2.5–13.7; P = 0.098), though not statistically significant.

Conclusion

The finding of a 10% HBV prevalence in this infant cohort is clinically significant. The non-statistically significant difference in HBV prevalence between the HIV-positive and HIV-negative infants suggests that high prevalence of HBV infection in children may be a problem independent of HIV.

Prevention of materno-foetal transmission of hepatitis B in sub-Saharan Africa: the evidence, current practice and future challenges

Hepatitis B (HBV) infection is highly endemic in sub-Saharan Africa (SSA), where more than 8% of the population remain chronic HBV carriers. SSA has one of the highest HBV-related liver cancer rates in the world (CA Cancer J Clin, 55, 2005, 74) and HBV-related liver cancer is the most common cause of premature death in West Africa (Lancet Oncol, 9, 2008, 683; Hepatology, 39, 2004, 211). As such, HBV represents a significant global threat to health in the African continent. Most SSA countries have elected to vaccinate all children against HBV through the WHO-sponsored Expanded Program of Immunization and the current recommendation from WHO-AFRO is for birth-dose HBV vaccination to prevent maternal/child transmission (MFT) and early horizontal transmission of HBV. However, in Africa, HBV vaccine coverage remains low and HBV birth-dose vaccination has not been implemented. HBV transmission from mother to child in the early perinatal period therefore remains a significant contributor to the burden of HBV-related disease in SSA. This review explores the evidence for materno-foetal transmission of HBV in SSA, outlining current practice for HBV MFT prevention and identifying the significant challenges to implementation of HBV prevention in SSA.

Modeling the impact of early antiretroviral therapy for adults coinfected with HIV and hepatitis B or C in South Africa

OBJECTIVE

There has been discussion about whether individuals coinfected with HIV and hepatitis C virus (HCV) or hepatitis B virus (HBV) (∼30% of all people living with HIV) should be prioritized for early HIV antiretroviral therapy (ART). We assess the relative benefits of providing ART at CD4 count below 500  cells/μl or immediate ART to HCV/HIV or HBV/HIV-coinfected adults compared with HIV-monoinfected adults. We evaluate individual outcomes (HIV/liver disease progression) and preventive benefits in a generalized HIV epidemic setting.

METHODS

We modeled disease progression for HIV-monoinfected, HBV/HIV-coinfected, and HCV/HIV-coinfected adults for differing ART eligibility thresholds (CD4 <350  cells/μl, CD4 <500  cells/μl, immediate ART eligibility upon infection). We report disability-adjusted life-years averted per 100 person-years on ART (DALYaverted/100PYonART) as a measure of the health benefits generated from incremental changes in ART eligibility. Sensitivity analyses explored impact on sexual HIV and vertical HIV, HCV, and HBV transmission.

RESULTS

For HBV/HIV-coinfected adults, a switch to ART initiation at CD4 count below 500  cells/μl from CD4 below 350  cells/μl generates 9% greater health benefits per year on ART (48 DALYaverted/100PYonART) than for HIV-monoinfected adults (44 DALYaverted/100PYonART). Additionally, ART at CD4 below 500  cells/μl could prevent 25% and 32% of vertical transmissions of HIV and HBV, respectively. For HCV/HIV-coinfected adults, ART at CD4 below 500  cells/μl generates 10% fewer health benefits (40 DALYaverted/100PYonART) than for HIV monoinfection, unless ART reduces progression to cirrhosis by more than 70% (33% in base-case).

CONCLUSIONS

The additional therapeutic benefits of ART for HBV-related liver disease results in ART generating more health benefits among HBV/HIV-coinfected adults than HIV-monoinfected individuals, whereas less health benefits are generated amongst HCV/HIV coinfection in a generalized HIV epidemic setting.

The epidemiology of hepatitis B virus infection in HIV-infected and HIV-uninfected pregnant women in the Western Cape, South Africa

OBJECTIVES

Persistent hepatitis B virus (HBV) infection is a major cause of morbidity and mortality in sub-Saharan Africa. The HIV epidemic has the potential to affect its biology. Immunisation protocols established in the pre-HIV era are based upon data showing predominantly horizontal infant transmission. This study aimed to determine whether HIV co-infection will change the epidemiology of HBV both by increasing infectivity and by favouring the escape of viruses bearing phenotypically altered HBsAg.

METHODS

This retrospective cross-sectional study used antenatal samples from the 2008 Antenatal Sentinel HIV and Syphilis Prevalence Survey in the Western Cape, South Africa. All HIV-infected women were age and race-matched to HIV-uninfected women. Samples were tested for serological markers of HBV and HDV infection. HBV viral load, consensus sequencing and genotyping were performed. Luminex technology was used to determine HBsAg phenotype. All samples from HIV-infected women were tested for traces of antiretroviral drugs by mass spectrometry.

RESULTS

This study showed a trend toward loss of immune control of HBV in HIV-infected women with 3.4% of samples containing HBsAg, 18.9% contained HBeAg. In contrast, 2.9% of samples from HIV-uninfected women contained HBsAg and 17.1% of these HBeAg. The median HBV load in the HIV-infected group was 9.72×10(7)IU/ml and in the HIV-uninfected group 1.19×10(6)IU/ml. Genotyping showed 63/68 samples belonged to genotype A and the remainder genotype D. Mutations in the precore region were found in 35% and 33% of samples from HIV-infected and HIV-uninfected respectively. Although no major epitope ablation was found, marked variation in HBsAg profiles in HIV-infected group was demonstrated. No HDV infection was detected.

CONCLUSION

HIV-HBV co-infected women exhibit a degree of immune escape. One in six HBV-infected pregnant women, irrespective of HIV status is HBeAg seropositive. HBV immunization of newborns in sub-Saharan Africa should be implemented.

An update after 16 years of hepatitis B vaccination in South Africa

Hepatitis B (HB) virus (HBV) infection is highly endemic with at least 65 million chronic HB surface antigen (HBsAg) carriers in Africa, 25% of whom are expected to die from liver disease. Before the introduction of the HB vaccine, the prevalence of chronic carriage of HBV in black South Africans was 9.6%, with 76% having been previously exposed to HBV. The major transmission route in South Africa is unexplained horizontal transmission between toddlers, with most transmission occurring before the age of 5 years. During adolescence and early adulthood, sexual transmission becomes the dominant route, while healthcare workers (HCWs) are also at risk for parenteral/percutaneous transmission during occupational exposures. In 1995 the South African Department of Health (SADoH) incorporated the HB vaccine, administered as a monovalent, into the Expanded Programme on Immunisation (EPI) at 6, 10, and 14 weeks of age, and studies conducted thereafter have found it to be safe and highly effective. Catch-up vaccination for adolescents was not introduced and there is no schools-based vaccination programme. The SADoH recommends HB vaccination of HCWs, but this is not mandatory and there is no national policy, thus HB vaccination uptake in HCWs is sub-optimal. Since 1995, studies on children have found that the prevalence of chronic HBsAg carriage has decreased, as has the incidence of paediatric hepatocellular carcinoma and HBV-related membranous nephropathy. The SADoH should focus their efforts on attaining a high infant HB vaccine coverage, prepare for introducing a HB birth dose, and consider using a hexavalent vaccine (DTaP-IPV-Hib-HepB). The department may also want to consider including targeted HB vaccination for 12 year-olds, if their Road to Health Cards show they were not vaccinated as infants. A national policy is needed for HCWs to ensure that they are fully vaccinated and protected against HBV infection.

Hepatitis B virus infection in human immunodeficiency virus infected southern African adults: occult or overt--that is the question

Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) share transmission routes and are endemic in sub-Saharan Africa. The objective of the present study was to use the Taormina definition of occult HBV infection, together with stringent amplification conditions, to determine the prevalence and characteristics of HBV infection in antiretroviral treatment (ART)-naïve HIV(+ve) adults in a rural cohort in South Africa. The presence of HBV serological markers was determined by enzyme linked immunoassay (ELISA) tests. HBV DNA-positivity was determined by polymerase chain reaction (PCR) of at least two of three different regions of the HBV genome. HBV viral loads were determined by real-time PCR. Liver fibrosis was determined using the aspartate aminotransferase-to-platelet ratio index. Of the 298 participants, 231 (77.5%) showed at least one HBV marker, with 53.7% HBV DNA(-ve) (resolved) and 23.8% HBV DNA(+ve) (current) [8.7% HBsAg(+ve): 15.1% HBsAg(-ve)]. Only the total number of sexual partners distinguished HBV DNA(+ve) and HBV DNA(-ve) participants, implicating sexual transmission of HBV and/or HIV. It is plausible that sexual transmission of HBV and/or HIV may result in a new HBV infection, superinfection and re-activation as a consequence of immunesuppression. Three HBsAg(-ve) HBV DNA(+ve) participants had HBV viral loads <200 IU/ml and were therefore true occult HBV infections. The majority of HBsAg(-ve) HBV DNA(+ve) participants did not differ from HBsAg(+ve) HBV DNA(+ve) (overt) participants in terms of HBV viral loads, ALT levels or frequency of liver fibrosis. Close to a quarter of HIV(+ve) participants were HBV DNA(+ve), of which the majority were HBsAg(-ve) and were only detected using nucleic acid testing. Detection of HBsAg(-ve) HBV DNA(+ve) subjects is advisable considering they were clinically indistinguishable from HBsAg(+ve) HBV DNA(+ve) individuals and should not be overlooked, especially if lamivudine is included in the ART.

Genotyping and molecular characterization of hepatitis B virus from human immunodeficiency virus-infected individuals in southern Africa

Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) are hyperendemic in sub-Saharan Africa. The HBV genotypes prevailing in HIV-infected Africans are unknown. Our aim was to determine the HBV genotypes in HIV-infected participants and to identify clinically significant HBV mutations. From 71 HBV DNA^+ve HIV-infected participants, 49 basic core promoter/precore (BCP/PC) and 29 complete S regions were successfully sequenced. Following phylogenetic analysis of 29 specimens in the complete S region, 28 belonged to subgenotype A1 and one to D3. Mutations affecting HBeAg expression at the transcriptional (1762T1764A), translational (Kozak 1809–1812, initiation 1814–1816, G1896A with C1858T), or post translational levels (G1862T), were responsible for the high HBeAg-negativity observed. The G1862T mutation occurred only in subgenotype A1 isolates, which were found in one third (7/21) of HBsAg^−ve participants, but in none of the 18 HBsAg^+ve participants (p<0.05). Pre-S deletion mutants were detected in four HBsAg^+ve and one HBsAg^−ve participant/s. The following mutations occurred significantly more frequently in HBV isolated in this study than in strains of the same cluster of the phylogenetic tree: ps1F25L, ps1V88L/A; ps2Q10R, ps2 R48K/T, ps2A53V and sQ129R/H, sQ164A/V/G/D, sV168A and sS174N (p<0.05). ps1I48V/T occurred more frequently in females than males (p<0.05). Isolates with sV168A occurred more frequently in participants with viral loads >200 IU per ml (p<0.05) and only sS174N occurred more frequently in HBsAg^−ve than in HBsAg^+ve individuals (p<0.05). Prior to initiation of ART, ten percent, 3 of 29 isolates sequenced, had drug resistance mutations rtV173L, rtL180M+rtM204V and rtV214A, respectively. This study has provided important information on the molecular characteristics of HBV in HIV-infected southern Africans prior to ART initiation, which has important clinical relevance in the management of HBV/HIV co-infection in our unique setting.

Presence of occult HBV, but near absence of active HBV and HCV infections in people infected with HIV in rural South Africa

Human immunodeficiency (HIV), hepatitis B (HBV), and hepatitis C (HCV) viruses are endemic in Sub-Saharan Africa, but data regarding the prevalence of hepatitis co-infections in HIV-positive individuals residing there are limited. The aim of the study was to determine the prevalence of HBV, HCV, and occult HBV (presence of HBV-DNA in the absence of HBsAg) in a rural, South African cohort. The results were compared to various ethnic groups in a Dutch cohort of people infected with HIV. Antiretroviral-naïve individuals with HIV from both a rural South African clinic (n = 258), and a Dutch University hospital (n = 782), were included. Both serological (HBV and HCV) and molecular (occult HBV) assays were performed. Logistic regression analysis was used to define independent predictors of a hepatitis co-infection. HBV and HCV prevalence rates in the South African cohort were exceptionally low (0.4%, 1/242 and 0.8%, 2/242, respectively), compared to those observed in Caucasians (HBV 4.4% and HCV 10.9%) and African immigrants (HBV 8.9% and HCV 4.8%). Conversely, occult HBV was observed in a considerable proportion (10%, 6/60) of South African patients who were anti-HBc-positive but HBsAg-negative. Occult infections were less frequent in Caucasians and Africans in the Dutch cohort (3.2% and 1.4%, respectively). Independent predictors for occult HBV were not identified, but a trend towards more occult HBV at lower CD4 counts was observed. Local HBV/HCV prevalence data are needed to optimize vaccination and antiretroviral treatment strategies. Occult HBV in patients with HIV may be missed regularly when molecular analyses are not available.

Epidemiology and aetiology of maternal bacterial and viral infections in low- and middle-income countries

BACKGROUND

Maternal morbidity and mortality in low- and middle-income countries has remained exceedingly high. However, information on bacterial and viral maternal infections, which are important contributors to poor pregnancy outcomes, is sparse and poorly characterised. This review aims to describe the epidemiology and aetiology of bacterial and viral maternal infections in low- and middle-income countries.

METHODS

A systematic search of published literature was conducted and data on aetiology and epidemiology of maternal infections was extracted from relevant studies for analysis. Searches were conducted in parallel by two reviewers (using OVID) in the following databases: Medline (1950 to 2010), EMBASE (1980 to 2010) and Global Health (1973 to 2010).

RESULTS

Data from 158 relevant studies was used to characterise the epidemiology of the 10 most extensively reported maternal infections with the following median prevalence rates: Treponema pallidum (2.6%), Neisseria gonorrhoeae (1.5%), Chlamydia trachomatis (5.8%), Group B Streptococcus (8.6%), bacterial vaginosis (20.9%), hepatitis B virus (4.3%), hepatitis C virus (1.4%), Cytomegalovirus (95.7% past infection), Rubella (8.9% susceptible) and Herpes simplex (20.7%). Large variations in the prevalence of these infections between countries and regions were noted.

CONCLUSION

This review confirms the suspected high prevalence of maternal bacterial and viral infections and identifies particular diseases and regions requiring urgent attention in public health policy planning, setting research priorities and donor funding towards reducing maternal morbidity and mortality in low- and middle-income countries.

HIV-HBV coinfection among South African patients receiving antiretroviral therapy

There are approximately 33 million individuals with HIV infection worldwide. The majority of infections are in southern Africa where hepatitis B is also known to be endemic. As access to life-saving antiretroviral therapy (ART) increases, the possibility for hepatitis B treatment resistance increases because most ART regimens contain lamivudine. Patients coinfected with HBV are therefore receiving monotherapy for HBV infection, leading to possible HBV-resistant mutants and the concurrent public health effect thereof. Additional information is needed on the prevalence of HIV-HBV coinfection and treatment response to ART. We present a summary of the information available from South Africa to date.

Hepatitis B/C and HIV in sub-Saharan Africa: an association between highly prevalent infectious diseases. A systematic review and meta-analysis

OBJECTIVES

Hepatitis B virus (HBV), hepatitis C virus (HCV), and the human immunodeficiency virus (HIV) are endemic in Africa. However, hepatitis co-infection rates among HIV-infected individuals remain controversial. The aim of this review was to determine the prevalence of HBV and HCV in HIV-infected patients in sub-Saharan Africa and to analyze whether HIV is associated with a higher HBV/HCV prevalence in that region.

DESIGN AND METHODS

We performed a systematic review and meta-analysis. Studies reporting HBV and HCV prevalence data amongst HIV-infected patients in sub-Saharan Africa were included. Weighted means and medians across studies were calculated. Studies including an HIV-negative control group were used for meta-analysis. Risk ratios (RRs) were calculated using a random effects model.

RESULTS

Sixty studies were included. Among HIV-infected individuals, mean HBsAg and anti-HCV prevalence rates were 15% and 7%, respectively. RRs for a positive HBsAg and a positive anti-HCV were 1.40 (95% confidence interval (CI) 1.16-1.69) and 1.60 (95% CI 1.05-2.45) for HIV-infected, as compared to HIV-uninfected, patients.

CONCLUSIONS

Many HIV-positive individuals in sub-Saharan Africa are HBV or HCV co-infected. HIV is associated with a higher prevalence of both HBV and HCV in this region. However, this association is less evident than that observed in Western countries and varies between studies.

High rates of active hepatitis B and C co-infections in HIV-1 infected Cameroonian adults initiating antiretroviral therapy

OBJECTIVES

To investigate the presence of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA in HIV-infected patients initiating antiretroviral therapy in Cameroon.

METHODS

Baseline blood samples from 169 patients were tested retrospectively for hepatitis B surface antigens (HBsAg), anti-hepatitis B core (anti-HBc), anti-HCV and - if HBsAg or anti-HCV result was positive or indeterminate - for HBV DNA or HCV RNA, respectively, using the Cobas Ampliprep/Cobas TaqMan quantitative assay (Roche Diagnostics GmbH, Mannheim, Germany).

RESULTS

HBV DNA was detected in 14 of the 18 patients with positive or indeterminate HBsAg results [8.3% of the total study population, 95% confidence interval (CI) 4.6-13.5]. The median HBV viral load was 2.47 x 10(7) IU/mL [interquartile range (IQR) 3680-1.59 x 10(8); range 270 to >2.2 x 10(8)]. Twenty-one patients (12.4%, 95% CI 7.9-18.4) were found with HCV RNA (all with positive HCV serology). The median HCV viral load was 928 000 IU/mL (IQR 178 400-2.06 x 10(6); range 640-5.5 x 10(6)). No patient was co-infected with HBV and HCV. In multivariate analysis, HCV co-infection was associated with greater age [>or=45 years vs. <45 years, odds ratio (OR) 11.89, 95% CI 3.49-40.55, P<0.001] and abnormal serum alanine aminotransferase level [>or=1.25 x upper limit of normal (ULN) vs. <1.25 x ULN, OR 7.81, 95% CI 1.54-39.66, P=0.01]; HBV co-infection was associated with abnormal serum aspartate aminotransferase level (OR 4.33, 95% CI 1.32-14.17, P=0.02).

CONCLUSIONS

These high rates of active HBV and HCV co-infections in HIV-positive Cameroonian patients requiring antiretroviral therapy underline the need to promote: (i) screening for HBV and HCV before treatment initiation; (ii) accessibility to tenofovir (especially in HBV-endemic African countries); and (iii) accessibility to treatment for HBV and HCV infections.

Mutations associated with lamivudine-resistance in therapy-naïve hepatitis B virus (HBV) infected patients with and without HIV co-infection: implications for antiretroviral therapy in HBV and HIV co-infected South African patients

This was an exploratory study to investigate lamivudine-resistant hepatitis B virus (HBV) strains in selected lamivudine-naïve HBV carriers with and without human immunodeficiency virus (HIV) co-infection in South African patients. Thirty-five lamivudine-naïve HBV infected patients with or without HIV co-infection were studied: 15 chronic HBV mono-infected patients and 20 HBV-HIV co-infected patients. The latter group was further sub-divided into 13 occult HBV (HBsAg-negative) and 7 overt HBV (HBsAg- positive) patients. HBsAg, anti-HBs, anti-HBc, and anti-HIV 1/2 were determined as part of routine diagnosis using Axsym assays (Abbott Laboratories, North Chicago, IL). Serum samples were PCR amplified with HBV reverse transcriptase (RT) primers, followed by direct sequencing across the tyrosine-methionine-aspartate-aspartate (YMDD) motif of the major catalytic region in the C domain of the HBV RT enzyme. HBV viral load was performed with Amplicor HBV Monitor test v2.0 (Roche Diagnostics, Penzberg, Germany). HBV lamivudine-resistant strains were detected in 3 of 15 mono-infected chronic hepatitis B patients and 10 of 20 HBV-HIV co-infected patients. To the best of our knowledge, this constitutes the first report of HBV lamivudine-resistant strains in therapy-naïve HBV-HIV co-infected patients. The HBV viral loads for mono-infected and co-infected patients ranged from 3.32 x 10(2) to 3.82 x 10(7) and <200 to 4.40 x 10(3) copies/ml, respectively. It remains to be seen whether such pre-existing antiviral mutations could result in widespread emergence of HBV resistant strains when lamivudine-containing highly active antiretroviral (ARV) treatment (HAART) regimens become widely applied in South Africa, as this is likely to have potential implications in the management of HBV-HIV co-infected patients.