Prevalence and trends of hepatitis B and C virus biomarkers in Zimbabwe: comparative analyses of a nation's blood-donor surveillance data and meta-analyses of population studies

BACKGROUND

The disproportionate burden of viral hepatitis, particularly hepatitis B virus (HBV) is experienced by people living in low-resourced sub-Saharan Africa, where the estimated prevalence is 3-7 times the global average. Therefore to inform policy, we describe the seroprevalence and trends of hepatitis C (HCV) and HBV biomarkers: anti-HCV antibody and hepatitis B surface antigen (HBsAg), respectively, in Zimbabwe.

METHODS

We analysed data from 181,248 consecutive blood-donors, examined between January 2015 through December 2018. Additionally, we conducted a comprehensive literature review using PubMed and African Journals Online databases, meta-analysing selected papers from Zimbabwe, published between 1970 and 2020, that met specific criteria.

RESULTS

Overall age-standardized prevalence rate (ASPR) for anti-HCV was 8.67 (95%CI, 0.25-17.09) per 100,000, while that for HBsAg was 2.26 (95%, 1.89-2.63) per 1000 blood-donors, per year. Meta-analysis of 9 studies comprising 220,127 persons tested for anti-HCV revealed ASPR of 0.05% (95% 0%-0.19%) in blood-donors and 1.78% (95%CI, 0.01%-5.55%) in the general population, for an overall pooled ASPR of 0.44 (95%CI, 0.19%-0.76%). 21 studies comprising 291,784 persons tested for HBsAg revealed ASPR of 0.65% (95%CI, 0.31%-1.00%) in blood-donors and 4.31% (95%CI, 1.77%-6.50%) in the general population for an overall pooled ASPR of 4.02% (95%CI, 3.55%-4.48%), after HBV vaccine introduction. HBsAg prevalence was significantly higher before HBV vaccine introductions.

CONCLUSIONS

The prevalence of HBV is decreasing, consistent with the introduction of HBV vaccination, while HCV prevalence is increasing in Zimbabwe. This highlights the need for Improved blood-donor screening and more informative biomarker studies, particularly among repeat donors and children.

Hepatitis B virus infection (HBV) and HIV-HBV coinfection among men who have sex with men, transgender women, and genderqueer individuals in Harare and Bulawayo Zimbabwe, 2019

Objectives

To measure HIV and Hepatitis B virus (HBV) prevalence and associated risk behaviors among men who have sex with men (MSM) and transgender women/genderqueer individuals (TGW/GQ) in Zimbabwe.

Methods

We conducted a biobehavioral survey using respondent-driven sampling (RDS) among adult MSM and TGW/GQ in Harare and Bulawayo, Zimbabwe in 2019. Participants completed a questionnaire and underwent testing for HIV and HBV.

Results

Overall, 1,510 (Harare: 694, Bulawayo 816) participants were enrolled and consented to testing; 3.8 % (58) tested positive for HBV, 22.5 % (339) tested positive for HIV, and 2.2 % (33) tested positive for both HIV and HBV. HBV prevalence was higher among participants with HIV compared to HIV-negative participants (9.7 % vs. 2.1 %, p < 0.0001). Overall, HBV prevalence was not statistically different between MSM and TGW/GQ (3.7 % vs 4.5 %, p = 0.49) nor between Harare and Bulawayo (3.3 % vs 4.3 %, p = 0.33).

Conclusions

Our survey demonstrates the prevalence of HBV among MSM and TGW/GQ is lower than other estimates of HBV among MSM in Africa but remains high among our survey population living with HIV highlighting the need to expand HBV testing and treatment services, especially among people with HIV in Zimbabwe.

Atypical Hepatitis B Virus Serology Profile-Hepatitis B Surface Antigen-Positive/Hepatitis B Core Antibody-Negative-In Hepatitis B Virus/HIV Coinfected Individuals in Botswana

(1) Background: Hepatitis B core antibodies (anti-HBc) are a marker of hepatitis B virus (HBV) exposure; hence, a normal HBV serology profile is characterized by HBV surface antigen (HBsAg) and anti-HBc positivity. However, atypical HBV serologies occur, and we aimed to determine the prevalence of an atypical profile (HBsAg+/anti-HBc-) in a cohort of people with HIV-1 (PWH) in Botswana. (2) Methods: Plasma samples from an HIV-1 cohort in Botswana (2013-2018) were used. The samples were screened for HBsAg and anti-HBc. Next-generation sequencing was performed using the GridION platform. The Wilcoxon rank-sum test and Chi-squared tests were used for the comparison of continuous and categorical variables, respectively. (3) Results: HBsAg+/anti-HBc- prevalence was 13.7% (95% CI 10.1-18.4) (36/263). HBsAg+/anti-HBc- participants were significantly younger (p < 0.001), female (p = 0.02) and ART-naïve (p = 0.04) and had a detectable HIV viral load (p = 0.02). There was no statistically significant difference in the number of mutations observed in participants with HBsAg+/anti-HBc- vs. those with HBsAg+/anti-HBc+ serology. (4) Conclusions: We report a high HBsAg+/anti-HBc- atypical serology profile prevalence among PWH in Botswana. We caution against HBV-testing algorithms that consider only anti-HBc+ samples for HBsAg testing, as they are likely to underestimate HBV prevalence. Studies to elucidate the mechanisms and implications of this profile are warranted.

Comparative serologic profiles of hepatitis B Virus (HBV) between HIV/HBV co-infected and Hbv mono-infected patients in Ile-Ife, Nigeria

Hepatitis B virus (HBV) infects about 2 billion people globally and accounts for mortality of about 800,000 from liver cirrhosis and hepatocellular carcinoma. Sub-Saharan Africa accounts for 70% of the Human Immunodeficiency Virus (HIV) global burden. HIV/HBV co-infection results in the early development of HBV complications, alterations of serological biomarkers of HBV. Two hundred and fifty patients with HIV/AIDS were screened for HBV and 20 (8%) were identified. The same number of HBV mono-infected individuals were recruited into the study and subsequently, HBV serological profiles which include HBsAg, HBsAb, HBeAg, HBeAb, HBcAbIgM, and HBcAbIgG were assayed using HBV ELISA kits. Mean age of patients in the HBV/HIV cohort was 45.5 years while the HBV mono-infected infected cohort was 30.5 years. The majority of the HBV/HIV co-infected individuals were females (85%). The frequency of HBeAg among HIV/HBV co-infected cohort was 25% and 15% for HBV mono-infected, while the frequency of HBeAb was higher (60%) among the cohort of HBV/HIV co-infected patients in comparison with the HBV mono-infected cohorts (50%). Two patients among the HIV/HBV co-infected cohort have the isolated anti-HBcAg serologic pattern. The study broadened the available evidence of comparative serologic profiles of Hepatitis B virus between cohorts of HBV/HIV co-infected individuals and HBV mono-infected patients in Nigeria.

Hepatitis B in sub-Saharan Africa-How many patients need therapy?

Hepatitis B is endemic in sub-Saharan Africa with ~60 million people chronically infected. While prevention, through vaccination, is central to elimination strategies, only 11 countries have birth dose vaccination and full vaccine coverage remains at suboptimal levels. Furthermore, to fully realize elimination, those chronically infected need to be identified, assessed for therapy and then linked to care. Given current treatment criteria, the precise quantum of people warranting therapy, according to criteria, is essentially unknown. The issue is further complicated by data to suggest differences in the numbers of people requiring treatment when applying WHO as compared to European Association for the Study of the Liver, EASL, criteria. Optimal determination of treatment eligibility is further hindered by the lack of available tools to adequately assess individual patients. It is conceivable that accurately determining the number of those requiring treatment, given the heterogeneity of hepatitis B in Africa, is difficult. Better studies and data are required. More signifcantly, improved access and availability to the diagnostic tools needed to assess patients in additon to access to drugs are as, if not more important, to achieve elimination.

Mechanisms of HIV persistence in HIV reservoirs

The establishment and maintenance of HIV reservoirs that lead to persistent viremia in patients on antiretroviral drugs remains the greatest challenge of the highly active antiretroviral therapy era. Cellular reservoirs include resting memory CD4+ T lymphocytes, implicated as the major HIV reservoir, having a half-life of approximately 44 months while this is less than 6 hours for HIV in plasma. In some individuals, persistent viremia consists of invariant HIV clones not detected in circulating resting CD4+ T lymphocytes suggesting other possible sources of residual viremia. Some anatomical reservoirs that may harbor such cells include the brain and the central nervous system, the gastrointestinal tract and the gut-associated lymphoid tissue and other lymphoid organs, and the genital tract. The presence of immune cells and other HIV susceptible cells, occurring in differing compositions in anatomical reservoirs, coupled with variable and poor drug penetration that results in suboptimal drug concentrations in some sites, are all likely factors that fuel the continued low-level replication and persistent viremia during treatment. Latently, HIV-infected CD4+ T cells harboring replication-competent virus, HIV cell-to-cell spread, and HIV-infected T cell homeostatic proliferation due to chronic immune activation represent further drivers of this persistent HIV viremia during highly active antiretroviral therapy.

Cost effectiveness of adding nucleic acid testing to hepatitis B, hepatitis C, and human immunodeficiency virus screening of blood donations in Zimbabwe

BACKGROUND

The aim of this study was to assess the cost effectiveness of introducing individual-donation nucleic acid testing (ID-NAT), in addition to serologic tests, compared with the exclusive use of serologic tests for the identification of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) I and II among blood donors in Zimbabwe.

STUDY DESIGN AND METHODS

The costs, health consequences, and cost effectiveness of adding ID-NAT to serologic tests, compared with serologic testing alone, were estimated from a health care perspective using a decision-analytic model.

RESULTS

The introduction of ID-NAT in addition to serologic tests would lower the risk of HBV, HCV, and HIV transmission to 46.9, 0.3, and 2.7 per 100,000 donations, respectively. ID-NAT would prevent an estimated 25, 6, and 9 HBV, HCV, and HIV transfusion-transmitted infections per 100,000 donations, respectively. The introduction of this intervention would result in an estimated 212 quality-adjusted life-years (QALYs) gained. The incremental cost-effectiveness ratio is estimated at US$17,774/QALY, a value far more than three times the gross national income per capita for Zimbabwe.

CONCLUSION

Although the introduction of NAT could further improve the safety of the blood supply, current evidence suggests that it cannot be considered cost effective. Reducing the test costs for NAT through efficient donor recruitment, negotiating the price of reagents, and the efficient use of technology will improve cost effectiveness.

Molecular epidemiology of co-infection with hepatitis B virus and human immunodeficiency virus (HIV) among adult patients in Harare, Zimbabwe

The objective of this study was to determine the prevalence of co-infection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) and the genetic characteristics of both viruses among pre-HIV-treatment patients in Harare, Zimbabwe. This cross-sectional survey involved 176 remnant plasma samples collected from consenting HIV patients (median age 35 [18-74]) between June and September 2014. HBV seromarkers were determined by high-sensitivity chemiluminescence assays. Molecular evolutionary analyses were conducted on the basal core promoter/precore (BCP/PC) and S regions of HBV, as well as part of the HIV pol region. Of the 176 participants (65.7% female), 19 (10.8%) were positive for HBsAg (median 0.033 IU/ml (IQR 0.01-415). The HBsAg incidence was higher in men than women (P = 0.009). HBsAg-positive subjects had lower median CD4 counts (P = 0.016). HBV DNA was detectable in 12 HBsAg-positive samples (median 3.36 log cp/ml (2.86-4.51), seven being amplified and sequenced. All isolates were subgenotype A1 without HBV drug resistance mutations but each had at least one BCP/PC mutation. PreS deletion mutants and small S antigen variants M133I/T and D144G were identified. Of the 164 HIV isolates successfully genotyped, 163 (99.4%) were HIV-1 subtype C and only one was HIV-1 subtype F1. Sixteen (9.8%) had at least one drug resistance mutation, predominantly non-nucleoside reverse transcriptase inhibitor-related mutations, observed mostly among female participants. This study shows that co-infection with HBV is present among HIV patients enrolling into HIV care in Zimbabwe, suggesting that HBV screening and monitoring programmes be strengthened in this context. J. Med. Virol. 89:257-266, 2017. © 2016 Wiley Periodicals, Inc.