Screening, characterisation and prevention of Hepatitis B virus (HBV) co-infection in HIV-positive children in South Africa

Abstract

BackgroundIn South Africa, the first HBV vaccine dose is administered at age 6 weeks, leaving a potential window for vertical transmission. Insights into HBV seroprevalence in the vulnerable HIV-infected group are important to drive improvements in surveillance, treatment and prevention.ObjectivesWe set out to implement a screening program for HBV among HIV-infected children and adolescents in Kimberley, South Africa. Our aims were to demonstrate that screening is feasible and sustainable, to establish the prevalence of HBV, to characterise the HBV cases we identified, and to inform discussion about the infant vaccination schedule.Study designWe tested all HIV positive children (age 0–16) for Hepatitis B surface antigen (HBsAg), delivering this testing as part of routine state-funded care. We followed up HBsAg-positive cases with an extended panel of HBV serology tests, and HBV DNA viral load quantification.ResultsOur screening campaign was successfully incorporated into routine out-patient care. Among 625 patients tested, we found five positive for HBsAg (0.8%), of whom three were Hepatitis B e-antigen positive. Two additional children initially tested HBsAg-positive but were negative on repeat testing. Antiviral therapy in the HBsAg children was reviewed and adjusted if required.ConclusionsThe results testify to the overall success of the HBV vaccine campaign. However, we have demonstrated that ongoing vigilance is required to detect cases and prevent transmission events. Further evaluation of the optimum timing of the first vaccine HBV vaccine dose is required; a vaccine dose at birth could reduce prevalence further.

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

“…The mid‐point prevalence was 6.8% (IQR 2.5‐10.0). Prevalence ranged from 2% to 20% across six estimates from Nigeria and between 0% and 20.5% in South Africa . Extremely high prevalence (43%‐46%) was observed in Romania in two studies where HIV infection was acquired nosocomially prior to 1995.…”

“…Prevalence ranged from 2% to 20% across six estimates from Nigeria [37][38][39][40][41][42] and between 0% and 20.5% in South Africa. [43][44][45][46] Extremely high prevalence (43%-46%) was observed in Romania in two studies 47,48 where HIV infection was acquired nosocomially prior to 1995. A high prevalence (32.6%) was also found in Thailand among young people perinatally infected with HIV (mean age 14 years).…”

HBV vaccination and PMTCT as elimination tools in the presence of HIV: insights from a clinical cohort and dynamic model

“…A previous study of HBV serology in adults in the same setting found HBsAg prevalence of 9.5% (55/579) (4). Children were recruited as part of the C o-infection in S outh- A frican C hildren (‘COSAC’) study as previously described (19,20). The lower age limit of recruitment was 6 months in order to limit the detection of maternal anti-HBs.…”

“…KReC children were confirmed HIV-negative in 163 cases (93.7%). A further 11 children did not have an HIV test result recorded, but were assumed to be HIV-negative based on the clinical data recorded at the time of admission to hospital. HIV-positive children were recruited primarily from HIV out-patient clinics between September 2009 and July 2016 as previously described (19,20). We recorded date of commencement of anti-retroviral therapy (ART), CD4+ T cell count and percentage, and HIV RNA viral load using the time point closest to the sample that was analysed for HBV serology.…”

“…HIV-positive children were recruited primarily from HIV out-patient clinics between September 2009 and July 2016 as previously described (19,20). We recorded date of commencement of anti-retroviral therapy (ART), CD4+ T cell count and percentage, and HIV RNA viral load using the time point closest to the sample that was analysed for HBV serology.…”