Hepatitis B virus infection in HIV-exposed infants in the Western Cape, South Africa

Abstract

Hepatitis B virus infection (HBV) is a significant public health problem in sub-Saharan Africa. Universal infant vaccination with the hepatitis B (HB) vaccine has been implemented within the South African Expanded Programme of Immunization since April 1995 with concomitant reduction in HBV infection in children. However, the first vaccine dose is only administered at six weeks of age. This delay may lead to a failure to reduce the risk of perinatal HBV transmission to infants born to HIV/HBV co-infected women, in whom HBV infection is often upregulated. The aim of this study was to determine the prevalence of HBV infection in babies born to HIV-infected mothers in the Western Cape, South Africa. HBV serological markers were tested in all infant serum samples and following HB viral load testing, sequencing and genotyping were also performed. Three of 1000 samples screened tested positive for HBsAg and HBV DNA. An additional infant tested positive for HBV DNA alone. All babies had received the HB vaccine at 6, 10 and 14 weeks. The prevalence of HBV infection was therefore 4/1000 (0.4%; 95% CI, 0.01-0.79%). Three of four infants and all four mothers were followed-up. Two infants were persistently positive for HBsAg with viral loads above 10(8) International Units per millilitre. All four maternal samples were positive for HBsAg and HBeAg and one was also positive for anti-HBe. Sequencing analysis of two mother-child HBV pairs showed 100% sequence identity. This study demonstrates HBV infection in HIV-exposed infants despite HB vaccination from 6 weeks of age. A more strategic approach is needed to prevent mother to child transmission of HBV, including screening of pregnant women, HBV-targeted antiviral therapy and HB birth dose vaccine.

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

“…However, there is undoubtedly a need for ongoing vigilance and efforts to reduce transmission still further. Together with the recent results from the Western Cape [4], these studies suggest that strategies to prevent mother to child HBV transmission have been successful, but need to remain an important focus. Furthermore, there are ongoing challenges; HBV immunisation is not routinely available for adults in the public sector (though should be available for those at risk), and availability of the new hexavalent vaccine has been problematic.…”

“…Published around the same time, a study from the Western Cape reports 0.4% prevalence of HBV in HIV exposed-uninfected (HEU) infants, all of whom were HBV-immunised according to local policy [4]. Together, these data highlight that chronic HBV is a persistent problem in South African adults, irrespective of HIV status, and that infants remain vulnerable to vertical acquisition of HBV infection before receiving their first dose of vaccine.…”

“…HBV vaccination has been implemented in South Africa since 1995, but the locally recommended schedule is to postpone the first dose until age six weeks [3], [4]. Recently, HBV immunisation has been incorporated into a hexavalent vaccine together with diphtheria, tetanus, pertussis, inactivated poliomyelitis and Haemophilus influenzae type b (Hexaxim, Sanofi-Pasteur).…”

“…Together, these data highlight that chronic HBV is a persistent problem in South African adults, irrespective of HIV status, and that infants remain vulnerable to vertical acquisition of HBV infection before receiving their first dose of vaccine. In this setting, the high seroprevalence of HIV infection puts infants and young children at increased risk of co-infection and of complications of chronic HBV infection [4], [7]. Our recent study found HBsAg in 11% of HIV-positive mothers of children attending outpatient clinics in Kimberley [6], but HBV-screening has not been routinely incorporated into clinical care.…”

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

“…13 In the era of the South African HIV epidemic, a study conducted in the Western Cape in 2011 found the prevalence of HBV amongst HIV-exposed infants to be 0.4%. 14 The rate of HIV/HBV co-infection amongst infants and children remains poorly reported compared with reports of high exposure to HBV in HIV-infected pregnant women. 9 …”