Date Published: May 31, 2019
Publisher: Public Library of Science
Author(s): Nishi Prabdial-Sing, Lillian Makhathini, Sheilagh Brigitte Smit, Morubula Jack Manamela, Nkengafac Villyen Motaze, Cheryl Cohen, Melinda Shelley Suchard, Jason Blackard.
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).
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.
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 is a vaccine preventable disease and is notifiable in South Africa. There is no active national surveillance for hepatitis B. We estimated hepatitis B seroprevalence in South African children using residual sera from febrile rash surveillance.
Of 450 samples selected, 47% were females and 53% were males, with a median age of 5 years. Ages of included children were 11 aged 0–11 months, 217 aged 1–5 years, 174 aged 6–10 years and 48 aged 11–14 years (2.4%, 48%, 38.7% and 10.7% respectively). Provincial distribution of samples included Mpumalanga 14% (n = 65) Eastern Cape 13% (n = 59), North West Province 13% (n = 58), Northern Cape 12% (n = 55), KwaZulu Natal 11% (n = 51), Free State 10% (n = 43), Limpopo 10% (n = 47), Gauteng 9% (n = 42) and Western Cape 7% (n = 30).
Our finding of 0.4% prevalence of hepatitis B infection in children under 15 years of age adds an estimate of burden of infection in the post vaccine era. While other studies have focused on targeted clinics (antenatal, HIV, immunisation, outpatient clinics) or used hospital-based residual sera, we have studied a community-based population. We found two cases positive for HBsAg, which may reflect either horizontally or vertically acquired infections.