Hepatitis A seroprevalence in Western Cape Province, South Africa: Are we in epidemiological transition?

Background. Hepatitis A virus (HAV) is the most common cause of viral hepatitis worldwide. Hepatitis A vaccine is not included in the Expanded Programme on Immunisation in South Africa (EPI-SA), as the country is considered to be highly endemic for hepatitis A. Objectives. To determine the seroprevalence of hepatitis A infection in Western Cape Province (WCP), South Africa. Methods. We conducted a cross-sectional seroprevalence study in the 1 - 7-year age group in WCP. Our samples (N=482) were blood specimens left over after laboratory testing obtained from referral hospitals between August and October 2015. A Siemens enzyme immunoassay was used to test for total hepatitis A antibodies. We also analysed hepatitis A immunoglobulin G antibody results from the National Health Laboratory Service (NHLS) Disa(star)Lab database at Groote Schuur Hospital from 2009 to 2014, and included 2009 - 2014 acute hepatitis A (immunoglobulin M-positive) surveillance data from the National Institute for Communicable Diseases to look at trends in notified acute infections over the same period. Results. Our cross-sectional study showed 44.1% seroprevalence in the 1 - 7-year age group. Hepatitis A data from the NHLS database indicated a seroprevalence of <90% up to age 10 years, indicating intermediate endemicity. The surveillance data showed that a substantial number of symptomatic hepatitis A infections occurred in the 7 - 40-year age group, suggesting that an increasing proportion of the population is susceptible to HAV infection. Conclusions. These results suggest an urgent need for detailed evidence-based considerations to introduce hepatitis A vaccine into the EPI-SA.