Hepatitis E virus in South Africa

The hepatitis E virus (HEV) and hepatitis A virus (HAV) are phylogenetically unrelated, but both cause typical outbreak of clinical hepatitis associated with contaminated water and food. However, HAV causes outbreaks worldwide, but HEV only in certain areas, notable India and neighbouring countries, central Asia, China, Mexico and northern parts of Africa. Hepatitis E has major health implications in these countries and outbreaks with many thousands of cases are on record. Clinical cases are rare in parts of the world such as Europe, the UK, USA, South Africa, Australasia, Japan and South America. Seroprevalence studies using new technology now indicate that HEV may have a much wider distribution than previously thought. Recent surveys on populations in various parts of South Africa show sub-clinical infections in 2-15% of individuals. Reasons for the geographic association of clinical hepatitis E and outbreaks are not clear. Answers to these and related questions are essential for the formulation of strategies aimed at preventing the disease in countries such as South Africa, where cases are rare but conditions in many communities appear ideally suited for clinical disease and outbreaks.