Researchers at the Institute of Infection and Global Health, together with collaborators in Oxford, Malawi, and Ghana, have authored a new report on the epidemiology of Hepatitis Delta virus in sub-Saharan Africa, which appears in Lancet Global Health.
The team systematically compiled published epidemiology data on Hepatitis Delta virus in sub-Saharan Africa, added novel experimental data from populations in Ghana and Malawi, and estimated prevalence by region and population.
Seven million exposed
Lead author Professor Anna Maria Geretti said: “We estimate that around seven million people across sub-Saharan Africa have been exposed to the Hepatitis Delta virus. The results show substantial geographical variability however: there are pockets of high prevalence in West and Central Africa, whereas prevalence in Southern Africa is considerably lower”.
“Important gaps in knowledge remain: we found that published studies were few, addressed populations in disparate settings, and often had small sample sizes. Data from East Africa are lacking.”
Hepatitis Delta virus only occurs in people that also carry the Hepatitis B virus, and co-infection dramatically amplifies the risk of severe liver disease. As many as 80% of co-infected people develop liver cirrhosis within 5-10 years, and there is little that can be offered in terms of effective antivirals to treat infection with Hepatitis Delta virus.
Vigilance needed
Associate Professor Richard Odame Phillips, the principal study investigator at the Kwame Nkrumah University of Science and Technology in Ghana, said: “Studies are urgently needed to identify specific risk factors for Hepatitis Delta virus infection, and guide the formulation and implementation of prevention and management policies. This is challenging for sub-Saharan Africa, given the lack of adequate testing infrastructure and limited resources assigned to the care of patients with liver disease.”
Professor Geretti added: “Meanwhile, healthcare providers in the United Kingdom and elsewhere must remain vigilant, and offer testing for Hepatitis Delta virus to at-risk populations as part of routine practice.”
“Looking ahead, improving the implementation of measures against Hepatitis B virus – including vaccination, avoiding needle reuse in health care, quality-assured transfusion screening, and expansion of diagnosis and treatment services – will reduce the burden of both infections across sub-Saharan Africa and globally.
“Mathematical modelling suggests that maintaining levels of Hepatitis B virus vaccination coverage in infants above 80%, and improving rates of vaccination at birth for children born to Hepatitis B virus-positive mothers (presently less than 10% in sub-Saharan Africa), represents an effective strategy for the eradication of both Hepatitis B and D virus infection.”
The paper ‘Prevalence of hepatitis D virus infection in sub-Saharan Africa: a systematic review and meta-analysis’ is published in Lancet Global Health [http://dx.doi.org/10.1016/S2214-109X(17)30298-X]