Hepatitis A in Latin America: The current scenario

Abstract

This review aims to gather and disseminate updated information regarding hepatitisA virus (HAV) in Latin America (LA) in the last 11 years, including seroprevalence,post‐vaccination studies, virus detection in aqueous matrices and food samples, andoutbreak reports. Only 24 seroprevalence studies were published between 2012and 2023 with 55%–100% reported prevalences of anti‐HAV IgG. Among the 25 LAcountries, only eight of them have introduced HAV vaccines into their immunisationprograms. Outbreaks of hepatitis A occurred between 2017–2019, mainly affecting menwho have sex with men in Argentina, Brazil and Chile, probably as a consequence ofthe abrupt decline of young adults' immunity. This could be due to that young adulthave never been infected in childhood (due to socio‐health improvements) and areabove the cut‐off ages to be included when the vaccination programs were introduced.Although scarce, studies focused on environmental and food HAV surveillancehave shown viral presence in these samples. Surface waters presented HAVdetections between 1.2% and 86.7%, and untreated wastewaters between 2.8% and70.9%. Genotypes found in all cases were IA and IC. The only wastewater‐basedepidemiology study showed to be a useful tool as a complement of traditionalepidemiological surveillance. Only four LA countries have looked for HAV in foodsamples, with genome detection rates between 9% and 33%. Latin American HAVcirculation scenario is changing. In countries where socioeconomic and sanitaryconditions have not improved, the virus persists with high endemicity and the accessto the vaccine should be re‐evaluated by local governments. In countries whereaccess to clean water, better sanitary conditions and HAV immunisation programshave been implemented, the number of cases among young adults seems to beincreasing, alerting health authorities.