Declining hepatitis A seroprevalence: a global review and analysis

Abstract

Hepatitis A virus (HAV) is spread by faecal-oral contact or ingestion of contaminated food or water. Lifelong immunity is conferred by infection or vaccination, so anti-HAV seroprevalence studies can be used to indicate which populations are susceptible to infection. Seroprevalence rates are highly correlated with socioeconomic status and access to clean water and sanitation. Increasing household income, education, water quality and quantity, sanitation, and hygiene leads to decreases in HAV prevalence. Japan, Australia, New Zealand, Canada, the United States, and most European nations have low anti-HAV rates. Although anti-HAV rates remain high in most Latin American, Asian, and Middle Eastern nations, average seroprevalence rates are declining. Surveys from Africa generally indicate no significant decline in anti-HAV rates. Because the severity of illness increases with age, populations with a high proportion of susceptible adults should consider targeted vaccination programmes.

Marked decrease in the incidence and prevalence of hepatitis A in the Basque Country, Spain, 1986–2004

“…All together, the data in the present study confirm that the Basque Country is an area with low endemicity. Decreases in the seroprevalence and in infection rates are also currently observed in some countries and regions of southern Europe [8,9,[15][16][17][18] and in economies in transition in other continents [18]. The speed at which this change has taken place in the Basque Country is marked and although susceptibility to HAV infection increased in the general population, no large outbreak has occurred.…”

Hepatitis A virus infections in travelers, 1988–2004

“…This strategy was only partially effective, because many travelers, mainly those visiting friends or relatives or those to popular tourist destination close by (across the Mediterranean for Europeans, Mexico for US and Canadian travelers), often fail to seek travel health advice. Despite considerable reductions in incidence attributed to the impact of HAV vaccination and despite decreasing population-based HAV seroprevalence at many destinations [34,35], there is still potential for improvement. We should focus on the risk perceptions of travelers, such as those visiting friends and relatives and those going to popular destinations.…”

Methodology of a nationwide cross-sectional survey of prevalence and epidemiological patterns of hepatitis A, B and C infection in Brazil

“…Currently, Brazilian health policy recommends HBV vaccination, which is provided free of charge to infants, children and adolescents, besides the known risk groups 17 . With regard to hepatitis A, strategies adopted to deliver vaccination vary according to the severity of the endemic, and universal vaccination in areas of low and intermediate endemicity has been advocated 18 . In Brazil, the HAV vaccine is not universally recommended within the National Immunization Program and only a small proportion of the population has access to it.…”