Hepatitis A in the Eastern Mediterranean Region: a comprehensive review

Introduction With 583 million inhabitants, the Eastern Mediterranean Region (EMR) is a worldwide hub for travel, migration, and food trade. However, there is a scarcity of data on the epidemiology of the hepatitis A virus (HAV). Methods The MEDLINE and grey literature were systematically searched for HAV epidemiological data relevant to the EMR region published between 1980 and 2020 in English, French, or Arabic. Results Overall, 123 publications were extracted. The proportion of HAV cases among acute viral hepatitis cases was high. HAV seroprevalence rate ranged from 5.7% to 100.0% and it was decreasing over time while the average age at infection increased. Conclusion In the EMR, HAV remains a significant cause of acute viral hepatitis. The observed endemicity shift will likely increase disease burden as the population ages. Vaccinating children and adopting sanitary measures are still essential to disease prevention; vaccinating at-risk groups might reduce disease burden even further. PLAIN LANGUAGE SUMMARY What is the context? Hepatitis A is a viral liver disease caused by the hepatitis A virus. It is generally transmitted by ingestion of contaminated food or water or through contact with an infected person. Disease severity increases with age. Children under 6 years of age are usually asymptomatic, while adults are the most affected. Limited information exists on the number of cases and transmission of hepatitis A in the Eastern Mediterranean region, which includes 21 countries and Palestine, as defined by the World Health Organization. What is new? We performed a literature review to summarize data on hepatitis A disease in the Eastern Mediterranean region over the last 40 years (1980-2020). As information for many countries is scarce or outdated, most of the data is from Egypt, Iran and Saudi Arabia. We found that: Hepatitis A virus is the most common cause of acute viral hepatitis. Hepatitis A exposure varied according to the country's income level. Low- and middle-income countries showed a universal immunity to hepatitis A virus, although this is not the case anymore. What is the impact? Hepatitis A infections have decreased worldwide. Lower exposure to the virus has led to an increase in the susceptible population (including adolescent and adults). Hepatitis A vaccination for children and high-risk groups such travelers should be considered in the Eastern Mediterranean region.