Seroprevalence and Disease Burden of Acute Hepatitis A in Adult Population in South Korea

Background: Hepatitis A is a major cause of acute viral hepatitis. In adult, hepatitis A manifests more severe symptoms and complications than in childhood. Adult seroprevalence of hepatitis A is decreasing in developed countries including Korea, because of getting better general sanitation. Although hepatitis A vaccination had been approved in Korea more than 20 years ago, recent infection rate and seropositivity did not seem to be improved. In this study, we investigate anti-HAV IgG seroprevalence and national disease burden of acute hepatitis A in adult population using the data of health care center and national health insurance.

Methods: The adult seroprevalence data was collected from Health Promotion Center of Korea University Guro Hospital in Seoul, Korea from 2010 to 2014. The epidemiologic and clinical data were collected from Korean Statistical Information Service (KOSIS) and National Health Insurance Service (NHIS) database, from 2009 to 2013, which is including almost entire Korean population. The data was calculated and analyzed statistical significance between age group using chi-square test and ANOVA.

Results: Total 11,176 were tested anti-HAV IgG from 2010 to 2014. Age-related seroprevalence showed relatively low seropositivity in 20’s (26.7%) and early 30’s (50.5%) population. The incidence of acute hepatitis A was highest in 2009 (192.8 cases /100,000 population) and lowest in 2013 (26.7 cases /100,000 population). When categorized by age group, 20’s (46,413 infected, 27.8% admitted) and 30’s (61,670 infected, 55.6% admitted) were more infected and admitted than older adults (40’s ; 26,477 infected, 20.9% admitted, 50’s ; 11,243 infected, 15.0% admitted) by acute hepatitis A from 2009 to 2013. However, ICU admission rate, mechanical ventilator use, CRRT use and liver transplantation rate were high in older adults. Total insurance-covered cost was also high in older adults (20’s : 1,071,501, 30’s : 1,186,416, 40’s : 1,291,630, 50’s : 1,394,534, KRW, p-value <0.0001).

Conclusion: The seropositivity in Korean younger adult population was low and incidence of acute hepatitis A was high. Even more intensive procedures were done with high insurance-covered cost in older adults, 20’s and 30’s also bears considerable disease burden. More intensive hepatitis A vaccination towards younger adult would be necessary.