Infectivity and Pathogenicity of Hepatitis A Virus during an Outbreak in a Communal Living Setting

Hyun, Hee Jae; Park, So Yeon; Choi, Soon Uk; Ahn, Ju Young; Jung, Jun Oh; Lim, Su Jin; Yoo, Ji Won; Park, Sang Jun; Kim, Youn Kwon; Kim, Young Jung; Cho, Jae Hyun

Abstract

BACKGROUND/AIMS
Acute viral hepatitis A infection in adults is an emerging public health problem in Korea. The infectivity and pathogenicity of hepatitis A virus (HAV) among people living in close contact have not been studied previously. This study investigated the secondary attack rate and pathogenicity rate of HAV during an outbreak among auxiliary police in a communal living setting in Korea.
METHODS
A total of 70 people in close contact with a hepatitis A patient (index case) were enrolled in the study, which included a thorough oral history, physical examination, and laboratory testing. The subjects were part of an auxiliary police unit living in a communal setting (HAV contact group). Serum antibody titers were measured in the contact group at two points during the study. Subjects in another auxiliary police unit without exposure to hepatitis A were examined as a control group (HAV non-contact group). The secondary attack rate and pathogenicity rate were calculated from the data.
RESULTS
In the HAV non-contact group, none of the subjects had anti-HAV antibodies. In the HAV contact group, three subjects had both IgM and IgG anti-HAV antibodies, and two had only IgG anti-HAV antibodies. Two of three HAV-infected subjects were treated for hepatitis A.
CONCLUSIONS
The secondary attack rate of HAV was 4.3~7.1% and the pathogenicity rate was 40~66.7% in the group of young adults.