J Prev Med Public Health.  2021 Sep;54(5):370-375. 10.3961/jpmph.21.349.

Hepatitis A Outbreak in a Facility for the Disabled, Gyeonggi Province, Korea: An Epidemiological Investigation

• Chang Y
• Kim C
• Kim N
• Kim JJ
• Lee H

• KMID: 2520537
• DOI: http://doi.org/10.3961/jpmph.21.349

Abstract

Objectives
The number of cases of hepatitis A virus (HAV) infections has sharply increased in Korea, especially among young adults. In this study, an HAV outbreak in a facility for disabled people was investigated, and we found epidemiological differences both between 2 different generations and between generally abled and disabled groups.
Methods
We analyzed the incubation period and attack rate of an HAV outbreak and investigated the prevalence of HAV antibodies among the staff and residents of a facility for the disabled. We performed a retrospective cohort study during the HAV outbreak, which lasted from February 8 to 25, 2019, including examinations of HAV antibody tests and post-exposure HAV vaccination for the staff or residents of the facility.
Results
There were 9 confirmed cases in 2 staff members and 7 residents. Among 53 people (30 staff and 23 residents), except for the 9 confirmed cases and 1 staff member with a known history of HAV infection, HAV seroprevalence was seen in 16.7% of the staff under 40 years of age and 95.2% of those over 40 years of age, while the corresponding rates in the residents were 0.0% and 58.8%, respectively.
Conclusions
This result implies that it is necessary to prioritize HAV vaccination for vulnerable groups and workers of residential care facilities.

Keyword

Hepatitis A; Immunization; Vaccination; Seroepidemiologic studies