An outbreak of hepatitis A associated with salted clams in Busan, Korea
- Author:
Hyunjin SON
1
;
Miyoung LEE
;
Youngduck EUN
;
Wonseo PARK
;
Kyounghee PARK
;
Sora KWON
;
Seungjin KIM
;
Changhoon KIM
Author Information
- Publication Type:Epidemiologic investigation
- From:Epidemiology and Health 2022;44(1):e2022003-
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVES:In July 2019, there were multiple reports on patients with hepatitis A among the visitors of a restaurant in Busan. The current study presents the results of an epidemiological investigation and outlines the supplementary measures that would help with hepatitis A control.
METHODS:A cohort study was conducted for all 2,865 customers who visited restaurant A from June to July. Using a standardized questionnaire, participants reported the presence of hepatitis A symptoms and whether they had consumed any of 19 food items. As for participants who had visited public health centers, their specimens were collected.
RESULTS:From the study cohort, 155 participants (5.4%) had confirmed hepatitis A. The epidemic curve was unimodal, and the median number of days from the restaurant visit to symptom onset was 31 days. A genotype analysis indicated that 89 of 90 tested patients had hepatitis A virus (HAV) genotype 1A. The results of a multivariate logistic regression analysis indicated that the ingestion of salted clams increased the risk of hepatitis A by 68.12 times (95% confidence interval [CI], 9.22 to 510.87). In an unopened package of salted clams found and secured through traceback investigation, HAV genotype 1A was detected.
CONCLUSIONS:To prevent people from ingesting uncooked clams, there needs to be more efforts to publicize the dangers of uncooked clams; the food sampling test standards for salted clams should also be expanded. Furthermore, a laboratory surveillance system based on molecular genetics should be established to detect outbreaks earlier.
