Epidemiological and genetic analysis of a sustained community-wide outbreak of hepatitis A in the Republic of Korea, 2008: a hospital-based case-control study.
BACKGROUND
The epidemiological shift of hepatitis A has contributed to a sustained community-wide outbreak in Korea during 2008.


OBJECTIVE
To assess the risk factors associated with hepatitis A virus (HAV) propagation, and to analyze the circulating genotype in the sustained community-wide outbreak.


METHODS
The hospital-based case-control study was conducted in an 850-bed university hospital in Seoul from April to August, 2008. For molecular analysis of HAV isolates, a 488-bp gene fragment of the VP1 region was amplified and sequenced.


RESULTS
In the multivariated logistic regression model, the risk factors of HAV infection adjusted by age were contacts with hepatitis A case (OR 3.98, 95% CI: 1.36-11.66), residence with child aged <or=5 years (OR 3.43, 95% CI: 1.32-8.87), consuming uncooked lettuce (OR 3.98, 95% CI: 1.83-8.68) or carrot (OR 2.38, 95% CI: 2.38-5.09), drinking tap water (OR 3.68, 95% CI: 1.62-8.37) or portable spring water (OR 2.71, 95% CI: 1.11-6.62) supplied by water purifiers, and eating out (OR 3.87, 95% CI: 1.53-9.78). All isolates analyzed belonged to genotype IIIA. There were 42 nucleotide differences in the sequenced VP1 region among the isolates. Amino acid sequences were identical with each other.


CONCLUSIONS
Our study suggests that sporadically contaminated food- or water-borne sources as well as person-to-person transmission might lead a sustained community-wide HAV outbreak and pre-existing dominant genotype IA might be replaced with genotype IIIA as a major epidemic strain in Korea. Our findings urge the health authority to make public guidelines for HAV vaccination and outbreak control.
Yoon
Young Kyung
YK
Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, Republic of Korea.
Chun
Byung Chul
BC
Lee
Ha Kyung
HK
Seo
Yeon Seok
YS
Shin
Jung Ho
JH
Hong
Yoon Sik
YS
Sim
Hee Sun
HS
Kim
Jeoung Yeon
JY
Kim
Jeong Yeon
JY
Park
Yoon Seon
YS
Park
Dae Won
DW
Sohn
Jang Wook
JW
Kim
Min Ja
MJ
D000328:Adult; D016022:Case-Control Studies; D017714:Community-Acquired Infections / Q000453:epidemiology* / Q000821:virology; D004196:Disease Outbreaks; D005260:Female; D005516:Food Microbiology; D006506:Hepatitis A / Q000453:epidemiology* / Q000821:virology; D030041:Hepatitis A virus / Q000235:genetics*; D006761:Hospitals; D006801:Humans; D007723:Korea / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology / Q000379:methods; D015999:Multivariate Analysis; D010802:Phylogeny; D012307:Risk Factors; D015678:Viral Structural Proteins / Q000235:genetics; D014871:Water Microbiology
C096539:VP1 protein, hepatitis A virus; D015678:Viral Structural Proteins