J Agric Med Community Health.  2010 Dec;35(4):361-369.

Epidemiological Investigation on an Outbreak of Norovirus Infection at a High School in Gyeongju City, 2009

• Park JH
• Yoo SJ
• Lee K
• Lim HS

Abstract

OBJECTIVES
An outbreak of norovirus occurred at a high school in Gyeongju city in 2009. An epidemiological investigation was carried out to examine the infection source and the transmission route of norovirus, and to prevent a recurrence.
METHODS
A questionnaire survey was conducted for 520 male students and 8 food handlers. Rectal swabs were examined in 21 symptomatic students and the 8 food handlers by Gyeongsangbukdo Government Public Institute of Health & Environment, and an environmental investigation was performed. A case-control study was used to evaluate the association between risk factors and disease.
RESULTS
The attack rate was 21.3% (111/520) between January 29 and February 10, and norovirus GII was isolated from 12 of 21 students. Food handlers had no symptoms and their stool samples were negative. The case-control study revealed that seasoned soy bean sprouts {odds ratio (OR): 2.542, 95% CI=1.315-4.915} and drinking water from the purifiers in the cafeteria (OR: 2.854, 95% CI=1.107-7.358) supplied on February 3 were significant risk factors for the outbreak. Water pipes and waste pipes were located in the same place where was filled with some water and trace of high water level was detected.
CONCLUSIONS
The major risk factors for this norovirus outbreak were presumed to be the contaminated seasoned soy bean sprouts and drinking water from the purifiers in the cafeteria. More strict personal and environmental hygiene need to be enforced to prevent such outbreaks.

Keyword

Food contamination; Norovirus; Outbreaks; Water

MeSH Terms

Alkanesulfonic Acids
Case-Control Studies
Disease Outbreaks
Drinking Water
Food Contamination
Humans
Hygiene
Hypogonadism
Male
Mitochondrial Diseases
Norovirus
Ophthalmoplegia
Piperazines
Risk Factors
Seasons
Soybeans
Water
Surveys and Questionnaires
Alkanesulfonic Acids
Drinking Water
Hypogonadism
Mitochondrial Diseases
Ophthalmoplegia
Piperazines
Water