Epidemiological and molecular analysis of a waterborne outbreak of norovirus GII.4

• Published in: Epidemiology and infection 2012-12, Vol.140 (12), p.2282-2289
• Main Authors: ZHOU, X., LI, H., SUN, L., MO, Y., CHEN, S., WU, X., LIANG, J., ZHENG, H., KE, C., VARMA, J. K., KLENA, J. D., CHEN, Q., ZOU, L., YANG, X.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Caliciviridae Infections - epidemiology; Caliciviridae Infections - virology; China - epidemiology; Diarrhea - virology; Disease Outbreaks; Drinking water; Drinking Water - chemistry; Drinking Water - virology; Epidemics; Feces - chemistry; Feces - virology; Female; Food contamination & poisoning; Fundamental and applied biological sciences. Psychology; Gastroenteritis; Gastroenteritis - epidemiology; Gastroenteritis - virology; Genotype; Genotype & phenotype; Genotypes; Humans; Male; Medical laboratories; Microbiology; Miscellaneous; Norovirus; Norovirus - classification; Norovirus - genetics; Original Papers; Phylogeny; Retrospective Studies; Reverse Transcriptase Polymerase Chain Reaction; River water; RNA polymerase; RNA, Viral - analysis; Schools; Specimens; Students; Tap water; Teachers; Virology; Viruses; Vomiting - virology; Water - chemistry; Water Microbiology; Water samples; Water supply; Water Wells - chemistry; Water Wells - virology
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268812000374

Contaminated water is one of the main sources of norovirus (NoV) gastroenteritis outbreaks globally. Waterborne NoV outbreaks are infrequently attributed to GII.4 NoV. In September 2009, a NoV outbreak affected a small school in Guangdong Province, China. Epidemiological investigations indicated that household use water, supplied by a well, was the probable source (relative risk 1·9). NoV nucleic acid material in concentrated well-water samples was detected using real-time RT—PCR. Nucleotide sequences of NoV extracted from diarrhoea and well-water specimens were identical and had the greatest sequence identity to corresponding sequences from the epidemic strain GII.4-2006b. Our report documents the first laboratory-confirmed waterborne outbreak caused by GII.4 NoV genotype in China. Our investigations indicate that well water, intended exclusively for household use but not for consumption, caused this outbreak. The results of this report serve as a reminder that private well water intended for household use should be tested for NoV.