An outbreak of norovirus gastroenteritis associated with a secondary water supply system in a factory in south China
1 Department of infectious disease prevention and control, Shenzhen bao’an center for disease control and prevention, 116 Longjinger Road, Shenzhen, 51810, China
2 Department of STD and AIDS Prevention and Control, Jiangsu provincial center for disease control and prevention, 172 Jiangsu Road, Nanjing, 210009, China
3 Department of comprehensive prevention and control, Shanhai Huangpu center for disease control and prevention, 181 Zhizaolu Road, Shanghai, 200011, China
4 Department of epidemiology, Shenzhen bao’an center for disease control and prevention, 116 Longjinger Road, Shenzhen, 518100, China
5 Microbiology laboratory, Shenzhen center for disease control and prevention, 8 Longyuan Road, Shenzhen, 518055, China
6 The office of Chinese field epidemiology training, Chinese center for disease control and prevention, 155 Changbai Road, Beijing, 102206, China
7 The institute of virology, Chinese center for disease control and prevention, 155 Changbai Road, Beijing, 102206, China
8 Rollins School of Public Health, Emory University, 1518 Clifton Road, Atlanta, 30322, USA
BMC Public Health 2013, 13:283 doi:10.1186/1471-2458-13-283Published: 28 March 2013
Between September 17 and October 3, 2009, hundreds of workers employed in a manufacturing factory in Shenzhen, a city in south China developed a sudden onset of acute gastroenteritis. A retrospective cohort study is designed to identify the risk factors and control this outbreak.
Information on demographic characteristics, working place, the history of contact with a person having diarrhea and/or vomiting, drink water preference and frequency, eating in the company cafeteria or outside the company, hand-washing habits and eating habits is included. Furthermore, in order to find the contamination source, we investigated the environment around the underground reservoir and collected water samples from the junction between municipal supply water system and underground reservoir to test potential bacteria and virus, examine the seepage tracks on the wall of the underground reservoir from the side of septic tank, and check the integrity and attitude of this lid. Relative risk was presented and Chi-square test was performed. All the analyses were performed with OpenEpi software version 2.3.1 online.
The cohort study demonstrated that the workers who had direct drink water were 3.0 fold more likely to suffer from acute gastroenteritis than those who consumed commercial bottled water. The direct drinking water, water of the tank of buildings, and the underground reservoir were positive only for norovirus. Norovirus was also detected from stool and rectal swab samples from patients with acute gastroenteritis. The underground reservoir was found to be the primary contamination source. Further environmental investigation showed that the norovirus contaminated substance entered into the underground reservoir via access holes in lid covering this underground reservoir.
This acute gastroenteritis outbreak was caused by the secondary supply system contaminated by norovirus in this factory. The outbreak of gastroenteritis cases caused by norovirus frequently occurred in China due to a lack of surveillance and supervision, and due to faults in the construction of such water systems. Therefore, more attentions should pay to the secondary supply water system in China.