Ice-associated norovirus outbreak predominantly caused by GII.17 in Taiwan, 2015

Abstract

BackgroundOn 5 March 2015, Taiwan Centers for Disease Control was notified of more than 200 students with gastroenteritis at a senior high school during excursion to Kenting. We conducted an outbreak investigation to identify the causative agent and possible vehicle of the pathogen.MethodsWe conducted a retrospective cohort study by using a structured questionnaire to interview all students for consumed food items during their stay at the resort. Students were defined as a gastroenteritis case while having vomiting or diarrhea after the breakfast on 4 March. We inspected the environment to identify possible contamination route. We collected stool or vomitus samples from ill students, food handlers and environmental specimens for bacterial culture for common enteropathogens, reverse transcription polymerase chain reaction (RT-PCR) for norovirus and enzyme-linked immunosorbent assay (ELISA) for rotavirus. Norovirus PCR-positive products were then sequenced and genotyped.ResultsOf 267 students enrolled, 144 (54%) met our case definition. Regression analysis revealed elevated risk associated with iced tea, which was made from tea powder mixed with hot water and self-made ice (risk ratio 1.54, 95% confidence interval 1.22–1.98). Ice used for beverages, water before and after water filter of the ice machine and 16 stool and vomitus samples from ill students were tested positive for norovirus; Multiple genotypes were identified including GI.2, GI.4 and GII.17. GII.17 was the predominant genotype and phylogenetic analyses showed that noroviruses identified in ice, water and human samples were clustered into the same genotypes. Environmental investigation revealed the ice was made by inadequate-filtered and un-boiled water.ConclusionsWe identified the ice made by norovirus-contaminated un-boiled water caused the outbreak and the predominant genotype was GII.17. Adequately filtered or boiled water should be strongly recommended for making ice to avoid possible contamination.

Detection of norovirus in food samples collected during suspected food‐handler‐involved foodborne outbreaks in Tokyo

“…Ice-associated NoV outbreaks have been reported previously (Boccia et al 2002;Cheng et al 2017). In previous studies, ice prepared from NoV-contaminated water caused gastroenteritis; thus, the route of viral transmission was through water.…”

Natural Host–Environmental Media–Human: A New Potential Pathway of COVID-19 Outbreak

“…By analyzing the literature published in the past 120 years, we found at least 198 viral infection cases with 28 different strains of viruses that occurred through direct contact with environmental media ( Table 3 [123] , [124] , [125] , [126] , [127] , [128] , [129] , [130] , [131] , [132] , [133] , [134] , [135] , [136] , [137] , [138] , [139] , [140] , [141] , [142] , [143] , [144] , [145] , [146] , [147] , [148] , [149] , [150] , [151] , [152] , [153] , [154] , [155] , [156] , [157] , [158] , [159] , [160] , [161] , [162] , [163] , [164] , [165] , [166] , [167] , [168] , [169] , [170] , [171] , [172] , [173] , [174] , [175] , [176] , [177] , [178] , [179] , [180] , [181] , [182] , [183] , [184] , [185] , [186] , [187] , [188] , ...…”

An outbreak of norovirus infection caused by ice cubes and a leaking air ventilation valve

“…However, a number of foodborne outbreaks remain obscure in terms of the source of the infection [15]. Ice [16–18] and drinking-water [19, 20] outbreaks are also common, often involving multiple pathogens from wastewater leaking to drinking water [21–23]. Ice usually becomes contaminated through wastewater leakage to drinking water somewhere along the water distribution line [16–18].…”

“…Ice [16–18] and drinking-water [19, 20] outbreaks are also common, often involving multiple pathogens from wastewater leaking to drinking water [21–23]. Ice usually becomes contaminated through wastewater leakage to drinking water somewhere along the water distribution line [16–18]. Airborne transmission is possible through aerosols generated by vomiting or flushing the toilet [7, 24, 25].…”