Incubation Period, Spore Shedding Duration, and Symptoms of Enterocytozoon bieneusi Genotype C Infection in a Foodborne Outbreak in Denmark, 2020. (13th November 2021)

• Record Type: Journal Article
• Authors: Michlmayr, Daniela; Alves de Sousa, Luís; Müller, Luise; Jokelainen, Pikka; Ethelberg, Steen; Vestergaard, Lasse Skafte; Schjørring, Susanne; Mikkelsen, Sarah; Jensen, Carl Widstrup; Rasmussen, Lasse Dam; Rune Stensvold, Christen
• Is Part Of: Clinical infectious diseases. Volume 75:Number 3(2022)
• Page Start: 468
• Page End: 475
• Publication Date: 2021-11-13
• Subjects: Enterocytozoon -- foodborne disease -- microsporidia -- microsporidiosis -- outbreak; Communicable diseases -- Periodicals; 616.905
• DOI: 10.1093/cid/ciab949
• Languages: English
• ISSNs: 1058-4838

Abstract

Abstract: Background: Microsporidia are rarely reported to cause outbreaks of diarrhea. We describe a foodborne outbreak of microsporidiosis from a workplace canteen in November 2020 in Denmark. Methods: A probable case was defined as any person using the canteen between 4 November and 13 December 2020, reporting at least one gastrointestinal symptom, whereas a confirmed case also had an Enterocytozoon bieneusi positive stool sample. A web-based questionnaire was used to collect clinical, epidemiological, and food exposure data. We performed a retrospective cohort study and tested stool samples from affected individuals for bacterial, viral, and parasitic pathogens, including E. bieneusi . Results: Altogether, 195 individuals completed the questionnaire. We identified 52 cases (65% male; median age 45 years [range 25–65]). Diarrhea (90%), fatigue (83%), and abdominal pain (79%) were the most commonly reported symptoms. Eight cases were laboratory-confirmed and had E. bieneusi genotype C. The incubation period was between 5 and 12 days, and polymerase chain reaction (PCR)-detectable spore shedding occurred up to 43 days after symptom onset. Disease was associated with consuming food from the workplace canteen on 4 November 2020 (relative risk [RR[, 2.8 [95% confidence interval [CI]: 1.4 – 5.4]) and lunchboxes containing open sandwiches (RR, 3.2 [95% CI: 1.4 – 7.2]) served that day. Conclusions: This is the second documented foodborne outbreak of E. bieneusi genotype C - associated diarrhea worldwide. Epidemiological findings advocated an open sandwiches lunchbox from 4 November 2020, as a likely source. E. bieneusi may be an under-reported cause of outbreaks of diarrhea, and testing for it might be useful in foodborne outbreak investigations. Abstract : Enterocytozoon bieneusi was identified as the cause of a foodborne outbreak of diarrhea affecting >70 individuals. The incubation period was 5–12 days. Spores were shed in stool for up to 43 days after symptom onset.