title: First reported foodborne outbreak associated with microsporidia, Sweden, October 2009.
abstract: Microsporidia are spore-forming intracellular parasites that infrequently cause disease in immunocompetent persons. This study describes the first report of a foodborne microsporidiosis outbreak which affected persons visiting a hotel in Sweden. Enterocytozoon bieneusi was identified in stool samples from 7/11 case-patients, all six sequenced samples were genotype C. To confirm that this was not a chance finding, 19 stool samples submitted by healthy persons from a comparable group who did not visit the hotel on that day were tested; all were negative for microsporidia. A retrospective cohort study identified 135 case-patients (attack rate 30%). The median incubation period was 9 days. Consumption of cheese sandwiches [relative risk (RR) 4·1, 95% confidence interval (CI) 1·4-12·2] and salad (RR 2·1, 95% CI 1·1-4) were associated with illness. Both items contained pre-washed, ready-to-eat cucumber slices. Microsporidia may be an under-reported cause of gastrointestinal outbreaks; we recommend that microsporidia be explored as potential causative agents in food- and waterborne outbreaks, especially when no other organisms are identified.
authors: Department of Analysis and Prevention, Swedish Institute for Communicable Disease Control, Solna, Sweden. valerie.decraene@smi.se
authors: V
authors: V
authors: Decraene
authors: M
authors: M
authors: Lebbad
authors: S
authors: S
authors: Botero-Kleiven
authors: A-M
authors: AM
authors: Gustavsson
authors: M
authors: M
authors: Löfdahl
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004271:DNA, Fungal / Q000235:genetics; D004196:Disease Outbreaks; D021862:Enterocytozoon / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D005260:Female; D005517:Foodborne Diseases / Q000453:epidemiology*; D005838:Genotype; D006801:Humans; D008297:Male; D016881:Microsporidiosis / Q000453:epidemiology*; D008875:Middle Aged; D012189:Retrospective Studies; D013548:Sweden / Q000453:epidemiology
chemical_list: D004271:DNA, Fungal