Outbreak of diarrhoeal illness in participants in an obstacle adventure race, Alpes-Maritimes, France, June 2015.
An acute gastroenteritis (AG) outbreak occurred among participants in an obstacle race in France in the summer of 2015. An investigation in two phases was conducted to identify the source of infection and document the extent of the outbreak. First, a message on a social media website asked racers to report any symptoms by email to the Regional Health Agency of Provence-Alpes-Côte d'Azur. Second, a retrospective cross-sectional study was conducted through an interactive questionnaire for all participants, followed by an analytical study of potential risks factors. Of 8,229 persons registered, 1,264 adults reported AG resolved within 48 hours. Of adults who reported AG, 866 met the case definition. Age group, departure time and ingestion of mud were associated with AG. Twenty stool specimens tested negative for bacteria. All four stool samples tested for viruses were positive for norovirus genogroup I and genotype 2. No indicator bacteria for faecal contamination were found in drinking water but muddy water of ponds tested positive. The outbreak was possibly caused by human-to-human transmission of a norovirus introduced by one or more persons and transmitted through contaminated mud. Risks related to similar races should be assessed and recommendations be proposed to raise awareness among health authorities and organisers.
Santé publique France, French national public health agency, Regional unit (Cire Provence-Alpes-Côte d'Azur and Corsica), Marseilles, France.
Caroline
C
Six
Samer
S
Aboukais
Sandra
S
Giron
Jean-Christophe
JC
D'Oliveira
Françoise
F
Peloux-Petiot
Florian
F
Franke
Hervé
H
Terrien
Fabrice
F
Dassonville
Joël
J
Deniau
Katia
K
Ambert-Balay
Thierry
T
Chesnot
Raymond
R
Ruimy
Michel
M
Pélandakis
Patrick
P
Basset
Manuel
M
Munoz Rivero
Philippe
P
Malfait
D000293:Adolescent; D000328:Adult; D016358:Contact Tracing / Q000379:methods / Q000706:statistics & numerical data; D003967:Diarrhea / Q000453:epidemiology* / Q000821:virology*; D004196:Disease Outbreaks / Q000706:statistics & numerical data*; D005260:Female; D005602:France / Q000453:epidemiology; D000068957:Games, Recreational; D006801:Humans; D008297:Male; D008875:Middle Aged; D029322:Norovirus / Q000302:isolation & purification*; D015995:Prevalence; D012307:Risk Factors; D012420:Running / Q000706:statistics & numerical data*; D014777:Virus Diseases / Q000453:epidemiology* / Q000821:virology; D055815:Young Adult
France; epidemiology; gastrointestinal disease; norovirus; outbreaks; parasitic infections; viral infections