Detection of multiple noroviruses associated with an international gastroenteritis outbreak linked to oyster consumption.

Françoise S S. Le Guyader (1) , Fabienne F. Bon (2) , Dario D. Demedici (3) , Sylvain Parnaudeau (1) , Alessandra A. Bertone (4) , Silvia S. Crudeli (5) , Aoife Doyle (6) , Mohamed Zidane (1) , Elisabetta Suffredini (3) , Evelyne Kohli (2) , Francesco Maddalo (4) , Marina Monini (5) , Anne A. Gallay (6) , Monique Pommepuy (1) , Pierre Pothier (2) , Franco M Ruggeri (5)

1 EMP - Unité Environnement, Microbiologie et Phycotoxines
2 LIMA - Laboratoire Interactions Muqueuses Agents Transmissibles
3 Centro Nazionale per la Qualita` degli Alimenti e per i Rischi Alimentari
4 Azienda Unita` Sanitaria Locale
5 Dipartimento di Sanita` Alimentare e Animale, Istituto Superiore di Sanita`
6 INVS - De´partement Maladies Infectieuses, Unite´ Infections Ente´riques, Alimentaires et Zoonoses

An international outbreak linked to oyster consumption involving a group of over 200 people in Italy and 127 total subjects in 13 smaller clusters in France was analyzed using epidemiological and clinical data and shellfish samples. Environmental information from the oyster-producing area, located in a lagoon in southern France, was collected to investigate the possible events leading to the contamination. Virologic analyses were conducted by reverse transcription-PCR (RT-PCR) using the same primer sets for both clinical and environmental samples. After sequencing, the data were analyzed through the database operated by the scientific network FoodBorne Viruses in Europe. The existence of an international collaboration between laboratories was critical to rapidly connect the data and to fully interpret the results, since it was not obvious that one food could be the link because of the diversity of the several norovirus strains involved in the different cases. It was also demonstrated that heavy rain was responsible for the accidental contamination of seafood, leading to a concentration of up to hundreds of genomic copies per oyster as detected by real-time RT-PCR.

Mots clés: Adolescent; Adult; Aged; 80 and over; Animals; Child; Preschool; Disease Outbreaks; Feces; Female; Foodborne Diseases; Gastroenteritis; Humans; Male; Middle Aged; Norovirus; Ostreidae; Reverse Transcriptase Polymerase Chain Reaction

Domaines: Microbiologie et Parasitologie

Françoise S S. Le Guyader, Fabienne F. Bon, Dario D. Demedici, Sylvain Parnaudeau, Alessandra A. Bertone, et al.. Detection of multiple noroviruses associated with an international gastroenteritis outbreak linked to oyster consumption.. Journal of Clinical Microbiology, 2006, 44 (11), pp.3878-82. ⟨10.1128/JCM.01327-06⟩. ⟨hal-00452289⟩