Outbreak of Q fever, Florac, Southern France, Spring 2007

Publié le 1 Avril 2011
Mis à jour le 5 juillet 2019

INTRODUCTION: In May 2007, five patients with Q fever-like symptoms were reported in an agricultural educational center in the rural southern French town of Florac. An investigation was undertaken to identify the outbreak source and risk factors for infection, and to implement control measures. MATERIALS AND METHODS: We undertook active case finding. Patients were defined as individuals with an unexplained fever of e38.5°C who lived in, worked in, or visited Florac between April 1 and June 30, 2007. Patients were confirmed by a positive Q fever serology test. A cross-sectional survey with a seroprevalence component was carried out in the educational center and surrounding area. A standardized questionnaire on known risk factors for the infection was used and serological testing was carried out on finger prick blood specimens from participants. The veterinary services investigated local herds within a 5-mile radius using polymerase chain reaction and serological tests. (R.A.) RESULTS: One hundred twenty-two people were included in the cross-sectional survey. Eighteen serologically confirmed acute cases were identified, of whom 12 were from the educational center. The statistical analysis showed an independent association between acute infection and living or working near an area where manure had been spread (p = 0.0.042) and male gender (p = 0.022). Frequenting the educational center's canteen was also associated with infection (p = 0.008) among staff and students. The veterinary investigations identified 11 of the 26 tested flocks of goats and sheep as seropositive for Coxiella burnetii, including 2 ovine flocks located northwest of Florac that had high shedding levels of the bacterium. DISCUSSION: The observed excess of cases of Q fever in Florac, an area endemic for this infection, in spring 2007 could be explained by an aerial transmission from infectious ovine flocks situated close to the town. All local herd owners were re-educated about the risks and prevention practices for Q fever. (R.A.)

Auteur : King LA, Goirand L, Tissot Dupont H, Giunta B, Giraud C, Colardelle C, Duquesne V, Rousset E, Aubert M, Thiéry R, Calatayud L, Daurat G, Hocqueloux L, Cicchelero V, Golliot F, de Valk H
Vector Borne & Zoonotic Diseases, 2011, n°. 4, p. 341-7