New concerns with human brucellosis in France in the beginning of the 3rd millenium

Abstract number: 1733_726

Mailles A., Garin-Bastuji B., Maurin M., Vaillant V.

Context: Human brucellosis is mandatorily notifiable in France. Due to a veterinary policy based on stamping out and vaccination carried out since the 1970s, France is considered ``officially brucellosis free'' for cattle since 2005 and no cases have been identified in sheep nor goats since 2003. In this context, we studied human brucellosis diagnosed in France to assess remaining risk factors and make specific recommendations.

Methods: Our descriptive study included all human cases notified in mainland France from 1st June 2002 to 31st May 2004. A case was defined as any patient with clinical signs consistent with brucellosis. A confirmed case had a bacterial isolation from any biological sample, or a fourfold increase in anti-Brucella antibodies in 2 samples taken at 2-week interval or a seroconversion. A probable case had a single elevated titre in anti-Brucella antibodies and no alternative diagnosis. For all patients, data were collected using a standardised questionnaire.

Results: During the 2-year period of the study, 105 patients were notified, including 72 cases and 26 false cases who did not meet the case definitions' criteria. The annual incidence of human brucellosis was 0.05 cases per 100,000 inhabitants. Of all cases, 32% had localised infections, mainly arthritis. The disease was diagnosed by bacterial isolation in 49 cases (65%). Eighty percent of cases were imported, having been infected while travelling in an enzootic country or by eating raw milk products imported from an enzootic country. The countries where cases were most frequently contaminated were Portugal (n = 14), Algeria (n = 7) and Turkey (n = 6). Cases had more frequent contacts with animals in enzootic countries than false cases (p = 0.05) and had eaten more frequently raw milk products from enzootic countries than false cases (p = 0.004). One case had a laboratory acquired brucellosis.

Conclusions: Our study confirmed the efficiency of the veterinary policy against animal brucellosis. The incidence of human brucellosis has dramatically decreased and most cases are now imported. Considering the very low prevalence of brucellosis, the direct diagnosis must be preferred to serology to avoid false cases. Recommendations are made to increase the specificity of the surveillance, such as modifying the case definition and consider only bacterial isolation and the increase of serological titre as reliable tests. Specific recommendations are made to prevent the increase of laboratory acquired cases.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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