France has been officially brucellosis-free since 2005. In 2012, an autochtonous human case, related to an infected dairy herd and a reservoir in wildlife, was identified in the French Alps. We report the investigation, and discuss the antibioprophylaxis in people exposed to Brucella sp.
Veterinary investigation was conducted to determine the origin of human cases and of cattle infection. Strains isolated from humans, cattle and wildlife were compared. Asymptomatic people with at-risk exposure were tested for brucellosis. Due to the absence of evidence-based recommendations for Brucellaexposure in the community, a panel of infectious diseases specialists was consulted with regards to antibioprophylaxis for people with an exposure to infected animals or raw-milk cheese.
Brucellosis strains from human, bovine and ibex cases were identical in multiple loci VTNR analysis.
Eleven people had a confirmed exposure to the infected cheese or animals. Two human cases were detected among them during a 12-month period. It was decided not to prescribe antibiotics to exposed people in the absence of symptoms suggestive brucellosis and a laboratory confirmation.
A dairy herd was found to be the source of human cases and was culled. The raw-milk cheeses from this herd were withdrawn, but more cheese had been sold to people who could not be easily identified. The source of cattle infection was later confirmed as an Alpine Ibex population, acting as a silent reservoir for years in mountains where cattle herds pasture in summer. All local ruminant herds tested negative after transhumance. The management of the infection in alpine Ibex was challenging due to their status of protected species and the threat it represents for the dairy production.
This is the first time that wildlife ruminants acts as a silent reservoir of brucellosis, emphasizing the need to maintain a surveillance after the elimination of the disease. People with at-risk exposure were not prescribed antibiotics but maintained on a clinical follow-up. The onset of the second human case one year after the index case challenged this decision. However, there is limited evidence that any post-exposure antibacterial prophylaxis would have prevented the second case.
S. Rautureau, None
B. Garin-Bastuji, None
J. Hars, None
P. Tattevin, None
O. Catelinois, None
V. Le Bourg, None
V. Mick, None
F. Lucht, None
V. Vaillant, None
J. Garau, None
J. P. Stahl, None
J. P. Bru, None