A Q fever outbreak in a psychiatric care institution in The Netherlands.

In May 2008 the Nijmegen Municipal Health Service (MHS) was informed about an outbreak of atypical pneumonia in three in-patients of a long-term psychiatric institution. The patients had been hospitalized and had laboratory confirmation of acute Q fever infection. The MHS started active case finding among in-patients, employees of and visitors to the institution. In a small meadow on the institution premises a flock of sheep was present. One of the lambs in the flock had been abandoned by its mother and cuddled by the in-patients. Samples were taken of the flock. Forty-five clinical cases were identified in employees, in-patients and visitors; 28 were laboratory confirmed as Q fever. Laboratory screening of pregnant women and persons with valvular heart disease resulted in one confirmed Q fever case in a pregnant woman. Of 27 samples from animals, seven were positive and 15 suspect for Coxiella burnetii infection. This outbreak of Q fever in a unique psychiatric setting pointed to a small flock of sheep with newborn lambs as the most likely source of exposure. Care institutions that have vulnerable residents and keep flocks of sheep should be careful to take adequate hygienic measures during delivery of lambs and handling of birth products.