Atypical outbreak of Q fever affecting low-risk residents of a remote rural town in New South Wales.

We investigated an outbreak of Q fever in a remote rural town in New South Wales, Australia. Cases identified through active and passive case finding activities, and retrospective laboratory record review were interviewed using a standard questionnaire. Two sets of case-case analyses were completed to generate hypotheses regarding clinical, epidemiological and exposure risk factors associated with infection during the outbreak. Laboratory-confirmed outbreak cases (n=14) were compared with an excluded case group (n=16) and a group of historic Q fever cases from the region (n=106). In comparison with the historic case group, outbreak cases were significantly more likely to be female (43% vs. 18% males, P = 0.04) and identify as Aboriginal (29% vs. 7% non-Aboriginal, P = 0.03). Similarly, very few cases worked in high-risk occupations (21% vs. 84%, P < 0.01). Most outbreak cases (64%) reported no high-risk exposure activities in the month prior to onset. In comparison with the excluded case group, a significantly increased proportion of outbreak cases had contact with dogs (100% vs. 63%, P = 0.02) or sighted kangaroos on their residential property (100% vs. 60%, P = 0.02). High rates of tick exposure (92%) were also reported, although this was not significantly different from the excluded case group. While a source of this outbreak could not be confirmed, our findings suggest infections likely occurred via inhalation of aerosols or dust contaminated by Coxiella burnetii, dispersed through the town from either an unidentified animal facility or from excreta of native wildlife or feral animals. Alternatively transmission may have occurred via companion animals or tick vectors.

Q fever outbreak during the Czech Army deployment in Bosnia.

An epidemic of Q fever was identified among soldiers from the Czech Republic serving in the U.N. Stabilization Force in Bosnia and Herzogovina in 1997. There were 26 serologically confirmed infections, or 4.6% of those exposed. There were 14 cases of febrile illness and 12 subclinical infections. Prodromal symptoms of malaise, headache, backache, and fatigue were followed by fever > or = 39 degrees C with an intermittent course. Physical findings were unremarkable except in five cases with radiographically confirmed pneumonia. Cases were treated with doxycycline, trimethoprim-sulfamethoxazole, or ceftriaxone and supportive care. Q fever occurred at four U.N. Stabilization Force bases with the highest incidence at Dolna Ljubija (attack rate 9.4% vs. 2.3% at other locations (risk ratio = 4.0; 95% confidence interval [CI] = 2.7-5.9; p < 0.05). A sheep farm with active lambing was located 100 m from the base. Helicopter operations at a nearby landing zone may have generated infectious environmental aerosols and may have been a cause of the Q fever outbreak.