Q fever in Alberta, Canada: 1998-2011.

Establishing the diagnosis of Q fever (Coxiella burnetii) is important in directing the application of therapy to prevent severe manifestations of the infection. In Alberta, Canada, the presence of high livestock density creates a significant risk of infection, but to date, there has been no comprehensive analysis of local Q fever epidemiological trends and exposure patterns. Between 1998 and 2011, there were 39 cases and an overall adjusted case rate of 0.087 per 100 000 person-years. Cases were identified most commonly during the May-June season (Figure 2). The median age at date of diagnosis was 49.0 (range: 8.7-71.5) with slightly higher percentage of cases in men (56.4%) than in women (43.6%). There was an apparent geographical clustering of cases. The majority of these cases, with exposure data (n = 31), reported contact with farms and/or livestock, predominantly cattle (6), sheep (5) and goats (5). Cases tended to occur in census divisions with higher density of sheep, goats and cattle. Our findings suggest the need for an increase in targeted messages about Q fever to those in the livestock industry, as more targeted case finding among patients with a high index of suspicion for Q fever. In addition, widespread implementation of a standard questionnaire for cases would enhance surveillance of Q fever in Alberta.