Seroepidemiology of Q fever in New Brunswick and Manitoba.

A seroepidemiological survey, using an indirect immunofluorescence test, was carried out on serum samples obtained from New Brunswick and Manitoba blood donors during 1986. The antigens were Coxiella burnetii phase I and phase II from strain Nine Mile. Eighty of the 503 (15.9%) Manitoba blood donors had a phase II antibody titer of greater than or equal to 1:8, while 41 (4.2%) of the 966 New Brunswick blood donors had such antibodies. We have recently diagnosed three cases of Q fever in New Brunswick but none have been diagnosed in Manitoba. Our data suggest that Q fever may be increasing in New Brunswick and repeated seroepidemiological studies are indicated. It is likely that undetected cases of Q fever are occurring in Manitoba.