Ovine-associated Q fever

In Atlantic Canada, the traditional risk factor for acquisition of Q fever infection has been exposure to infected parturient cats or newborn kittens. In this study we describe the first case of Q fever in Nova Scotia acquired as a result of direct exposure to sheep. A serosurvey of the associated flock was undertaken using an indirect immunofluorescence assay (IFA) testing for antibodies to phase I and phase II Coxiella burnetii antigens. This serosurvey revealed that 23 of 46 sheep (50%) were seropositive for the phase II antibody. Four of these sheep had titres of 1:64 including three nursing ewes, one of which had delivered two lambs that died shortly after delivery. Only one ewe had phase I antibodies but had the study's highest phase II antibody titre (1:128). Molecular studies using polymerase chain reaction (PCR) failed to detect C. burnetii DNA in any of the milk specimens.