Australian companion animals and Coxiella burnetii (Q fever)

Abstract

Introduction: Outbreaks of Q fever, an emerging worldwide zoonosis caused by Coxiella burnetii, were associated with periparturient companion animals in veterinary hospitals in Australia. These outbreaks initiated feline and canine seroprevalence studies, a national cat breeder survey, a molecular study looking for C. burnetii within food sources, and a canine vector-borne diseases study in dogs from Aboriginal communities, with the aim of increasing our understanding of the epidemiology of C. burnetii infection in companion animals. Method: Seroprevalence studies evaluated three methodologies; indirect immunofluorescence assay, enzyme linked immunosorbent assay and complement fixation testing. The Q fever cat breeder survey recruited registered cat breeders to determine their knowledge, attitudes and practices. The molecular study utilised real-time PCR to screen raw meat (n=59) intended for pet consumption containing kangaroo (n=55) and non-kangaroo tissues (n=4). Results: Seroprevalence was highest in cattery-confined breeding cats (9.3%) and in dogs from Aboriginal communities (6.5%). A significant Q fever knowledge gap was present amongst cat breeders, with potential associations between risky husbandry practices and Q fever transmission. C. burnetii DNA was detected in 64% of samples, all of kangaroo origin, with sequence confirmation and genotyping of three Australian strains isolated from human Q fever patients. Anaemia and thrombocytopenia the most common haematological abnormalities in dogs from Aboriginal communities were likely attributable to Anaplasma platys and Babesia vogeli infections, but also affected by nutritional, parasitic and other environmental stressors. Conclusion: Australian cats and dogs have been exposed to C. burnetii; reproducing infected animals pose a potential public health threat to those present at parturition. A comprehensive risk assessment of novel sources of C. burnetii infection for companion animals and humans is required.