A human case of Q fever associated with cat in China: a neglected risk factor of Q fever

Q fever is a globally distributed zoonosis caused by Coxiella burnetii, which is mainly harbored by farm ruminants. Although some studies have reported the presence of C. burnetii in cats, cat-associated Q fever is very rare. In this study, we report the case of a 30-year-old man who was diagnosed with Q fever in May 2024. The diagnosis was based on the results of next-generation sequencing and confirmed by nested PCR. Epidemiological investigations suggest that he had not come into contact with any infection sources other than two cats, one of which was a parturient cat. The blood samples of the cats were collected and tested by nested PCR and immunofluorescence assay. The results showed that the serum of the parturient cat was positive for both phase I and phase II Q fever antigens, suggesting that it had been infected with C. burnetii. This is a rare human case of Q fever transmitted by a domestic cat in China. Importantly, it shows that the pet cat may be a neglected risk factor of Q fever in China.