Absence of anti-Coxiella burnetii antibodies in animal-hoarding individuals and their dogs living in a highly populated area

This study aimed to investigate the presence of anti-C. burnetii antibodies in animal-hoarding owners and their dogs living in Curitiba, the eighth biggest city in Brazil with 1.8 million habitants. A total of 19 animal-hoarding individuals from 21 households and their 264 dogs were sampled. Serum samples were tested by the indirect immunofluorescence assay (IFA) for IgG antibodies against C. burnetii. Surprisingly, no hoarding owner or dog was seropositive, significantly contrasting (p = 0.0001) with the previous survey in policemen and their working dogs in the same city. The absence of seropositivity herein has indicated that, despite poor living conditions, hoarding dogs may not be exposed to C. burnetii, highlighting the role of environmental and behavioral isolation to the Q fever epidemiology. Thus, One Health approach to C. burnetii should always include concomitant human-animal serosurveys, essential to establish the pathogen cycle in different environments and contributing for effective control strategies.