Coxiella burnetii in Dogs and Cats from Portugal: Serological and Molecular Analysis

Abstract

Dogs and cats are potential sources of infection for some zoonotic diseases such as Q fever, caused by Coxiella burnetii, a multiple host pathogen. Q fever outbreaks in dogs and cats have been related with parturition and abortion events, and ticks have a potential role in the transmission of this pathogen. This study aimed to screen for C. burnetii in dogs and cats, and in ticks collected from infested animals. An observational descriptive study was conducted in Portugal at two time points nine years apart, 2012 and 2021. Sera obtained from dogs and cats (total n = 294) were tested for C. burnetii antibodies using a commercial ELISA adapted for multi-species detection. C. burnetii DNA was screened by qPCR assay targeting IS1111 in uterine samples and in ticks. A decrease in the exposure to C. burnetii was observed in cats from 17.2% (95% CI: 5.8–35.8%) in 2012 to 0.0% in 2021, and in dogs from 12.6% (95% CI: 7.7–19.0%) in 2012 to 1.7% (95% CI: 0.3–9.1%) in 2021 (p < 0.05). Overall, and despite differences in the samples, rural habitat seems to favour the exposure to C. burnetii. The DNA of C. burnetii was not detected in ticks. The low seropositivity observed in 2021 and the absence of C. burnetii DNA in the tested samples, suggest that dogs and cats from Portugal are not often exposed to the pathogen. Nevertheless, the monitoring of C. burnetii infection in companion animals is an important tool to prevent human outbreaks, considering the zoonotic potential for owners and veterinarians contacting infected animals, mainly dogs and cats from rural areas which often come into contact with livestock.

Seropositivity for Coxiella burnetii in Wild Boar (Sus scrofa) and Red Deer (Cervus elaphus) in Portugal

“…In Portugal, only one wild mammal molecular prevalence study has been performed, but red deer and wild boar were negative to C. burnetii [ 6 ]. Other studies performed in Portugal have reported Q fever in domestic ruminants [ 6 , 37 , 38 , 39 , 40 ], dogs and cats [ 41 ], and humans [ 42 , 43 , 44 , 45 ]. Nevertheless, this study is the first report of C. burnetii antibodies in red deer and wild boar in east–central Portugal.…”

Coxiella burnetii Infection in Cats

“…An observational descriptive study was conducted in Portugal at two time points nine years apart, 2012 (29 cats) and 2021 (47 cats). Sera obtained from dogs and cats (total 294 sera) were tested for C. burnetii antibodies using a commercial ELISA adapted for multi-species detection; whereas a 17.2% prevalence was found among cats in 2012, when a higher percentage of animals from rural areas were analyzed, no positive cats were detected in 2021 [41]. Moreover, a molecular survey on reproductive tissues and/or endometrial swabs from 107 cats detected no positive cats [41].…”

“…ELISA is able to detect both anti-phase I and II antibodies, and is sensitive but laborious [79]. Commercial kits are available for the diagnosis of Q fever in humans and farm animals, but not for cats and dogs; therefore, the test has to be adapted to these investigated animal species [30,33,[38][39][40][41]43].…”

Current Research on Infectious Diseases of Domestic Animals from a One Health Perspective

“…The risk of close contact between humans and wild animals is relatively low, but when pet animals are considered, this risk is much higher. The paper of Anastàcio et al [ 9 ] showed that the monitoring of C. burnetii infections in companion animals is an important tool that may be used to prevent human outbreaks, considering the zoonotic potential of owners and veterinarians in contact with infected animals. The importance of proper surveillance was also highlighted in the paper of Pappa et al [ 10 ] on leishmaniasis, which is a neglected tropical disease affecting humans and domesticated animals, with high mortality in endemic countries.…”