Fujishiro MA, Scorza A, Gookin JL, Lappin MR. Evaluation of associations among Coxiella burnetii and reproductive abnormalities in cats. J Feline Med Surg. 2015 May 5. (Winn-funded study)
Coxiella burnetii is the cause of Q fever in humans, a worldwide zoonotic disease. The obligate intracellular bacterium is also associated or potentially associated with reproductive abnormalities in a number of species, cats being one. In humans, Q fever produces a fever and mild flu-like symptoms. Consideration is that some outbreaks of Q fever in people are potentially caused by direct and indirect contact with parturient cats. Abortions associated with Coxiella have been demonstrated in cats, but the organism has been demonstrated from cats after normal births.
The authors’ laboratory demonstrated in a previous study the prevalence of C burnetii DNA in the uterine tissues of client-owned cats at 8.5%. Other infectious causes of abortion can range from viral (panleukopenia virus, feline leukemia virus, feline rhinotracheitis virus) to bacterial (Brucella species, Escherichia coli, Streptococcus species) and to rickettsial sources like C. burnetii. Non-infectious causes involve nutritional deficiencies, endocrine failures and endometrial diseases.
C burnetii diagnosis is made by serologic testing but such testing by determining the presence of antibodies does not distinguish previous exposure from current infection. The organism is difficult to identify by histopathology. This study’s purpose was to determine if C burnetii DNA is associated with inflammatory lesions of the uterus or reproductive abnormalities in cats. Since they wished to evaluate this potential cause of disease in cats by molecular methods, they performed C burnetii PCR assays on reproductive tissues of cattery cats looking for associations with histopathologic findings and clinical history.
In this study, samples of uterine tissue from 37 cats (26 normal cats and 11 cats with hispathological evidence of uterine disease or reproductive abnormalities) were examined for evidence of C burnetii. Three of the 37 samples found amplified DNA consistent with the size of C burnetii but not enough DNA presence to sequence. The three cats testing DNA positive were an 18-mo Tonkinese with pyometra and a history of abortion and early kitten death, a 7-year old Ragdoll with normal uterine histopathology and history of stillborn kittens and early kitten death, and last a 3-year old Ragdoll with normal uterine histopathology and no reproductive abnormalities. In these three PCR-positive cases, C burnetii could not documented by immunohistochemistry. Yet, if the samples were truly positive for C burnetii, the prevalence of 8.1% in this study would be similar to what was found in the prior study.
The authors believe that their results indicate further studies are needed to evaluate what role C burnetii has in reproductive problems in cats. Because Coxiella burnetii is a zoonotic organism and causes Q fever in humans, safety precautions should be considered when attending aborting, parturient cats and neonatal kittens. Precautions would include wearing a mask and gloves during this time. (VT)
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