Littermate cats rescued from a shelter succumbed to acute, primary toxoplasmosis associated with TOXO DB genotype #4, generally circulating in wildlife

Authors: CROUCH, ESTHER - Cornell University; MITTEL, LINDA - Cornell University; SOUTHARD, THERESA - Cornell University; CERQUEIRA-CEZAR, CAMILA - Non ARS Employee; MURATA, FERNANDO - Non ARS Employee; Kwok, Oliver; SU, CHUNLEI - University Of Tennessee; Dubey, Jitender

Submitted to: Parasitology International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/14/2019
Publication Date: 10/1/2019
Citation: Crouch, E.E., Mittel, L.D., Southard, T.L., Cerqueira-Cezar, C.K., Murata, F.H., Kwok, O.C., Su, C., Dubey, J.P. 2019. Littermate cats rescued from a shelter succumbed to acute, primary toxoplasmosis associated with TOXO DB genotype #4, generally circulating in wildlife. Parasitology International. 72(2019):101942. https://doi.org/10.1016/j.parint.2019.101942.
DOI: https://doi.org/10.1016/j.parint.2019.101942

Interpretive Summary: Toxoplasmosis, caused by the single celled parasite, Toxoplasma gondii, continues to be a public health problem worldwide. This parasite infects all warm-blooded hosts, including humans. It causes mental retardation and loss of vision in children, and abortion in livestock. The ingestion of food and water contaminated with resistant stage of the parasite, the oocyst, is a major mode of transmission of this parasite. Of all the hosts infected, only cats are known to excrete oocysts in feces. Cats can excrete millions of oocysts after eating an infected prey, such as a mouse or a bird. Oocysts can survive outdoors for months and they are highly infectious to humans. Clinical toxoplasmosis in cats is relatively rare. Here, authors report sudden death in littermate kittens that were in Humane Society Shelter and had been adapted. Histological evidence suggested that kittens acquired toxoplasmosis recently and probably excreted Toxoplasma oocysts. Precautions for handling Toxoplasma infected cats and oocysts are outlined. These results will be of interest to biologists, veterinarians and parasitologists.

Technical Abstract: Cats are important in the epidemiology of Toxoplasma gondii infection because they are the only hosts that can excrete the environmentally resistant oocysts in the environment. Although exposure is common (approximately 30% of cats in the USA), clinical toxoplasmosis is relatively rare. Here, we report overwhelming disseminated toxoplasmosis in two litter mate 8-week-old kittens, thought to have acquired toxoplasmosis postnatally. Five domestic shorthair kittens, approximately 2-3 weeks of age, and the queen were found in upstate New York by a rescue group in spring of 2018. The kittens and queen were placed in a foster home for approximately 4-5 weeks and then transferred to a shelter. Two kittens died unexpectedly following a short illness. Postmortem examination of the two deceased kittens revealed overwhelming toxoplasmosis and the presence of entero-epithelial stages in small intestine, suggestive of recent ingestion of infected tissues. Antibodies to T. gondii were found in the deceased kittens and the queen but not in the three asymptomatic littermate kittens. No obvious cause of immunosuppression was demonstrated. Genetic typing of T. gondii from DNA extracted from liver and lungs of both kittens revealed Toxo DB #4 genotype, commonly found in wildlife. Owners and veterinarians should be aware of dangers of feeding raw meat to cats and contact with infected cat feces. Procedures to safely handle T. gondii infected feces in hospital setting are outlined.