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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Parasitic Diseases Laboratory » Research » Publications at this Location » Publication #420612
Research Project: Foodborne Parasites and their Impact on Food Safety

Location: Animal Parasitic Diseases Laboratory

Title: First report of acute, visceral, fatal toxoplasmosis in a naturally infected calf (Bos taurus)

Author
item Dubey, Jitender
item JULIAN, ALAN - Idexx Laboratories

Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2024
Publication Date: 12/7/2024
Citation: Dubey, J.P., Julian, A. 2024. First report of acute, visceral, fatal toxoplasmosis in a naturally infected calf (Bos taurus). Veterinary Parasitology. 334. Article e110373. https://doi.org/10.1016/j.vetpar.2024.110373.
DOI: https://doi.org/10.1016/j.vetpar.2024.110373

Interpretive Summary: Food safety is of public health importance. Toxoplasmosis is a parasitic infection that cause death and human suffering and economic losses to farmers. The ingestion of uncooked/undercooked meat is one of the main modes of transmission of the parasite to humans. Among the food animals, sheep, goats, and pigs are more commonly infected than cattle. Cattle are considered resistant to toxoplasmosis and there is no well documentation of clinical toxoplasmosis in cattle. Here the authors report first case of overwhelming toxoplasmosis in a calf from New Zealand. Researchers at ARS pioneered research on control of toxoplasmosis and because of success achieved, the Toxoplasma research was redirected by ARS in 2018 to other food safety problems. This research was performed in 2012, publication was delayed due to relocation of one of the authors (Dr. Julian). The results will be of interest to veterinarians, public health workers, and epidemiologists

Technical Abstract: Cattle are considered resistant to clinical toxoplasmosis and viable Toxoplasma gondii is rarely isolated from bovine tissues. Currently, there is no histologically confirmed case of clinical toxoplasmosis in cattle. Here, the first confirmed case of acute toxoplasmosis in cattle is reported. A calf from New Zealand died of acute toxoplasmosis in 2012. Severe lesions were found in the intestinal mesentery and mesenteric lymph nodes. The mesenteric lymph nodes were edematous, and necrosis affected the entire parenchyma including blood vessels, associated with enormous numbers of tachyzoites. Lesions in liver were inflammatory, affecting periportal areas and central veins. Some hepatocytes were engorged with tachyzoites, and tissue cysts were present in the parenchyma. Focal pneumonitis and nephritis were associated with tachyzoites. Tachyzoites were seen in bronchioles, in renal glomeruli and in renal tubules. Diagnosis was confirmed immunohistochemically using T. gondii specific antibodies, but not Neospora caninum -specific antibodies. The presence of numerous tissue cysts was confirmed by immunohistochemical staining with bradyzoite-specific T. gondii antibodies (BAG1).