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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 #319937


Location: Animal Parasitic Diseases Laboratory

Title: Toxoplasmosis in sentinel chickens (Gallus domesticus) in New England farms: seroconversion, distribution of tissue cysts in brain, heart, and skeletal muscle by bioassay in mice and cats

item Dubey, Jitender
item LEHMANN, TOVI - Centers For Disease Control And Prevention (CDCP) - United States
item LAUTNER, FRED - Retired Non ARS Employee
item Kwok, Oliver
item GAMBLE, RAY - National Academy Of Sciences - United States

Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2015
Publication Date: 11/30/2015
Citation: Dubey, J.P., Lehmann, T., Lautner, F., Kwok, O.C., Gamble, R. 2015. Toxoplasmosis in sentinel chickens (Gallus domesticus) in New England farms: seroconversion, distribution of tissue cysts in brain, heart, and skeletal muscle by bioassay in mice and cats. Veterinary Parasitology. 214:55-58.

Interpretive Summary: Toxoplasmosis is a parasitic infection of humans and animals and it continues to be public health, responsible for approximately 24% of all estimated deaths attributed to foodborne pathogens in the U.S. People become infected with T. gondii by consuming infected uncooked meat, or by ingesting food and water contaminated with the environmentally resistant stage of the parasite excreted by cats. Pigs, sheep, and goats are considered the main meat source of T. gondii infection in humans. Little is known of the role of chickens as source of infection for humans. In the present papers authors indicate that T. gondii persists in meat of naturally acquired toxoplasmosis in chickens. The results will be of interest to biologists, parasitologists, veterinarians, and epidemiologists.

Technical Abstract: Free-range chickens are a good indicator of soil contamination with oocysts because they feed from the ground and they are also an important source of infection for cats that in turn shed oocysts after eating tissues of intermediate hosts. Little is known of the epidemiology of toxoplasmosis in chickens. In the present study 90 Toxoplasma gondii seronegative, sentinel chickens were placed on three (30 each) swine farms in New England in November, 2003. Chickens were bled monthly and their sera were tested for T. gondii antibodies by the modified agglutination test (MAT, cut-off 1:25). Chickens that seroconverted were euthanized and their tissues were bioassayed in mice, cats, or both. Over the course of the experiment (7 months), 31 of 71 chickens seroconverted (MAT 1:100 or higher); three chickens after one month, eight chickens after two months, five chickens after three months, two chickens after four months, one chicken after five months, and seven chickens after six months. Nineteen chickens were lost from farms by the termination of the experiment in July 2004. Tissues of 26 seropositive chickens were bioassayed in both cats and mice; viable T. gondii was isolated, by bioassay in mice, from hearts (whole) of all 26 chickens, brains (whole) of 3 chickens and leg muscles (25g) of 11 chickens; 21 of 26 cats fed 250 g of muscle from seropositive chickens excreted T. gondii oocysts. Results indicated that the density of T. gondii in poultry muscle is low but heart is the tissue of choice for isolation of viable parasites.