Toxoplasma gondii

  • Toxoplasmosis in Deer: Feral Cats Spread the Parasite , Buck Mananger, Jan 12, 2016Hunters are often concerned about feral hogs impacting a local deer herd, but feral cats? Well… it turns out that free-ranging house cats are doing more out in the woods than just killing mice and raiding songbird nests. Feral cats are also spreading parasites to white-tailed deer, other animals and maybe even to you. The problem is toxoplasmosis, a parasitic disease caused by the protozoan Toxoplasma gondii.
  • Congenital transmission of Neospora caninum in white tailed deer (Odocoileus virginianus). Vet Parasitol. 2013Neosporosis is an important cause of bovine abortion worldwide. Many aspects of transmission of Neospora caninum in nature are unknown. The white-tailed deer (Odocoileus virginianus) is considered one of the most important wildlife reservoirs of N. caninum in the USA. During the hunting seasons of 2008, 2009, and 2010, brains of 155 white-tailed deer fetuses were bioassayed in mice for protozoal isolation. Viable N. caninum (NcWTDMn1, NcWTDMn2) was isolated from the brains of two fetuses by bioassays in mice, and subsequent propagation in cell culture. Dams of these two infected fetuses had antibodies to N. caninum by Neospora agglutination test at 1:100 serum dilution. DNA obtained from culture-derived N. caninum tachyzoites of the two isolates with Nc5 PCR confirmed diagnosis. Results prove congenital transmission of N. caninum in the white tailed deer for the first time.
  • Study: Dangerous Cat Parasites May Be Infecting Deer, Outdoorhub, Jan 7, 2015When it comes to the host of dangers that wild deer face, few people think of feral cats. However, a study by researchers at Ohio State University found that feral cats may be responsible for the presence of a dangerous parasite in deer called Toxoplasma gondii. According to the study, which was recently published in the journal Ecohealth, the number of deer infected with the parasite coincided with the number of wild cats in their area. Researchers collected samples from over 400 whitetail deer in the Cleveland, Ohio area and found that almost 60 percent of the animals showed signs of infection. Comparatively, 200 wild cats in the region were tested for the parasite and over 65 percent of the felines were afflicted with the parasite.

    “This study documents the widespread infection of deer populations in northeastern Ohio, most likely resulting from feral cats, and highlights the need for consumers of venison to make absolutely certain that any deer meat planned for consumption is thoroughly and properly cooked.
  • Deer, cats don’t mix in NE Ohio, Ohio Outdoor News, Jan 2015Washington, D.C., — A new peer-reviewed study published in the journal EcoHealth has found that a large percentage of the Greater Cleveland area’s white-tailed deer – a species widely hunted and harvested by thousands of sportsmen throughout the U.S. – is infected with a parasite associated with feral domestic cats. According to the study, the “difference between urban and suburban cat densities is the most likely reason for an increased (prevalence of infection) in urban white-tailed deer.”
    The authors went on to say that “these data have public health implications for individuals living near or visiting urban areas where outdoor cats are abundant as well as those individuals who may consume white-tailed deer venison.” Although human infection by the T. gondii parasite is often associated with improperly cooked meat, the staggering growth in the number of free-roaming cats is increasingly viewed as a key transmission vector in the U.S.
  • Parasite infects more than half the deer in NE Ohio; cats the primary carriers, per OSU study,, Dec 30,2014A common but relatively unpublicized parasite infects more than half the white-tailed deer in Northeast Ohio, and more than 65 percent of free-roaming cats tested, according to a recently released Ohio State University study. Symptoms of toxoplasmosis infection vary, according to the Centers for Disease Control and Prevention. Most people who are infected are not aware of it. Some victims may feel flu-like symptoms with swollen lymph glands or muscle aches and pains that last for a month or more. In severe cases, toxoplasmosis can cause brain or eye damage.
  • Study Finds Feral Cats Likely Driving Disease Among Deer, The Wildlife Society, December 27, 2014. gondii is a parasitic protozoan that can infect all warm-blooded species but relies on felids to complete its life cycle. According to a new study published in EcoHealth, feral cats are likely driving white-tailed deer (Odocoileus virginianus) infections in northeastern Ohio (Ballash et al. 2014). Cats that host T. gondii excrete oocysts into the environment in their feces, and a single cat can deposit hundreds of millions of oocysts, which may remain infectious for up to 18 months
  • Seroprevalence of Toxoplasma gondii in White-Tailed Deer (Odocoileus virginianus) and Free-Roaming Cats (Felis catus) Across a Suburban to Urban Gradient in Northeastern Ohio, EcoHealth, Oct 1,2014Results indicate White-Tailed Deer are exposed by horizontal transmission, and this occurs more frequently in urban environments.
  • Occurrence, isolation, and genetic characterization of Toxoplasma gondii from white tailed deer (Odocoileus virginianus) in New Jersey. , Journal of Parasitology, Oct 2013White tailed deer (WTD) is an important reservoir host for Toxoplasma gondii. Each yr hundreds of thousands WTD are hunted or die in road accidents in the U.S.A. Humans and animals can become infected with T. gondii by eating infected venison. Wild felids that eat infected deer tissues can shed oocysts and contaminate the environment. In the present study, we tested 264 WTD from New Jersey for T. gondii infection during the 2011-2012 hunting season. Serum samples were tested for antibodies to T. gondii by the modified agglutination test starting at 1:25 serum dilution; 76 (28.7%) of 264 WTD were seropositive. Heart muscle samples from 64 seropositive WTD were digested in pepsin and the digests were bioassayed in mice for the isolation of T. gondii. Viable T. gondii was isolated from the myocardium of 9 WTD; tachyzoites from infected mouse tissues were further propagated in cell culture. One of the 9 strains was virulent for outbred mice Swiss Webster mice. The DNA isolated from culture-derived tachyzoites of these 9 T. gondii isolates was characterized using 11 PCRRFLP markers (SAG1, 5’- and 3’-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). Six genotypes were found, including ToxoDB genotype #2 (Type III), #3 (Type II variant), #4 (Type 12), #216, #220 and #221. The latter 2 were new genotypes that were reported for the first time. This is the first report of T. gondii infection in deer from this region of the U.S.A.
  • Prevalence of antibodies to Toxoplasma gondii in white-tailed deer (Odocoileus virginianus) in New York State, USA, Journal of Wildlife Disease, Oct 2013Abstract- White-tailed deer are a useful sentinel for risk of human and domestic animal exposure to Toxoplasma oocysts and pose a potential risk for infection to humans and other animals by ingestion of the meat. White-tailed deer share grazing space with domestic animals raised for meat and are likely to be exposed by horizontal transmission through oocyst consumption, similar to other grazing species of economic concern.
  • Surveillance for Toxoplasma gondii in the white-tailed deer (Odocoileus virginianus) in Ohio
    , The Ohio Journal of Science, June, 1999 This is the first report of T.gondii antibodies from a game animal in Ohio. Pregnant women should thoroughly
    cook venison before it is consumed to avoid complications from this pathogen.

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