Recent evidence for epidemiologic significance of Toxoplasma gondii infections in turkeys, ducks, ratites, and other wild birds: 2009-2020

Authors: Dubey, Jitender; MURATA, F.H.A. - Non ARS Employee; CERQUEIRA-CEZAR, C.K. - Non ARS Employee; Kwok, Oliver; SU, C. - University Of Tennessee

Submitted to: Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/12/2020
Publication Date: 1/1/2021
Citation: Dubey, J.P., Murata, F., Cerqueira-Cezar, C., Kwok, O.C., Su, C. 2021. Recent evidence for epidemiologic signifcance of Toxoplasma gondii infections in turkeys, ducks, ratites, and other wild birds: 2009-2020. Parasitology. 148(1):1-30. https://doi.org/10.1017/S0031182020001961.
DOI: https://doi.org/10.1017/S0031182020001961

Interpretive Summary: Food safety research is of paramount importance for agriculture and the public. Foodborne protozoon infections are a leading cause of death from foodborne illness in the United States, especially for individuals with weak immune systems such as children and HIV patients. USDA research in this area has borne undeniable results – including helping to cut the prevalence of Toxoplasma gondii by as much as 50 percent in the United States. The USDA provided the veterinary, clinical, and public health communities an indispensable resource by disseminating up to date scientific information on toxoplasmosis and its prevention. Humans become infected mostly by ingesting food and water contaminated with oocysts or by eating infected under cooked meat. Wild and domestic birds are excellent sentinels of environmental contamination with T. gondii oocysts because herbivorous birds feed from the ground, and birds of prey consume hundreds of rodents and other small mammals that are important intermediate hosts of T. gondii. Migratory birds (penguins, geese and others) can transport the parasite across seas. Some species (turkeys, geese, ducks, ostriches) are part of food supply for humans. The authors have reviewed T. gondii infections in wild birds. This information will support veterinarians, physicians, and federal agencies seeking to advance additional research needed in this area regarding human health.

Technical Abstract: Toxoplasma gondii infections are common in humans and animals worldwide. Wild and domestic avian species are important in the epidemiology of T. gondii infections because felids prey on them and excrete millions of oocysts in the environment, disseminating the infection. Herbivorous birds are also excellent sentinels of environmental contamination with T. gondii oocysts because they feed from the ground. Toxoplasma gondii infections in birds of prey reflect infections in intermediate hosts. Humans can become infected by consuming undercooked avian tissues. Here, the authors reviewed prevalence, persistence of infection, clinical disease, epidemiology, and genetic diversity of T. gondii strains isolated from avian species (excluding chickens) worldwide 2009-2020. Genetic diversity of 102 T. gondii DNA samples isolated worldwide is discussed. The role of migratory birds in dissemination of T. gondii infection is discussed. This paper will be of interest to biologists, epidemiologists, veterinarians and parasitologists.