Prevalence of antibodies to Toxoplasma gondii in wild birds in Portugal

Authors: LOPES, CAROLINA - University Of Tras-Os-montes And Alto Douro; BRANDAO, RICARDO - Collaborator; LOPES, ANA FILIPA - Collaborator; SARGO, ROBERTO - University Of Tras-Os-montes And Alto Douro; CASERO, MARIA - Collaborator; NUNES, CAROLINA - Collaborator; SILVA, FILIPE - University Of Tras-Os-montes And Alto Douro; Dubey, Jitender; CARDOSO, LUIS - University Of Tras-Os-montes And Alto Douro; LOPES, ANA PATRICIA - University Of Tras-Os-montes And Alto Douro

Submitted to: Pathogens
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/1/2021
Publication Date: 9/5/2021
Citation: Lopes, C., Brandao, R., Lopes, A., Sargo, R., Casero, M., Nunes, C., Silva, F., Dubey, J.P., Cardoso, L., Lopes, A. 2021. Prevalence of antibodies to Toxoplasma gondii in wild birds in Portugal. Pathogens. 10:1144. https://doi.org/10.3390/pathogens10091144.
DOI: https://doi.org/10.3390/pathogens10091144

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. Here, authors report T. gondii antibodies in several species of wild birds from different regions of Portugal. This information will support veterinarians, physicians, and federal agencies seeking to advance additional research needed in this area regarding human health. This research was conducted before the redirection of ARS research on toxoplasmosis.

Technical Abstract: Toxoplasma gondii is a worldwide zoonotic parasite. According to the “One Health” approach, studies on toxoplasmosis are essential since it affects humans, domestic and wild animals. In the present study, antibodies to T. gondii were determined in serum samples from 263 wild birds 27 located in five wildlife rehabilitation centers in mainland Portugal by using the modified agglutination test (MAT) with a cut-off titer of 20. An overall seroprevalence of 36.5% (95% confidence interval [CI]: 30.7'42.6) was observed. For the first time, antibodies to T. gondii were detected in some avian species, including pallid swift (Apus palidus) (33.3%), black-backed gull (Larus fuscus) 31 (39.3%), European turtledove (Streptopelia turtur) (100%), bee-eater (Merops apiaster) (50.0%), carrion crow (Corvus corone) (33.3%) and Egyptian vulture (Neophron percnopterus) (100%), which expands the list of intermediate hosts of T. gondii. A lower seroprevalence was found in juvenile birds (31.9%) compared to adults (48.7%) (p = 0.016). The central region of Portugal was considered a risk factor for T. gondii infection in wild birds (odds ratio: 3.61; 95% CI: 1.09–11.91). This study suggests a considerable degree of environmental contamination by T. gondii in Portugal and underlines the importance of conducting future studies to improve the control and prevention of this zoonosis.