Toxoplasma gondii Detection in Urban Hawai´i

Abstract

Feral cats have flourished in urban areas of Hawai´i due to the state's favorable climate and people's positive perception of cats. However, the presence of large numbers of feral cats has raised concern both in terms of predation of native species and as vectors of disease. One disease, in particular, that has aroused a great deal of attention is toxoplasmosis, caused by the Toxoplasma gondii parasite. Cats are the definitive host of T. gondii and concerns arise regarding transmission to humans due to the relationships people have with cats. Another concern is the fact that the parasite has infected endemic and endangered species found in the state. Toxoplasma gondii oocysts are shed in cat excrement and can persist in soil between 1 and 4 years. The presence of T. gondii at cat colony sites could be an important factor when making decisions for the management of feral cats in the state. We intend to test soil samples taken from cat colony sites at the University of Hawai´i at Manoa for T. gondii oocysts using molecular identification methods. Cat colony sites are defined by feeding stations maintained by cat colony caretakers. Given that cats are definitive hosts of T. gondii, we hypothesize that the presence of toxoplasmosis in soil is correlated to cat colony locations. Because most cats within a colony remain in close proximity to their feeding location, we predict that toxoplasmosis is spatially contained within tight proximity to cat colonies. If T. gondii oocysts are present in soil at the University of Hawai´i at Manoa, then cat colonies may cause potential health hazards for landscaping personnel, students, staff, and visitors.