Animal reservoirs of Toxoplasma gondii : An update in France

Abstract

Toxoplasmosis is a disease widely distributed throughout the world. It is caused by Toxoplasma gondii, a protozoan parasite, having the Felidae as final host (the cat) and warm-blooded vertebrates as intermediate hosts. Human infection is mainly orally, either by the ingestion of oocysts excreted with the cat faeces or by ingestion of tissue cysts which may be present in a wide variety of meat products. Direct transmission from a cat to its owner is probably less common; however the cat population represents the main source of environmental contamination. In France, nationwide studies that have been conducted in fresh mutton, beef and pork meat intended for human consumption, have highlight a seroprevalence of Toxoplasma gondii which varies according to animal species and age from 2.46% for piglets to 69.5% for adult sheep. The role of wildlife as hosts of the parasite should also to be considered in the epidemiology of toxoplasmosis firstly as a vector and secondly as a potential human source of contamination. In French Guyana, the hypothesis of the existence of a wild cycle of Toxoplasma gondii has been present for the last several years, involving the wild felids and their prey, mammals and birds, some of which beeing hunting products for humans.