Researchers from the Centre d’Écologie Fonctionnelle et Évolutive (CNRS/Université de Montpellier/Université Paul Valéry Montpellier 3/EPHE) in France have shown that chimpanzees infected with toxoplasmosis are attracted by the urine of their natural predators, leopards, but not by urine from other large felines. The study, published in the February 8, 2016 issue of Current Biology, suggests that parasite manipulation by Toxoplasma gondii is specific to each host. The article is titled “Morbid Attraction to Leopard Urine in Toxoplasma-Infected Chimpanzees.” The new result fuels an ongoing debate on the origin of behavioral modifications observed in humans infected with toxoplasmosis: they probably go back to a time when our ancestors were still preyed upon by large felines. Parasites such as those that cause toxoplasmosis take various pathways, some of them complex, in order to develop into their adult form and reproduce in a so-called definitive host. These pathways may include stages consisting in the infection of an intermediary host. In order to pass from one such host to another, some parasites are able to induce behavioral changes in their hosts. However, this process, known as parasite manipulation, is rarely observed in mammals. The agent of toxoplasmosis, Toxoplasma gondii, is an exception. This protozoan, which infects a wide range of species including humans, can only reproduce in felines, which become infected by ingesting a parasitized prey. Studies on mice have shown that this parasite induces olfactory modifications in parasitized rodents: unlike healthy individuals, parasitized mice appear to be attracted by the odor of cat urine, thus making it more likely for the parasite that its intermediate hosts, mice, are eaten by cats, a definitive feline host.Login Or Register To Read Full Story