The need for a One-health approach against zoonosis risk has been recognized in recent years. Based on an understanding of the human-animal-ecosystem transmission process of zoonotic diseases, the One-health approach attempts to intervene in the transmission cycle of zoonotic diseases in the field, for example, through wildlife, livestock and ecosystem management, in order to reduce the risk of infectious diseases in humans. Until now, infectious disease control has mainly involved medical measures such as treatment and vaccine prophylaxis, but the One-health approach is expected to be a new option for infectious disease control.
In this presentation, we show the transmission process of the feline zoonosis Toxoplasma gondii in the field on Tokunoshima Island, Kagoshima Prefecture, and discuss the practical possibility of a One-health approach.
In this island, predation of free-ranging cats on endangered species such as the Amami rabbit has become a problem. It has been revealed that the problem is caused by cats subsidized by human residents mainly in cattle barns for rat control, which, in turn, invade forests inhabited by endangered species. On the other hand, seropositivity rates of the Toxoplasma gondii in free-ranging cats and black rats were found to be high, averaging 49% and 69.5%, respectively, and in areas where there were many cattle barns, both cats and rats had extremely high antibody retention rates of over 80%. In addition, the seropositivity rate in cats was found to be higher where the density of rodents was higher. These results indicate that the use of cats for rat control could increase the risk of Toxoplasmosis infection. In order to reduce this risk, we need to shift away from the customary perception of using cats for rodent control, and stop feeding cats, which causes the high density of free-ranging cats on the islands. This could also help solve the problem of cat predation on endangered species.