Trypanosomiasis Caused by Trypanosoma evansi in Indonesia

抄録

It is possible that Trypanosoma evansi was introduced into Indonesia at the end of the 19th century since records of the occurrence or disease date from this time. Trypanosomiasis caused by T. evansi (“surra”) is considered to be one of the most important parasitic diseases of domesticated livestock in lndonesia and occurs in most of the islands, including Irian Jaya. Trypanosoma evansi infections in buffalo and cattle are usually chronic or asymptomatic, and result in production losses, including reduced draught power. However, acute cases leading to sudden death have been reported, and occasional epidemics with a high death rate do occur. Infections in horses, which are the livestock species most susceptible to infection with T. evansi, are usually fatal, but surra in this species appears to be of importance only in Sulawesi. The abundance of biting flies throughout the Indonesian archipelago facilitates transmission of T. evansi, and the extensive movements of livestock over recent years within and between the islands have no doubt assisted in its dissemination. Trypanosoma evansi infects wild animals as well as domesticated species and it is possible, though not proven. That certain mammals, such as wild deer, act as reservoirs of infection.
Control of the disease requires identification of the infected animals, and in the field, parasitological diagnostic techniques involving microscopical examination of wet blood films, together with examination of Giemsa’s stained blood smears (thick or thin) are widely used. A number of serodiagnostic tests have been used for screening animals, including fluorescent antibody tests, card agglutination tests, and enzyme immunoassays to detect trypanosomal antibodies or antigen. These techniques have not been widely applied however, although they have been shown to have a higher sensitivity than parasitological techniques, and have been used in preliminary studies in controlling infection in animals at risk. Serological tests have given a more comprehensive indication of the distribution of surra, the prevalence in different areas, the risk from infection, and the economic impact of the disease. Control of surra has been directed at the treatment of clinical cases or prevention of disease outbreaks by prophylactic treatment of animals at risk. For many years, suramin has been the mainstay of treatment for surra in cattle, buffaloes and horses in Indonesia as it has both a curative and a prophylactic action. Not surprisingly, the long term use of a single drug has elicited the appearance of drug resistant stocks, but there is no indication of the extent of the problem. Diminazene aceturate has been shown effective in control of infections in buffalo in Central Java; isometamidium chloride appears to be less effective, although it has not been widely tested.