Leishmaniasis is a widespread protozoan disease in the New World from southern parts of USA at the north to northern parts of Argentina at the south. The disease is principally divided into three forms, i.e., cutaneous, mucocutaneous and visceral leishmaniasis, mainly based on the clinical manifestations in patients and on the species of the causative agents, Leishmania. The leishmaniases are well known as a considerable public health problem in endemic areas of the disease in the New World, except Canada, Chile and Urguay where no such a disease occurs. In this review, an attempt was made to understand a global situation of the epidemiology of the New World leishmaniases, laying an emphasis on the pick-up of known endemic areas, vectors and reservoir hosts of different species of the genus Leishmania in each country. From the information published hitherto, it was found that an intensive leishmaniasis research has been made in Central and South American countries, such as Belize, Panama, Venezuela and Brazil. The study, however, was poorly done in many other countries of the New World, without limiting endemic areas or deciding vectors and reservoir hosts of the disease. In the present text, the author emphasized on a future research importance of epidemiological characteristics including the transmission mode of New World leishmaniases, in order to search for suitable control measure in each endemic area of different countries. Most of the transmission of leishmaniasis in the New World have been found in dense tropical rain forests with various species of Leishmania, sand flies and mammals as shown in Table 1. In such circumstances of endemic areas of leishmaniasis in the New World, the difficulty of the prophylaxis and control has frequently been pointed out by several investigators. At the present situation of leishmaniasis research without a suitable vaccine and sufficient epidemiological data, ones have commented that the only control measure for New World leishmaniasis is to remove all the inhabitants of communities from regions at risk of the disease, or to perform thoroughly deforestrations around dwelling areas or working places. Past trials of several control measures, such as the spraying of insecticides, destruction of reservoir hosts, application of some vaccines and etc. were also briefly reviewed in this text.

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In two Ecuadorian endemic areas of Chagas' disease, Pedro Carbo in coastal low-land and Zaruma in high-land of the Andes, a seroepidemiological survey of the human infection and a search for reservoir hosts were performed during the period between June 1983 and March 1984.
Indirect hemaggultination (IHA) test-positive rate of inhabitants was 4.3 per cent (10/233) in Pedro Carbo, and 15.5 per cent (67/433) in Zaruma. The positive rate of high school students was 2.2 per cent (10/446) and 3.9 per cent (12/305) in each area, respectively.
Trypanosoma cruzi was found in two species of peridomestic mammals, Didelphis marsupialis (opossum) and Dasypus novemcinctus (armadillo). The infection rate of D. marsupialis was 25.0 per cent (17/68) in Pedro Carbo and 18.5 per cent (5/27) in Zaruma. Only one of the 70 babies from pouch of D. marsupialis examined was found to be positive for T. cruzi, though the mother and the other litter mates were negative for the flagellata. One of four D. novemcinctus was positive for the parasite in Zaruma. No trypanosome was recognized in all the rodents and bats examined. The result suggests that D. marsupialis is the principal reservoir host of Chagas' disease in various endemic areas of Ecuador.

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Extrapulmonary infection or heterotopic parasitism caused by the genus Paragonimus in the human body is well documented in case reports. Here, two cases of abdominal paragonimiasis were reported. In case 1, a patient was an 81-year-old Japanese female, who complained of epigastric pain, and received the laparatomy with a diagnosis of cecum cancer. After the operation, many eggs were found in the excised nodules around the greater omentum and were identified as those of the Paragonimus species on the basis oftheir size and shape. In a second patient, a 64-year-old Japanese female, who complained of stomach discomfort, the laparatomy was performed with a diagnosis of gastric cancer, and many Paragonimus eggs were also discovered in the excised nodules around the greater omentum. These cases were regarded as ectopic parasitism of the Paragonimus species. But, the name of species could not be determined, because no adult flukes were found in the contents of the nodules.

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Vietnamese refugees seem to be a unique population in Japan, because of their possible high frequency in parasitic infections. The precise knowledges on the health status of these people are important from the public health point of view. The present contribution deals with the parasitological survey on Vietnamese refugees (51 cases) who are temporarily staying in Gose Catholic Church, Nara Prefecture, Japan.
The feces were examined for the eggs of intestinal helminth by the thick smear method, formalin-ether sedimentation method (MGL method), Harada and Mori's cultivation method and floatation technique (using saturated sodium chloride solution). Twenty-one refugees out of 51 (41.2%) were infected with one or more intestinal helminth species. A variety of helminth infections were detected, including Ascaris lumbricoides infection (31.4% in infection rate), hookworm (5.9%) Trichuris trichiura (3.9%) and Trichostrongylus sp. (2.0%). In this population, 28 cases were examined peripheral blood smear. All of these cases were negative for Plasmodium ssp. Both the number of peripheral eosinophils and serum IgE level correlated with incidence of hookworm and T. trichiura infections. Thus the unusually high frequency of intestinal parasitic infection in Vietnamese refugees compared with Japanese community strongly recommends clinical examination and treatment for new-coming Vietnamese refugees.

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