Several areas in Japan where people suffered from life threatening diseases of unknown origin have occurred in the past. In 1904, Profs. F. Katsurada and A. Fujinami discovered Schistosoma japonicum the causative agent of schistosomiasis. In 1909, Prof. K. Miyairi and Dr. M. Suzuki discovered the intermediate snail host Oncomelania nosophora. Afterwards, two scientists from Britain visited Japan and confirmed these discoveries. They then started investigations on the intermediate host snails Schistosoma haematobium and Schistosoma manasoni in Africa and the near East. These discoveries and other efforts made possible the beginning of schistosomiasis control. Schistosomiasis japonica was finally eradicated from Japan through medical treatment and the use of molluscicides in 1996. This was the first eradication of schistosomiasis on a large scale. Today, approximately 0.2 billion people are estimated to still be infected with schsitosomes in the world.

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The main endemic areas of schistosomiasis japonica in Japan were three sites in Yamanashi Prefecture, Hiroshima Prefecture and Fukuoka/Saga Prefectures, and ubiquity of distribution is governed by the intermediate host Oncomelania nosophora. The presenter has to date, undertaken to clarify these factors that govern distribution through the implementation of local surveys and breeding experiments. In Japan, numerous direct and indirect eradication measures were implemented immediately after the discovery of O. nosophora. These measures resulted in the declaration of safety being made in relation to the Kofu Basin in 1996, and in Japan, schistosomiasis was thought to have ended. However, since O. nosophora still inhabit the Kofu Basin, etc. the monitoring of habitation status is important. Consequently, with regards to the Kofu Basin, working with habitation density distribution maps from the end of the 1960s and around 2000, GIS was used to clarify the range of distribution and changes in habitation density. From Japan's satellite images, paddy fields were isolated, and by combining the range of risk areas with various maps, the areas that should be monitored for O. nosophora were isolated. We are currently establishing more effective monitoring systems by implementing local surveys using GPS remote sensing using satellite images.

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Epidemiological records were not reported before the discovery of the causative agent Schistosoma japonicum. The first comprehensive epidemiological survey was conducted in 1911. Out of 69,131 patients, 7,893 were recorded to have a high infection rate of 11.4%. Countermeasures for snail control since 1909 when the intermediate snail host was discovered are historically divided into three stages. The first stage was from 1913 when the life history of the parasite was elucidated to the end of the World War II in 1945. In 1916, Yamanashi Prefecture provided funds for the systematic control of the disease including snail control. In 1924, molluscicides of lime were introduced. In 1932, the Japanese government created a law to support parasite control. The second stage was from 1946 after the end of the World War II to eradication in 1996. During occupancy, the United States army started surveys and instructional programs. Na-PCP was introduced and used until 1971 when it was incriminated as a water pollution agent. Starting in 1950, cementing of rice paddy ditches was shown effective so an official fund of 11 billion yen was provided until 1985. In 1996 Yamanashi Prefecture finally declared the area safe with cessation of the epidemic. The third stage was from 1997 when the disease was not reported anymore and vigilant activities continue to examine possible infections from the snails till date. Now the snail survives and even proliferates in the Kofu Basin without infection.

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Schistosoma japonicum is currently endemic in Asian countries, especially China and the Philippines. Endemic foci in China are located in two cities and 7 provinces along the Yangze river and known to still be actively endemic. The intermediate snail hosts Oncomelania hupensis hupensis and O. h. robertosoni are both subspecies of snails distributed in Japan. From the viewpoint of disease control, the Chinese situations are much more difficult than those in Japan, because of environmental factors observed with seasonal changes in water levels of the Yangze river. Endemic foci in China are divided into three types according to the geographical areas, namely marshland type, water canal type and hHilly type. In each endemic focus, countermeasures should be planned considering the vegetation, soil content and agricultural environment. The Chinese government decided to implement nation-wide activities aimed to eradicate schisotosomiasis no later than 2020. For this purpose, comprehensive control activities are being strategically carried out. Those activities must be monitored to determine whether the outcomes are successful. Together with those activities, new tools for disease control are being intensively introduced in endemic areas of China. In his review, currently implemented control activities in China are described and future prospects of the disease endemicity is discussed.

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Schistosomiasis mekongi is endemic in the Mekong river basin from Khong Island in southern Laos to 200 km downstream in Kratie of eastern Cambodia. The intermediate host snail of Schistosoma mekongi is a tiny hydrobiid snail Neotricula aperta consisting of three races (α, β and γ). The γ-N. aperta race is known to be naturally infected and epidemiologically significant. Transmission of the disease in the Mekong river basin occurs during the low-water period, only a few months in March, April and May. Inhabitants of the lower Mekong tend to rise early to bathe, defecate, wash and work on the river bank, children join their parents.
This paper on Mekong schistosomiasis and the intermediate host snail in the Mekong region consists of discussion on the parasitic disease in the past, present epidemiology, malacology, transmission dynamics, control implementation, application of immunodiagnosis for epidemiology and difference in the schistosomiasis problems of Laos and Cambodia.

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Thirty years after the eradication of schistosomiasis japonica from Japan, schistosomiasis still remains a huge burden for people living in rural Africa. Since humans are practically speaking the main host of African schistosomiasis and most victims are school-age children, the current approach to control the disease focuses on providing treatment for children. However, other approaches such as hygiene, clean water and sanitation should also be included to prevent transmission. These approaches were some of the methods Japan implemented for success in eradication of the disease.

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Although praziquantel is an excellent anti-schistosomaiasis medicine, the selection of time for treatment is very important. Treatment of patients should be avoided when infection occurs. Surveys were carried out in two adjacent villages, Mwachinga and Mtsangatamu Villages. In these areas, two rainy seasons, a long rainy season from April to June and a short rainy season in November, occur each year. Mwachinga Village is located on a dry hill and snails infected with Schistosona haematobium are mainly collected between October and February. On the other hand, Mtsangatamu Village is located on the slopes of wooded hills, and infected snails are mainly collected between March and May. The removal of intermediate snails from the riverbed during the dry season was used as a measure for disease control in Mwachinga Village. The river in Mtsangatamu Village is a swamp because of slow water flow, so a trench was dug in the center of the river to increase the flow rate. Significant decreases in the number of intermediate snails were observed in both areas.

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The utility of cytochrome c oxidase subunit I (COI) DNA barcoding for the identification of 37 mosquito species belonging to the genera Anopheles (6 spp.), Aedes (14 spp.) and Culex (17 spp.) including subspecies from nine islands of the Ryukyu Archipelago, Japan was examined. A 658 bp fragment of the COI gene was sequenced from 228 specimens. Nucleotide sequence divergences were calculated using the Kimura-two parameter (K2P) distance model and a neighbor-joining (NJ) phylogenetic tree analysis was performed to provide a graphic display of the patterns in divergence among species. The mean intraspecific variations of 35 species including the medically important vector species showed a less than 2% range with 0–1.5% divergences, but higher divergences of more than 2% were detected in Ae. aureostriatus okinawanus Bohart (2.2%) and Cx. hayashii ryukyuanus Tanaka et al. (3.3%). They showed differences in divergence between specimens from different islands. All 37 species were discriminated as distinct clusters in the NJ tree. The results in this study prove the utility of DNA barcoding for identification of mosquitoes from the Ryukyu Archipelago, Japan.

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A new genus Lehisca gen. nov.is established with a new species L. cameroni sp. nov. The new species is described based on specimens of both sexes collected from the montane forest of Cameron Highlands in Malaysia. The combination of morphological characters and the result of molecular analysis suggested this new species belongs to a distinct genus of the tribe Sarcophagini. This new genus has the combination of external and genitalic characteristics in both sexes. It is easily distinguished from the other genera of the tribe by having only two strong sternopleural bristles and the shape of male and female genitalia.

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A genetic tree of the Japanese species of the genus Polypedilum (Chironomidae: Diptera) was constructed based on the DNA sequences of mitochondrial cytochrome oxidase I region. P. (Polypedilum) tamanigrum Sasa and P. (Po.) okiflavum Sasa; P. (Po.) tamahosohige Sasa and P. (Po.) sp.; and P. (Po.) pedestre (Meigen) and P. (Po.) tamaharaki Sasa each constructed a small cluster. However, P. (Po.) nubifer Skuzeand P. (Tripodula) unifascium (Tokunaga); P. (Po.) nubeculosum (Meigen) and P. (T.) decematoguttatum (Tokunaga); P. (Po.) takaoense Sasa and P. (Uresipedilum) hiroshimaense Kawai et Sasa; and P. (Po.) kyotoense (Tokunaga) and P. (U.) tamasemusi Sasa each constructed a small cluster despite the combinations of different subgenera. In addition, 3 species of the subgenus Pentapedilum each occurred in distinct clusters. These results suggest that a remarkable convergence has occurred among a wide range of species of Polypedilum and that the present taxonomic systems should be reconstituted in order to reflect evolutionary processes.

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Culex pipiens pallens is a member of the Cx. pipiens complex in Japan. The ecological conditions favorable for overwintering of Cx. p. pallens in urban areas are unknown. In two culverts of an urban environment in Saitama Prefecture, we collected 163 and 65 overwintering Culex adult mosquitoes in February 2005, and 133 and 51 in early March 2006, respectively. Molecular identification of 89 mosquitoes collected from culvert A in 2005 showed that all specimens were Cx. p. pallens. Our finding shows that the overwintering sites of Cx. p. pallens in an urban environment. It is important to understand the ecology of overwintering of Cx. p. pallens in an urban areas and consequently contribute to control of overwintering mosquitoes.

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