Investigation On Epidemic Focus Oi Angiostrongylus Cantonesis In The Four Border Cities Of Yunnan Province And The Construction Of Geographic Information System

[Objective]To master the infection characteristics of intermediate host snails and final host rodents four port in Yunnan province, we had an angiostrongyliasis investigation of natural epidemic focus in Yingjiang, Ruili, Hekou, Jingshui port. In order to study whether the placs were Angiostrongyliasis natural epidemic focus and whether the border crossings were directly related with angiostrongyliasis natural epidemic focus in Yunnan, We investigated the circumstances of Yingjiang, Hekou port. We established angiostrongyliasis epidemiology database by using geographic information systems of Yingjiang, Ruili, Jinping, estuaries in Yunnan and assessed the Angiostrongyliasis risk of transmission in the four port areas.[Methods]1.With the puopose of learning the distribution characteristics and regular pattern of intermediate host snails and final host rodents in Yingjiang, Ruili, Jinping, Hekou, we explicited the historical data and documents of angiostrongyliasis natural epidemic focus in Jinping, Hekou.2. we checked out large amounts of data and selected the snail breeding season to investigate. We investigated and collected angiostrongyliasis intermediate host and the definitive host according to the forecast figure.3.We classified and counted snails, and then detected infection situation of angiostrongyliasis that was in the third stage larvae with pepsin digestion and lung examination method. We classified and counted Rodents, and then detected infection situation of angiostrongylus that were mature and larvae of the first period with a heart-lung biopsy method and mouse droppings with the check method of microscope.We detected Ig G in Mouse serum with the enzyme-linked immunosorbent assay. The angiostrongyliasis which were collected were used to establish laboratory animal models. We had a epidemiological survey on the local health care system and the CDC, and collected Ig G in serum enzyme-linked immunosorbent assay.4. We analysed epidemiological data of Angiostrongylus of four border crossings by Spss19.0, the visualization descripition of infection situation of Angiostrongylus and the geographic information system software.[Results]1. In this survey we had captured all 5261 snails, including five kinds of snail intermediate host, such as Cipangopaludina chinensis Gray, Pomacea canaliculata,Bellamyaaerugin-osa, Achatina fulica, Turritella terebra bacillum.2. We had captured three kinds of mice as final host of Angiostrongylus, there were166, which were Rattus flavipectus(96), Rattus norvegicus(45), Mus musculus Linnaeus(18). We didn’t find angiostrongyliasis in the mature mices or in the alarvae stage ones no matter in rat droppings or by Cardiopulmonary Anatomy method; We found that the collected 48 mouse sera angiostrongyliasis specific Ig G antibodies were negative by enzyme-linked immunosorbent assay.3. We detected that the collected 200 blood serum by using angiostrongyliasis specific Ig G antibodies with enzyme-linked immunosorbent assay, 39 of them were positive,the positive rate was 19.5%. The positive rate of Hekou port was the highest, the positive rate was 50%. Seroprevalence among minority populations was higher than Han; The people with the habit of drinking unboiled water outdoors were higher than the ones without the habit; The population with the low cultural level were higher than the population with the high cultural level.4.The specimens were GPRS locating. We used geographic information system software to establish Angiostrongylus cantonensis focus survey database of the Yunnan border area and also described the data with the visual technology.5.We used the positive intermediate host Snail in hekou port to establish the animal model. After 40 days, half of the 12 male and female rats have died.[Conclusion]1. There was an infection of intermediate host snail in estuary port. We found that the crowd of the four port might infect angiostrongylus.2. Hekou port was still the angiostrongyliasis natural epidemic focus, compared with2008 the intermediate host infection has not been controlled and eliminated. Currently Jinping, Yingjiang and Ruili port temporarily could not be considered as angiostrongyliasis natural epidemic focus.3. The source of angiostrongyliasis infection of Snail in estuary port need to further study.4. Geographic information systems could be described as the distribution of angiostrongyliasis, and could provide a theoretical basis for angiostrongyliasis control strategies.5. Seropositive samples distributed along the river, was aggregated distribution; the potential spread risk of Red River, Jin Shui River, South River within two estuary ports were highest. Yingjiang, Ruili, Jinshui, residence estuary port town of inhabitants of the area were located in almost the potential spread of moderate or high risk areas.