This survey may indicate the necessity of the development on the specific staging in schistosomiasis mekongi
2. Seroepidemiological Surveys
In our previous seroepidemiological surveys for schistosomiasis mekongi in Kratie Province, a total of 597 blood samples were collected from school children starting from Kampong Krabei to Han Chey Leu along the Mekong River. The measurement of antibody against egg antigen of Schistosoma japonicum by ELISA was carried out in the Department of Medical Zoology, Dokkyo University School of Medicine. The results obtained are summarized in Figure 1.
2.1. Kratie Province
As a continuance of our seroepidemiological surveys to search for the southern limit of endemic transmission of Schistosoma mekongi infection in the Mekong River in Province of Kratie, a total of 161 blood samples (80 in Chambok, 50 river Km downstream of Kratie; 82 in Bang Rey, 55 Km downstream of Kratie ) were collected by venipuncture from school children. Moreover, 91 blood samples in Thamar Kol, 4 Km upstream of Kompong Cham were also obtained.
2.2. Stung Treng Province
To monitor and evaluate of schistosomiasis in Stung Treng Province, a total of 436 blood samples were collected from school children in Koh Preah on Koh Preah Island, Siem Bok, Pchol on Koh Srolay Island, Kaing Cham, Hang Khosoun, Veal Ksach along Mekong River, Kam Phoun of the Tonle San and Sdau of the Tonle Kong, covering at least 133 river Km ( Fig.2 , Tab.1).
A small amount of blood sample was collected onto filter papers from 172 school children in Stung Treng Province for further comparative study on immunodiagnosis.
After blood donation, each child received tablets of Vitamin-C, paracetamol and mebendazole together with a note book and a pencil. The serum samples will be analysed for humoral antibody responses using different autigen-antibody assays in the Department of Medical Zoology, Dokkyo University School of Medicine. You will be informed as soon as the result was obtained.
Acknowledgements
We are grateful to the Honourable Under Secretary of state for Health, Dr. Mam Bunheng, for permission to conduct these epidemiological surveys. We wish to record our deep appreciation of the encouragement received from Dr. Cheam Saem, Director, Kratie Provincial Health Department, Dr. Nguon Sim An, Director, Kampon Cham Provincial Health Department and Dr. Heng Nhoeu, Director, Stung Treng Provincial Health Department. Special gratitude is expressed to Dr. D. Socheat, Vice Director, National Malaria Centre, Dr. Peter Odermatt, MSF, Phnom Penh and Dr. Jean-Philippe Dousset, MSF, Stung Treng, for their valuable advices. Many thanks are due to Dr. Suon Siela, Dr. Leang Rithba, CNM, Dr. C. Seng Ly, Kratie Provincial Health Department and Dr. Poly, Stung Treng Provincial Health Department, for joining us during our field survey. We are grateful to the technical staff of Kratie, Kampong Cham and Stung Treng Provincial Health Department, for their help and support. To village leaders and villagers who have extended their kinds of cooperation and hospitality to us we wish to express our special gratitude. It should also be emphasized that the present survey would have been impossible without intimate collaboration with teachers and children in the primary schools we visited.
With best regards,
