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Opisthorchiasis and intestinal fluke infections in Northern Thailand
Special F o r u m I Parasitology International 47 (Suppl.) (1998) 101-104
103
International Collaboration for Parasitic Diseases S-F-1
EPIDEMIOLOGY AND CONTROL OF SCHISTOSOMIASIS
S-F-3
JAPONIC:4 1N CHINA
Ynan HC Shanghai Medical Uul~dsity. P.KChina Schistosomiasis japonica has a long history and wide distribution in China. Since 1955 a national schistosomiasis control campaign has been initiated, which could be divided into two phases: the first three decades and recent 10 years. The aim of schistosonuasis control in China has been to control it in all the amenable areas, i.e to intermlX the transmis.~aon. A comprehensive control measure had been used. Through 30 years' endeavor, schistosomiasis has been successfully continUed in 4 provinces (including municipality and automonons region). 2/3 endemic counties (265 counties) and more than 2/30ncomelama snail ridden areas (11.2 billion rn2) have been successfully controlled. However, the remmnder endemic areas of lake regions and high mountainous regions become the focal and difficult paints of schistosomiasis control. The endemic statue is related to the • ecological and epidemiological features of schistosonuasis there. Socioeconomic factors also have a great impact on the transmission of schistosomiasis in these areas. Therefore the objectives and strategies of schistosomiasis in the near future has been amended. Control morbidity due to schistosonuasis is the first step and transmission control is implemented in some amenable areas. From 1989 to 1995, the number of infected residents and prevalance of infection had been reduced 47.2% and 52.1%, respe~valy. The prevalance of cattle and buffalo infection had been reduced 31%. In Zbejiang province, the successful control criteria (transmission has been interrupted) was achieved. Since the snail ridden areas almost remain in the same situation and reinfection occurs frequently, a maintenance phase is urgently needed to consolidate the programs of morbidity control. Schistosomiasis control in China has made great achievements, however. soccessful control of schistosomiasis in the whole country is still a long-terro task.
S-F-2
WUCHERERIA
BANCROFTI
USING IMMUNOLOGICAL
IN SRI LANKA
We have performed parasite infection control trials in a J I C A project and an international cooperation study funded by the Pfizer Foundation. In these trials, we integrated parasite infection control with PHC. 1) In the J1CA project, we performed an interview survey of parasite infection in a pilot area, followed by parasitological examinations for infection. The examinations c o n f i r m e d the validity of the interview survey, suggesting that this kind of survey m a y be useful as a tool for field studies. W e are now trying to extend these results by integrating parasite control with primary health education. 2) In the international cooperation study, we integrated a project for the treatment of C h a g a s ' disease in newborn babies with PHC. W e collected blood samples from pregnant w o m e n in a pilot area for T. cruzi antibody detection utelizing the system of syphilis testing at pregnancy w h i c h was conducted by the Ministry o f Health in Paraguay. Seropositive w o m e n were registered, and their babies w e r e examined for the existence of blood worms. This project is continuing and expanding to broad areas in Paraguay. From our experiences in these trials, we will discuss the integration of parasite infection control with PHC.
OPISTItORCHIASISAND INTESTINM, F L t KE INFECTIONSIN NORTHERNTHAILAND
I~agcrla Radomycm~, Thitima Wongsaroj', Polrat Wilairatana , Prayong Radomyos. I ~ Pranvanich', Vura Messomboon~'~Prapasri Joagsuntikul ~ttoupital for Tropical Diseases. Faculty of Tropical Medicine,Mahidol I~niversity. Balikok. Thailand ; 'Department of Communicalble Disease Control. Mmistr~ o[ Public Realth,. Noathaburi, Thailand
TESTS
K i m u r a E*, W e e r a s o o r i y a MV**, I t o h M*, G u n a w a r d e n a NK**, Mudalige MPS**, Samarawickrema
Sendo F*, Saito S . . . . . . , Watanabe T*, R u s s o m a n d o G**, Balbuena B . . . . . . . . , Matsuguchi M . . . . , K o b a y a k a w a T . . . . . *Dept Immunol Parasitol Y a m a g a t a Univ Sch Med Y a m a g a t a Japan, **Inst de Invest en Ciencias de la Salud A s u n c i o n P a r a g u a y , *** Ministry of Public Health and Social Welfare Paraguay, ** **Comm Health Project Jpn lnt Coop A g e n c y (JICA), *. . . . Dept Im Affair Trop Med Tokyo W o m e n ' s Med College T o k y o J a p a n
S-F-4
FINDING NEW ENDEMIC FOCI OF
AN ATTEMPT TO INTEGRATE PARASITE CONTROL AND PRIMARY HEALTH CARE (PHC) IN P A R A G U A Y
WA**
*Aichi Medical University, Japan and **Filariasis Research Unit, University of Ruhuna, Sri Lanka I n o r d e r t o e l i m i n a t e l y m p h a t i c f i l a r i o s i s , i t is i m p o r t a n t t o f i n d o u t h i d d e n foci o f i n f e c t i o n a n d c l a r i f y a r e a s t o b e treated. Reports given by local people on elephantiosis
cases
could be useful information to identify endemic areas. Recently, antigen detection assays such as Og4C3 ELISA and ICT test have increasingly been used for parasitological diagnosis. PCR to detect W.bancrofti DNA in vector mosquitoes will also facilitate the process. These different methods should be utilized in combination to delineate endemic areas with minimum
efforts and cost.
In f i l a r i o s i s c o n t r o l p r o g r a m i n S r i L a n k a , w e a r e planning to utilize information from people, and antigen/ antibody assays• For use under unfavorable local conditions, the Og4C3 ELISA system has been modified for a blood sample absorbed in a filter paper. Antibody assay has been d e v i s e d t o u s e u r i n e a s s a m p l e s i n s t e a d o f s e r a , i n o r d e r to facilitate sample collection.
Four hundred and thirty-one residents from 16 prtvinces m north Thailand who had previously been iound positive for Opisthorrhis viverrini or Opisthorchis viverrini-like ~ were given praziquantel 10 mg/kg The stop[ was collected for l to 6 times and examined for adult worms. The prevalence of Opistfion'his viverrini ill this group wan 11.6%. Intestinal flukes, ffaplorehis taichui and Haplorchis ¥oko$'awh were predominantly found in 63.11% andt0.14% respectively Other intestinal tulles (Centrocestns caninus. Echino~toma malayanura. Haplorehispumilio. Plsaneropsolus bonnei, Plagiorchid flukes. Prosthodendrium moienkanlpi and SSellantch~us fakatus) were also fouad in small numbers.
103
International Collaboration for Parasitic Diseases S-F-1
EPIDEMIOLOGY AND CONTROL OF SCHISTOSOMIASIS
S-F-3
JAPONIC:4 1N CHINA
Ynan HC Shanghai Medical Uul~dsity. P.KChina Schistosomiasis japonica has a long history and wide distribution in China. Since 1955 a national schistosomiasis control campaign has been initiated, which could be divided into two phases: the first three decades and recent 10 years. The aim of schistosonuasis control in China has been to control it in all the amenable areas, i.e to intermlX the transmis.~aon. A comprehensive control measure had been used. Through 30 years' endeavor, schistosomiasis has been successfully continUed in 4 provinces (including municipality and automonons region). 2/3 endemic counties (265 counties) and more than 2/30ncomelama snail ridden areas (11.2 billion rn2) have been successfully controlled. However, the remmnder endemic areas of lake regions and high mountainous regions become the focal and difficult paints of schistosomiasis control. The endemic statue is related to the • ecological and epidemiological features of schistosonuasis there. Socioeconomic factors also have a great impact on the transmission of schistosomiasis in these areas. Therefore the objectives and strategies of schistosomiasis in the near future has been amended. Control morbidity due to schistosonuasis is the first step and transmission control is implemented in some amenable areas. From 1989 to 1995, the number of infected residents and prevalance of infection had been reduced 47.2% and 52.1%, respe~valy. The prevalance of cattle and buffalo infection had been reduced 31%. In Zbejiang province, the successful control criteria (transmission has been interrupted) was achieved. Since the snail ridden areas almost remain in the same situation and reinfection occurs frequently, a maintenance phase is urgently needed to consolidate the programs of morbidity control. Schistosomiasis control in China has made great achievements, however. soccessful control of schistosomiasis in the whole country is still a long-terro task.
S-F-2
WUCHERERIA
BANCROFTI
USING IMMUNOLOGICAL
IN SRI LANKA
We have performed parasite infection control trials in a J I C A project and an international cooperation study funded by the Pfizer Foundation. In these trials, we integrated parasite infection control with PHC. 1) In the J1CA project, we performed an interview survey of parasite infection in a pilot area, followed by parasitological examinations for infection. The examinations c o n f i r m e d the validity of the interview survey, suggesting that this kind of survey m a y be useful as a tool for field studies. W e are now trying to extend these results by integrating parasite control with primary health education. 2) In the international cooperation study, we integrated a project for the treatment of C h a g a s ' disease in newborn babies with PHC. W e collected blood samples from pregnant w o m e n in a pilot area for T. cruzi antibody detection utelizing the system of syphilis testing at pregnancy w h i c h was conducted by the Ministry o f Health in Paraguay. Seropositive w o m e n were registered, and their babies w e r e examined for the existence of blood worms. This project is continuing and expanding to broad areas in Paraguay. From our experiences in these trials, we will discuss the integration of parasite infection control with PHC.
OPISTItORCHIASISAND INTESTINM, F L t KE INFECTIONSIN NORTHERNTHAILAND
I~agcrla Radomycm~, Thitima Wongsaroj', Polrat Wilairatana , Prayong Radomyos. I ~ Pranvanich', Vura Messomboon~'~Prapasri Joagsuntikul ~ttoupital for Tropical Diseases. Faculty of Tropical Medicine,Mahidol I~niversity. Balikok. Thailand ; 'Department of Communicalble Disease Control. Mmistr~ o[ Public Realth,. Noathaburi, Thailand
TESTS
K i m u r a E*, W e e r a s o o r i y a MV**, I t o h M*, G u n a w a r d e n a NK**, Mudalige MPS**, Samarawickrema
Sendo F*, Saito S . . . . . . , Watanabe T*, R u s s o m a n d o G**, Balbuena B . . . . . . . . , Matsuguchi M . . . . , K o b a y a k a w a T . . . . . *Dept Immunol Parasitol Y a m a g a t a Univ Sch Med Y a m a g a t a Japan, **Inst de Invest en Ciencias de la Salud A s u n c i o n P a r a g u a y , *** Ministry of Public Health and Social Welfare Paraguay, ** **Comm Health Project Jpn lnt Coop A g e n c y (JICA), *. . . . Dept Im Affair Trop Med Tokyo W o m e n ' s Med College T o k y o J a p a n
S-F-4
FINDING NEW ENDEMIC FOCI OF
AN ATTEMPT TO INTEGRATE PARASITE CONTROL AND PRIMARY HEALTH CARE (PHC) IN P A R A G U A Y
WA**
*Aichi Medical University, Japan and **Filariasis Research Unit, University of Ruhuna, Sri Lanka I n o r d e r t o e l i m i n a t e l y m p h a t i c f i l a r i o s i s , i t is i m p o r t a n t t o f i n d o u t h i d d e n foci o f i n f e c t i o n a n d c l a r i f y a r e a s t o b e treated. Reports given by local people on elephantiosis
cases
could be useful information to identify endemic areas. Recently, antigen detection assays such as Og4C3 ELISA and ICT test have increasingly been used for parasitological diagnosis. PCR to detect W.bancrofti DNA in vector mosquitoes will also facilitate the process. These different methods should be utilized in combination to delineate endemic areas with minimum
efforts and cost.
In f i l a r i o s i s c o n t r o l p r o g r a m i n S r i L a n k a , w e a r e planning to utilize information from people, and antigen/ antibody assays• For use under unfavorable local conditions, the Og4C3 ELISA system has been modified for a blood sample absorbed in a filter paper. Antibody assay has been d e v i s e d t o u s e u r i n e a s s a m p l e s i n s t e a d o f s e r a , i n o r d e r to facilitate sample collection.
Four hundred and thirty-one residents from 16 prtvinces m north Thailand who had previously been iound positive for Opisthorrhis viverrini or Opisthorchis viverrini-like ~ were given praziquantel 10 mg/kg The stop[ was collected for l to 6 times and examined for adult worms. The prevalence of Opistfion'his viverrini ill this group wan 11.6%. Intestinal flukes, ffaplorehis taichui and Haplorchis ¥oko$'awh were predominantly found in 63.11% andt0.14% respectively Other intestinal tulles (Centrocestns caninus. Echino~toma malayanura. Haplorehispumilio. Plsaneropsolus bonnei, Plagiorchid flukes. Prosthodendrium moienkanlpi and SSellantch~us fakatus) were also fouad in small numbers.