Large water management projects and schistosomiasis control, Dongting Lake region, China.

Construction of the Three Gorges Dam across the Yangtze River will substantially change the ecology of the Dongting Lake in southern China. In addition, the Chinese Central and Hunan Provinces' governmental authorities have instigated a Return Land to Lake Program that will extend the Dongting Lake surface area from the current 2,681 km2 to 4,350 km2. The previous construction of embankments and the large silt deposits made by the Yangtze River and other connecting rivers have contributed to frequent disastrous flooding.

[Study on the relationship between the degree of periportal fibrosis, hepatic parenchymatous fibrosis and diameter of portal vein in Schistosoma japonicum infection].

The degree of periportal fibrosis, hepatic parenchymatous fibrosis and the diameter of portal vein in fishermen from highly endemic area of schistosomiasis japonica in Dongting Lake region were measured. The results showed a significant correlation between the degree of periportal fibrosis and parenchymatous fibrosis and the portal venous diameter with a correlation coefficient of 0.375 and 0.

Applications and outcomes of periodic epidemiological surveys for schistosomiasis and related economic evaluation in the People's Republic of China.

The great success in schistosomiasis control in China is attributable to a range of factors. Periodic epidemiological surveys (PES) used for monitoring and adapting control interventions over time are an integral feature of the national schistosomiasis control programme. PES have enabled the dynamic trends of schistosomiasis epidemics to be closely pursued and have assisted in analysing subtle changes in endemicity.

A double-blind field trial on the effects of artemether on Schistosoma japonicum infection in a highly endemic focus in southern China.

To further strengthen the evidence-base of artemether for the control of schistosomiasis japonica, a randomised controlled trial was carried out in the Poyang Lake region, a highly endemic area in southern China. A total of 783 individuals, aged 6-60 years, were enrolled. They were first given a single oral dose of praziquantel (50 mg/kg).

Field assessment of recombinant Schistosoma japonicum 26 kDa glutathione S-transferase in Chinese water buffaloes.

We have shown previously that anti-fecundity immunity can be induced experimentally against recombinant 26 kDa glutathione S-transferase (reSjc26GST) in Chinese water buffaloes (Bos buffelus), important reservoir hosts for Schistosoma japonicum in China. In the field study described here, we immunized buffaloes with reSjc26GST to induce protective immunity against S. japonicum and to evaluate its effectiveness in controlling schistosomiasis japonica.

Cost-effectiveness analysis of the impacts on infection and morbidity attributable to three chemotherapy schemes against Schistosoma japonicum in hyperendemic areas of the Dongting Lake region, China.

A study was carried out in 8 villages endemic with S. japonicum in Hunan Province, China from 1998 to 2000 to evaluate the cost-effectiveness in preventing schistosome infection and related morbidity under three chemotherapy schemes: (1) 'clue' chemotherapy, consisting of treatment to those with contact with infected water and/or symptoms of infection; (2) 'mass' chemotherapy-treatment to all the villagers except those not able to take praziquantel; and (3) 'screen' chemotherapy-treatment prescribed to the stool egg positive cases after Kato-Katz examination. An itemized cost menu was used to estimate the cost incurred to each scheme, from the perspective of the health care provider.

[A study on the recombinant 26 kDa glutathione-S-transferase as a vaccine candidate: dynamics of antibodies in immunized buffaloes and protection against Schistosoma japonicum infections].

Objective: To observe the dynamics of antibodies and protection against Schistosoma japonicum infections in buffaloes after immunized with recombinant 26 kDa glutathione-S-transferase (reSjc26GST).

Methods: Buffaloes in 2 villages endemic for schistosomiasis japonica were selected as test and control groups, respectively. In test group initially 96 buffaloes were vaccinated with reSjc26GST, and 90 buffaloes in the control group did not experience vaccination.

[Preliminary observation on specific antibody level and reduction of ovulation induced by recombinant Schistosoma japonicum 26 kDa GST antigen in water buffaloes].

Objective: To observe the specific antibody level and reduction of egg-laying induced by a recombinant Schistosoma japonicum 26 kDa GST antigen (rSjc26 GST) in water buffaloes.

Methods: 20 water buffaloes were randomly divided into two groups, the vaccination group and control group, with 10 buffaloes each. The subjects in vaccination group were immunized with rSjc26 GST antigen while the control received adjuvant only.

Effect of Schistosoma japonicum infection on serum testosterone levels in mice.

Objective: To determine the effect of Schistosoma japonicum infection on the testoterone level in the sera from male C57BL/6 mice.

Methods: Radioimmunoassay was used to examine testosterone levels in sera of 9 male mice experimentally infected with Schistosoma japonicum.

Results: The serum testosterone levels reduced significantly in all experimentally infected animals 45 days after infection, as compared with the uninfected controls.

Antibody isotype responses to Schistosoma japonicum antigens in subjects from a schistosomiasis area with repeated praziquantel chemotherapy compared with a new endemic zone in Hunan Province, P.R. China.

To demonstrate the dynamics of specific antibody isotypes against schistosome adult worm (AWA) and soluble egg (SEA) antigens, we evaluated (in 1999-2000) 112 subjects infected with Schistosoma japonicum from 2 regions of Hunan Province, China. Fifty-eight subjects were from Area A, a well-known endemic area with repeated chemotherapy. Area B (n = 54) is a new endemic focus in another part of the same province.

Determinants of hepato- and spleno-megaly in Hunan, China: cross-sectional survey data from areas endemic for schistosomiasis.

In order to understand the determinants of schistosome-related hepato- and spleno-megaly better, 14,002 subjects aged 3-60 years (59% male; mean age = 32 years) were randomly selected from 43 villages, all in Hunan province, China, where schistosomiasis caused by Schistosoma japonicum is endemic. The abdomen of each subject was examined along the mid-sternal (MSL) and mid-clavicular lines, for evidence of current hepato- and/or spleno-megaly, and a questionnaire was used to collect information on the medical history of each individual. Current infections with S.

Efficacy of praziquantel against Schistosoma japonicum: field evaluation in an area with repeated chemotherapy compared with a newly identified endemic focus in Hunan, China.

This study conducted in 1999/2000 was designed to evaluate the efficacy of praziquantel against Schistosoma japonicum in an area with repeated chemotherapy (Area A) compared with a newly identified endemic focus (Area B) in Hunan Province, China. The population size was 2015 and 2180 in Areas A and B, respectively, of which 1129 and 1298 subjects received stool examination. A total of 230 subjects were identified by the Kato-Katz technique (4 smears per person) as being infected with S.

Immunological characteristics of natural resistance in Microtus fortis to infection with Schistosoma japonicum.

Objective: To explore the immunological characteristics of natural resistance to Schistosoma japonicum infection in Microtus fortis (MF) living in the Dongting Lake area.

Methods: Passive transfer of sera from uninfected laboratory bred MF (BMF) to albinao mice (AM) was performed to observe the acquired protection. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunoblotting (ELIB) methods were used to recognize 4 different life-cycle stage antigens of S.

Is equity being sacrificed? Willingness and ability to pay for schistosomiasis control in China.

Decentralization of the health care system in China has led to an increasing need for income generation at all operational levels, both for curative services and for public health programmes. In general, people have accepted the costs of curative services, although the impact of charges on health-seeking behaviour has yet to be assessed. Public health programmes present particular problems in terms of revenue generation, however, because of the less direct impact of these activities on individual health and well-being.

[Quantitative determination of niphensamide by high performance liquid chromatography (HPLC)].

An HPLC method for the quantitative determination of Niphensamide in pesticide powder was developed. Column:Micropak-CH 5 microns (300 mm x 4.0 mm i.

Highlights on the World Bank Loan Schistosomiasis Control Program in China (1991-1998): a special focus on Hunan Province.

A region-wide sampling survey was conducted in 1995 in order to evaluate the current epidemiological status of schistosomiasis japonica in Hunan Province, China. A total of 45,590 humans and 3,726 domestic animals, from 52 villages, were examined parasitologically and/or serologically for current Schistosoma japonicum infections. In uncontrolled endemic areas (43 villages) the overall human prevalence of S.

Natural antibodies in Microtus fortis react with antigens derived from four stages in the life-cycle of Schistosoma japonicum.

The levels of antibodies which react with the cercarial antigens (CA), schistosomulum stage antigens (SSA), adult-worm antigens (AWA) and soluble egg antigens (SEA) of Schistosoma japonicum were investigated in Microtus fortis and albino mice, using an indirect ELISA. The M. fortis studied fell into three groups: animals caught in the wild; laboratory-bred animals left unchallenged; and laboratory-bred animals that had been challenged with S.

An evaluation of Schistosoma japonicum infections in three villages in the Dongting lake region of China. I. Prevalence, intensity and morbidity before the implementation of adequate control strategies.

We examined three Chinese villages (one farming village and two fishing villages) in an area highly endemic for schistosomiasis japonica in order to study the prevalence, intensity of infection and the associated morbidities before the implementation of adequate control strategies. Socio-economic status, medical histories including the frequency and type of water contact, physical examinations, parasitological examinations and questionnaires relevant to the knowledge of schistosomiasis were performed on a random sample of 1542 individuals (45% female; 55% male). The prevalence of Schistosoma japonicum was 9.

Schistosomiasis control in China.

Well-organized programmes combining local involvement and major government projects have been successful in controlling schistosomiasis to a large extent in China. The task is far from complete, however, especially in some lacustrine and mountainous areas, where conditions are highly favourable for the vector snails, and difficult to modify. A long-term programme of health education, medical care and infrastructure development is needed.

Factors contributing to reinfection with schistosomiasis japonica after treatment in the lake region of China.

The prevalence of schistosomiasis due to S. japonicum is focally high in the lake regions of China, and reinfection after treatment with praziquantel is frequent. In this study, the total reinfection rate among 740 treated persons was 12.

A multivariate analysis of the relationship between work ability and S. japonicum infection in Dongting Lake region, in China.

A cross-sectional case-control study on the association between the reduced work ability and S. japonicum infection was carried out in a moderate endemic area for schistosomiasis japonica in the southern part of Dongting lake in China. A total of 120 cases with reduced work ability and 240 controls paired to the case by age, sex, occupation and without reduced work ability, participated in the study.

Studies on antibiotic 230 as a molluscicide.

In the course of studying molluscicidal effects of microorganisms, a microorganism belonging to Streptomycetaceae, Streptomyces griseolus (Strain 230) was isolated from soil and a certain microbial ingredient proved to have a molluscicidal activity. The effective substance was named antibiotic 230. As a result of several investigations on the antibiotic, the following chemical features were made clear.

A study and analysis of the deaths due to advanced Schistosoma japonicum infection in the Dongting Lake area of China.

This study collected records of 245 cases of death due to advanced schistosomiasis japonica in the eastern Dongting Lake area between 1985 and 1990. The mean survival of the patients was 5.16 years.

[Role of human and domestic animal reservoirs of schistosomiasis japonica in Dongting and Boyang Lake regions].

In Dongting and Boyang Lake regions, the main reservoirs of schistosomiasis were farm cattle (mostly buffaloes), pigs and mobile nonnatives. However, the role of these reservoirs in different types of endemic areas were not the same in the transmission of schistosomiasis. In islet-beach type area, the main infectious sources were pigs and local residents.

Schistosoma japonicum infection among migrant fishermen in the Dongting Lake region of China.

An epidemiological survey of Schistosoma japonicum infection was made among 316 persons, fishermen and their family members, in 5 sites of the Dongting Lake region. Their medical history was taken and physical and stool examinations were carried out. The infected persons were divided into 3 groups; 2 were treated with one or 2 doses of praziquantel and one, the control group, was given no treatment.