Objective To explore the epidemical pattern of acute schistosomiasis in Poyang Lake area so as to provide the scientific evidence for control-strategy-making. Methods The data of acute schistosomiasis in 12 counties along Poyang Lake from 1960 to 2007, including the data of 2 special investigations from 1982 to 1984 and from 1987 to 1989 were collected and analyzed with the retrospective investigation methods. Results There were 29 864 cases of acute schistosomiasis in 12 counties of Poyang Lake area from 1960 to 2007, accounting for 85.5% of the total acute schistosomiasis cases of Jiangxi Province. The largest number of cases existed in Yugan County, accounting for 18. 7%. The peak of acute schistosomiasis prevalence was in 1987 with 2 088 cases. However, the case of acute schistosomiasis declined significantly, keeping at a low level, since 1990. During the 2 special investigations, the people whose age were lower than 30 years old, were the susceptible populations of acute schistosomiasis (86. 1% and 82. 9% , respectively) , most of them were peasants and students, and the infection rates were 57. 4% and 21.2%, 61.7% and 21. 8%, respectively. Fishing and swimming were the main infection ways, with the infection rates of 43.0% and 44.9% , respectively. The peak season of infection was from April to October. Conclusions The river bank and continent of Poyang Lake are the main infection areas, the spring and autumn are the main epidemic seasons and the susceptible populations are the peasants, fishmen and young students. It is very important to enhance the comprehensive prevention and treatment measures in the key areas and population for schistosomiasis control.

Objective To understand the effect of the three-cell latrine and B-type tilted ellipsoid methane tank for eliminating eggs of schistosome in different seasons and temperatures in order to evaluate their values for popularization and application in schistosomiasis endemic areas.Methods The eggs of schistosome collected from infected rabbits were put into the three-cell latrines and methane tanks in different seasons.The miracidia were observed and counted after collecting the eggs for hatching experiments on the 5th,10th,15th,20th,25th,30th,40th,50th,and 60th day,respectively.Results In the three-cell latrine,the time of eliminating eggs completely in the fecal residue in winter,spring(autumn),and summer was 50,30,15 days,respectively,and the time of completely eliminating 100 eggs of schistosome was 40,20,10 days,respectively.Correspondingly,in the methane tank,the time of eliminating eggs completely in the fecal residue in winter,spring(autumn),and summer was 30,15,10 days,respectively,and the time of completely eliminating 100 eggs of schistosome was 20,15,5 days,respectively.Conclusions The three-cell latrine and B-type tilted ellipsoid methane tank could effectively eliminate schistosome eggs in human and animal excreta and achieve the national hygienic standard on night soil in the endemic areas of Jiangxi Province.

Objective To investigate risk factors for the development of advanced schistosomiasis. Methods The case\|control study was designed with a match of 1∶1 and 1∶2. Healthy persons and chronic schistosomiasis patients were used as control. Each group was composed of 213 cases. Items investigated included: history of schistosomiasis and treatment, exposure to the contaminated water, social\|economical condition and nutritional status, other concomitant diseases. Cellular and humoral immunity, HBVMs and ABO blood groups were also detected. Statistical analysis was performed by 1∶1 and 1∶2 matched single and stepwise conditional logistic regression analysis with SAS software. Results By stepwise conditional logistic regression analysis, it was revealed that number of schistosomiasis examination(OR=1\^168-1\^311), interval from first infection to last treatment(OR=1\^142), interval from first infection to this investigation (OR=1\^089), \{HBsAg\++\}(OR=4\^683-10\^759), \{HBcAb\++\} (OR=2\^873), \{HBsAg\++\}+\{HBeAb\++\}+\{HBcAb\++\}(OR=7\^64) were risk factors of developing advanced schistosomiasis. The average living space and cellular immunity were lower in advanced schistosomiasis patients than others. No association was found between advanced schistosomiasis and ABO blood groups. Conclusion The development of advanced schistosomiasis is associated with repeated infections, and delayed or incomplete treatment. Combined infection with hepatitis B, poor socio\|economic conditions and impaired cellular immunity may increase the pathogenetic risk of schistosomiasis.