ABSTRACT
Objective To evaluate the potential risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City,so as to provide evidences for establishing a post?transmission surveillance system for schistosomiasis in marsh?land regions. Methods The water infectivity,floating boatmen and fishermen infection,reservoir host infection and wild feces contamination were investigated in five districts/counties along the Yangtze River in Yangzhou City,including Guangling,Hanji?ang,Jiangdu,Yizheng and Development Zone,and the transmission factors and risky characteristics were assessed after inter?ruption of schistosomiasis transmission in marshland regions. Results A total of 15 key water regions were identified in the area along the Yangtze River in Yangzhou City in 2015. A total of 1 500 sentinel mice were placed,after breeding,their overall sur?vival rate was 99.33%;1 490 were dissected,with no schistosome infection. Of the 5 576 floating boatmen and fishermen exam?ined,no schistosome infection was observed,and among the 3 566 domestic animals(including 171 cattle,1 895 sheep and 1 500 pigs),no infections were detected. During the period between January and March,2016,there were 3 200 mouse traps placed on 8 marshlands,and 62 wild mice were captured from 6 marshlands,with a capture rate of 1.94%,and no schistosome?infected wild mice were seen. In addition,there were 35 pieces of fresh wild feces captured from 7 marshlands,including 11 pieces of bovine feces(31.43%),17 pieces of sheep feces(48.57%),2 pieces of dog feces(5.71%)and 5 pieces of other feces (14.29%),and no infections were detected. Conclusions There is a low risk of schistosomiasis transmission in the area along the Yangtze River in Yangzhou City. However,the contamination of feces from bovine and sheep that are freely pastured on marshlands is a big threat to schistosomiasis control.
ABSTRACT
Objective To explore and integrate the key techniques used in the surveillance and forecast of schistosomiasis in the water regions along the Yangtze River,so as to provide technical support for identifying rapidly the risk of schistosomiasis transmission and implementing control measures targeting the risk. Methods According to the distribution of water systems and water regions along the Yangtze River in Jiangsu Province,the demonstration sites for surveillance and forecast of schistoso? miasis were set across the province,where the integration and demonstration of the techniques regarding monitoring of Schistoso?ma japonicum infection in sentinel mice,human and animal activities,release of forecast information,and emergency treat?ment of water regions at risk of infection were performed. The pattern of human and animal activities was compared with the S. ja?ponicum infection in sentinel mice in the demonstration sites,and the operability of the release of information and emergency treatment of the risk of S. japonicum infection was evaluated. Results A total of 50 demonstration sites for surveillance and forecast of schistosomiasis were set in fixed anchor points,opening of the navigation lock to the Yangtze River,freight terminal, agritainment places,ferry,large construction places,and places for guaranteeing the Youth Olympic Games in 23 counties(dis?tricts)of 5 cities,Jiangsu Province. During the period between May and September,2014,the infectivity of water body was monitored by using 5 batches of sentinel mice,with a 99.06%(4 954/5 001)gross recovery rate of mice. S. japonicum infection was detected in a demonstration site,and an infected mouse was found,with a 0.02%(1/4 933)gross positive rate of sentinel mice. The field survey showed 2 088 person?times contacting water,including 91.95%(1 920/2 088)contacting water due to the production such as capturing fish,harvesting and cultivating crops,and repairing and building boats,and 8.05%(168/2 088)contacting water due to the life activity,such as fishing,washing vegetables and playing with water. The people contacted water predominantly in August and September(49.57%). A total of 859 boats containing 1 877 boatmen were observed,68.22%(586/859)of which were fishing boats containing 1 306 fishermen(69.58%). There were 32 sheep found in 4 demonstration sites,and 3 sheep were seen in the demonstration site with infected sentinel mouse. Four blue forecasts(emergence of water con?tact)and one orange forecast(S. japonicum?infected sentinel mouse detected)were released across the province,with one fore?cast map released which showed 5 sites with fishing and one site with sheep grazing,one emergency response system initiated, mollusciciding implemented in 10 hm2 high?risk regions,120 sheep grazed in fence,and 35 fishermen given health?education materials,schistosomiasis examination and preventive therapy. In addition,no acute schistosomiasis occurred in the demonstra?tion site with S. japonicum?infected sentinel mice. Conclusions The integration and demonstration of the techniques regarding monitoring of S. japonicum infection in sentinel mice,human and animal activities,release of forecast information,and emer?gency treatment of water regions at risk of infection provides an effective approach for the large?scale surveillance and forecast of schistosomiasis.
ABSTRACT
Objective To establish the surveillance and risk assessment system of schistosomiasis in Jiangsu Province,so as to provide technical support for timely understanding of the risk of schistosomiasis transmission and implementation of target-ed control measures. Methods The surveillance sites of schistosomiasis were assigned according to the epidemic status and en-demic type of schistosomiasis as well as the characteristics of the water system,and the prevalence of Schistosoma japonicum in humans and domestic animals,and snail status were investigated. In addition,the quality control of serum detection of S. japon-icum infections was performed. The prevalence of human and animal S. japonicum infections,snail status and missing diagnosis of serum detection were analyzed and compared among regions. Results A total of 27 surveillance sites of schistosomiasis were set up in 26 counties of 10 cities,Jiangsu Province,including 14 sites in transmission-interrupted villages and 13 sites in trans-mission-controlled villages,and 15 sites in marshland and lake regions,9 sites in plain regions with water network and 3 sites in mountainous region. In the 27 surveillance sites,a total of 16 617 residents were screened for S. japonicum infection by using dipstick dye immunoassay(DDIA),and 326 were sero-positive,with a sero-prevalence of 1.96%(2.17%for men and 1.8%for women). Of the 326 individuals undergoing parasitological examination,2 positive cases were detected in the marshland and lake region,with a S. japonicum human prevalence of 0.01%. Of the 762 floating population detected,10 were positive for blood test,with a sero-prevalence of 1.31%,and no egg-positive individuals were detected. No infection was found in the 476 do-mestic animals. Of the 746 settings surveyed,a total of 240.7 hm2 snail area was detected,with a mean snail density of 0.06 snails/0.1 m2,and no infected snails were found. There were 780 quality-control sera detected in 26 surveillance sites of schisto-somiasis,and the gross coincidence rate was 95.13%,with misdiagnosis rate of 1.28%and missing diagnosis rate of 19.23%. Conclusion The surveillance sites of schistosomiasis show reasonable distribution in Jiangsu Province,and the endemic situa-tion of schistosomiasis appears a low level in the whole province.