[Establishment and application of rapid assessment system of environment with high transmission risk of schistosomiasis in marshland and lake regions II establishment and application of measures for field survey].
OBJECTIVE
To establish the measures of schistosomiasis field survey and evaluate the efficacy of their application according to the content of indexes of rapid assessment system to high transmission risks in schistosomiasis endemic areas of lake regions.


METHODS
In 2012, based on the analysis of Oncomelania hupensis snail situation, and schistosomiasis epidemic data of human and cattle from 2008-2010, 60 villages from Hunan, Hubei, Jiangxi and Anhui provinces were selected and investigated, and the content of the investigation included the field feces, snail status, and epidemic situation of human and cattle. The systemic sampling was applied for snail investigation; the feces collected from snail investigation field were examined by the hatching test (3 bottles for 1 sample). A cluster random sampling was carried out with more than 300 people in each village. By using the hatching test (3 bottles for 1 sample) , the human stool examination was carried out for the identification of the infected persons who were positive in the immunity test screening. The hatching test was applied for cattle of all the villages (3 bottles for 1 sample).


RESULTS
A total of 65 field feces spots were surveyed in 60 villages, field feces were found in 78.46% (51/65) of spots, and the positive rate of field feces was 1.07% (9/842). There were 73.33% (44,160)of villages with cattle, and the largest amount cattle with 329 was found in Wufeng Village, Jiangxi Province. The cattle infection rate was 1.5 1% (4,913,242) in 3242 investigated cattle. The highest cattle infection rate was 4% in Tongxin Village, Jiangxi Province. The population of 47 099 was surveyed, the infection rate was 0.77% (364/47 099), and the highest was 4.37% in Xumuchang Village, Hunan Province. The infection rate was 0 in 43.33% (26/60) of villages. No acute schistosomiasis cases were reported in all the villages in 2011 and 2012. Totally, 77 snail spots in 60 villages were investigated, and 51 spots were marshland and 26 spots were ditches. The schistosome-infected snails were detected in 5.88% (3/51 )of the marshland spots and the living snails were found in 80.39%(41/51) of the spots. The highest density of living snails was 3.20/0.1 m2 in Xumuchang Village, Hunan Province. The average density of infected snails was 0.00045/0.1 m2 (4/8942). The infected snail spots were distributed in Liujiadi Village and Liuhe Village of Hubei Province, and Jiangkou Village of Anhui Province. No infected snails were detected in 26 ditches spots. The living snails were detected in 53.85% (14/26) of the ditches spots. The highest average density of living snails was 3.76/0.1 m2 in Huakou Village, Hubei Province.


CONCLUSIONS
The measures of field survey for rapid assessment system of high transmission risks in schistosomiasis endemic areas of lake regions are established and applied with scientific, impersonal and rapid characteristics.
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Chun-li
CL
Cao
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Zi-ping
ZP
Bao
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Hong-qing
HQ
Zhu
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Tie-wu
TW
Jia
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Qing
Q
Yu
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Zhi-qiang
ZQ
Qin
Jiangsu Provincial Institute of Schistosomiasis Control, China.
You-sheng
YS
Liang
Institute of Parasitic Diseases, Sichuan Provincial Center for Disease Control and Prevention, China.
Bo
B
Zhong
Hunan Provincial Institute of Schistosomiasis Control, China.
Guang-hui
GH
Ren
Hubei Provincial Center for Disease Control and Prevention, China.
Xi-bao
XB
Huang
Jiangxi Provincial Institute of Parasitic Diseases, China.
Dan-dan
DD
Lin
Anhui Provincial Institute of Schistosomiasis Control, China.
Shi-qing
SQ
Zhang
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Jing
J
Xu
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Shi-zhu
SZ
Li
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Jia-gang
JG
Guo
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention; Key Laboratory of Parasite and Vector Biology, Ministry of Public Health; WHO Collaborating Center for Malaria, Schistosomiasis and Filariasis, Shanghai 200025, China.
Xiao-nong
XN
Zhou
D000818:Animals; D002417:Cattle; D002681:China / Q000453:epidemiology; D004777:Environment; D006801:Humans; D060106:Lakes; D011156:Population Density; D012306:Risk; D012552:Schistosomiasis / Q000635:transmission*; D012908:Snails; D053833:Wetlands