Schistosomiasis in China: acute infections during 2005-2008.
BACKGROUND
Significant progress has taken place over the past 50 years in the control of schistosomiasis japonica in China. However, the available data suggested that schistosomiasis has re-emerged shortly after the World Bank Loan Project which was conducted from 1992 to 2001. The national control program with a revised strategy to control schistosomiasis by using integrated measures has been implemented since 2005. In this study, we aimed to evaluate the effect of the national program on schistosomiasis control from 2005 to 2008.


METHODS
A retrospective study was carried out to analyze the epidemic patterns of acute infections with Schistosoma japonicum (S. japonicum), based on the number of acute cases annually collected from the web-based national communicable diseases reporting system from 2005 to 2008.


RESULTS
A total of 564, 207, 83 and 57 acute cases infected with S. japonicum were reported nationwide in 2005, 2006, 2007 and 2008, respectively, with an average annual reduction rate of 46.35% during last four years. Six outbreaks of acute infection with S. japonicum were reported in 2005 but none in the period of 2006 to 2008. All acute cases that were reported mainly came from the lake regions and became infected during the higher risk periods from the 27th to 43rd weeks of the year. Most of these cases are students (44.87%), farmers (31.51%) and fishermen (7.79%) who got the infection by water contact mainly through swimming (41.49%) and production activities (40.25%). With time, the proportion of imported cases among all acute cases increased due to more frequent movement of people that has occurred with a more mobile population.


CONCLUSIONS
The national control program on schistosomiasis aliened with the revised control strategy has been effectively brought into effect. However, there is still a significant risk of infection among students, farmers and fishermen living in the lake regions. Therefore, it is important to strengthen control measures among risk populations in the high risk areas of transmission, or the lake regions.
Li
Shi-zhu
SZ
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, China.
Luz
Acosta
A
Wang
Xian-hong
XH
Xu
Li-li
LL
Wang
Qiang
Q
Qian
Ying-jun
YJ
Wu
Xiao-hua
XH
Guo
Jia-gang
JG
Xia
Gang
G
Wang
Li-ying
LY
Zhou
Xiao-nong
XN
D000208:Acute Disease / Q000453:epidemiology*; D000818:Animals; D002681:China / Q000453:epidemiology; D006801:Humans; D012189:Retrospective Studies; D012549:Schistosoma japonicum / Q000472:pathogenicity; D012552:Schistosomiasis / Q000453:epidemiology*