Epidemiologic analysis on case survey of malaria in Chongqing City from 1998 to 2006

Objective To get a general idea of case distribution of malaria,and analyze effects of imported cases on local malaria by case study.Methods The malaria cases were selected in 1998-2006,and classified by time,areas,population distribution,origin of case,to analyze the relationship between imported case and incidence of local malaria.Results Of all 501 cases reported between 1998-2006,58.88% were local cases and imported cases were 41.12%.The cases happened all around the year with the highest rate of 63.47% between May and September.The ratio of male and female was 3.11∶1(male:75.65%;female:24.35%).The age of high incidence was 20 to 39,and the cases were up to 49.70%.Most of the cases were peasants(87.03%).There was a significantly positive relationship between cases in hyper-endemic areas and incidence rate of local malaria(P0.005).The relationship showed that the cases from hyper-endemic areas impacted local malaria incidence.There was also a positive relationship between cases in hypo-endemic areas and incidence rate of local malaria,but there was no significance(P0.05).Conclusion The malaria situation in Chongqing was relatively steady.The incidence rate of years was maintained at a low level.The local cases were very dispersive.The peak time of incidence still existed.The mostly cases were the male farmer of 20-39 years old.The cases from hyper-endemic areas impacted local malaria incidence.The malaria monitoring and floating population managing should be strengthened.