Epidemic characteristics of malaria in China: 2009-2014

Objective To examine the situation of the malaria epidemics in China from 2009 to 2014 and to provide evidences for malaria elimination in China.Methods Data on malaria patients reported between January 2009 through September 2014 in China were collected from the Public Health Scientific Data Center (excluding Hong Kong,Macao and Taiwan regions) and the National Malaria Epidemic Report System.Excel 2010 and SPSS 19.0 were adopted in data analyses.Results A total of 34 843 malaria cases were reported during the period,with an average annual incidence rate of 0.43/100 000.The incidence of malaria was generally decreased during the period (χ²=3.012,P=0.003),with the annual incidence rate of 1.06,0.55,0.30,0.18,0.29,and 0.22 per 100 000 population for the year of 2009,2010,2011,2012,2013,and 2014,respectively.More malaria cases were reported in summer season,especially between June and August of a year,and 42.05% of the cases were reported during the 3-month period.The top 5 provinces with higher number of reported malaria cases were Anhui (8 868 cases,25.45% of all cases reported),Yunnan (7 546,21.66%),Henan (3 390,9.73%),Jiangsu (1 975,5.67%),and Guangxi Zhuang Autonomous Region (1 888,4.88%)and the number of malaria cases reported in the 5 provinces accounted for 67.92% of all cases reported.Among the cases reported,the proportions of vivax,falciparum,and unclassified malaria were 59.57% (20 758),28.04% (9 769),and 12.39% (4 316).The ratio of local malaria infection in China decreased from 90.57% in 2009 to 1.92% in 2014,while the ratio of imported cases increased yearly from 9.43% to 98.08%.Conclusion The malaria epidemics in China has a distinct seasonal and regional distribution and the imported malaria has became the most important source of malaria infection in China.