Epidemiological characteristics of imported malaria cases in Puyang, Henan, 2005-2015

Objective To analyze the epidemiologic characteristics of 119 imported malaria cases of Puyang, Henan province, and provide evidenceto improve the prevention and control of malaria. Methods Descriptive epidemiological analysis was conducted by using the data of epidemiological survey, epidemic response, blood detection records and hospital case records. Results All the types of malaria were detected in 119 imported malaria cases reported in Puyang, including 84 falciparum malaria cases, 16 vivax malaria cases, 16 ovale malaria cases, 3 quartan malaria cases. The cases were from 19 countries in Africa (101 cases, 84.87%) and in southeast Asia (18 cases, 15.13%). The stay length of the cases ranged from 10 to 1097 days; and the cases mainly returned before wheat harvest season, autumn harvest season and Spring Festival (93 cases, 78.15%). The case number in Puyang county was highest (62 cases, 52.10%); Up to 95.80% of patients were young adults aged 20-49 years.Ninety six cases were migrant workers (80.87%).The average time of onset was at 9thday after returning, but 16 cases occurred 30 days later, and 6 falciparum malaria cases occurred more than 30 days later (7.14%), and 10 other type malaria cases occurred more than 30 days later too (28.57%). The average interval between the onset and the diagnosis was 3.71 days, but 107 cases were diagnosed within 30 days (89.92%). Conclusion Since the strengthened surveillance for malaria from 2010, the number of imported malaria cases increased year by year. So it's necessary to further strengthen malaria screening and health education in people returned from high malaria endemic areas; and improve the diagnosis and treatment in medical institutions at county level to reduce mortality and secondary transmission risk and reach the goal of eliminating malaria.