Epidemiological characteristics of malaria before and after the elimination in Hangzhou / 预防医学

ABSTRACT

Objective To compare the epidemiological characteristics of malaria before and after the elimination in Hangzhou, and to provide scientific basis for formulating malaria control strategies. Methods We collected the data of confirmed malaria cases in Hangzhou from 2005 to 2016. We compared the differences in epidemiological characteristics (demographic features of malaria cases, source of infection, plasmodium species, etc.) and vectors of malaria before (2005-2010) and after (2011-2016) the elimination of malaria. Results Totally 340 malaria cases were reported before the elimination in Hangzhou with the annual incidence rate of 0.16/10 million, while 227 cases were reported after the elimination with the annual incidence rate of 0.25/10 million. Local cases accounted for 11.47% before the elimination, while no local cases but all imported cases were reported after the elimination. Compared the sex, occupation and age of malaria cases, epidemic season, report area, source of infection and species before and after the elimination, the proportion of men increased from 67.65% to 89.87%; the proportion of 18-60 years old group increased from 75.88% to 96.04%; the proportion of children / students decreased from 17.35% to 7.49%;the epidemic season changed from July to October to no obvious season; the main report area changed from suburb (55.88%) to urban area (81.06%); the source of infection changed from the domestic provinces (77.94%) to foreign countries (99.12%) ;the main species of malaria parasites changed from vivax malaria (88.24%) to ciparum malaria (71.81%) . The Anopheles mosquitoes caught by vector monitoring were Anopheles sinensis. The average density of Anopheles sinensis before and after the elimination was 10.0 and 5.0 /(person·night) . Conclusion After the elimination of malaria in Hangzhou, imported malaria cases from abroad were dominant. and the men and women who returned to and from abroad and 18-60 years old were the key prevention and control groups in the future.The epidemiological characteristics of malaria after the elimination in Hangzhou have changed greatly. The men who are 18-60 years old and return from abroad are the focus of malaria prevention and control.