Epidemiological characteristics of malaria in Ningbo City, China 2000-2011

The objective of this study was to explore the trend and the epidemiological characteristics of malaria in Ningbo from 2000 through 2011 and provide scientific evidence for the prevention and control. Using the retrospective study, data relating to malaria epidemics during 2000-2011 in Ningbo were collected through the questionnaires of the cases and other important surveillance data. Adult mosquitoes were collected using CDC light traps baited with CO2. Results showed that Plasmodium vivax was the main species, and Anopheles sinensis was the only vector species of malaria. The annual incidence rates (per 100000) ranged from 0.156 to 3.224, and about 95.41% of the cases were imported. The cases occurred mainly between May and November and the incidence showed two peaks, and the local transmission of malaria was determined by vector density. Considering the vast majority of these infections were imported vivax malaria cases from domestic endemic areas (particularly Anhui province), and may lead to limited local transmission, strengthening the routine monitoring of imported malaria, ensuring timely diagnosis, improving case detection rate, giving a standardized treatment to patients and intensifying public health education on malaria prevention are extremely important to malaria prevention and control activities.