[Malaria surveillance in Shanghai from 2005 to 2012].

OBJECTIVE:To understand the status of malaria prevalence in Shanghai, so as to provide the evidence for evaluating and promoting malaria elimination. METHODS:The data of population, malaria endemic and monitoring in Shanghai from 2005 to 2012 were collected and analyzed. The malaria positive rates in febrile patients and normal population, the malaria antibody levels of the floating population and location pupils, and the species and density of mosquitoes were investigated and the results were analyzed. RESULTS:The blood examples from 400,177 febrile patients with 0.36% of the total population were examined for malaria, and the annual rates of blood examination varied from 0.15% to 0.83% in the period of 2005 to 2012. Before 2010, the annual blood examination rate was lower than 0.20%, but increased significantly since 2010 because of the implementation of the Action of Malaria Elimination in Shanghai from 2010 to 2020. Totally 604 malaria cases were found and the positive rate of blood examination was 0.15%. During the period of 2006 to 2008, more than 100 malaria cases were found every year, but the number of malaria cases decreased since 2009, and only 26 cases was found in 2012. Since 2011, all the malaria cases have been found infected out of China according to the questionnaire investigation. The malaria positive rate of blood examinations decreased from 0.61% to 0.03% yearly. The proportion of local residents who had the blood examination was 79.02%, but that of the malaria positive in floating population was 83.44%. The active case detection was carried out in 15,759 persons and five cases were found in 2007 and 2008, respectively. The level of malaria antibody was tested in 1 239,440 floating population with the average positive rate of 0.04%. The level of malaria antibody was also tested in 7,065 local pupils but there was no positive for malaria. Only Anopheles sinensis was found in Shanghai suburb, but no other Anopheles mosquitoes were found at the city or towns. The peak of Anopheles den- sity was from the end of July to August. CONCLUSIONS:Malaria surveillance is carried out efficiently in Shanghai, and the result shows Shanghai is in the phase of malaria elimination. The more attention should be paid to persons coming from malaria endemic areas for the malaria blood examination and the general and advanced hospital should maintain the ability of malaria blood examinations simultaneously.