[Epidemiological analysis on malaria prevalence in Shanghai from 2003 to 2012].

OBJECTIVE: To understand the epidemiological characteristics of malaria in Shanghai. METHODS: Data related to malaria cases during 2003 to 2012 year in Shanghai was collected and analyzed according to the 3 stages as malaria pre-elimination (2003-2008), pilot malaria elimination (2009-2010) and malaria elimination (2011-2012), respectively. RESULTS: A total number of 936 malaria cases were collected, including 616 cases of Plasmodium (P.) vivax, 110 cases of P. falciparum and 210 cases of unidentified plasmodium. The overall annual incidence rate of malaria was lower than 1 per one hundred thousand and showing a gradual downward trend after 2008. P. vivax was mostly seen during 2003-2008 while the proportion of P. falciparum increased gradually during 2009-2010 and the case of P. falciparum occupied the most during 2011-2012. During 2003-2008, most malaria cases were infected in other provinces but diagnosed in Shanghai. However, between 2008 and 2012, malaria cases were mainly imported from overseas which accounted for 82.80% of the total identified cases, particularly in 2012 that all the malaria cases were imported from Africa and South-East Asia. No indigenous malaria case had been identified since 2009. CONCLUSION: The annual incidence rate of malaria in Shanghai showed a gradual downward trend. Not a single indigenous malaria case had been found for the last 4 years. However, the fact that the situation of importation called for special attention.