Analysis of Epidemiological Changes and Prevention Effects for Malaria in Weifang, Shandong Province, China from 1957 to 2017

Background We aimed to conduct a retrospective analysis of the epidemiological changes and prevention effects for malaria in Weifang, Shandong Peninsula, China from 1957 to 2017. Methods The malaria data from a web-based reporting system were analyzed to explore malaria epidemiological characteristics and prevention effects in Weifang. Results Overall, 1, 704, 890 malaria cases were reported in Weifang from 1957 to 2017, of which two major malaria epidemics occurred in 1961 (827.28/10, 000) and 1971 (366.14/10, 000). Prior to 1997, all malaria patients (1, 704, 829) were infected with Plasmodium vivax (P. vivax). After 2007, the cases of Plasmodium falciparum (P. falciparum) showed an upward trend (76.8%). The reported cases after the 21st century were mainly imported cases, and the last indigenous case was a patient that infected with P. vivax in 2006. Overall, 36 imported cases were reported from 2010 to 2017, of which 88.9% were acquired in Africa. Except for one 32-year-old woman, the rest were male (97.2%), in which laborers and farmers represented the vast majority (66.6%). From 1987 to 2017, there were 1, 224, 474 cases of fever with blood tests, and the average blood test rate was 4.9%. From 1957 to 2017, a total of 1, 704, 890 malaria patients were treated, 96 cases were treated during resting phase from 1987 to 2017. Conclusion Weifang should continue to strengthen the management of the migrant population, making blood tests for fever patients and patient treatment as important means of malaria control and monitoring.