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.