[Epidemic status of imported malaria before and after malaria elimination in Jiaozuo City of Henan Province].

Objective: To analyze and compare the epidemiological characteristics of imported malaria in Jiaozuo City before and after malaria elimination, so as to provide insights into the malaria surveillance during the post-elimination stage and prevention of re-establishment of imported malaria.
Methods: Data pertaining to the epidemic situation and individual investigation of malaria in Jiaozuo City before (from 2010 to 2016) and after malaria elimination (from 2017 to November, 2020) were captured from the National Notifiable Disease Reporting System and the Information System for Parasitic Diseases Control and Prevention of Chinese Center for Disease Control and Prevention and were analyzed statistically.
Results: A total of 74 imported malaria cases were reported in Jiaozuo City from 2010 to 2021. Imported cases were predominantly Plasmodium falciparum malaria cases in Jiaozuo City before and after malaria elimination, and there was no significant difference in the proportion of malaria parasite species ( χ ² = 0.234, P > 0.05). The imported malaria cases was predominantly reported in Wuzhi County, and was identified in overseas male farmers and businessmen at ages of 20 to 59 years, while the greatest number of imported malaria cases was reported in June and December before and after malaria elimination. The imported malaria cases predominantly acquired malaria parasite infections in sub-Saharan African countries; however, the proportion of imported malaria cases returning from Southeast Asian counties increased after malaria elimination than before malaria elimination ( χ ² = 5.989, P < 0.05). The longest duration from onset to definitive diagnosis of malaria reduced from 27 days before malaria elimination to 18 days after malaria elimination, and the median duration reduced from 3 days to 2 days, while the proportion of definitive diagnosis of malaria increased from 60.47% before malaria elimination to 83.87% after malaria elimination ( χ ² = 4.724, P < 0.05). In addition, the proportion of malaria cases definitively diagnosed and reported by medical institutions increased after malaria elimination than before malaria elimination ( χ ² = 5.406, P < 0.05).
Conclusions: The imported malaria patients were predominantly P. falciparum malaria cases in Jiaozuo City during 2010 to 2021, and the patient's medical care-seeking awareness and medical staff's diagnosis and treatment ability have improved after malaria elimination. It is necessary to strengthen and improve malaria surveillance and response system and prevent the re-establishment of overseas imported malaria.