Abstract:

Objective To analyze the epidemiological status of imported malaria in Tengchong City, Yunnan Province during 2016-2019 and provide reference for surveillance of imported malaria after malaria elimination.Methods Information on malaria endemic status, investigation and management of epidemic foci, and case treatment in Tengchong City during 2016-2019 was collected and analyzed by Microsoft Excel 2010.Results A total of 123 malaria cases were reported in Tengchong City during 2016-2019, including 55, 28, 18 and 22 on each year, and all were imported cases, among them most were vivax malaria (95.93%, 118/123), with a small portion of falciparum malaria (4.07%, 5/123). In 2019, no imported falciparum malaria case was reported for the first time. Imported malaria cases were reported in every month, with the highest number of cases reported in May and June, accounting for 40.65% (50/123) of the total. The reported cases comprised 104 males and 19 females, with a male-to-female ratio of 5.47 ∶ 1; the youngest case were at the age 3, while the eldest at age 63, with the most cases occurred in the age group of 31-40 years (39.02%, 48/123). The occupation distribution showed that farmers and migrant workers were in the majority (91.87%, 113/123). The infection source mostly came from Myanmar (86.18%, 106/123), followed by Laos (10.57%, 13/123). The confirmation rate of laboratory diagnosis was 100% (123/123); the definite diagnosis was made in county disease prevention and control institutions (44.71%, 55/123) and county medical institutions (39.84%, 49/123). The median time from onset to diagnosis was 5 days, with the longest time spent being 23 days. Verified by provincial Institute of Parasitic Diseases Prevention and Control, the coincidence rate of diagnosis results with those made by township clinics, county medical settings, and county institute of disease prevention and control were 86.36%, 90.74%, and 98.21%, respectively. The 24 h epidemic reporting rate was 100%, the epidemiological tracing of cases within 3 days was completed by 100% (123/123), and the epidemic site management rate within 7 days was 100% (117/117).Conclusion The imported malaria cases in Tengchong City, Yunnan Province showed a trend of decrease in recent years. The key to control and prevention of imported malaria after malaria elimination includes enhancing the capability in diagnosis and treatment, standardizing the management of infection source, improving the surveillance system for cases and mosquito vectors, and strengthening health education for out-going migrant workers.

Key words: Malaria, Imported case, Tengchong City