关键词: 疟疾, 输入性病例, 流行病学特征, 湖北省

Abstract:

Objective To analyze the characteristics of imported malaria cases in Hubei Province from 2016 to 2020 to provide scientific basis for optimizing the control strategies for post-elimination phase. Methods The data of reported malaria cases in Hubei Province during 2016—2020 were collected from the National Infectious Disease Surveillance Reporting and Management System to analyze Plasmodium species, infection source, three compartment distribution and the experience of seeking medical care. The χ² test was applied for comparison of the correctness rate of initial diagnosis among different medical institutions. Results A total of 560 malaria cases were reported in Hubei Province during 2016—2020, all of them were imported from abroad. In total, 387 cases were infected with P. falciparum (69.11%), 75 with P. vivax (13.39%), 80 with P. ovale (14.29%), 16 with P. malariae (2.86%) and 2 with mixed infection (0.36%). The number of malaria cases reported by year in Hubei Province was 151, 96, 127, 151 and 35 in 2016—2020, respectively, among them the number reported in 2020 decreased by 76.82% compared to 2019. All the reported cases were imported from 39 countries in four continents. The top five countries with the highest imported number were the Democratic Republic of the Congo (117), Nigeria (49), Ethiopia (48), Angola (45) and the Republic of Congo (32). During this period, malaria cases were reported all year round, with the reporting peak in January (77), February (76) and November (51). Malaria cased were reported from all 16 cities (prefecture) except Shennongjia Forestry District, mainly from Wuhan (184), Yichang (81), Huangshi (56), Xiangyang (39), and Shiyan (36). Among all cases, 85.36% (478/560) occurred in the age group 20-49; 540 cases were in males and 20 in females, with a gender ratio of 27 : 1. Most of the malaria cases (361, 64.47%) visited doctor 2 days after outset of disease, but 69 cases (12.32%) consulted doctor over 11 days after outset. Overall, 396 cases were diagnosed as malaria, with a correctness rate of diagnosis 70.71% at the initial visit. Of the reported cases, 410 sought initial visit in county-based medical institutions or higher settings (410/560, 73.21%), and the correctness rate of diagnosis was 77.32% (317/410); The numbers of cases seeking initial visit to town health center, individual doctor or village clinic were 45, 16 and 27, respectively, with the correctness rate of diagnosis of 40.00% (18/45), 1/16, and 11.11% (3/27), respectively. The correctness rate of diagnosis was significantly different among different medical institutions (χ² = 103.744, P < 0.05). In addition, 55.89% (313/560) of the cases were diagnosed as malaria within 24 hours; 26.43% (148/560) of the cases spent more than 4 days of time span from initial visit to confirmed diagnosis. Most of the cases (80.89%, 453/560) were diagnosed as malaria in medical institutions. Two death cases of imported falciparum malaria were reported in the province during 2016—2020. Conclusion During 2016—2020, all reported cases in Hubei Province were imported cases, and most of them were caused by P. falciparum. The cases were mainly distributed in Wuhan City, in males and in the age group of 20-49 years. The majority cases sought health consultation in medical institutions, and the correctness rate of diagnosis upon the initial visit was higher in county-based medical institutions or settings at higher level.

Key words: Malaria, Imported case, Epidemic characteristics, Hubei Province