关键词: 疟疾, 流行病学特征, 广东省

Abstract:

Objective To analyze the epidemiological characteristics of malaria cases reported in Guangdong Province from 2015 to 2024, so as to provide insights into improving the malaria control strategy and preventing re-establishment of imported malaria. Methods Data on malaria cases and epidemiological case investigation forms for malaria reported in Guangdong Province from 2015 to 2024 were collected from the Infectious Disease Reporting Information Management System and the Parasitic Disease Prevention and Control Information System of Chinese Center for Disease Control and Prevention. The malaria parasite species, origin of acquiring infections, and the temporal, spatial and population distribution characteristics, healthcare-seeking behaviors and diagnosis of malaria cases were statistically analyzed with the software Microsoft Excel 2016 and SPSS 26.0. Results A total of 1 879 malaria cases were reported in Guangdong Province from 2015 to 2024, including 1 871 overseas imported cases, 2 transfusion-transmitted cases, and 6 cases with recrudescent long-latency Plasmodium malariae malaria, and a total of 16 deaths occurred. The number of reported malaria cases appeared an overall tendency towards a rise from 2015 to 2019, and the annual average number of reported malaria cases was all lower during the COVID-19 pandemic (from 2020 to 2022) than the 10-year mean number. Laboratory confirmation showed 1 559 cases (83.0%) with P. falciparum malaria, and the proportion of P. falciparum malaria cases ranged from 80.4% to 86.8% in all malaria cases from 2015 to 2024. Among 1 871 imported malaria cases, 1 785 cases (95.4%) acquired infections in Africa. Malaria cases were reported across Guangdong Province except in Chaozhou City, and were primarily found in the Pearl River Delta region (1 680 cases, 89.4%). The monthly number of malaria cases was 1 to 65, with a median of 15 cases per month. The annual number of malaria cases peaked in June and during the period between August and October. The ratio of male to female cases was 8.8:1, and age distribution peaked at 30 to 39 years (32.5%, 611/1 879) and 40 to 49 years (26.7%, 501/1 879). Malaria cases were reported by 191 institutions, and 78.4% (1 472/1 879) of cases sought healthcare services within 3 days of onset, with a higher proportion seen among P. falciparum malaria cases (79.7%, 1 242/1 559) than among cases with other types of malaria (χ² = 8.17, P < 0.01). The proportion of correct initial diagnosis was 83.1% (1 562/1 879), and the percentages of correct initial diagnosis at city-level and higher, county (district)-level and grassroots healthcare facilities were 90.6% (1 096/1 210), 81.7% (402/492), and 36.2% (64/177), respectively (χ² = 327.04, P < 0.01). The median interval from healthcare-seeking to definitive diagnosis was 1 day, with 86.6% (1 627/1 879) of cases that were definitively diagnosed within 3 days of healthcare-seeking, and the proportion of P. falciparum malaria cases that were definitively diagnosed within 3 days was higher than that of cases with other types of malaria (χ² = 12.44, P < 0.01). Severe malaria was reported in 69 cases (3.7%, 69/1 879), all of which were caused by P. falciparum infection. Conclusion The risk of imported malaria continues to rise in Guangdong Province, with P. falciparum malaria predominating among reported cases. Future control efforts should focus on reinforcement of health education among individuals enter and exit China and improvements in the early-stage diagnostic capability in grassroots healthcare facilities.

Key words: Malaria, Epidemiological characteristics, Guangdong Province