ABSTRACT
@#Abstract: Objective To collect and organize malaria case data in Hubei Province from 2017 to 2021, compare and analyze the malaria epidemic characteristics on the before and after malaria elimination, and provide scientific support for Hubei Province to further optimize the comprehensive strategies to prevent re-transmission after the elimination of malaria. Methods The study was conducted by collecting the data of reported malaria cases of Hubei during 2017-2021 from the Infectious Disease Surveillance Reporting and Management System, and conducting the epidemiological characteristics of malaria on pre-elimination (2017-2019) and post-elimination (2020-2021). Results A total of 429 cases of imported malaria were reported in Hubei Province from 2017 to 2021, and the malaria epidemic showed an obvious trend of rising first and then falling. On the pre-malaria elimination, 374 malaria cases were reported, including 262 cases of P.falciparum (70.05%); on the post-malaria elimination, 55 malaria cases were reported, including 25 cases of P.falciparum (45.45%). There was a statistically significant difference in the proportion of infections caused by the four types of malaria parasites before and after the elimination of malaria (χ2=14.248, P<0.05). On the pre-malaria elimination, the peak of disease onset mainly occurred in January, July, and November; on the post-malaria elimination, the peak of disease onset mainly occurred in January to February, and December. Both before and after malaria elimination, the reported cases were mainly concentrated in Wuhan, Yichang, Huangshi, Xiangyang, Shiyan and Huanggang, but the range of cases showed a clear trend of narrowing. Before and after malaria elimination, malaria cases in Hubei Province were mainly among young and middle-aged males aged 30-49. The proportions of workers and migrant workers increased from 37.70% and 9.09% before the elimination to 50.91% and 18.18% after the elimination, respectively, with a statistically significant difference (χ2=17.839, P<0.05). The percentage of interval from onset of illness to initial diagnosis ≥ 5d decreased from 21.66% before the elimination to 10.91% after the elimination (χ2=6.448, P<0.05). The percentage of definitive diagnosis of malaria at initial diagnosis in town clinic increased from 18.18% before the elimination to 50.00% after the elimination. The proportion of malaria cases diagnosed by county-level medical institutions increased from 22.73% before the elimination to 34.55% after elimination. There was no statistically significant difference in the proportion of malaria cases diagnosed by medical institutions at all levels before and after the elimination of malaria (χ2=5.630, P>0.05). The proportion of cases with the interval between initial diagnosis and diagnosis within 24h increased from 43.85% before the elimination to 70.91% after the elimination. There was a statistically significant difference in the proportion of cases with the interval between initial diagnosis and diagnosis before and after the elimination of malaria (χ2=14.006, P<0.05). Before and after malaria elimination, all reported cases were mainly imported from African countries. Conclusions There are imported malaria cases reported every year in Hubei Province before and after the elimination of malaria, which poses a great challenge to the prevention of re-transmission. Therefore, it is necessary to strengthen the surveillance system, detect and standardize the treatment of imported malaria cases in a timely manner, conduct targeted retransmission risk surveys and assessments, and consolidate the achievements of malaria elimination.