[Epidemiological characteristics of imported malaria in Shandong province, 2017-2018]

Objective: To understand epidemiological characteristics of imported cases of malaria in Shandong province and provide scientific basis for timely adjustment of prevention and control measures. Methods: The incidence data of malaria, case investigation data and case review data by Shandong Provincial Reference Laboratory for Malaria Diagnosis from 2017 to 2018 were collected. Software SPSS 18.0 was used for statistical analysis and software QGIS 2.18 was used for mapping. Results: A total of 442 imported cases of malaria were reported in Shandong from 2017 to 2018, and the main infection source was in Africa (97.96%, 433/442). All the 17 prefectures in Shandong reported imported malaria cases, mainly in Jining (88 cases), Yantai (65 cases), Weihai (46 cases), Qingdao (44 cases) and Dezhou (42 cases), accounting for 64.48% (285/442). The cases were distributed in 77.37%(106/137) of counties of the province. The cases were reported in every month without seasonal characteristics. The median (M) of time interval between onset and the first medical care seeking was 2 days, and the interquartile range (IQR) was 3 days. The M of time interval between the first medical care seeking and final diagnosis was 0 day, and the IQR was 3 days. The proportion of medical care seeking on onset day was only 27.83% (123/442). Only 69.68% (308/442) of cases were diagnosed with malaria in the first medical care seeking, and the diagnostic accuracy of medical institutions below the county level was lower than other medical institutions (all P<0.01). Only 51.13% (226/442) of cases were diagnosed with malaria in the first medical care seeking, the differences in the rates among medical institutions at different levels were not significant (P>0.05). Conclusions: The imported malaria in Shandong was characterized by a large number of cases, multiple infection sources and wide area distribution during 2017-2018. The awareness of timely medical care seeking in the cases was low, meanwhile the awareness and ability of malaria diagnosis and treatment in primary medical institutions were still inadequate. It is necessary to adjust the prevention and control measures accordingly.