Abstract:

Objective To analyze the status of blood smear examination for Plasmodium in patients with fever in Zhumadian City, and explore appropriate monitoring method for local management of the infection after malaria elimination, so as to prevent re-transmission of malaria imported from abroad. Methods The data, including blood smear examination for Plasmodium in febrile patients in Zhumadian City, the testing results reviewed in both provincial and municipal laboratories, the epidemic situation data of malaria reported through network and the epidemiological investigation data of positive malaria cases in Zhumadian City were collected from 2011 to 2021. Then the results, including blood tests in febrile patients, distribution of positive cases and reexamination of blood smears, were analyzed. Results A total of 435 748 individuals with fever in Zhumadian City underwent blood smear tests, which revealed Plasmodium infection in 49 patients. The positive rate was 1.12 per 10 000 people. In the 49 patients with positive findings, Plasmodium falciparum malaria was predominant (26 cases, 53.06%), followed by plasmodium vivax malaria (17 cases, 34.69%). Males were the most affected (45 cases, 91.84%), and the age is mainly concentrate in 21 to 50 years old (44 cases, 89.80%). Forty-four cases (89.80%) were imported from abroad. The main source of infection was in African countries (41 cases, 83.67%). The top 3 counties (districts) with the highest number of patients reported with positive blood smears were Yicheng District (14 cases), Xiping County (12 cases) and Biyang County (10 cases). From 2011 to 2021, a total of 12 886 blood smears were reviewed at the municipal level, of which the negative consistency rate was 99.98% (12 830/12 833) and the positive consistency rate was 86.79% (46/53). Conclusion The blood smear examination for Plasmodium in febrile patients plays an important role in the process of malaria elimination in Zhumadian City, and the fever patients returning from malaria endemic areas should be the focus of monitoring through blood smear examination after elimination. Meanwhile, it is necessary to continually consolidate the level of professionals in diagnosis of malaria in order to eliminate the hidden danger of transmission in a timely manner.

Key words: Malaria, Febrile patient, Blood smear examination, Zhumadian City