关键词: 疟疾, 流行特征, 防控策略, 保山市

Abstract:

To consolidate the achievements of malaria elimination and understand the epidemiological characteristics of malaria in Baoshan City, malaria endemic data in Baoshan City before malaria elimination (2011-2017) and after malaria elimination (2018-2024) were collated and analyzed. Malaria endemic data from January 1, 2011 to December 31, 2024 in Baoshan City were collected through the China Disease Prevention and Control Information System. Databases were established using the software Microsoft Office Excel 2011, and descriptive statistical analyses were performed using the software SPSS 26.0. A total of 1 725 malaria cases were reported in Baoshan City from 2011 to 2024, with the highest number of cases reported in 2011 (406 cases) and the lowest in 2022 (7 cases), showing an overall declining trend in the number of reported cases year by year. Before malaria elimination, a total of 1 459 cases (85.58%) were reported, while 266 cases (15.42%) were reported after malaria elimination. The predominant infecting Plasmodium species was P. vivax (1 500 cases, 86.96%), with no change in the distribution of infecting Plasmodium species before and after malaria elimination. Reported cases were mainly distributed in Tengchong City (1 154 cases, 66.90%), with no change in regional distribution before and after malaria elimination. Cases were reported every month from 2011 to 2024, with the highest cumulative number of cases reported in May (330 cases, 19.13%), and the peak reporting period was from April to July (1 029 cases, 59.65%). The reported cases were predominantly male (1 486 cases, 86.14%), with farmers being the main occupational group (1 343 cases, 77.85%), and the age group mainly distributed between 20 and 55 years old (1 556 cases, 90.20%). The main population affected before and after malaria elimination consisted of young and middle-aged male farmers. The reported cases were mainly imported (1 707 cases, 98.96%), including 1 449 cases imported from abroad and 276 cases imported domestically. Before malaria elimination, 98.77% (1 441/1 459) of the reported cases were imported, and 79.80% (1 165/1 459) were imported from abroad. After malaria elimination, all 266 reported cases were imported from abroad. The main source of imported infections from abroad was Myanmar. A total of 1 648 malaria cases were diagnosed by medical institutions at all levels within the jurisdiction of Baoshan City from 2011 to 2024. A total of 1 384 cases were diagnosed before malaria elimination, mainly confirmed cases (1 343 cases, 97.04%), with county-level Centers for Disease Control and Prevention being the main diagnostic units (598 cases, 43.21%). A total of 264 malaria cases were diagnosed after malaria elimination, all of which were laboratory-confirmed cases, with municipal and county-level general hospitals being the main diagnostic units (180 cases, 68.18%). Before malaria elimination, the shortest time interval from onset to seeking medical care for reported cases was 0-day, and the longest was 214-day. After malaria elimination, the shortest time interval was 0-day, and the longest was 17-day. The main prevention and control measures in Baoshan City focused on reducing and eliminating local infections before malaria elimination, and the prevention and control emphasis shifted to the timely detection of imported cases and the prevention of local re-transmission after malaria elimination. The survey results showed that Baoshan City had reported no locally infected cases for 11 consecutive years since 2014, indicating remarkable achievements in malaria elimination. However, due to its proximity to Myanmar, the situation regarding the prevention and control of imported malaria in Baoshan City remains severe.

Key words: Malaria, Epidemiological characteristic, Prevention and control strategies, Baoshan City