关键词: 土源性线虫, 感染率, 监测, 山东省

Abstract:

In order to understand the current situation of soil-transmitted nematode infections in humans in Shandong Province and provide the scientific basis for optimizing prevention and control strategies, from 2021 to 2022, 27 counties in Shandong Province were randomly selected as surveillance sites. Each surveillance site was divided into five regions (east, west, south, north, and central) based on geography, and one administrative village from one township was randomly selected in each region. A total of 200 permanent residents with an age of over 3 years were taken as the surveillance object from each village by cluster sampling method. Basic information and the fecal samples were collected, and the worm eggs were examined in duplicates using the modified Kato-Katz thick smear method (one sample, two slide-readings) and counted. Hookworm species were identified using the tube filter paper culture technique. Children aged 3-9 years old were tested for Enterobius termicularis by anal transparent tape. A database was established, and SPSS 26.0 software was used to perform the statistical analysis. The infection rate and Infectivity were calculated. The infection rates were analyzed using the Chi-square test. A total of 29 622 people were detected in the province in 2021-2022, and the total infection rate of soil-transmitted nematode was 0.55% (162/29 622). The infection rates of hookworm, Ascaris lumbricoides and Trichuris trichiura were 0.02% (7/29 622), 0.02% (6/29 622) and 0.51% (152/29 622), respectively. The hookworm samples were all identified as Ancylostoma duodenale. Among the 152 trichuriasis patients, 2 were severely infected, 6 were moderately infected, and the rest were slightly infected. Six A. lumbricoides infections and seven hookworm infections were mild infections. The prevalence of soil-transmitted nematode was 0.97% (118/12 208), 0.84% (43/5 117), 0.01% (1/7 140), 0 (0/5 157) in southern, eastern, northwestern and central Shandong. The infection rate of soil-transmitted nematode was 0.55% (79/14 362) in males and 0.54% (83/15 260) in females (χ² = 0.005, P > 0.05). The age group of 60-99 had the highest infection rate among all age groups accounting for 1.11% (107/9 612) (χ² = 86.274, P > 0.05). Farmers had the highest infection rate among different occupational groups, accounting for 0.78% (148/18 863) (χ² = 54.078, P < 0.05). The illiterate or semi-illiterate group had the highest infection rate among different education levels, accounting for 2.43% (60/2 468) (χ² = 175.458, P < 0.05). A total of 2 584 children were examined, and the infection rate of E. vermicularis was 1.16% (30/2 584). The infection rate in boys and girls was 1.60% (22/1 375), 0.66% (8/1 209) (χ² = 4.936, P < 0.05). The highest rate was found in 7-year-old children, accounting for 4.50% (15/333) (χ² = 39.798, P < 0.05). The distribution of soil-transmitted nematode in Shandong Province was unbalanced among regions and populations, which indicated that the prevention and control of soil-transmitted nematode should be strengthened in key areas and carry out effective health education for key populations to reduce the infection rate continuously.

Key words: Soil-transmitted nematode, Infection rate, Surveillance, Shandong Province