Abstract:

Objective To investigate the prevalence status of major food-borne parasitic infections in Sichuan Province for evidence to optimize the prevention and control strategies. Methods From 2020 to 2024, two fixed monitoring sites were initially selected in Sichuan Province. Additionally, no fewer than 13 mobile monitoring sites will be chosen using a stratified multi-stage random sampling method based on ecological zones, ethnic composition, and economic levels. All monitoring sites were divided into 5 regions (east, west, south, north and central) according to their geographical locations. In each region, a random survey was conducted on no fewer than 200 permanent residents aged 3 and above. The modified Kato-Katz thick smear (two slides for one stool sample) was used to detect the food-borne parasitic infections in the population. Results A total of 101 831 subjects were surveyed, in whom 427 infections were identified, with an overall infection rate being 0.42%. Of these infected cases, 412 were positive for Taenia spp., 9 for Hymenolepis diminuta, and 6 for Clonorchis sinensis. No mixed infections were detected. The annual overall infection rate showed a significant upward trend (χ²_trend=51.830, P<0.01), rising from 0.33% in 2020 to 0.55% in 2024. By regional distribution, Aba Tibetan and Qiang Autonomous Prefecture had the highest overall infection rate (2.76%, 228/8 264), followed by Ganzi Tibetan Autonomous Prefecture (1.81%, 163/9 020). The infection rate was significantly different among different cities (prefectures) (χ²=1 798.623, P<0.01). The overall infection rate was 0.42% (204/48 016) for males and 0.41% (223/53 815) for females, with no statistical difference (χ²=0.067, P>0.05). Higher overall infection rates were seen in the population aged 20-29 years (1.03%, 69/6 691), herdsmen (3.27%, 67/2 048), Tibetan ethnicity (3.21%, 390/12 138), and individuals with primary school education or below (0.71%, 394/55 724). Significant differences in overall infection rates were observed across different age groups, occupations, ethnicities, and education levels (χ²=167.622, 481.554, 2 594.768, 245.903; all P<0.01). Conclusion The western pastoral areas of Sichuan Province have a relatively high prevalence of food-borne parasitic infections, and the infection is primarily associated with Taenia. In order to control the prevalence of taeniasis, it is necessary to carry out targeted health education, improve management of the livestock husbandry, and implement regular collective deworming for high-risk populations.

Key words: Food-borne parasites, Surveillance, Taenia, Clonorchis sinensis, Hymenolepis diminuta, Sichuan Province