1.Surveillance of soil-borne nematodiasis among rural populations in Tiantai County
Qingrong CUI ; Haiyan HU ; Saifei LUO ; Wei RUAN ; Tianlan PANG ; Dingling CHEN
Journal of Preventive Medicine 2022;34(9):937-940
Objective:
To investigate the prevalence of soil-borne nematode infections among rural residents in Tiantai County, Zhejiang Province, so as to provide insights into improving the control strategy.
Methods:
According to the Zhejiang Provincial Surveillance Programme on Soil-borne Nematodiasis and Clonorchiasis, 5 administrative villages were randomly selected in Tiantai County according to geographical locations on April, 2021, and all permanent residents at ages of 3 years and older were sampled from each village using a cluster sampling method. Subjects' gender, age, occupation, education level and deworming were collected. Subjects' stool samples were collected, and soil-borne nematode eggs were detected using the modified Kato-Katz technique, and larval culture was performed using a filter-paper culture method among hookworm egg positives for identification of hookworm species. In addition, the intensity of infection was evaluated using hookworm eggs per gram stool sample.
Results:
A total of 1 013 residents participated in the survey, including 495 men (48.86%) and 518 women (51.14%), and there were 502 participants at ages of 51 to 70 years (49.56%), 874 farmers (86.28%) and 436 subjects with an education level of primary school (43.04%). However, no subjects received deworming. The prevalence of hookworm infections was 3.85% among the study subjects, and only Necator americanus was identified. There were 31 cases with mild infections (79.49%), 5 cases with moderate infections (12.82%) and 3 cases with severe infections (7.69%), and all infections occurred in farmers. The prevalence of hookworm infections was 3.84% among men and 3.86% among women. No hookworm infection was detected among residents at ages of <41 years, and the prevalence of hookworm infections appeared a tendency towards a rise with age among residents at ages of 51 years and older (χ2trend=24.091, P<0.001), while the prevalence of hookworm infections appeared a tendency towards a decline with educational levels among residents (χ2trend=19.534, P<0.001). The greatest prevalence of hookworm infections was found in Qianyang Village (10.95%).
Conclusions
Hookworm disease is the predominant type of soil-borne nematodiasis in Tiantai County, and the middle-aged and elderly farmers with a low education level are high-risk populations for soil-borne nematodiasis control.