Abstract:

To understand the infection status and infection risks of Clonorchiasis sinensis and soil-transmitted nematodes (STNs) in population in Qingxin district of Qingyuan city, Guangdong Province, a survey was performed in this area from October to December, 2018. Fecal samples were collected from people living in this area and the eggs of C. sinensis, hookworm, roundworm and whipworm in the collected feces were examined under microscope in duplicate using modified Kato-Katz thick smear method. The larvae were cultured from hookworm egg positive feces using filter tube method to determine hookworm species. A transparent adhesive tape test around anus was used to examine pinworm eggs for children with 3-9 years old. Total 1 254 residents were participated in this survey and 30 of them were infected with C. sinensis (2.3%), 36 infected with STNs (2.7%). Among them, the infection rate for hookworm was 0.3%, whipworm 0.2%, roundworm 0.5% and pinworm of 1.9%. The infection rate of C. sinensis in male people (3.0%, 22/747) was higher than that in female (1.6%, 8/507), however, the difference was not statistically different (P > 0.05). With respect to the different occupations, age and education related to the infection of C. sinensis, people with farmer as occupation (7.9%, 10/126), age over 60 (4.2%, 11/260) (P < 0.01) and education lower than elementary school (3.6%, 14/386）(P < 0.01) had the highest infection rates. The risk for infection of C. sinensis was positively correlated with the eating habit with raw fish or fish porridge (P < 0.01). The STN infections in male was 3.2%（24/747), which was higher than that in female (2.4%, 12/507), but without significance (P > 0.05). The highest STN infection rates happened in pre-school children (11.4%, 23/201), children with age 3-9 years old (9.5%, 24/252) and people with education lower than elementary school (8.6%, 33/386). The risk for STN infections was positively correlated to the lack of washing hands before eating and after pooping (P < 0.01). This survey results suggested that prevention and control of C. sinensis infection should focus on the intervention of the people with low education level and elder population. More intervention measures of prevention and control of STN infection should focus on the children and people with low education.

Key words: Clonorchis sinensis, Soil-transmitted nematode, Infection, Survey