[Investigation on human intestinal parasitic diseases in ecological regions of Qinba Mountains in Henan Province in 2015].

OBJECTIVE: To understand and analyze the epidemic status of human intestinal parasitic diseases in the ecological region of the Qinba Mountains in Henan Province, so as to provide the evidence for the control of the diseases in this region. METHODS: According to the methods of National Survey Scheme on Major Human Parasitic Diseases, 26 survey spots were selected in 8 counties (cities) in ecological regions of Qinba Mountains in Henan Province in 2015. After collecting the human fecal samples, the eggs of intestinal helminthes were detected with the modified Kato-Katz thick smear method, the species of Ancylostoma of the hookworm egg-positive samples were identified with the tube fecal culture method, the eggs of Enterobius vermicularis were detected by using the adhesive tape method in children aged 3 to 6 years, and the cyst and trophozoite of intestinal protozoa were examined by iodine staining. The infections of intestinal parasites in different populations and the related influencing factors were analyzed. RESULTS: Totally 6 706 residents were recruited in this study, 8 kinds of parasites were found including 3 species of helminthes and 5 species of protozoans. The overall infection rate of intestinal parasites was 3.39%, covering 2.92% for helminthes and 0.49% for protozoans. The infection rate of E. vermicularis in children aged 3 to 6 years was 3.93%. The 3 identified helminthes were Ascaris lumbricoides, E. vermicularis, and Dicrocoelium dendriticum, with the highest infection rate of E. vermicularis (2.68%, χ2 = 306.362, P < 0.05). The 5 identified protozoans were Entamoeba hartmani, E. coli, Endolimax nana, Giardia lamblia, and Blastocystis hominis, and the infection rate of E. nana was the highest (χ2 = 23.842, P < 0.05). Among the 8 counties (cities), the highest infection rate of helminthes, mainly with Enterobius infection, existed in Ruyang County, and the infection rate of protozoans in Xin'an County was the highest, mainly with E. nana infection. There was a significant difference in the infection rates of helminthes and protozoans among the 8 counties (cities) (helminthes: χ2 = 357.525, P < 0.05; protozoans: χ2 = 38.795, P < 0.05). There was no significant difference in the helminth infection rate between males and females ( χ2 = 0.034, P > 0.05), but the protozoan infection rate of the males was higher than that of the females ( χ2 = 12.946, P < 0.05). The helminth infection rate of the 0-9 years old group was the highest ( χ2 = 62.600, P < 0.05), up to 6.60%, mainly with E. vermicularis infection. There was no significant difference in the infection rate of intestinal parasites among nationalities ( χ2 = 0.212, P > 0.05). The helminth infection rate of preschool children was the highest and up to 8.43%, mainly with E. vermicularis infection. The infection of A. lumbricoides was mainly happened among farmers, with the infection rate of 0.31%. There was a significant difference in the helminth infection rate among different occupations (χ2 = 84.333, P < 0.05). The intestinal parasites infection rate of the illiterate population was the highest and up to 7.63%, there was a significant difference among the populations with different educational levels (χ2 = 72.013, P < 0.05). The helminth infection rate of plain areas was higher than that of valley and hill ( χ2 = 11.690, P < 0.05). The helminth infection rate of people with low-income was the highest and up to 10.32% (χ2 = 244.999, P < 0.05). The protozoan infection rate of people with middle-income was the highest, who had the annual per capita net income of 6 000 to 7 999 Yuan ( χ2 = 24.749, P < 0.05). The helminth infection rate of people drinking well water was much higher than that of people drinking tap water (χ2 = 62.255, P < 0.05). The protozoan infection rate of people without insect repellent was higher than that of people with insect repellent (χ2 = 5.235, P < 0.05). CONCLUSIONS: The infection rates of human intestinal parasites in the ecological region of the Qinba Mountains in Henan Province have decreased sharply. E. vermicularis infection in children should be the main point of prevention and treatment of parasitic diseases in the future.