Abstract:

Objective  To investigate the epidemic trend of intestinal nematodiasis in Huai'an district of Huai’an city for evidences to plan scientific preventive and control measures for this infection. Methods The survey was yearly conducted in a population of 1000 aged over 2 years, randomly selected from a village under an administrative township. Children under 14 years of age accounted for ≤1/3 in the subjects surveyed. Modified Kato-Katz method was used to detect the eggs of intestinal nematode, and the total infection rate, single worm infection rate and infection degree were calculated. Results A total of 5104 subjects were surveyed from 2011 through 2015. Intestinal nematode infection ranged from 0.10% to 0.95%(average 0.61%), and hookworm infection accounted for 58.06% of the infected species. The difference was significant regarding the average infection rate by individual species (χ2＝8.99, P＜0.05).Mean infection degree was 1 944.00, 247.11 and 576.00 for roundworm, hookworm and whipworm, respectively. Severe infection and multiple infection were free. The infection rate was decreased by 87.34% from 0.79% in 2011 to 0.10% in 2015, and was significant between years(χ2＝9.65, P＜0.05), yet the single worm infection rate remained no difference (χr2＝1.84, P＞0.05. χh2＝6.79, P＞0.05. χw2＝3.85, P＞0.05). Infection was seen in different age groups except for subjects aged 20 years. Those aged over 50 years accounted for 70.97% of the total infected population. The infection rate was not statistically different between males and females( 0.44% vs. 0.75%; χ2＝2.05, P＞0.05). Infection with intestinal nematodes occurred in population with different occupations except for cadres, yet the difference was not significant between occupations (χ2＝0.65, P＞0.05). Conclusion Intestinal nematode infection tends to drop year by year in population in Huai'an district, and following prevention and control of the infection should target at the middle aged and the elderly farmers.

Key words: Intestinal nematode, Roundworm, Hookworm, Whipworm, Huai'an City