Abstract:

 Objective To understand the current status of human intestinal protozoal infection in Henan Province. Methods An epidemiological survey was carried out in Henan Province according to the Protocol of National Survey Scheme on Major Human Parasitic Diseases, in counties selected based on the ecological and economic conditions. A stratified sampling method was used to select one village in each county, and 250 residents in each village were examined. Fresh human fecal samples were collected, in which trophozoites and/or cysts of intestinal protozoa were examined by physiological saline direct smear method and iodine stain method, respectively. The infection rate was compared between different populations using the chi-square test. 　Results  A total of 26 866 persons from 104 villages in 35 counties(cities) were examined, and the overall infection rate of intestinal protozoa was 0.57%(152/26 866). Seven species of intestinal protozoa were detected: Iodamoeba buetschlii, Entamoeba hartmani, Endolimax nana, Entamoeba histolytica, Entamoeba coli, Giardia lamblia and Blastocystis hominis, of which the Endolimax nana conferred the highest infection rate (0.19%, 50/26 866). There was a significant difference in infection rate among the species (P < 0.05). Among the 4 ecological regions, the North China Plain Ecological Region had higher infection rate (0.67%, 45/6 696), with no significant difference (P > 0.05). After normalization, Xiangcheng had the highest infection rate among the 27 counties (cities) detected with human intestinal protozoa (2.69%). The infection rate was higher in males (0.73%, 95/12 965) than in females (0.41%, 57/13 901) (P < 0.05). Among different age groups, the infection rate was higher in the groups of < 20 (0.66%, 31/4 667) and 20- (0.66%, 18/2 742), predominated by Blastocystis hominis. Furthermore, among different occupations, infection rate in workers and farmers was 0.76% (4/528) and 0.54% (96/17 896), respectively. Populations with a level of high school or above and a primary school showed an infection rate of 0.71% (18/2 550) and 0.52% (42/8 014), respectively. The Han ethnicity had a higher infection rate (0.57%, 151/26 434) (P < 0.05). The average annual income per farmer in the survey was 1 200-23 590 yuan, with a median of 5 950 yuan. There was no significant difference in the intestinal protozoa infection rate in age, occupation, education level, or income (P > 0.05).  Conclusion Seven species of intestinal protozoa are identified with a low rate of infection in Henan Province.

Key words: Human, Intestinal protozoa, Infection status, Henan Province