[Surveillance of human intestinal parasitic diseases in Nanping City from 2014 to 2018]

OBJECTIVE

To investigate the status of human intestinal parasitic diseases in Nanping City from 2014 to 2018, so as to provide reference for the development of the effective control measures.

METHODS

Administrative villages were selected using the two-stage cluster sampling in Nanping City from 2014 to 2018, and surveillance of human intestinal parasitic diseases was performed in 5 administrative villages in each county (district) of Nanping City. Intestinal parasitic infections were detected using a modified Kato-Katz thick smear method (two smears for a single stool sample) in villagers, and the hookworm species was differentiated. In addition, the eggs of Enterobius vermicularis were detected using the adhesive tape method in children aged 3 to 6 years.

RESULTS

A total of 6 317 villagers were detected in Nanping City from 2014 to 2018, and the overall prevalence of human intestinal parasitic infections was 2.15%. There was year- (χ² = 10.53, P < 0.05) and gender-specific prevalence of human intestinal parasitic infections in Nanping City during the study period (χ² = 17.00, P < 0.01). The prevalence of human intestinal parasitic infections increased with age, and there was age-specific prevalence of human intestinal parasitic infections in Nanping City (χ² = 102.62, P < 0.01). A total of 945 children at ages of 3 to 6 years were detected, and the prevalence of E. vermicularis infection was 3.28%.

CONCLUSIONS

The prevalence of human intestinal parasitic infections is at a low level in Nanping City from 2014 to 2018, and the infection mainly occurs in villagers of advanced age and low education levels. Further comprehensive measures are required to control intestinal parasitic infections in key populations.

[Prevalence and influencing factors of intestinal parasitic diseases among rural children in Henan Province]

OBJECTIVE

To understand the epidemic status and influencing factors of intestinal parasitic diseases among rural children in Henan Province.

METHODS

According to the Scheme for The National Survey on Current Status of Major Human Parasitic Diseases in China, the survey counties were selected based on the ecological zones and economic levels in Henan Province between 2014 and 2015. Then, the included counties were stratified according to the topography and economic levels. A township was randomly sampled from each stratum, and a village was randomly sampled from each township as the study site. Finally, a total of 104 study sites from 35 counties were enrolled for the survey of intestinal parasitic diseases in children. At least 250 fresh stool samples were collected from each study site for detection of intestinal helminth eggs with the Kato-Katz technique, for the identification of Necator americanus and Ancylostoma duodenale with the fecal culture method, and for the detection of intestinal protozoa trophozoite and cyst with the physiological saline smear and iodine staining techniques. In addition, the Enterobius vermicularis and tapeworm eggs were detected in children aged 3 to 6 years using the adhesive cellophane-tape perianal swab method.

RESULTS

The overall prevalence of intestinal parasitic infections was 3.21% (214/6 671) among rural children in Henan Province, and the prevalence of intestinal helminthes (2.62%, 175/6 671) was higher than that of intestinal protozoa (0.60%, 40/6 671). A total of 12 species of intestinal parasites were found, including 4 nematodes species, one trematode species, and 7 protozoa species, and the highest infection was seen in E. vermicularis (2.47%, 161/6 671). Among the four ecological zones in Henan Province, the greatest prevalence of intestinal parasitic infections was detected among children in the Qinba Mountain Ecological Zone (5.85%, 90/1 538). There was no gender-specific difference in the prevalence of intestinal parasitic infections in children (P > 0.05); however, there were age- (χ² = 32.762, P < 0.05) and education level-specific differences in the prevalence of intestinal parasitic infections in children (χ² = 67.507, P < 0.05), with the greatest prevalence of E. vermicularis infection seen in all species of intestinal parasites in children at all age groups. Multivariate non-conditional logistic regression analysis showed that high education level, high coverage of harmless toilets, drinking tap water and deworming were protective factors for intestinal parasitic infections in children in Henan Province. The overall prevalence of intestinal parasitic infections appeared a tendency towards a gradual decline among children in Henan Province as compared to the previous two surveys.

CONCLUSIONS

The overall prevalence of intestinal parasitic infections shows a tendency towards a remarkable decline among children in Henan Province. E. vermicularis infection should be given a priority for future parasitic disease control activities among rural children in Henan Province.

[Effect of control program of human intestinal parasitic diseases in Nanping City]

OBJECTIVE

To understand the epidemic status of human intestinal parasitic diseases and evaluate the effect of the control program in Nanping City, so as to provide an evidence for improving the disease control.

METHODS

The villages were selected by the stratified cluster sampling method and the residents in these villages were surveyed for human intestinal parasitic diseases, and kindergartens were also selected and the children in these kindergartens were surveyed for Enterobius vermicularis infection.

RESULTS

In 2007, before the control program, 9 851 residents of Nanping City were surveyed, with the parasitic infection rate of 9.10% (896 infection cases), and the infection rate of E. vermicularis of children was 18.56% (328/1 767). From 2011 to 2014, when the control program was performed, 4 679 residents were surveyed, with the infection rate of 4.06% (190 infection cases), and the infection rate of E. vermicularis of children was 3.87% (33/853). After the control program was launched, the infection rates of human intestinal parasites were decreased. The overall parasitic infection rate and hookworm infection rate showed increasing trends by age (χ² = 49.03 and 53.58 respectively, both P < 0.01).

CONCLUSIONS

The infection situation of human intestinal parasites is decreased after the implementation of the control program but the infection rate is still at a high level, and the control work should be strengthened.