[Epidemiological Survey on Intestinal Parasitic Infections in Lhasa City in 2014].

OBJECTIVE

To investigate the prevalence of parasitic infections in Lhasa, Tibet.

METHODS

The residents in Chengguan District, Dangxiong County, Dazi County and Qushui County were selected to participate in the study in 2014, using the stratified random sampling method. Infections with the soil-borne nematodes in feces were examined in triplicates using the Kato-Katz method. Further, the Enterobius vermicularis were examined using the cellophane anal swab method in children aged 3-12 years, and the intestinal protozoa were detected by iodine staining. The parasitic infection was analyzed by sex, age, and occupation. Comparisons were made using Chi-square test.

RESULTS

A total of 1 015 residents（39.3±18.2 years: age range, 1-89 years） participated in the study, including 391 males（38.6%） and 623 females（61.4%）. Two hundred and forty-nine participants were positive for parasitic infections, with an overall infection rate of 24.5%（249/1 015）. The infection rate was 21.7%（220/1 015） for Taenia sp., 0.2%（2/1 015） for Trichuris trichiura and E. vermicularis respectively, 4.1%（42/1 015） for Entamoeba coli, 0.4%（4/1 015） for Giardia lamblia, 0.2%（2/1 015） for Iodamoeba butschlii. No infection was found for other parasites. There was no significant sexual difference in the infection rate of Taenia (male 21.2%, 83/391; female 22.0%, 137/624), T. trichiura (male 0; female 0.3%, 2/624), E. vermicularis (male 0.3%, 2/391; female 0.2%, 1/624), E. coli (male 5.4%, 21/391; female 3.4%, 21/624), G. lamblia (male 0.8%, 3/391; female 0.2%, 1/624), or I. butschlii (male 0; female 0.3%, 2/624) (P>0.05). The Taenia sp. infection rate in the age groups of 0-17, 18-29, 30-39, 40-49, 50-59 and ≥ 60 years was 10.9%（18/165）, 14.0%（18/129）, 23.0%（43/187）, 25.3%（61/241）, 26.5%（41/155）, and 28.3%（39/138）, respectively, with significant differences between groups of 0-17 and 40-49 years and between groups of 50-59 and ≥ 60 years (P<0.01). The infection rate of E. coli, T. trichiura and I. butschlii was highest in the age group of 50-59 years（6.5%, 10/155; 0.7%, 1/155; 1.3%, 2/155 respectively）. Among various occupations, farmers showed the highest infection rate for Taenia（44.5%, 147/330）, E. coli（6.4%, 21/33）, E. vermicularis （0.6%, 2/330） and I. butschlii（0.3%, 1/330）; housewives had the highest infection rate for T. trichiura（2.5%, 1/40）; and the students had the highest infection rate for G. lamblia (0.7%, 1/134).

CONCLUSION

There are infections with various intestinal parasites in the participants of Lhasa City, among which taenia infection reaches 20.7% while others have a low level of infection.