Abstract:

Objective To understand the endemic status of soil-transmitted helminth (STH) infections in Fujian Province so as to provide evidence-based information for the better prevention and control. Methods An epidemiological survey was performed in pilot sites selected by stratified cluster random sampling method based on the ecological zone, economic level and geographic location in Fujian Province from 2014 to 2015. The modified Kato-Katz thick smear method was used to examine fecal samples in duplicate to detect eggs of STH. The Enterobius vermicularis infection in children under 12 years old was examined using an anal tape test. The chi-square test was used to determine the statistical difference in infection rates between different population and areas. Results The fecal examination was performed in total 17 090 people from 63 pilot study sites in 25 counties, Fujian Province. Among them 560 people were found to be infected with STH’ with average infection rate of 3.28%. The prevalence of STH has been reduced by 95.76% compared with the infection rate of 77.30% (41 290/53 416) in the first province-wide survey in 1992 and by 90.89% compared to the second survey performed in 2003 (36.01%, 7 300/20 195). Among the three STH, hookworm had the highest infection rate in the investigated population (3.03%, 518/17 090), followed by infections of Trichuris trichiura (0.20%, 34/17 090) and Ascaris lumbricoides (0.05%, 8/17 090). Regarding the infection location, the infection rate of STH in Sanming area was among the highest (9.21%, 154/1 673), and Ningde was among the lowest (0.20%, 3/1 514). The prevalence in female people was 3.72% (325/8 728), which was higher than 2.81% (235/8 362) in males with statistical difference (χ² = 11.24, P < 0.01). The prevalence of STH infection in the areas of Zhejiang/Fujian Mountain Ecological Zone was 3.52% (271/7 701), which was not statistically different (χ² = 2.60, P > 0.05) compared to the prevalence in the areas of Yunnan/Guangxi/Guangdong/Fujian Mountain Ecological Zone. Generally, the prevalence of STH infections in different age groups increased with age, with the lowest infection rate in children of 3-9 years old (0.43%, 9/2 076) and the highest infection rate in old people of 60-69 years old (7.34%, 180/2 453) (χ² = 314.64, P < 0.01). The farmers had the highest infection rate of 4.33% (524/12 095) compared with other occupations with statistical significance (χ² = 151.02, P < 0.01). The prevalence of STH was higher in people with primary school education only (4.09%, 322/7 875) compared with people with higher education level (χ² = 48.00, P < 0.01). A total of 3 472 children under the age of 12 were examined for E. vermicularis infection and 205 people were found to be positive with a infection rate of 5.90%. Conclusion The infection rate of soil-transmitted helminthes in Fujian Province has continuously declined since the first survey in 1992, and it is at a low prevalence level. However, farmers and the elderly are the key groups of people that need more attention to pay for the prevention and control of STH. Hookworm is the major STH that infects people in the Province and children is still vulnerable to the infection of E. vermicularis.

Key words: Fujian Province, Soil-transmitted helminth, Infection, Survey