Abstract:

Objective To understand and analyze the prevalence and endemic status of Ascaris lumbricoides infection in Jiangxi province, so as to provide scientific basis for the development of control strategy. Methods A survey was performed in Jiangxi Province according to the protocol detailed by the 3rd National Investigation of Human Key Parasitic Infections in 2014. Total 92 survey sites in 32 counties were chosen using stratified cluster sampling method based on the different ecological, economical and geographical status. More than 250 permanent residents with age over 3 years old were involved in each site. The stool samples were collected from each participant and the eggs of A. lumbricoides in the stool samples were microscopically examined by Kato-Katz technique in duplicate. The difference in infection rate was compared between different groups of participants using the chi-square test. Results A total of 23 606 villagers were surveyed and the overall prevalence of A. lumbricoides infection among the investigated population was 0.87% (206/23 606). The infection of A. lumbricoides was found in the 20 of 32 surveyed counties with highest prevalence in Yudu (5.35%, 42/785), which is statistically different compared with prevalence in other surveyed counties (P < 0.01). For the prevalence in different ecological regions, the prevalence in Nanling ecological region(1.65%, 78/4 742) was significantly higher than that in Zhejiang/Fujian ecological region (0.10%, 6/5 887)（P < 0.05). The prevalence of A. lumbricoides infection in male villagers was 0.75% (86/11 538) that is not significantly different compared with the prevalence in female (0.99%, 120/12 068)(P > 0.05). Among 206 infected people, 97 were identified with fertilized eggs (47.09%), 109 were identified with unfertilized eggs (52.91%), and 46 were identified with mixed fertilized and unfertilized eggs. The infection was found in all age groups with the highest infection rate in the 30-39 year group(1.14%, 28/2 465). For the occupation distribution, the infection rate was highest in businessman (1.50%, 4/267) and lowest in unemployed people (0). In terms of education, the infection rate was highest in the people with illiteracy (1.13%, 43/3 818), and lowest in people with high school (0.49%, 8/1 631). There is statistical difference among the people with different age groups, occupations, and education level, respectively (P < 0.01). Conclusion The prevalence of A. lumbricoides has dropped to the lowest level in Jiangxi Province. More unfertilized eggs were identified than fertilized eggs in the infected people. However, the regional distribution of A. lumbricoides infection was regionally discrepant with some areas with high infection, which is still one of the key issues for the control of ascariasis in Jiangxi Province.

Key words: Parasitic disease, Ascaris lumbricoides, Epidemic, Jiangxi Province