ABSTRACT
Large-scale impact assessments of soil-transmitted helminth (STH) programs are essential for determining the frequency of mass drug administration (MDA). In baseline surveys, the prevalence of STHs in the Indian States of Chhattisgarh and Himachal Pradesh was 80.2% in 2015 and 29.0% in 2016, respectively. In 2018, we estimated the prevalence and intensity of STHs after six rounds of biannual MDA in Chhattisgarh and annual MDA in Himachal Pradesh. We conducted multistage cluster sampling surveys in preschool-age children (PSAC), school-age children (SAC), and adolescent cohorts. Stool samples from 3,033 respondents (PSAC, n = 625; SAC, n = 1,363; adolescents, n = 1,045) in Chhattisgarh and 942 respondents (PSAC, n = 192; SAC, n = 388; adolescents, n = 362) in Himachal Pradesh were examined for presence of STH infection using the Kato-Katz method. The overall cluster-adjusted prevalence in Chhattisgarh was 11.6% among all age groups (95% CI, 5.6-22.4)-an 85.5% reduction in the prevalence since 2015. Prevalence was not significantly different across cohorts (PSAC, 11.0% [95% CI, 5.0-22.6]; SAC, 10.9% [95% CI, 5.2-21.6]; adolescents, 12.8% [95% CI, 6.2-24.5]). Ascaris lumbricoides was the most common helminth, with most infections of light intensity. In Himachal Pradesh, only three STH infections were detected in 2018, resulting in a cluster-adjusted prevalence of 0.3% (95% CI, 0.1-1.7)-a 99.0% reduction in prevalence since 2016. All infections were of light intensity. Both states showed substantial improvements in socioeconomic and water, sanitation, and hygiene (WASH) indicators since the baseline surveys. Extensive reductions in prevalence and intensity are linked to sustained, high deworming coverage, as well as socioeconomic WASH indicators.
ABSTRACT
Soil-transmitted helminth (STH) infections are highly prevalent in many developing countries, affecting the poorest and most deprived communities. We conducted school-based surveys among children studying in first to fifth standard in government schools in the Indian States of Chhattisgarh, Telangana, and Tripura to estimate the prevalence and intensity of STH infections during November 2015 and January 2016. We adopted a two-stage cluster sampling design, with a random selection of districts within each agro-climatic zone in the first stage. In the second stage, government primary schools were selected by probability proportional to size method from the selected districts. We collected information about demographic details, water, sanitation, and hygiene (WASH) characteristics and stool samples from the school children. Stool samples were tested using Kato-Katz method. Stool samples from 3,313 school children (Chhattisgarh: 1,442, Telangana: 1,443, and Tripura: 428) were examined. The overall prevalence of any STH infection was 80.2% (95% confidence interval [CI]: 73.3-85.7) in Chhattisgarh, 60.7% (95% CI: 53.8-67.2) in Telangana, and 59.8% (95% CI: 49.0-69.7) in Tripura. Ascaris lumbricoides was the most prevalent STH infection in all three states. Most of the STH infections were of light intensity. Our study findings indicate that STH infections were highly prevalent among the school children in Chhattisgarh, Telangana, and Tripura, indicating the need for strengthening STH control program in these states. The prevalence estimates from the survey would serve as a baseline for documenting the impact of the National Deworming Day programs in these states.
ABSTRACT
BACKGROUND: Soil-transmitted helminth (STH) infections often affect the poorest and most deprived communities. In order to generate reliable data for planning a school based deworming program, we conducted a survey among primary school children studying in government schools in the Indian state of Uttar Pradesh. The objectives of our survey were to estimate the prevalence and intensity of STH infections. METHODS: We conducted a cross-sectional survey among children studying in 130 primary schools from 9 agro-climatic zones, during May - August 2015. Information about socio-demographic details, defecation and hand-hygiene practices, and stool samples were collected from the school children. Stool samples were examined using the Kato-Katz method. RESULTS: Stool samples from 6421 school children were examined. The overall weighted prevalence of any STH in the State was 75.6% (95% CI: 71.2-79.5). The prevalence was more than 50% in six of the nine agro-climatic zones. A. lumbricoides was the most prevalent STH (prevalence: 69.6%), followed by hookworm (prevalence: 22.6%) and T. trichura (4.6%). The majority of the STH infections were of low intensity. The practice of open defecation and not washing hands with soap after defecation and residence in kutcha house were significant risk factors of STH infection. CONCLUSIONS: STH prevalence among primary school children in Uttar Pradesh was high. Given the WHO guidelines on deworming frequency according to STH prevalence, Govt of Uttar Pradesh needs to implement a school-based deworming program with bi-annual frequency. The findings of our survey would also help monitor the performance of school based deworming programme.
