Unprogrammed Deworming in the Kibera Slum, Nairobi: Implications for Control of Soil-Transmitted Helminthiases

Abstract

BackgroundPrograms for control of soil-transmitted helminth (STH) infections are increasingly evaluating national mass drug administration (MDA) interventions. However, “unprogrammed deworming” (receipt of deworming drugs outside of nationally-run STH control programs) occurs frequently. Failure to account for these activities may compromise evaluations of MDA effectiveness.MethodsWe used a cross-sectional study design to evaluate STH infection and unprogrammed deworming among infants (aged 6–11 months), preschool-aged children (PSAC, aged 1–4 years), and school-aged children (SAC, aged 5–14 years) in Kibera, Kenya, an informal settlement not currently receiving nationally-run MDA for STH. STH infection was assessed by triplicate Kato-Katz. We asked heads of households with randomly-selected children about past-year receipt and source(s) of deworming drugs. Local non-governmental organizations (NGOs) and school staff participating in school-based deworming were interviewed to collect information on drug coverage.ResultsOf 679 children (18 infants, 184 PSAC, and 477 SAC) evaluated, 377 (55%) reported receiving at least one unprogrammed deworming treatment during the past year. PSAC primarily received treatments from chemists (48.3%) or healthcare centers (37.7%); SAC most commonly received treatments at school (55.0%). Four NGOs reported past-year deworming activities at 47 of >150 schools attended by children in our study area. Past-year deworming was negatively associated with any-STH infection (34.8% vs 45.4%, p = 0.005). SAC whose most recent deworming medication was sourced from a chemist were more often infected with Trichuris (38.0%) than those who received their most recent treatment from a health center (17.3%) or school (23.1%) (p = 0.05).ConclusionUnprogrammed deworming was received by more than half of children in our study area, from multiple sources. Both individual-level treatment and unprogrammed preventive chemotherapy may serve an important public health function, particularly in the absence of programmed deworming; however, they may also lead to an overestimation of programmed MDA effectiveness. A standardized, validated tool is needed to assess unprogrammed deworming.

The Role of Child Health Days in the Attainment of Global Deworming Coverage Targets among Preschool-Age Children

“…This data gap is due to incomplete reporting of CHD activities to WHO Geneva. Similar reporting gaps have been observed previously for deworming medications delivered by non-governmental organizations [ 26 ] and for deworming drugs delivered outside of national STH control programs [ 27 ]. Ideally, national Ministry of Health NTD focal persons would collect and report deworming coverage to WHO Geneva.…”

Compliance with anthelmintic treatment in the neglected tropical diseases control programmes: a systematic review

“…Although rarely mentioned by respondents, another reason for non-compliance is already having received treatment by sources other than nationally-run STH control programmes. “Unprogrammed deworming” occurs frequently, and although it may play an important role in the absence of government deworming, it may also overestimate the effectiveness of PCT [ 45 ] and has complicated implications on reports of coverage and compliance. This is undoubtedly another crucial area that will require further attention and research.…”

A Cross-Sectional Study of Water, Sanitation, and Hygiene-Related Risk Factors for Soil-Transmitted Helminth Infection in Urban School- and Preschool-Aged Children in Kibera, Nairobi

“…Among children selected, 82.1% currently attend nursery, primary, or secondary school. In all, 56.2% of children were reported to have received anthelminthic medication in the last 12 months from a variety of sources, described elsewhere [ 22 , 37 ]. Deworming in the last 12 months was significantly associated with a reduction in STH infection prevalence (PR = 0.80; 95%CI = 0.66–0.96).…”