Effects, equity, and cost of school-based and community-wide treatment strategies for soil-transmitted helminths in Kenya: a cluster-randomised controlled trial

Abstract

Summary Background School-based deworming programmes can reduce morbidity attributable to soil-transmitted helminths in children but do not interrupt transmission in the wider community. We assessed the effects of alternative mass treatment strategies on community soil-transmitted helminth infection. Methods In this cluster-randomised controlled trial, 120 community units (clusters) serving 150 000 households in Kenya were randomly assigned (1:1:1) to receive albendazole through annual school-based treatment targeting 2–14 year olds or annual or biannual community-wide treatment targeting all ages. The primary outcome was community hookworm prevalence, assessed at 12 and 24 months through repeat cross-sectional surveys. Secondary outcomes were Ascaris lumbricoides and Trichuris trichiura prevalence, infection intensity of each soil-transmitted helminth species, and treatment coverage and costs. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov , number NCT02397772 . Findings After 24 months, prevalence of hookworm changed from 18·6% (95% CI 13·9–23·2) to 13·8% (10·5–17·0) in the annual school-based treatment group, 17·9% (13·7–22·1) to 8·0% (6·0–10·1) in the annual community-wide treatment group, and 20·6% (15·8–25·5) to 6·2% (4·9–7·5) in the biannual community-wide treatment group. Relative to annual school-based treatment, the risk ratio for annual community-wide treatment was 0·59 (95% CI 0·42–0·83; p<0·001) and for biannual community-wide treatment was 0·46 (0·33–0·63; p<0·001). More modest reductions in risk were observed after 12 months. Risk ratios were similar across demographic and socioeconomic subgroups after 24 months. No adverse events related to albendazole were reported. Interpretation Community-wide treatment was more effective in reducing hookworm prevalence and intensity than school-based treatment, with little additional benefit of treating every 6 months, and was shown to be remarkably equitable in coverage and effects. Funding Bill & Melinda Gates Foundation, the Joint Global Health Trials Scheme of the Medical Research Council, the UK Department for International Development, the Wellcome Trust, and the Children's Investment Fund Foundation.

Implementer and recipient perspectives of community-wide mass drug administration for soil-transmitted helminths in Kwale County, Kenya

“…Multiple studies have focused on the effectiveness and acceptability of MDA for these diseases [5][6][7][8]; however, there is limited evidence supporting the use of community-wide MDA for STH. The TUMIKIA Project, conducted in Kenya, was the first cluster randomized control trial assessing the effectiveness, equity, and cost of school-based versus community-wide treatment strategies on the prevalence and intensity of STH infection [9,10]. The impact results concluded that community-wide MDA was more effective in reducing hookworm prevalence and intensity across all age groups than school-based delivery, providing much needed evidence on the feasibility and effectiveness of community-wide MDA for STH control [9].…”

The ‘breakpoint’ in transmission for soil-transmitted helminths: dynamical behaviour near the equilibria and the impact of infected human migration

“…(B.11) 11 There is a subtlety here in the choice of initial condition: due to the discontinuity at the boundary, an additional component of βδL(t pul ) t pul e −µ 2 (t−t pul ) dt β µ 2 δL(t pul ) must be added to the initial worm burden from the infectious reservoir pulse, such that M(t 0 ) = M(t pul ) + β µ 2 δL(t pul ).…”

“…Eqs. (11) and (13) thus immediately indicate that a mechnism for fluctuation to or away from the equilibria in, e.g., Fig. 1, is possible and that a deeper study of the dynamics of the system is necessary in order to fully understand the ramifications.…”

“…In these circumstances, recent research has focused on the question of whether MDA (if administered * r.hardwick@imperial.ac.uk at high coverage, frequently and targeted at large sections of the community) can, on its own, eliminate helminth parasite transmission [7,8,9,10]. For STH, a number of large-scale trials are currently underway in regions of endemic infection to test this notion [11,12].…”

Domains of transmission and association of community, school, and household sanitation with soil-transmitted helminth infections among children in coastal Kenya

“…Study design, baseline findings, and impact have been described previously (17, 18) (Halliday KE, Oswald WE, Mcharo C, Beaumont E, Gichuki PM, Kepha S, et al Community-level epidemiology of soil-transmitted helminths in the context of school-based deworming: Baseline results of a cluster randomised trial on the coast of Kenya. In Press).…”