Prospects for elimination of soil-transmitted helminths

Abstract

a,bPurpose of review Soil-transmitted helminths (STH) are endemic in 120 countries and are associated with substantial morbidity and loss of economic productivity. Although current WHO guidelines focus on morbidity control through mass drug administration (MDA), there is global interest in whether a strategy targeting disease elimination might be feasible in some settings. This review summarizes the prospects for switching from control to an elimination strategy.Recent findings STH control efforts have reduced the intensity of infections in targeted populations with associated reductions in morbidity. However, adults are not frequently targeted and remain important reservoirs for reinfection of treated children. Recent modeling suggests that transmission interruption may be possible through expanded community-wide delivery of MDA, the feasibility of which has been demonstrated by other programs. However, these models suggest that high levels of coverage and compliance must be achieved. Potential challenges include the risk of prematurely dismantling STH programs and the potential increased risk of antihelminthic resistance. SummaryElimination of STH may offer an opportunity to eliminate substantial STH-related morbidity while reducing resource needs of neglected tropical disease programs. Evidence from large community trials is needed to determine the feasibility of interrupting the transmission of STH in some geographic settings.

Comparison of multi-parallel qPCR and double-slide Kato-Katz for detection of soil-transmitted helminth infection among children in rural Bangladesh

“…Mass drug administration (MDA) programs have yielded large reductions in STH infection prevalence and intensity to date [4]. While the World Health Organization has set goals for STH focused on morbidity control [5], there is an active body of research focused on whether local elimination of STH is possible in endemic settings through community-wide MDA for deworming [6][7][8][9]. As STH infection intensity and prevalence wane, increasingly sensitive diagnostic methods are required to determine whether STH transmission has been interrupted and when interventions can be scaled back or discontinued [10].…”

Evaluation of Hookworm Diagnosis Techniques from Patients in Amhara Region, Ethiopia: Cross sectional study

“…The prevention and control of hookworm infection involves many approaches like sanitary disposal of feces, early diagnosis, and chemotherapy and Health education (7)(8)(9)(10). However, improper diagnosis and emergence of drug resistances could threaten the prevention and control of the parasite (11,12).…”

Defining stopping criteria for ending randomized clinical trials that investigate the interruption of transmission of soil-transmitted helminths employing mass drug administration

“…As such, only targeting a small fraction of the infected community results in the requirement for ongoing MDA for morbidity control [ 3 – 6 ]. If interruption of transmission can be achieved, cost savings will be observed in countries that can phase out STH MDA programs and drug donations by pharmaceutical companies could cease [ 7 , 8 ]. At present, the possibility of broadening treatment coverage to include adults for STH (in line with the lymphatic filariasis MDA programme), with the longer-term DeWorm3 goal of interrupting STH transmission beyond 2020 using MDA alone is being investigated.…”

“…From the 1970’s, several countries (including South Korea) scaled up their MDA programmes (SAC) and prevalence was reduced to less than 0.1% for all STH species by 2004, though this coincided with economic development and hygiene improvement [ 8 , 12 ]. Such improvements are slow to materialize in many countries that currently have endemic STH infections [ 13 , 14 ].…”