02589nas a2200241 4500000000100000008004100001653003900042653003100081653001900112100001500131700001400146700001500160700001400175700001100189700001200200700001500212245015400227856003300381300001400414490000700428520189800435022001402333 2018 d10aNeglected tropical diseases (NTDs)10aSoil-transmitted helminths10aWHO Guidelines1 aFarrell SH1 aCoffeng L1 aTruscott J1 aWerkman M1 aToor J1 aVlas SJ1 aAnderson R00aInvestigating the effectiveness of current and modified World Health Organization guidelines for the control of soil-transmitted helminth infections. uhttps://tinyurl.com/yatlvxox aS253-S2590 v663 a

Background: Considerable efforts have been made to better understand the effectiveness of large-scale preventive chemotherapy therapy for the control of morbidity caused by infection with soil-transmitted helminths (STHs): Ascaris lumbricoides, Trichuris trichiura, and the 2 hookworm species, Necator americanus and Ancylostoma duodenale. Current World Health Organization (WHO) guidelines for STH control include mass drug administration (MDA) programs based on prevalence measurements, aiming at reducing morbidity in pre-school-aged children (pre-SAC) and school-aged children (SAC) by lowering the prevalence of moderate- to heavy-intensity infections to <1%.

Methods: We project the likely impact of following the current WHO guidelines and assess whether the WHO morbidity goals will be achieved across a range of transmission settings. We also investigate modifications that could be made to the current WHO treatment guidelines, and project their potential impacts in achieving morbidity and transmission control.

Results: While the standard guidelines are sufficient at low transmission levels, community-wide treatment (ie, involving pre-SAC, SAC, and adults) is essential if WHO morbidity goals are to be met in moderate- to high-transmission settings. Moreover, removing the recommendation of decreasing the treatment frequency at midline (5-6 years after the start of MDA) further improves the likelihood of achieving morbidity control in SAC.

Conclusions: We meld analyses based on 2 mathematical models of parasite transmission and control by MDA for the dominant STH species, to generate a unified treatment approach applicable across all settings, regardless of which STH infection is most common. We recommend clearly defined changes to the current WHO guidelines.

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