{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,29]],"date-time":"2026-08-29T06:49:22Z","timestamp":1787986162756,"version":"build-2784847793"},"update-to":[{"DOI":"10.12688\/gatesopenres.13077.1","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2019,12,4]],"date-time":"2019-12-04T00:00:00Z","timestamp":1575417600000}}],"reference-count":32,"publisher":"F1000 Research Ltd","license":[{"start":{"date-parts":[[2019,12,4]],"date-time":"2019-12-04T00:00:00Z","timestamp":1575417600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003246","name":"Nederlandse Organisatie voor Wetenschappelijk Onderzoek","doi-asserted-by":"publisher","award":["016.Veni.178.023"],"award-info":[{"award-number":["016.Veni.178.023"]}],"id":[{"id":"10.13039\/501100003246","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000865","name":"Bill and Melinda Gates Foundation","doi-asserted-by":"publisher","award":["OPP1184344"],"award-info":[{"award-number":["OPP1184344"]}],"id":[{"id":"10.13039\/100000865","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["gatesopenresearch.org"],"crossmark-restriction":false},"short-container-title":["Gates Open Res"],"abstract":"<ns4:p>Soil-transmitted helminths (STHs) are a group of parasitic worms that infect humans, causing a wide spectrum of disease, notably anaemia, growth retardation, and delayed cognitive development. The three main STHs are <ns4:italic>Ascaris lumbricoides<\/ns4:italic>, <ns4:italic>Trichuris trichiura<\/ns4:italic> and hookworm (<ns4:italic>Necator americanus<\/ns4:italic> and <ns4:italic>Ancylostoma duodenale<\/ns4:italic>). Approximately 1.5 billion people are infected with STHs worldwide. The World Health Organization goal for 2030 is morbidity control, defined as reaching &lt;2% prevalence of medium-to-high intensity infections in preschool-age children and school-age children (SAC). Treatment guidelines for achieving this goal have been recommended. The Neglected Tropical Diseases Modelling Consortium has developed mathematical and statistical models to quantify, predict, and evaluate the impact of control measures on STHs. These models show that the morbidity target can be achieved following current guidelines in moderate prevalence settings (20-50% in SAC). In high prevalence settings, semi-annual preventive chemotherapy (PC) ideally including adults, or at least women of reproductive age, is required. For <ns4:italic>T. trichiura<\/ns4:italic>, dual therapy with albendazole and ivermectin is required. In general, stopping PC is not possible without infection resurgence, unless effective measures for improved access to water, hygiene, and sanitation have been implemented, or elimination of transmission has been achieved. Current diagnostic methods are based on egg counts in stool samples, but these are known to have poor sensitivity at low prevalence levels. A target threshold for novel, more sensitive diagnostics should be defined relative to currently preferred diagnostics (Kato-Katz). Our analyses identify the extent of systematic non-access to treatment and the individual patterns of compliance over multiple rounds of treatment as the biggest unknowns and the main impediment to reaching the target. Moreover, the link between morbidity and infection intensity has not been fully elucidated. By providing more insights on all the above, we aim to inform discussions on the goals and treatment guidelines for STHs.<\/ns4:p>","DOI":"10.12688\/gatesopenres.13077.2","type":"journal-article","created":{"date-parts":[[2019,12,4]],"date-time":"2019-12-04T07:45:08Z","timestamp":1575445508000},"page":"1632","update-policy":"https:\/\/doi.org\/10.12688\/gatesopenres.crossmark-policy","source":"Crossref","is-referenced-by-count":15,"title":["Insights from quantitative analysis and mathematical modelling on the proposed WHO 2030 goals for soil-transmitted helminths"],"prefix":"10.12688","volume":"3","author":[{"name":"NTD Modelling Consortium discussion group on soil-transmitted helminths","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"2560","published-online":{"date-parts":[[2019,12,4]]},"reference":[{"key":"ref-1","article-title":"Soil-transmitted helminth infections"},{"key":"ref-2","first-page":"35-42","article-title":"A comparison 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Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/gatesopenresearch.org\/articles\/3-1632\/v2\/xml","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/gatesopenresearch.org\/articles\/3-1632\/v2\/pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/gatesopenresearch.org\/articles\/3-1632\/v2\/iparadigms","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,12,4]],"date-time":"2019-12-04T07:45:10Z","timestamp":1575445510000},"score":1,"resource":{"primary":{"URL":"https:\/\/gatesopenresearch.org\/articles\/3-1632\/v2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,12,4]]},"references-count":32,"URL":"https:\/\/doi.org\/10.12688\/gatesopenres.13077.2","relation":{},"ISSN":["2572-4754"],"issn-type":[{"value":"2572-4754","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,12,4]]},"assertion":[{"value":"Indexed","URL":"https:\/\/gatesopenresearch.org\/articles\/3-1632\/v2#article-reports","order":0,"name":"referee-status","label":"Referee status","group":{"name":"current-referee-status","label":"Current Referee Status"}},{"value":"10.21956\/gatesopenres.14216.r28131, Rubina Imtiaz, Children Without Worms, The Task Force for Global Health, Decatur, GA, USA, 05 Nov 2019, version 1, indexed","URL":"https:\/\/gatesopenresearch.org\/articles\/3-1632\/v1#referee-response-28131","order":0,"name":"referee-response-28131","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"10.21956\/gatesopenres.14216.r28134, Suzy J. Campbell, Evidence Action: Deworm the World Initiative, Washington, DC, USA, 18 Nov 2019, version 1, indexed","URL":"https:\/\/gatesopenresearch.org\/articles\/3-1632\/v1#referee-response-28134","order":1,"name":"referee-response-28134","label":"Referee Report","group":{"name":"article-reports","label":"Article Reports"}},{"value":"<b>Luc Edgar Coffeng<\/b>; \n<i>Posted: 02 Dec 2019<\/i>; \n<b>Reviewer 2: <\/b>Is the authors\u2019 recommendation of 75% community-wide coverage applicable to all settings, or has this extended beyond what is required for the current morbidity control goal?&nbsp;\n<b>Answer: <\/b>As mentioned in the paper, community-wide coverage of 75% is especially important for settings where hookworm is the dominant STH. This is because of the age-prevalence profile of hookworm where adults bear the main burden of infection. In settings where \n<i>A. lumbricoides<\/i> or \n<i>T. trichiura<\/i> are the dominant species 75% coverage in adults is probably not strictly necessary provided that the coverage in pre-SAC and SAC is sufficiently high, because the age-prevalence profile peaks in children. We have not run simulations to determine the minimum PC coverage of adults required to reach the morbidity target in settings where \n<i>A. lumbricoides<\/i> or \n<i>T. trichiura<\/i> are the dominant species, given that 75% coverage of preSAC and SAC is achieved. The minimum PC coverage of adults required in these settings will depend on the baseline prevalence and transmission intensity.&nbsp;\n<b>Reviewer 2:<\/b> The authors are kindly requested to elucidate further on the statement (Discussion) that \u201cit is predicted that EOT can be achieved in low-transmission settings where \n<i>Ascaris lumbricoides<\/i> or \n<i>T. trichiura<\/i> are the dominant parasites by annual treatment of SAC\u201d. If this is the case, but this manuscript has investigated achieving the goal for scenarios \n<u>above 20%<\/u>, it seems unlikely that EOT would enter into consideration and thus, preventive chemotherapy would have to continue.&nbsp;\n<b>Answer:<\/b> The conclusion that EOT can be reached in low-transmission settings comes from earlier simulation studies that classified transmission settings using the basic reproductive number R\n<sub>0,<\/sub> rather than baseline prevalence (1). Any given value of R\n<sub>0<\/sub> does not directly translate into a particular prevalence of infection, because the prevalence also depends on other model parameters, such as the aggregation parameter k (describes the tendency that a few individuals will be infected by many worms while most individuals will have low-intensity infections) and the density-dependence of female worm fecundity. However, in general, low-prevalence settings will also have low transmission intensities (low R\n<sub>0<\/sub>) values. Therefore, one can predict that EOT can be achieved in low-transmission\/low-prevalence settings. Moreover, it is possible that some moderate-prevalence settings also have low-transmission intensity as measured by R\n<sub>0<\/sub>. This needs to be estimated on a case-by-case basis. In these settings, EOT can also be achieved.It is true that in settings where EOT cannot be achieved using current MDA strategies (all high-prevalence settings and some moderate-prevalence settings) and WASH facilities are not improved to the degree that transmission ceases, MDA would have to be continued indefinitely.&nbsp;\n<b>Reviewer 2:<\/b> If neither WASH access nor EOT are feasible, then preventive chemotherapy needs to be sustained. This recommendation for indefinite preventive chemotherapy warrants further projections, for example to a second impact assessment, to determine for how long this may need to be the case. Potentially there could be recommendations for a second assessment layer to the decision trees (e.g., hypothetically after 10 years of MDA).&nbsp;\n<b>Answer:<\/b> We agree with Reviewer 2 that repeated impact assessments are necessary where EOT cannot be achieved by MDA and\/or WASH measures.\n<b>Reviewer 2:<\/b> The authors recommend co-administered albendazole-ivermectin against\n<i> T. trichiura<\/i>, and also community-wide treatment when hookworm is the dominant infection. This differentiation of some of the STH is welcomed, but WHO guidelines are for undifferentiated STH. Can the authors please advise what level of \n<i>T. trichiura<\/i> prevalence\/intensity would be the recommended \u2018trigger\u2019 for co-administration? What level of hookworm prevalence\/intensity would be the trigger for risk mitigation activities such as expanding treatments to additional cohorts? Were helminth-specific cutpoints considered in the modelling to arrive at the optimum treatment requirements?&nbsp;\n<b>Answer:<\/b> In the simulation models, cut-off points were investigated for each helminth species separately. We did not investigate settings where several STH species are present simultaneously. However, we would expect that cut-off values for one species would still be valid, regardless for the presence of other STH species. It follows that co-administration of albendazole-ivermectin in the case of \n<i>T. trichiura<\/i> or community-wide treatment in the case of hookworm are recommended when the prevalence of either species is above 20%. We have not investigated if intensified PC strategies are necessary where species-specific prevalences are lower.&nbsp;\n<b>Reviewer 2<\/b>: Similarly, can the authors please indicate what aspects of \u201ceffective WASH\u201d were modelled \u2013 was this access to a latrine, access to a water source, combined interventions, etc?&nbsp;\n<b>Answer:<\/b> The WASH simulation study (2) distinguished two WASH modalities: sanitation, which reduces individuals\u2019 contributions to environmental contamination, for example, access to latrines; and hygiene, which reduces individuals\u2019 exposure to infection, for example hand washing, access to clean water sources. Both sanitation and hygiene measures in isolation and in combination were investigated. One interesting finding was that the impact of hygiene is determined more by the effectiveness of the intervention than its overall uptake, whereas the impact of sanitation depends more directly on the product of uptake and the effectiveness.&nbsp;&nbsp;&nbsp;1.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Truscott JE, Hollingsworth TD, Brooker SJ, Anderson RM. Can chemotherapy alone eliminate the transmission of soil transmitted helminths? Parasites &amp; vectors. 2014;7:266.2.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Coffeng LE, Vaz Nery S, Gray DJ, Bakker R, de Vlas SJ, Clements ACA. Predicted short and long-term impact of deworming and water, hygiene, and sanitation on transmission of soil-transmitted helminths. PLoS neglected tropical diseases. 2018;12(12):e0006758.","URL":"https:\/\/gatesopenresearch.org\/articles\/3-1632\/v2#referee-comment-3247","order":2,"name":"referee-comment-3247","label":"Referee Comment","group":{"name":"article-reports","label":"Article Reports"}},{"value":"This work was supported by the Bill and Melinda Gates Foundation [OPP1184344]. Luc E. Coffeng was supported by a personal grant from the Dutch Research Council (Nederlandse Organisatie voor Wetenschappelijk Onderzoek [016.Veni.178.023]). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.","order":3,"name":"grant-information","label":"Grant Information"},{"value":"This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.","order":0,"name":"copyright-info","label":"Copyright"}]}}