{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,29]],"date-time":"2026-08-29T06:49:23Z","timestamp":1787986163642,"version":"build-2784847793"},"reference-count":47,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,3,24]],"date-time":"2021-03-24T00:00:00Z","timestamp":1616544000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100004330","name":"GlaxoSmithKline","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100004330","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Public Health"],"abstract":"<jats:p>Kenya, just like other countries with endemic soil-transmitted helminths (STH), has conducted regular mass drug administration (MDA) program for the last 5 years among school aged children as a way to reduce STH infections burden in the country. However, the point of interruption of transmission of these infections still remains unclear. In this study, we developed and analyzed an age structured mathematical model to predict the elimination period (i.e., time taken to interrupt STH transmission) of these infections in Kenya. The study utilized a deterministic age structured model of the STH population dynamics under a regular treatment program. The model was applied to three main age groups: pre-school age children (2\u20134 years), school age children (5\u201314 years), and adult populations (\u226515 years) and compared the impact of two interventions on worm burden and elimination period. The model-simulated results were compared with the 5 year field data from the Kenyan deworming program for all the three types of STH (<jats:italic>Ascaris lumbricoides, Trichuris trichiura<\/jats:italic>, and hookworm). The model demonstrated that the reduction of worm burden and elimination period depended heavily on four parameter groups; drug efficacy, number of treatment rounds, MDA and water, sanitation and hygiene (WASH) coverage. The analysis showed that for STH infections to be eliminated using MDA alone in a short time period, 3-monthly MDA plan is desired. However, complementation of MDA with WASH at an optimal (95%) coverage level was most effective. These results are important to the Kenyan STH control program as it will guide the recently launched <jats:italic>Breaking Transmission Strategy<\/jats:italic>.<\/jats:p>","DOI":"10.3389\/fpubh.2021.637866","type":"journal-article","created":{"date-parts":[[2021,3,24]],"date-time":"2021-03-24T04:28:50Z","timestamp":1616560130000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":9,"title":["Modeling the Interruption of the Transmission of Soil-Transmitted Helminths Infections in Kenya: Modeling Deworming, Water, and Sanitation Impacts"],"prefix":"10.3389","volume":"9","author":[{"given":"Collins","family":"Okoyo","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Graham","family":"Medley","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Charles","family":"Mwandawiro","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nelson","family":"Onyango","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,3,24]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1186\/1756-3305-7-37","article-title":"Global numbers of infection and disease burden of soil transmitted helminth infections in 2010","volume":"7","author":"Pullan","year":"2014","journal-title":"Parasit Vectors"},{"key":"B2","volume-title":"Accelerating Work to Overcome the Global Impact of Neglected Tropical Diseases: A Roadmap for Implementation: Executive Summary","year":"2012"},{"key":"B3","volume-title":"Investing to Overcome the Global Impact of Neglected Tropical Diseases: Third WHO Report on Neglected Tropical Diseases 2015","year":"2015"},{"key":"B4","doi-asserted-by":"publisher","first-page":"341","DOI":"10.1016\/j.idc.2012.02.006","article-title":"Nematode infections: soil-transmitted helminths and Trichinella","volume":"26","author":"Knopp","year":"2012","journal-title":"Infect Dis Clin"},{"key":"B5","doi-asserted-by":"publisher","first-page":"e0006758","DOI":"10.1371\/journal.pntd.0006758","article-title":"Predicted short and long-term impact of deworming and water, hygiene, and sanitation on transmission of soil-transmitted helminths","volume":"12","author":"Coffeng","year":"2018","journal-title":"PLoS Negl Trop Dis"},{"key":"B6","doi-asserted-by":"publisher","first-page":"928","DOI":"10.1016\/j.ijheh.2017.05.007","article-title":"The impact of sanitation on infectious disease and nutritional status: a systematic review and meta-analysis","volume":"220","author":"Freeman","year":"2017","journal-title":"Int J Hyg Environ Health"},{"key":"B7","volume-title":"Working to Overcome the Global Impact of Neglected Tropical Diseases: First WHO Report on Neglected Tropical Diseases","year":"2010"},{"key":"B8","doi-asserted-by":"publisher","first-page":"197","DOI":"10.1016\/S0065-308X(10)73008-6","article-title":"The drugs we have and the drugs we need against major helminth infections","volume":"73","author":"Keiser","year":"2010","journal-title":"Adv Parasitol"},{"key":"B9","doi-asserted-by":"publisher","first-page":"413","DOI":"10.1645\/0022-3395(2001)087[0413:ACSODA]2.0.CO;2","article-title":"A comparative study of different albendazole and mebendazole regimens for the treatment of intestinal infections in school children of Usigu Division, western Kenya","volume":"87","author":"Muchiri","year":"2001","journal-title":"J Parasitol"},{"key":"B10","volume-title":"Guideline: Preventive Chemotherapy to Control Soil-Transmitted Helminth Infections in At-Risk Population Groups","year":"2017"},{"key":"B11","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1186\/s13071-017-1979-x","article-title":"Assessing the interruption of the transmission of human helminths with mass drug administration alone: optimizing the design of cluster randomized trials","volume":"10","author":"Anderson","year":"2017","journal-title":"Parasit Vectors"},{"key":"B12","doi-asserted-by":"publisher","first-page":"e0006166","DOI":"10.1371\/journal.pntd.0006253","article-title":"Assessing the feasibility of interrupting the transmission of soil-transmitted helminths through mass drug administration: the DeWorm3 cluster randomized trial protocol","volume":"12","author":"\u00c1sbj\u00f6rnsd\u00f3ttir","year":"2018","journal-title":"PLoS Negl Trop Dis"},{"key":"B13","volume-title":"Helminth Control in School-Age Children: A Guide for Managers of Control Programmes","year":"2011"},{"key":"B14","doi-asserted-by":"publisher","first-page":"123","DOI":"10.1186\/s13071-016-1406-8","article-title":"Efficacy and reinfection with soil-transmitted helminths 18-weeks post-treatment with albendazole-ivermectin, albendazole-mebendazole, albendazole-oxantel pamoate and mebendazole","volume":"9","author":"Speich","year":"2016","journal-title":"Parasit Vectors"},{"key":"B15","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1186\/s13071-017-2206-5","article-title":"The importance of patient compliance in repeated rounds of mass drug administration (MDA) for the elimination of intestinal helminth transmission","volume":"10","author":"Farrell","year":"2017","journal-title":"Parasit Vectors"},{"key":"B16","doi-asserted-by":"publisher","first-page":"389","DOI":"10.1017\/S0031182000078422","article-title":"The development and validation of an age-structured model for the evaluation of disease control strategies for intestinal helminths","volume":"109","author":"Chan","year":"1994","journal-title":"Parasitology"},{"key":"B17","doi-asserted-by":"publisher","first-page":"159","DOI":"10.1111\/j.1468-0262.2004.00481.x","article-title":"Worms: identifying impacts on education and health in the presence of treatment externalities","volume":"72","author":"Miguel","year":"2004","journal-title":"Econometrica"},{"key":"B18","doi-asserted-by":"publisher","first-page":"e0004214","DOI":"10.1371\/journal.pntd.0004214","article-title":"The case for mass treatment of intestinal helminths in endemic areas","volume":"9","author":"Hicks","year":"2015","journal-title":"PLoS Negl Trop Dis"},{"key":"B19","doi-asserted-by":"publisher","first-page":"198","DOI":"10.1186\/1756-3305-6-198","article-title":"Monitoring and evaluating the impact of national school-based deworming in Kenya: study design and baseline results","volume":"6","author":"Mwandawiro","year":"2013","journal-title":"Parasit Vectors"},{"key":"B20","doi-asserted-by":"publisher","first-page":"76","DOI":"10.1186\/s13071-019-3322-1","article-title":"Results of a national school-based deworming programme on soil-transmitted helminths infections and schistosomiasis in Kenya: 2012\u20132017","volume":"12","author":"Mwandawiro","year":"2019","journal-title":"Parasit Vectors"},{"key":"B21","doi-asserted-by":"publisher","first-page":"408","DOI":"10.1186\/s13071-016-1679-y","article-title":"Monitoring the impact of a national school based deworming programme on soil-transmitted helminths in Kenya: the first three years, 2012\u20132014","volume":"9","author":"Okoyo","year":"2016","journal-title":"Parasit Vectors"},{"key":"B22","doi-asserted-by":"publisher","first-page":"e0008604","DOI":"10.1371\/journal.pntd.0008604","article-title":"Prevalence, intensity and associated risk factors of soil-transmitted helminth and schistosome infections in Kenya: impact assessment after five rounds of mass drug administration in Kenya","volume":"14","author":"Okoyo","year":"2020","journal-title":"PLoS Negl Trop Dis"},{"key":"B23","doi-asserted-by":"publisher","first-page":"e0007514","DOI":"10.1371\/journal.pntd.0007514","article-title":"Sampling strategies for monitoring and evaluation of morbidity targets for soil-transmitted helminths","volume":"13","author":"Giardina","year":"2019","journal-title":"PLoS Negl Trop Dis"},{"key":"B24","doi-asserted-by":"publisher","first-page":"211","DOI":"10.1017\/S0031182000075016","article-title":"A quantitative framework for evaluating the effect of community treatment on the morbidity due to ascariasis","volume":"106","author":"Medley","year":"1993","journal-title":"Parasitology"},{"key":"B25","doi-asserted-by":"publisher","first-page":"1392","DOI":"10.1093\/ije\/26.6.1392","article-title":"Transmission patterns and the epidemiology of hookworm infection","volume":"26","author":"Chan","year":"1997","journal-title":"Int J Epidemiol"},{"key":"B26","doi-asserted-by":"publisher","first-page":"e3323","DOI":"10.1371\/journal.pntd.0003323","article-title":"Modeling the interruption of the transmission of soil-transmitted helminths by repeated mass chemotherapy of school-age children","volume":"8","author":"Truscott","year":"2014","journal-title":"PLoS Negl Trop Dis"},{"key":"B27","doi-asserted-by":"publisher","first-page":"266","DOI":"10.1186\/1756-3305-7-266","article-title":"Can chemotherapy alone eliminate the transmission of soil transmitted helminths?","volume":"7","author":"Truscott","year":"2014","journal-title":"Parasit Vectors"},{"key":"B28","doi-asserted-by":"publisher","first-page":"133","DOI":"10.1016\/bs.apar.2016.08.002","article-title":"Soil-transmitted helminths: mathematical models of transmission, the impact of mass drug administration and transmission elimination criteria","volume":"94","author":"Truscott","year":"2016","journal-title":"Adv Parasitol"},{"key":"B29","doi-asserted-by":"publisher","first-page":"557","DOI":"10.1038\/297557a0","article-title":"Population dynamics of human helminth infections: control by chemotherapy","volume":"297","author":"Anderson","year":"1982","journal-title":"Nature"},{"key":"B30","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1038\/318323a0","article-title":"Vaccination and herd immunity to infectious diseases","volume":"318","author":"Anderson","year":"1985","journal-title":"Nature"},{"key":"B31","volume-title":"Infectious Diseases of Humans: Dynamics and Control","author":"Anderson","year":"1992"},{"key":"B32","doi-asserted-by":"publisher","first-page":"e2027","DOI":"10.1371\/journal.pntd.0002027","article-title":"How effective is school-based deworming for the community-wide control of soil-transmitted helminths?","volume":"7","author":"Anderson","year":"2013","journal-title":"PLoS Negl Trop Dis"},{"key":"B33","volume-title":"2030 Targets for Soil-Transmitted Helminthiases Control Programmes","year":"2020"},{"key":"B34","doi-asserted-by":"publisher","first-page":"e2684","DOI":"10.1371\/journal.pntd.0002684","article-title":"Control of neglected tropical diseases in Burundi: partnerships, achievements, challenges, and lessons learned after four years of programme implementation","volume":"8","author":"Ndayishimiye","year":"2014","journal-title":"PLoS Negl Trop Dis"},{"key":"B35","year":"2012","journal-title":"A Master Plan for National Neglected Tropical Diseases Programmes in the African Region"},{"key":"B36","doi-asserted-by":"publisher","first-page":"e126","DOI":"10.1371\/journal.pntd.0000126","article-title":"Controlling soil-transmitted helminthiasis in pre-school-age children through preventive chemotherapy","volume":"2","author":"Albonico","year":"2008","journal-title":"PLoS Negl Trop Dis"},{"key":"B37","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1016\/j.epidem.2014.09.006","article-title":"Nine challenges for deterministic epidemic models","volume":"10","author":"Roberts","year":"2015","journal-title":"Epidemics"},{"key":"B38","doi-asserted-by":"publisher","first-page":"6721919","DOI":"10.1155\/2020\/6721919","article-title":"Mathematical model for optimal control of soil-transmitted helminth infection","volume":"2020","author":"Lambura","year":"2020","journal-title":"Comput Math Methods Med"},{"key":"B39","volume-title":"Kenya Census 2019","year":"2019"},{"key":"B40","doi-asserted-by":"publisher","first-page":"e948","DOI":"10.1371\/journal.pntd.0000948","article-title":"Assessment of the anthelmintic efficacy of albendazole in school children in seven countries where soil-transmitted helminths are endemic","volume":"5","author":"Vercruysse","year":"2011","journal-title":"PLoS Negl Trop Dis"},{"key":"B41","doi-asserted-by":"publisher","first-page":"1071","DOI":"10.4269\/ajtmh.2009.09-0377","article-title":"Changing patterns of soil-transmitted helminthiases in Zanzibar in the context of national helminth control programs","volume":"81","author":"Knopp","year":"2009","journal-title":"Am J Trop Med Hyg"},{"key":"B42","year":"2016","journal-title":"Framework for Control and Prevention of Soil-Transmitted Helminthiases in the WHO European Region 2016\u20132020"},{"key":"B43","doi-asserted-by":"publisher","first-page":"e1548","DOI":"10.1371\/journal.pntd.0001548","article-title":"A research agenda for helminth diseases of humans: modelling for control and elimination","volume":"6","author":"Bas\u00e1\u00f1ez","year":"2012","journal-title":"PLoS Negl Trop Dis"},{"key":"B44","first-page":"720","article-title":"Stochastic models of host-macroparasite interaction","volume":"5","author":"Isham","year":"1995","journal-title":"Ann Appl Probabil"},{"key":"B45","doi-asserted-by":"publisher","first-page":"110076","DOI":"10.1016\/j.jtbi.2019.110076","article-title":"The breakpoint of soil-transmitted helminths with infected human migration","volume":"486","author":"Hardwick","year":"2020","journal-title":"J. Theor. Biol"},{"key":"B46","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1186\/s13071-019-3757-4","article-title":"The Geshiyaro Project: a study protocol for developing a scalable model of interventions for moving towards the interruption of the transmission of soil-transmitted helminths and schistosome infections in the Wolaita zone of Ethiopia","volume":"12","author":"Mekete","year":"2019","journal-title":"Parasit Vectors"},{"key":"B47","doi-asserted-by":"publisher","first-page":"429","DOI":"10.7763\/IJSSH.2015.V5.494","article-title":"Household latrines to control environmental contamination and helminthiasis: an exploratory study in Indonesia","volume":"5","author":"Park","year":"2015","journal-title":"Int J Soc Sci Hum"}],"container-title":["Frontiers in Public Health"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpubh.2021.637866\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,3,24]],"date-time":"2021-03-24T04:28:58Z","timestamp":1616560138000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fpubh.2021.637866\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,3,24]]},"references-count":47,"alternative-id":["10.3389\/fpubh.2021.637866"],"URL":"https:\/\/doi.org\/10.3389\/fpubh.2021.637866","relation":{},"ISSN":["2296-2565"],"issn-type":[{"value":"2296-2565","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,3,24]]},"article-number":"637866"}}