Soil-transmitted helminths and childhood development: Nutrition, anemia, cognitive outcomes, and school-based deworming

Abstract

Infections with soil-transmitted helminths (STHs) are one of the most common neglected tropical diseases globally and drive poor childhood development, which is a cycle within low and middle-income countries (LMICs). The infection is caused by Ascaris lumbricoides, Trichuris trichiura, and the hookworms (Necator americanus, Ancylostoma duodenale) and disproportionately affects school-age children and adolescents in the impoverished areas where water, sanitation, and hygiene are inadequate. This review is an integration to understand the association between STH infection and 4 key domains of childhood development: nutrition status, anemia, cognitive function and effect of school-based deworming, a public health intervention. At the global level, 37.16% of school-age children in LMICs are infected with STH, and the highest prevalence can be found in the Western Pacific (50.41%) and in Africa (37.10%). Chronic STH infection causes damage to nutritional status by inducing intestinal blood loss, malabsorption of nutrients and anorexia, directly contributing to stunting and underweight. In addition, hookworm infection worsens iron deficiency anemia, which is closely associated with cognitive development problems and lower academic attainment. Preventive chemotherapy, which is deworming for STH at school, is the main method for controlling STH at the global level and the World Health Organization recommends that children be dewormed annually or biannually depending on endemicity. Recent programmatic evaluations indicate that school-based deworming can decrease STH prevalence, improve nutritional markers, and can have long-term cognitive and economic impacts. Despite this, there are still barriers to be addressed: suboptimal deworming coverage in many areas, high risk of reinfection following deworming, low efficacy against Trichuris and Strongyloides, and a limited number of large-scale RCTs that provide evidence of benefit with regards to hemoglobin concentrations and cognitive function. The current review summarizes epidemiological data from the different regions, explains how STH is related to poor developmental outcomes, and summarizes the effectiveness of school-based deworming. It also identifies key areas of uncertainty that require research such as long-term cohort studies, identifiable and standardized integrated deworming protocols, and scalable protocols to help ensure the sustainability of deworming benefits.

Keywords

Anemia / Cognitive development / Deworming / Nutrition / Soil-transmitted helminths

References

[1] World Health organization. Soil-transmitted helminth infections. [Online]. Available from: https://www.who.int/news-room/fact-sheets/detail/soil-transmitted-helminth-infections/. [Accessed on 25 July 2026].

[2] Agrawal R, Pattnaik S, Kshatri JS, Kanungo S, Mandal N, Palo SK, et al. Prevalence and correlates of soil-transmitted helminths in schoolchildren aged 5 to 18 years in low- and middle-income countries: A systematic review and meta-analysis. Front Public Health 2024; 12: 1283054.

[3] Parija SC, Chidambaram M, Mandal J. Epidemiology and clinical features of soil-transmitted helminths. Trop Parasitol 2017; 7(2): 81-85.

[4] Luvira V, Siripoon T, Phiboonbanakit D, Somsri K, Watthanakulpanich D, Dekumyoy P. Strongyloides stercoralis: A neglected but fatal parasite. Trop Med Infect Dis 2022; 7(10): 310.

[5] World Health organization. Soil-transmitted helminth infections. [Online]. Available from: https://www.who.int/westernpacific/newsroom/fact-sheets/detail/soil-transmitted-helminth-infections. [Accessed on 25 July 2026].

[6] Begum A, Liza FT, Mukutmoni M, Oishee KF, Nath TC. Prevalence and risk factors of soil-transmitted helminth infections in Northwestern Bangladesh: A cross-sectional study on Bengali and Santal women. Parasit Epidemiol Control 2026; 32: e00473.

[7] Ezeamama AE, Bustinduy AL, Nkwata AK, Martinez L, Pabalan N, Boivin MJ, et al. Cognitive deficits and educational loss in children with schistosome infection-A systematic review and meta-analysis. PLoS Neglect Trop Dis 2018; 12(1): e0005524.

[8] Anderson RM, Truscott JE, Pullan RL, Brooker SJ, Hollingsworth TD. How effective is school-based deworming for the community-wide control of soil-transmitted helminths? PLoS Neglect Trop Dis 2013; 7(2): e2027.

[9] Brooker SJ, Mwandawiro CS, Halliday KE, Njenga SM, McHaro C, Gichuki PM, et al. Interrupting transmission of soil-transmitted helminths: A study protocol for cluster randomised trials evaluating alternative treatment strategies and delivery systems in Kenya. BMJ Open 2015; 5(10): e008950.

[10] Yang L, Chen W, Zeng J, Pan S. Regional differences in spatial determinants of land urbanization in China. Environment Sci Pollut Res 2023; 30(56): 119260-119274.

[11] Webster JP, Molyneux DH, Hotez PJ, Fenwick A. The contribution of mass drug administration to global health: Past, present and future. Philos Trans R Soc Lond B Biol Sci 2014; 369(1645): 20130434.

[12] Traore M, Maiga FK, Keita M, Guindo B, Sacko M, Doumbia SS, et al. Achieving elimination of soil-transmitted helminthiasis as a public health problem in Mali. BMJ Global Health 2025; 10(11): e017092.

[13] Montresor A, Mupfasoni D, Mikhailov A, Mwinzi P, Lucianez A, Jamsheed M, et al. The global progress of soil-transmitted helminthiases control in 2020 and World Health Organization targets for 2030. PLoS Neglect Trop Dis 2020; 14(8): e0008505.

[14] Toor J, Adams ER, Aliee M, Amoah B, Anderson RM, Ayabina D, et al. Predicted impact of COVID-19 on neglected tropical disease programs and the opportunity for innovation. Clin Infect Dis 2021; 72(8): 1463-1466.

[15] Maddren R, Anderson RM. Measuring heterogeneities in soil-transmitted helminth transmission and control. Trend Parasitol 2024; 40(1): 45-59.

[16] Zeynudin A, Degefa T, Tesfaye M, Suleman S, Yesuf EA, Hajikelil Z, et al. Prevalence and intensity of soil-transmitted helminth infections and associated risk factors among household heads living in the peri-urban areas of Jimma town, Oromia, Ethiopia: A community-based cross-sectional study. PLoS One 2022; 17(9): e0274702.

[17] Kattula D, Sarkar R, Rao Ajjampur SS, Minz S, Levecke B, Muliyil J, et al. Prevalence & risk factors for soil transmitted helminth infection among school children in south India. Indian J Med Res 2014; 139(1): 76-82.

[18] Dewey KG, Mayers DR. Early child growth: How do nutrition and infection interact? Matern Child Nutr 2011; 7(Suppl 3): 129-142.

[19] Gabain IL, Ramsteijn AS, Webster JP. Parasites and childhood stunting-A mechanistic interplay with nutrition, anaemia, gut health, microbiota, and epigenetics. Trend Parasitol 2023; 39(3): 167-180.

[20] Loukas A, Maizels RM, Hotez PJ. The yin and yang of human soil-transmitted helminth infections. Int J Parasitol 2021; 51(13-14): 1243-1253.

[21] Stein E, Patel AV, He P, Patel AH. Trichuriasis in differential diagnosis: A case of colonoscopic identification. ACG Case Rep J 2025; 12(8): e01806.

[22] Guerrant RL, Oriá RB, Moore SR, Oriá MO, Lima AA. Malnutrition as an enteric infectious disease with long-term effects on child development. Nutr Rev 2008; 66(9): 487-505.

[23] Wang H, Foong JPP, Harris NL, Bornstein JC. Enteric neuroimmune interactions coordinate intestinal responses in health and disease. Mucosal Immunol 2022; 15(1): 27-39.

[24] Scott ME, Koski KG. Soil-transmitted helminths: Does nutrition make a difference? In: Humphries DL, Scott ME, Vermund SH, editors. Nutrition and infectious diseases: Shifting the clinical paradigm. Cham: Springer International Publishing; 2021, p. 325-364.

[25] Donkoh ET, Berkoh D, Fosu-Gyasi S, Boadu WIO, Raji AS, Asamoah S, et al. Evidence of reduced academic performance among schoolchildren with helminth infection. Int Health 2023; 15(3): 309-317.

[26] Kusumasari RA, Adi H, Satoto TBT, Wahab A, Murhandarwati EEH. Malnutrition among children under 7 years of age linked to ascariasis: Evidence from West Sumba, Indonesia, despite ongoing deworming program. BMC Public Health 2025; 25(1): 3920.

[27] Rahut DB, Mishra R, Bera S. Geospatial and environmental determinants of stunting, wasting, and underweight: Empirical evidence from rural South and Southeast Asia. Nutrition 2024; 120: 112346.

[28] de Gier B, Nga TT, Winichagoon P, Dijkhuizen MA, Khan NC, van de Bor M, et al. Species-specific associations between soil-transmitted helminths and micronutrients in Vietnamese schoolchildren. Am J Trop Med Hyg 2016; 95(1): 77-82.

[29] Taylor-Robinson DC, Maayan N, Soares-Weiser K, Donegan S, Garner PJ. Deworming drugs for soil-transmitted intestinal worms in children: Effects on nutritional indicators, haemoglobin, and school performance. Cochrane Database Syst Rev 2015; 7: CD000371. doi: 10.1002/14651858.CD000371.pub6.

[30] Derso A, Birhanie M, Belew AK, Abere A, Tegegne Y, Setegn A, et al. An exploratory study on soil-transmitted helminths, growth, and micronutrient status in Northwest Ethiopian schoolchildren. BMC Nutr 2025; 11(1): 206.

[31] Lubis R, Satria FB, Rasmaliah R, Jemadi J, Nasution SK, Zaki RA. Impact of soil-transmitted helminths infections on anemia burden: A global analysis of children under five and reproductive-age women. BMC Public Health 2025; 25(1): 1356.

[32] Wijaya W, Pasaribu AP, Yanni GN, Suteno E, Husin N, Pasaribu S. Correlation between soil-transmitted helminths and anemia incidence in primary school children in Talawi, Batubara regency. Open Access Macedonian J Med Sci 2021; 9(T3): 325-329.

[33] Ronquillo AC, Puelles LB, Espinoza LP, Sánchez VA, Luis PVJ. Ancylostoma duodenale as a cause of upper gastrointestinal bleeding: A case report. Braz J Infect Dis 2019; 23(6): 471-473.

[34] Layden AJ, Täse K, Finkelstein JL. Neglected tropical diseases and vitamin B12: A review of the current evidence. Trans R Soc Trop Med Hyg 2018; 112(10): 423-435.

[35] Ueda N, Takasawa K. Impact of inflammation on ferritin, hepcidin and the management of iron deficiency anemia in chronic kidney disease. Nutrients 2018; 10(9): 1173.

[36] Steinbaum L, Kwong LH, Ercumen A, Negash MS, Lovely AJ, Njenga SM, et al. Detecting and enumerating soil-transmitted helminth eggs in soil: New method development and results from field testing in Kenya and Bangladesh. PLoS Neglect Trop Dis 2017; 11(4): e0005522.

[37] Liu Y, Ren W, Wang S, Xiang M, Zhang S, Zhang F. Global burden of anemia and cause among children under five years 1990-2019: Findings from the global burden of disease study 2019. Front Nutr 2024; 11: 1474664.

[38] Kumari A, Kumari A, Mudgal SK, Patidar V, Singh AK, Ganguly A, et al. Regional burden of anemia among adolescent girls in India: A systematic review and meta-analysis. Nepal J Epidemiol 2025; 15(3): 1386-1396.

[39] Yewodiaw TK, Alemayehu MA, Teshome DF. Anemia status and associated factors among adolescent girls under weekly iron and folic acid supplementation (WIFAS) and non-WIFAS programs in public schools in Janamora district, Northwest Ethiopia 2023; a comparative cross-sectional study. BMC Nutr 2025; 11(1): 50.

[40] Taylor-Robinson DC, Maayan N, Donegan S, Chaplin M, Garner P. Public health deworming programmes for soil-transmitted helminths in children living in endemic areas. Cochrane Database Syst Rev 2019; 9(9): Cd000371.

[41] Casey GJ, Montresor A, Cavalli-Sforza LT, Thu H, Phu LB, Tĩnh TT, et al. Elimination of iron deficiency anemia and soil transmitted helminth infection: Evidence from a fifty-four month iron-folic acid and de-worming program. PLoS Neglect Trop Dis 2013; 7: e2146.

[42] Gerber M, Lang C, Beckmann J, du Randt R, Gall S, Seelig H, et al. How are academic achievement and inhibitory control associated with physical fitness, soil-transmitted helminth infections, food insecurity and stunting among South African primary schoolchildren? BMC Public Health 2021; 21(1): 852.

[43] Beckmann J, Lang C, du Randt R, Gresse A, Long KZ, Ludyga S, et al. Prevalence of stunting and relationship between stunting and associated risk factors with academic achievement and cognitive function: A cross-sectional study with south African primary school children. Int J Environ Res Public Health 2021; 18(8): 4218.

[44] Tandoh MA, Mills-Robertson FC, Wilson MD, Anderson AK. Nutritional and cognitive deficits of school-age children: A study in helminth-endemic fishing and farming communities in Ghana. Nutrition Food Sci 2019; 50(3): 443-462.

[45] Alemayehu B, Geyit M, Haile K, Mekonnen B. Helminthic infection, its determinants and implication to academic achievements among school-age children in southwest Ethiopia. Sci African 2025; 27: e02508.

[46] Ahmed A, Al-Mekhlafi HM, Azam MN, Ithoi I, Al-Adhroey AH, Abdulsalam AM, et al. Soil-transmitted helminthiasis: A critical but neglected factor influencing school participation of aboriginal children in rural Malaysia. Parasitology 2012; 139(6): 802-808.

[47] Sakti H, Nokes C, Hertanto WS, Hendratno S, Hall A, Bundy DA, et al. Evidence for an association between hookworm infection and cognitive function in Indonesian school children. Trop Med Int Health 1999; 4(5): 322-334.

[48] Shang Y, Tang LH. Intelligence level and characteristics of cognitive structure in school-age children infected with soil-transmitted helminthes. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2010; 28(6): 423-426.

[49] Kuong K, Fiorentino M, Perignon M, Chamnan C, Berger J, Sinuon M, et al. Cognitive performance and iron status are negatively associated with hookworm infection in Cambodian schoolchildren. Am J Trop Med Hyg 2016; 95(4): 856-863.

[50] Nga TT, Winichagoon P, Dijkhuizen MA, Khan NC, Wasantwisut E, Wieringa FT. Decreased parasite load and improved cognitive outcomes caused by deworming and consumption of multi-micronutrient fortified biscuits in rural Vietnamese schoolchildren. Am J Trop Med Hyg 2011; 85(2): 333-340.

[51] Ezeamama AE, Friedman JF, Acosta LP, Bellinger DC, Langdon GC, Manalo DL, et al. Helminth infection and cognitive impairment among Filipino children. Am J Trop Med Hyg 2005; 72(5): 540-548.

[52] Usang AU, Imalele EE, Effanga EO, Ukoha UK, Eleng IE. Soil-transmitted helminth infections and nutritional indices among children (5-9 years) and adolescents (10-12 years) in Calabar, Nigeria. BMC Public Health 2025; 25: 1. doi: 10.1186/s12889-024-21210-4.

[53] Adu AM, Simpong DL, Donkor DM, Manu KS, Antwi MH, Kpelle L, et al. Parasitic infections and associated cognitive outcome among school-aged children in Africa: A systematic review. Brain Behav 2026; 16(4): e71326.

[54] Piazzesi A, Putignani L. Impact of helminth-microbiome interactions on childhood health and development-A clinical perspective. Parasit Immunol 2023; 45(4): e12949.

[55] Olopade BO, Idowu CO, Oyelese AO, Aboderin AO. Intestinal parasites, nutritional status and cognitive function among primary school pupils in Ile-Ife, Osun State, Nigeria. Afr J Infect Dis 2018; 12(2): 21-28.

[56] Jumbe D, Siwila J. Relationship between soil transmitted helminths, nutritional status and cognitive function among school children in Lusaka district, Zambia. J Parasit Dis 2025; 49(2): 426-432.

[57] World Health organization. Control of neglected tropical diseases. [Online]. Available from: https://www.who.int/teams/control-of-neglected-tropical-diseases/soil-transmitted-helminthiases/control-strategy. [Accessed on 25 July 2026].

[58] Casulli AJ. New global targets for NTDs in the WHO roadmap 2021-2030. California USA: Public Library of Science San Francisco; 2021, p. e0009373.

[59] Gichuki PM, Mbugua G, Kiplelgo EK, Irungu TW, Mwandawiro C. Long term school based deworming against soil-transmitted helminths also benefits the untreated adult population: Results from a community-wide cross sectional survey. J Trop Med 2019; 2019: 4151536.

[60] Mogaji HO, Adekunle ON, Surakat OA, Oyewumi JO, Nwokolo JA, Oluwaokere M, et al. Prevalence and risk factors of soil transmitted helminthiasis in some research-naïve communities in Ekiti State, Southwestern Nigeria: A cross-sectional study. Discover Public Health 2026; 23(1): 357.

[61] Lin Y, Barth-Jaeggi T, Hürlimann E, Beinamaryo P, Kyarisiima H, Harkare HV, et al. Cost comparison of school-based mass drug administration of albendazole and ivermectin versus albendazole alone for soil-transmitted helminth control in Uganda. PLoS Neglect Trop Dis 2026; 20(1): e0013913.

[62] Bartlett AW, Mendes EP, Dahmash L, Palmeirim MS, de Almeida MC, Peliganga LB, et al. School-based preventive chemotherapy program for schistosomiasis and soil-transmitted helminth control in Angola: 6-year impact assessment. PLoS Neglect Trop Dis 2023; 17(5): e0010849.

[63] Keller L, Welsche S, Patel C, Sayasone S, Ali SM, Ame SM, et al. Long-term outcomes of ivermectin-albendazole versus albendazole alone against soil-transmitted helminths: Results from randomized controlled trials in Lao PDR and Pemba Island, Tanzania. PLoS Neglect Trop Dis 2021; 15(6): e0009561.

[64] Montresor A, Mwinzi P, Mupfasoni D, Garba A. Reduction in DALYs lost due to soil-transmitted helminthiases and schistosomiasis from 2000 to 2019 is parallel to the increase in coverage of the global control programmes. PLoS Neglect Trop Dis 2022; 16(7): e0010575.

[65] Deocades EIC, Bacon QJM. Lived experiences of health workers in the implementation of soil-transmitted helminthiasis deworming program in South Cotabato: A phenomenological inquiry. Acta Med Philipp 2025; 59(4): 78-89.

[66] Jullien S, Sinclair D, Garner P. The impact of mass deworming programmes on schooling and economic development: An appraisal of long-term studies. Intern J Epidemiol 2016; 45(6): 2140-2153.

[67] Strunz EC, Addiss DG, Stocks ME, Ogden S, Utzinger J, Freeman MC. Water, sanitation, hygiene, and soil-transmitted helminth infection: A systematic review and meta-analysis. PLoS Med 2014; 11(3): e1001620.

[68] Dumevi CY, Amekudi PW, Eyeson NAS, Aryee HNA, Asiamah JJ, Vicar EK, et al. Prevalence of intestinal parasitic infections and associated factors among rural Ghanaian school children: A cross-sectional study in Tokuroano, Krachi east municipality. Public Health Chall 2026; 5(1): e70176.

[69] Buonfrate D, Bradbury RS, Watts MR, Bisoffi Z. Human strongyloidiasis: Complexities and pathways forward. Clin Microbiol Rev 2023; 36(4): e00033-23.

[70] Buonfrate D, Bisanzio D, Giorli G, Odermatt P, Fürst T, Greenaway C, et al. The global prevalence of Strongyloides stercoralis infection. Pathogens 2020; 9(6): 468.

[71] Bekele T, Lachisa L, Tsegaye A, Bacha K, Ketema T. Efficacy of albendazole and mebendazole against soil transmitted infections among pre-school and school age children: A systematic review and meta-analysis. J Epidemiol Glob Health 2024; 14(3): 884-904.

[72] Kirolos A, Goyheneix M, Kalmus EM, Chisala M, Lissauer S, Gladstone M, et al. Neurodevelopmental, cognitive, behavioural and mental health impairments following childhood malnutrition: A systematic review. BMJ Global Health 2022; 7(7): e009330.

[73] Belizario V Jr. , Delos Trinos J, Sison O, Miranda E, Molina V, Cuayzon A, et al. High burden of soil-transmitted helminth infections, schistosomiasis, undernutrition, and poor sanitation in two Typhoon Haiyan-stricken provinces in Eastern Philippines. Pathogen Global Health 2021; 115(6): 412-422.

[74] Suchdev PS, Davis SM, Bartoces M, Ruth LJ, Worrell CM, Kanyi H, et al. Soil-transmitted helminth infection and nutritional status among urban slum children in Kenya. Am J Trop Med Hyg 2014; 90(2): 299-305.

[75] Rani NA, Arasegowda R, Mukherjee P, Dhananjay SY. Prevalence of nutritional deficiency anaemia and its impact on scholastic performance among undergraduate medical students. J Clin Diagn Res 2017; 11(3): Bc21-bc3.

[76] Agrawal S, Kumar S, Ingole V, Acharya S, Wanjari A, Bawankule S, et al. Does anemia affects cognitive functions in neurologically intact adult patients: Two year cross sectional study at rural tertiary care hospital. J Family Med Prim Care 2019; 8(9): 3005-3008.

[77] Jumbe D, Siwila J. Relationship between soil transmitted helminths, nutritional status and cognitive function among school children in Lusaka district, Zambia. J Parasit Dis 2025; 49(2): 426-432.

[78] Chakrabarti S, Ajjampur SSR, Waddington HS, Kishore A, Nguyen PH, Scott S. Deworming and micronutrient status by community open defecation prevalence: An observational study using nationally representative data from India, 2016-2018. PLoS Med 2024; 21(5): e1004402.

[79] Shaw JG, Friedman JF. Iron deficiency anemia: focus on infectious diseases in lesser developed countries. Anemia 2011; 2011: 260380.

[80] Baird S, Hicks JH, Kremer M, Miguel E. Worms at work: Long-run impacts of a child health investment. QJE 2016; 131(4): 1637-1680.

[81] Sarr B, Fernandes M, Banham L, Bundy D, Gillespie A, McMahon B, et al. The evolution of school health and nutrition in the education sector 2000-2015 in sub-Saharan Africa. Front Public Health 2016; 4: 271.

[82] Qian MB, Utzinger J, Li SZ, Montresor A, Zhou XN. Towards elimination of soil-transmitted helminthiasis in China. Lancet Reg Health Western Pac 2022; 22: 100455.

[83] Bundy DAP, de Silva N, Horton S, Patton GC, Schultz L, Jamison DT. Investment in child and adolescent health and development: key messages from Disease Control Priorities, 3rd Edition. Lancet 2018; 391(10121): 687-699.