Table 5. List of included studies with authors N–Z.
| Author [cite ID], Year - Country | Title of Article | Setting and Population | Sample Size | Diagnosis Method | Exposure Assessment and Study Method | Main WASH Components | Adjustment or Controlled Variables |
| Narain [84], 2000 - Indiaa | Prevalence of Trichuris trichiura in relation to socio-economic and behavioral determinants of exposure to infection in rural Assam | Dibrugarh district in upper Assam; adults and children aged <15 years | 580 | Formol-ether concentration technique | Questionnaire, cross-sectional | Floor material, improved latrine, improved water | Age, open defecation, type of flooring, family size, number of children in household |
| Nasr [66], 2013 - Malaysiaa | Towards an effective control programme of soil-transmitted helminth infections among Orang Asli in rural Malaysia. Part 1: Prevalence and associated key factors | 13 villages in Lipis district, Pahang; Orang Asli children aged ≤15 years | 484 | Formalin-ether sedimentation, Kato Katz, and Harada Mori | Questionnaire, cross-sectional | Handwashing, water, sanitation | Age, family size, other WASH practices |
| Nguyen [165], 2006 - Vietnam | Intestinal helminth infections among reproductive age women in Vietnam: prevalence, co-infection and risk factors | 53 provinces; reproductive-age women | 5,127 | Kato-Katz | Questionnaire, cross-sectional | Latrine, manure fertilizer use | Adjusted for infection with A. lumbricoides, T. trichiura, and interaction term between them. |
| Nishiura [81], 2002 - Pakistan | Ascaris lumbricoides among children in rural communities in the Northern Area, Pakistan: prevalence, intensity, and associated socio-cultural and behavioral risk factors | Five rural villages in the northern area of Pakistan; school children | 492 | Kato-Katz | Questionnaire, cross-sectional | Washing hands, latrine, eating soil, soap | Age, sex, living with child under age of 5, other WASH practices |
| Norhayati [166], 1999 - Malaysia | Some risk factors of Ascaris and Trichuris infection in Malaysian aborigine (Orang Asli) children | Children ages 1–13 | 205 | Kato-Katz and Harada Mori | Questionnaire, cross-sectional | Usage of well-water, usage of toilets | No adjusted WASH effect estimates identified |
| Nwaneri [83], 2012 - Nigeria | Intestinal helminthiasis in children with chronic neurological disorders in Benin City, Nigeria: intensity and behavioral risk factors | Benin City child neurology clinic; Children with chronic neurological disorders | 155 | Kato-Katz | Questionnaire, case-control with matching on age/sex | Hygiene practices | Age, sex |
| Olsen [167], 2001 - Kenya | A study of risk factors for intestinal helminth infections using epidemiological and anthropological approaches | Villages in Kisumu District, Nyanza Province, Kenya; All inhabitants over the age of 4 years | 333 | Kato-Katz (duplicate) | Questionnaire, cross-sectional | Latrine, soap | Adjusted for crowding in households, children under five years of age, soap use, latrine presence. |
| Ortiz Valencia [168], 2005 - Brazil | Spatial ascariasis risk estimation using socioeconomic variables. | Children ages 1–9 | 1,550 | Unclear | Interview, cross-sectional | Water filtration | No adjusted WASH effect estimates identified |
| Parajuli [129], 2009 - Nepala | Behavioral and Nutritional Factors and Geohelminth Infection Among Two Ethnic Groups in the Terai Region, Nepal | Parsauni village in the Sakhawaparsauni Village Development Committee (VDC) of Parsa district, Nepal; Mushar and Tharu (ethnic groups) inhabitants, aged 20–60 years | 95 | Direct wetmount Lugol's iodine thin-smear method | Questionnaire, cross-sectional | Soap, walking barefoot | Adjusts for age, ethnicity, gender, height. |
| Pham-Duc [115], 2013 - Vietnama | Ascaris lumbricoides and Trichuris trichiura infections associated with wastewater and human excreta use in agriculture in Vietnam | Nhat Tan and Hoang Tay communes in Kim Bang district, Hanam province; Individuals over 1 year old | 1,425 | Kato-Katz thick smear and formalin-ether concentration techniques | Questionnaire, cross-sectional | Water, sanitation, handwashing | Age, sex, and season. |
| Phiri [134], 2000 - Malawia | Urban/rural differences in prevalence and risk factors for intestinal helminth infection in southern Malawi | Two sites in the Blantyre area of Malawi: Ndirande a densely populated, poor, urban township in Blantyre city; and Namitambo, a poor rural community in Chiradzulu district; children between the age of 3–14 years | 273 | Stoll's egg count technique | Questionnaire, cross-sectional | Sewage, walking barefoot | Age, sex, mother's education, school attendance, sewage around house |
| Quintero [69], 2012 - Venezuela | Household social determinants of ascariasis and trichuriasis in North Central Venezuela | 55 municipalities of the North Central Venezuela states Aragua, Carabobo, Miranda, Vargas and Capital District; Children and adults (3 months–60 years old) | 3,388; ∼4.7 million with weights | Kato-Katz | Questionnaire, cross-sectional | Improved water, soil floor, sewage disposal | Rural/urban, house vulnerability, waste disposal practices |
| Riess [169], 2013 - Tanzania | Hookworm Infection and Environmental Factors in Mbeya Region, Tanzania: A Cross-Sectional, Population-Based Study | Participants from nine different sites in Mbeya region, south-western Tanzania | 6,375 | Kato-Katz | Questionnaire | Latrine coverage, latrine type | Age, previous anthelmintic treatment, clustering |
| Rísquez [170], 2010 - Venezuela | Condiciones higiénico-sanitarias como factores de riesgo para las parasitosis intestinales en una comunidad rural venezolana | Students in the Panaquire-Miranda school district | 69 | Formol-ether concentration | Questionnaire | Defecation practices | No adjusted WASH effect estimates identified |
| Roy [114], 2011 - Bangladesha | Patterns and risk factors for helminthiasis in rural children aged under 2 in Bangladesh | 10 villages in Rural Mirzapur; Rural children under 2 years old | 252 | Formalin-ether sedimentation technique | Questionnaire, longitudinal | Improved water, excreta disposal | Adjusted by age, sex, breastfeeding, seasonality, and disposal site of child feces |
| Saathoff [171], 2002 - South Africa | Geophagy and its association with geohelminth infection in rural schoolchildren from northern KwaZulu-Natal, South Africa | Pupils in third grade (average age of 10.7 years) | 1,161 | Kato-Katz | Interview, cross-sectional | Geophagy | Family |
| Schmidlin [126], 2013 - Côte d'Ivoirea | Effects of hygiene and defecation behavior on helminths and intestinal protozoa infections in Taabo, Côte d'Ivoire | People in villages/hamlets in south-central that were small populations and similar pop. structure | 1,894 | Kato-Katz | Questionnaire, interview, cross-sectional | Sanitation behavior, hygiene behavior | Socioeconomic status, age group, and sex |
| Scolari [172], 2000 - Brazil | Prevalence and distribution of soil-transmitted helminth (STH) infections in urban and indigenous schoolchildren in Ortigueira, State of Parana, Brasil: implications for control | School children ages 5–15 | 236 | Kato-Katz | Questionnaires (verified by local field assistant), cross-sectional | Toilet ownership, location of toilet, safe water access | No adjusted WASH effect estimates identified |
| Sherkhonov [173], 2013 - Tajikistan | National intestinal helminth survey among schoolchildren in Tajikistan: Prevalences, risk factors and perceptions | Schools from across country; school children, 7–11 years old | 1,642 | Kato-Katz | Questionnaire, cross-sectional | Water, sanitation, handwashing | Clustering, other final covariates unclear |
| Soares Magalhaes [174], 2011 - Ghana, Mali, and Burkina Faso | Geographical analysis of the role of water supply and sanitation in the risk of helminth infections of children in West Africa | West African children | 18,812 | Kato-Katz | Questionnaire (health survey), cross-sectional | Water source, toilet, floor material | No adjusted WASH effect estimates identified |
| Steenhard [175], 2009 - Guinea-Bissau | Concurrent infections and socioeconomic determinants of geohelminth infection: a community study of schoolchildren in periurban Guinea-Bissau | Poor semirural area (Bandim II and Belem, near Bissau); school children aged 4–12 | 706 | McMaster technique, formol-ether technique | Questionnaire, cross-sectional | Improved water, improved sanitation | No adjusted WASH effect estimates identified |
| Steinmann [79], 2010 - Kyrgyzstana | Rapid appraisal of human intestinal helminth infections among schoolchildren in Osh oblast, Kyrgyzstan | Osh oblast; school children (grades 2 or 3, age: 6–15 years) | 1,262 | Kato-Katz | Questionnaire, cross-sectional | Washing vegetables, water source, toilet use | Age, sex, ethnic group, washing vegetables before eating, clustering |
| Stothard [120], 2008 - Zanzibara | Soiltransmitted helminthiasis among mothers and their preschool children on Unguja Island, Zanzibar with emphasis upon ascariasis | 10 Ungujan villages; mothers and their pre-SAC, 322 mothers, 359 children | 681 | Kato-Katz | Questionnaire, cross-sectional | Latrine access, wearing shoes, playing on ground | Clustering, having infected household member |
| Teixeira [176], 2004 - Brazil | Environmental factors related to intestinal helminth infections in subnormal settled areas, Juiz de Fora, MG | Children (1–5 years old) in the subnormal settlement areas in the municipality of Juiz de Fora, Mina Gerais. | 753 | Hoffmann-Pons-Janer method | Questionnaire | Water quality complaints, feces disposal | Family income, age of child |
| Trang [121], 2007 - Vietnama | Helminth infections among people using wastewater and human excreta in peri-urban agriculture and aquaculture in Hanoi, Vietnam | Yen So commune (population 10,500 at the time of study), a rural area located about 10 km south of central Hanoi; adults of 15–70 years of age engaged in agricultural activities and preschool children (less than 72 months of age) | 807 | Direct smear method | Questionnaire, cross-sectional | Water source, latrine | Age, sex, socioeconomic status, other WASH practices |
| Trang [177], 2006 - Vietnam | Low risk for helminth infection in wastewater-fed rice cultivation in Vietnam | All females and males from 15–94 years old from 2 communes using different irrigation for rice cultivation (wastewater and river water) | 1,139 | Direct smear method | Questionnaire, interview, cross-sectional | Latrine availability, latrine status, handwashing (soap), availability of drinking water | Clustering, age, gender, excreta agricultural use |
| Traub [118], 2004 - Indiaa | The prevalence, intensities and risk factors associated with geohelminth infection in tea-growing communities of Assam, India | Three tea-growing communities in Assam, India; tea-growing communities of rural Assam (no age restrictions) | 328 | Kato-Katz | Questionnaire, cross-sectional | Shoes, water source, latrine use | Socioeconomic status, age, household crowding, level of education, religion, use of footwear when outdoors, defecation practices, pig ownership, water source |
| Ugbomoiko [178], 2009 - Nigeria | Socio-environmental factors and ascariasis infection among school-aged children in Ilobu, Osun State, Nigeria | Small rural village of Ilobu in Irepodu Local Government Area of Osun State, Nigeria; children below 16 years of age | 440 | Kato-Katz | Questionnaire, cross-sectional | Water source, latrine, distance to waste disposal | Sex, age, which parent reside with child, number of playmates <6 or >5 years old, period of residency, and previous treatment status. |
| Walker [179], 2011 - Bangladesh | Individual Predisposition, Household Clustering and Risk Factors for Human Infection with Ascaris lumbricoides: New Epidemiological Insights | Dhaka; households | 2,929 | Ether sedimentation technique | Questionnaire, longitudinal | Shared latrines, shared water sources, floor material | Clustering, age, sex, household socioeconomic status, ethnicity, and household characteristics |
| Wang [112], 2012 - Chinaa | Soil-Transmitted Helminth Infections and Correlated Risk Factors in Preschool and School-Aged Children in Rural Southwest China | 141 impoverished rural areas of Guizhou and Sichuan Provinces in Southwest China; SAC and Pre-sac (3–5-year-old group and an 8–10-year-old group) | 1,707 | Kato-Katz | Questionnaire, cross-sectional | Washing hands, boiling water, latrine type, use of manure fertilizer | STH treatment history, individual characteristics, health and sanitation behaviors, and household characteristics |
| Wordemann [97], 2006 - Cubaa | Prevalence and risk factors of intestinal parasites in Cuban children | San Juan y Martinez and Fomento; Cuban schoolchildren aged 4–14 | 1,320 | Kato-Katz | Questionnaire, cross-sectional | Water source, latrine use | Age, sex, municipality, urban/rural background, and interaction between municipality and urban/rural background |
| Worrell [74], 2013 - Kenya | Water, Sanitation, and Hygiene-Related Risk Factors for Soil-Transmitted Helminth Infection in Urban School- and Pre-School-Aged Children in Kibera, Nairobi | Kibera; pre-school and school-aged children | 676 | Kato-Katz (three stools) | Questionnaire, observations, cross-sectional | Numerous | Age, presence of an infected sibling(s) in the household, household crowding, deworming in the last year, ability to meet water needs, treating water, and soap use |
| Xu [75], 2001 - China | On cleanliness of hands in diminution of Ascaris lumbricoides infection in children | Shaowu, Fujian Province; Children (pupils in preliminary school) | 654 | Kato-Katz | Experimental, longitudinal | Handwashing | No adjusted WASH effect estimates identified |
| Yajima [180], 2009 - Vietnam | High latrine coverage is not reducing the prevalence of soil-transmitted helminthiasis in Hoa Binh province, Vietnam | Residents of Tien Xuan commune, Hoa Binh province, Vietnam | 155 | Kato-Katz | Questionnaire, cross-sectional | Latrine at home | No adjusted WASH effect estimates identified |
| Yori [88], 2006 - Peru | Seroepidemiology of strongyloidiasis in the Peruvian Amazon | Residents of Santo Tomas, Peru | 908 | Direct smear, Baermann, simple sedimentation agar plate, serologic assays (ELISA) | Questionnaire, cross-sectional | Source and storage of drinking water, human waste disposal, wearing of shoes | Age |
| Young [82], 2007 - Tanzaniaa | Association of geophagia with Ascaris, Trichuris and hookworm transmission in Zanzibar, Tanzania | Pemba Island, Zanzibar; pregnant women | 970 | Kato-Katz | Questionnaire, cross-sectional | Geophagy, improved sanitation | Geophagia during current pregnancy, age, urban/rural, number of durable goods, pit toilet in HH, formal education |
a
Studies contributed to a meta-analysis.
HAZ, height for age Z score; SES, socioeconomic status.