Katherine Elizabeth Halliday
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
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Research Interests
Katherine Elizabeth Halliday has a total of 324 co-authors. Here are the top co-authors by number of shared publications:
- William Edward Oswald
Global Health Division, International Development Group, RTI International, Durham, NC, USA
15 shared publications - Roy Malcolm Anderson
Imperial College London
12 shared publications Elizabeth Allen
Department of Medical Statistics, Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK
9 shared publications- Judd L. Walson
Department of Global Health, University of Washington , Seattle, Washington
8 shared publications - Rachel L. Pullan
Department of Disease Control, London School of Hygiene and Tropical Medicine, London, UK
8 shared publications - Simon Brooker
London School of Hygiene and Tropical Medicine, London, UK
8 shared publications
Latest Publications
- Open Access
Disparities in deworming coverage between children with and without disabilities: insights from the DeWorm3 trial in India
Background: Children with disabilities experience lower school enrollment rates and may be systematically excluded from school-based deworming programs. The DeWorm3 trial provided an opportunity to evaluate whether community-wide mass drug administration (cMDA) could reduce these disparities by reaching children outside the education system. Methods: We conducted a secondary analysis of the data from the DeWorm3 trial in Tamil Nadu, India. Children aged 5-17 years (n=82,417) who participated in at least one of the six rounds of cMDA were included. Disability was assessed using the UNICEF/Washington Group’s Child Functioning Module. Mixed-effects logistic regression models examined associations between disability status and treatment coverage, adjusting for sociodemographic factors. Results: Children with disabilities (1.1% of the population) had higher unadjusted odds of not receiving deworming treatment compared to children without disabilities (OR=1.49, 95% CI: 1.19-1.84), though this association was attenuated after adjustment (adjusted OR=1.10, 95% CI: 0.86-1.37). Among school-attending children who received treatment, those with disabilities had significantly lower odds of receiving school-based treatment (adjusted OR=0.57, 95% CI: 0.44-0.73). Subgroup analyses revealed that age, school attendance, parental marital status, geographic location, and the COVID-19 pandemic significantly modified these associations. Conclusion: While community-wide mass drug administration reduced some disparities in deworming coverage, children with disabilities remained less likely to receive school-based treatment. Public health programs should combine school-based approaches with targeted community outreach strategies to ensure equitable inclusion of children with disabilities, particularly those experiencing multiple vulnerabilities.
Open AccessDisparities in deworming coverage between children with and without disabilities: insights from the DeWorm3 trial in India
Background: Children with disabilities experience lower school enrollment rates and may be systematically excluded from school-based deworming programs. The DeWorm3 trial provided an opportunity to evaluate whether community-wide mass drug administration (cMDA) could reduce these disparities by reaching children outside the education system. Methods: We conducted a secondary analysis of the data from the DeWorm3 trial in Tamil Nadu, India. Children aged 5-17 years (n=82,417) who participated in at least one of the six rounds of cMDA were included. Disability was assessed using the UNICEF/Washington Group’s Child Functioning Module. Mixed-effects logistic regression models examined associations between disability status and treatment coverage, adjusting for sociodemographic factors. Results: Children with disabilities (1.1% of the population) had higher unadjusted odds of not receiving deworming treatment compared to children without disabilities (OR=1.49, 95% CI: 1.19-1.84), though this association was attenuated after adjustment (adjusted OR=1.10, 95% CI: 0.86-1.37). Among school-attending children who received treatment, those with disabilities had significantly lower odds of receiving school-based treatment (adjusted OR=0.57, 95% CI: 0.44-0.73). Subgroup analyses revealed that age, school attendance, parental marital status, geographic location, and the COVID-19 pandemic significantly modified these associations. Conclusion: While community-wide mass drug administration reduced some disparities in deworming coverage, children with disabilities remained less likely to receive school-based treatment. Public health programs should combine school-based approaches with targeted community outreach strategies to ensure equitable inclusion of children with disabilities, particularly those experiencing multiple vulnerabilities.
- Open Access
Evaluating impacts of improved flooring on enteric and parasitic infections in rural households in Kenya: study protocol for a cluster-randomised controlled trial
Introduction Earthen floors are often damp or dusty and difficult to clean, providing an ideal environment for faecal pathogens and parasites. Observational studies have revealed associations between household flooring and health outcomes, but robust experimental evidence is scant. This study will evaluate the impact of an improved household flooring intervention on enteric infections, soil-transmitted helminth (STH) infections and tungiasis through implementation of a cluster-randomised trial in two rural settings in Kwale and Bungoma Counties, Kenya. Methods and analyses 440 clusters (households) across both sites are allocated to control or intervention group, in which a low-cost, sealed, washable, cement-based floor is installed in eligible buildings of the dwelling, alongside a floor-care guide provided during an induction meeting. Following baseline assessments in both groups, all individuals over 1 year receive albendazole and those infected with tungiasis receive benzyl benzoate. Primary outcomes are as follows: prevalence of enteric infections in children under 5 years assessed via stool surveys and PCR; prevalence of tungiasis infection in children 1–14 years based on clinical exam; and prevalence of STH infection in all household members over 1 year assessed via Kato-Katz. Secondary outcomes include the following: intensity of STH and tungiasis infections; prevalence of caregiver-reported gastrointestinal illness in children under 5; quality of life and well-being measures; and environmental contamination. A process evaluation investigates intervention acceptability, durability, practicality and cost. Ethics and dissemination The protocol has been approved by ethics committees of The Kenya Medical Research Institute, The Kenya National Commission for Science Technology and Innovation, and The London School of Hygiene & Tropical Medicine. Following the 12-month implementation period and final assessments, control households are offered improved floors. Results will be disseminated within Kenya, to the Ministries of Health and of Lands, Public Works, Housing and Urban Development, and to subnational leadership and communities. Dissemination will also occur through publications and conference presentations. Trial registration number NCT05914363.
Open AccessEvaluating impacts of improved flooring on enteric and parasitic infections in rural households in Kenya: study protocol for a cluster-randomised controlled trial
Introduction Earthen floors are often damp or dusty and difficult to clean, providing an ideal environment for faecal pathogens and parasites. Observational studies have revealed associations between household flooring and health outcomes, but robust experimental evidence is scant. This study will evaluate the impact of an improved household flooring intervention on enteric infections, soil-transmitted helminth (STH) infections and tungiasis through implementation of a cluster-randomised trial in two rural settings in Kwale and Bungoma Counties, Kenya. Methods and analyses 440 clusters (households) across both sites are allocated to control or intervention group, in which a low-cost, sealed, washable, cement-based floor is installed in eligible buildings of the dwelling, alongside a floor-care guide provided during an induction meeting. Following baseline assessments in both groups, all individuals over 1 year receive albendazole and those infected with tungiasis receive benzyl benzoate. Primary outcomes are as follows: prevalence of enteric infections in children under 5 years assessed via stool surveys and PCR; prevalence of tungiasis infection in children 1–14 years based on clinical exam; and prevalence of STH infection in all household members over 1 year assessed via Kato-Katz. Secondary outcomes include the following: intensity of STH and tungiasis infections; prevalence of caregiver-reported gastrointestinal illness in children under 5; quality of life and well-being measures; and environmental contamination. A process evaluation investigates intervention acceptability, durability, practicality and cost. Ethics and dissemination The protocol has been approved by ethics committees of The Kenya Medical Research Institute, The Kenya National Commission for Science Technology and Innovation, and The London School of Hygiene & Tropical Medicine. Following the 12-month implementation period and final assessments, control households are offered improved floors. Results will be disseminated within Kenya, to the Ministries of Health and of Lands, Public Works, Housing and Urban Development, and to subnational leadership and communities. Dissemination will also occur through publications and conference presentations. Trial registration number NCT05914363.
- Open Access
- 5 February 2025
- Published by BMJ in BMJ Global Health
- Vol. 10 (2) , e016650
Understanding experiences of neglected tropical diseases of the skin: a mixed-methods study to inform intervention development in Ethiopia
Background: The WHO and Ethiopia’s Ministry of Health have developed strategies to expand and integrate services for co-endemic neglected tropical diseases (NTDs) which manifest in the skin. To inform these strategies, we aimed to understand the social, economic and health system context of skin NTD care in Kalu woreda, Amhara region, Ethiopia, where cutaneous leishmaniasis (CL) and leprosy are endemic. Methods: Between October 2020 and May 2022, we surveyed and reviewed records of 41 primary healthcare facilities and explored common disease experiences in focus group discussions (n=40) and interviews with people affected by leprosy (n=37) and CL (n=33), health workers (n=23), kebele authorities and opinion leaders (n=33) and traditional healers (n=7). Opportunities for integrated skin NTD service provision were explored through policy document review, interviews with health officials (n=25), and stakeholder meetings. Results: Availability of diagnostic supplies and health worker competence to provide skin care was very limited across primary healthcare facilities, particularly for CL. People with leprosy commonly sought care from healthcare facilities, while people with CL administered self-care or sought help from traditional healers. Travel and costs of care at specialised facilities outside the district inhibited timely care-seeking for both diseases. Transmission discourses shaped different understandings of who was affected by leprosy and CL and expectations of behaviour during and after treatment. Many policy actors felt that existing supply chain interventions, decentralised treatment approaches and community engagement initiatives for leprosy could also benefit CL, but others also warned against increasing care-seeking unless CL treatment could be provided on a scale commensurate with the large burden they perceived. Conclusion: Our findings demonstrate significant gaps in the provision of care for skin NTDs within primary healthcare, very different health-seeking patterns for leprosy and CL, and a need to develop new models of care, especially for CL.
- 5 February 2025
- Published by BMJ in BMJ Global Health
- Vol. 10 (2) , e016650
Open AccessUnderstanding experiences of neglected tropical diseases of the skin: a mixed-methods study to inform intervention development in Ethiopia
Background: The WHO and Ethiopia’s Ministry of Health have developed strategies to expand and integrate services for co-endemic neglected tropical diseases (NTDs) which manifest in the skin. To inform these strategies, we aimed to understand the social, economic and health system context of skin NTD care in Kalu woreda, Amhara region, Ethiopia, where cutaneous leishmaniasis (CL) and leprosy are endemic. Methods: Between October 2020 and May 2022, we surveyed and reviewed records of 41 primary healthcare facilities and explored common disease experiences in focus group discussions (n=40) and interviews with people affected by leprosy (n=37) and CL (n=33), health workers (n=23), kebele authorities and opinion leaders (n=33) and traditional healers (n=7). Opportunities for integrated skin NTD service provision were explored through policy document review, interviews with health officials (n=25), and stakeholder meetings. Results: Availability of diagnostic supplies and health worker competence to provide skin care was very limited across primary healthcare facilities, particularly for CL. People with leprosy commonly sought care from healthcare facilities, while people with CL administered self-care or sought help from traditional healers. Travel and costs of care at specialised facilities outside the district inhibited timely care-seeking for both diseases. Transmission discourses shaped different understandings of who was affected by leprosy and CL and expectations of behaviour during and after treatment. Many policy actors felt that existing supply chain interventions, decentralised treatment approaches and community engagement initiatives for leprosy could also benefit CL, but others also warned against increasing care-seeking unless CL treatment could be provided on a scale commensurate with the large burden they perceived. Conclusion: Our findings demonstrate significant gaps in the provision of care for skin NTDs within primary healthcare, very different health-seeking patterns for leprosy and CL, and a need to develop new models of care, especially for CL.
- Open Access
Representativeness of a mobile phone-based coverage evaluation survey following mass drug administration for soil-transmitted helminths: a comparison of participation between two cross-sectional surveys
Objectives With increasing mobile phone subscriptions, phone-based surveys are gaining popularity with public health programmes. Despite advantages, systematic exclusion of participants may limit representativeness. Similar to control programmes for neglected tropical diseases (NTDs), the DeWorm3 trial of biannual community-wide mass drug administration (MDA) for elimination of soil-transmitted helminth infection used in-person coverage evaluation surveys to measure the proportion of the at-risk population treated during MDA. Due to lockdown during the COVID-19 pandemic, a phone-based coverage evaluation survey was necessary, providing an opportunity for the current study to compare representativeness and implementation (including non-response) of these two survey modes. Design Comparison of two cross-sectional surveys. Setting The DeWorm3 trial site in Tamil Nadu, India, includes Timiri, a rural subsite, and Jawadhu Hills, a hilly, hard-to-reach subsite inhabited predominantly by a tribal population. Participants In the phone-based and in-person coverage evaluation surveys, all individuals residing in 2000 randomly selected households (50 in each of the 40 trial clusters) were eligible to participate. Here, we characterise household participation. Results Of 2000 households, 1780 (89.0%) participated during the in-person survey. Of 2000 households selected for the phone survey, 346 (17.3%) could not be contacted as they had not provided a telephone number during the census and 1144 (57.2%) participated. Smaller households, households with lower socioeconomic status and those with older, women or less educated household-heads were under-represented in the phone-based survey compared with censused households. Regression analysis revealed non-response in the phone-based survey was higher among households from the poorest socioeconomic quintile (prevalence ratio (PR) 2.3, 95% CI 2.0 to 2.7) and lower when heads of households had completed secondary school or higher education (PR 0.7, 95% CI 0.6 to 0.8). Conclusions Our findings suggest phone-based surveys under-represent households likely to be at higher risk of NTDs and in-person surveys are more appropriate for measuring MDA coverage within programmatic settings. Trial registration number NCT03014167.
Open AccessRepresentativeness of a mobile phone-based coverage evaluation survey following mass drug administration for soil-transmitted helminths: a comparison of participation between two cross-sectional surveys
Objectives With increasing mobile phone subscriptions, phone-based surveys are gaining popularity with public health programmes. Despite advantages, systematic exclusion of participants may limit representativeness. Similar to control programmes for neglected tropical diseases (NTDs), the DeWorm3 trial of biannual community-wide mass drug administration (MDA) for elimination of soil-transmitted helminth infection used in-person coverage evaluation surveys to measure the proportion of the at-risk population treated during MDA. Due to lockdown during the COVID-19 pandemic, a phone-based coverage evaluation survey was necessary, providing an opportunity for the current study to compare representativeness and implementation (including non-response) of these two survey modes. Design Comparison of two cross-sectional surveys. Setting The DeWorm3 trial site in Tamil Nadu, India, includes Timiri, a rural subsite, and Jawadhu Hills, a hilly, hard-to-reach subsite inhabited predominantly by a tribal population. Participants In the phone-based and in-person coverage evaluation surveys, all individuals residing in 2000 randomly selected households (50 in each of the 40 trial clusters) were eligible to participate. Here, we characterise household participation. Results Of 2000 households, 1780 (89.0%) participated during the in-person survey. Of 2000 households selected for the phone survey, 346 (17.3%) could not be contacted as they had not provided a telephone number during the census and 1144 (57.2%) participated. Smaller households, households with lower socioeconomic status and those with older, women or less educated household-heads were under-represented in the phone-based survey compared with censused households. Regression analysis revealed non-response in the phone-based survey was higher among households from the poorest socioeconomic quintile (prevalence ratio (PR) 2.3, 95% CI 2.0 to 2.7) and lower when heads of households had completed secondary school or higher education (PR 0.7, 95% CI 0.6 to 0.8). Conclusions Our findings suggest phone-based surveys under-represent households likely to be at higher risk of NTDs and in-person surveys are more appropriate for measuring MDA coverage within programmatic settings. Trial registration number NCT03014167.
- Open Access
- 5 January 2023
- Published by Elsevier in International Journal of Infectious Diseases
- Vol. 128, 230-243
Risk factors for SARS-CoV-2 infection in primary and secondary school students and staff in England in the 2020/2021 school year: a longitudinal study
- 5 January 2023
- Published by Elsevier in International Journal of Infectious Diseases
- Vol. 128, 230-243
Open AccessRisk factors for SARS-CoV-2 infection in primary and secondary school students and staff in England in the 2020/2021 school year: a longitudinal study
- Open Access
- 30 November 2022
- Published by Wiley in Journal of School Health
- Vol. 93 (4) , 266-278
Implementation of COVID‐19 Preventive Measures and Staff Well‐Being in a Sample of English Schools 2020‐2021
BACKGROUND: We examined fidelity and feasibility of implementation of COVID‐19 preventive measures in schools, and explored associations between adherence to these measures and staff well‐being, to inform policy on sustainable implementation and staff wellbeing.METHODS: Surveys were conducted across 128 schools in England with 107 headteachers and 2698 staff‐members with reference to autumn term 2020, examining school‐level implementation of preventive measures, adherence, and teacher burnout (response rates for headteacher and staff surveys were 84% and 59%, respectively).RESULTS: The median number of measures implemented in primary and secondary schools was 33 (range 23‐41), and 32 (range 22‐40), respectively; most measures presented challenges. No differences were found regarding number of measures implemented by school‐level socio‐economic disadvantage. High adherence was reported for staff wearing face‐coverings, staff regularly washing their hands, (secondary only) desks facing forwards, and (primary only) increased cleaning of surfaces and student hand‐washing. Adherence to most measures was reported as higher in primary than secondary schools. Over half of school leaders and 42% (517/1234) of other teaching staff suffered from high emotional exhaustion. Higher teacher‐reported school‐wide adherence with measures was consistently associated with lower burnout for leaders and other teaching staff.CONCLUSIONS: Findings indicate a tremendous effort in implementing preventive measures and an urgent need to support investments in improving teacher wellbeing.
- 30 November 2022
- Published by Wiley in Journal of School Health
- Vol. 93 (4) , 266-278
Open AccessImplementation of COVID‐19 Preventive Measures and Staff Well‐Being in a Sample of English Schools 2020‐2021
BACKGROUND: We examined fidelity and feasibility of implementation of COVID‐19 preventive measures in schools, and explored associations between adherence to these measures and staff well‐being, to inform policy on sustainable implementation and staff wellbeing.METHODS: Surveys were conducted across 128 schools in England with 107 headteachers and 2698 staff‐members with reference to autumn term 2020, examining school‐level implementation of preventive measures, adherence, and teacher burnout (response rates for headteacher and staff surveys were 84% and 59%, respectively).RESULTS: The median number of measures implemented in primary and secondary schools was 33 (range 23‐41), and 32 (range 22‐40), respectively; most measures presented challenges. No differences were found regarding number of measures implemented by school‐level socio‐economic disadvantage. High adherence was reported for staff wearing face‐coverings, staff regularly washing their hands, (secondary only) desks facing forwards, and (primary only) increased cleaning of surfaces and student hand‐washing. Adherence to most measures was reported as higher in primary than secondary schools. Over half of school leaders and 42% (517/1234) of other teaching staff suffered from high emotional exhaustion. Higher teacher‐reported school‐wide adherence with measures was consistently associated with lower burnout for leaders and other teaching staff.CONCLUSIONS: Findings indicate a tremendous effort in implementing preventive measures and an urgent need to support investments in improving teacher wellbeing.
- Open Access
- 10 November 2022
- Published by JMIR Publications Inc. in JMIR Research Protocols
- Vol. 11 (11) , e34075
The COVID-19 Schools Infection Survey in England: Protocol and Participation Profile for a Prospective Observational Cohort Study
Background: One of the most debated questions in the COVID-19 pandemic has been the role of schools in SARS-CoV-2 transmission. The COVID-19 Schools Infection Survey (SIS) aims to provide much-needed evidence addressing this issue. Objective: We present the study protocol and participation profile for the SIS study, aimed at assessing the role of schools in SARS-CoV-2 infection and transmission within school settings, and investigating how transmission within and from schools could be mitigated through the implementation of school COVID-19 control measures. Methods: SIS was a multisite, prospective, observational cohort study conducted in a stratified random sample of primary and secondary schools in selected local authorities in England. A total of 6 biobehavioral surveys were planned among participating students and staff during the 2020-2021 academic year, between November 2020 and July 2021. Key measurements were SARS-CoV-2 virus prevalence, assessed by nasal swab polymerase chain reaction; anti-SARS-CoV-2 (nucleocapsid protein) antibody prevalence and conversion, assessed in finger-prick blood for staff and oral fluid for students; student and staff school attendance rates; feasibility and acceptability of school-level implementation of SARS-CoV-2 control measures; and investigation of selected school outbreaks. The study was approved by the United Kingdom Health Security Agency Research Support and Governance Office (NR0237) and London School of Hygiene & Tropical Medicine Ethics Review Committee (reference 22657). Results: Data collection and laboratory analyses were completed by September 2021. A total of 22,585 individuals—1891 staff and 4654 students from 59 primary schools and 5852 staff and 10,188 students from 97 secondary schools—participated in at least one survey. Across all survey rounds, staff and student participation rates were 45.2% and 16.4%, respectively, in primary schools and 30% and 15.2%, respectively, in secondary schools. Although primary student participation increased over time, and secondary student participation remained reasonably consistent, staff participation declined across rounds, especially for secondary school staff (3165/7583, 41.7% in round 1 and 2290/10,374, 22.1% in round 6). Although staff participation overall was generally reflective of the eligible staff population, student participation was higher in schools with low absenteeism, a lower proportion of students eligible for free school meals, and from schools in the least deprived locations (in primary schools, 446/4654, 9.6% of participating students were from schools in the least deprived quintile compared with 1262/22,225, 5.7% of eligible students). Conclusions: We outline the study design, methods, and participation, and reflect on the strengths of the SIS study as well as the practical challenges encountered and the strategies implemented to address these challenges. The SIS study, by measuring current and incident infection over time, alongside the implementation of control measures in schools across a range of settings in England, aims to inform national guidance and public health policy for educational settings. International Registered Report Identifier (IRRID): RR1-10.2196/34075
- 10 November 2022
- Published by JMIR Publications Inc. in JMIR Research Protocols
- Vol. 11 (11) , e34075
Open AccessThe COVID-19 Schools Infection Survey in England: Protocol and Participation Profile for a Prospective Observational Cohort Study
Background: One of the most debated questions in the COVID-19 pandemic has been the role of schools in SARS-CoV-2 transmission. The COVID-19 Schools Infection Survey (SIS) aims to provide much-needed evidence addressing this issue. Objective: We present the study protocol and participation profile for the SIS study, aimed at assessing the role of schools in SARS-CoV-2 infection and transmission within school settings, and investigating how transmission within and from schools could be mitigated through the implementation of school COVID-19 control measures. Methods: SIS was a multisite, prospective, observational cohort study conducted in a stratified random sample of primary and secondary schools in selected local authorities in England. A total of 6 biobehavioral surveys were planned among participating students and staff during the 2020-2021 academic year, between November 2020 and July 2021. Key measurements were SARS-CoV-2 virus prevalence, assessed by nasal swab polymerase chain reaction; anti-SARS-CoV-2 (nucleocapsid protein) antibody prevalence and conversion, assessed in finger-prick blood for staff and oral fluid for students; student and staff school attendance rates; feasibility and acceptability of school-level implementation of SARS-CoV-2 control measures; and investigation of selected school outbreaks. The study was approved by the United Kingdom Health Security Agency Research Support and Governance Office (NR0237) and London School of Hygiene & Tropical Medicine Ethics Review Committee (reference 22657). Results: Data collection and laboratory analyses were completed by September 2021. A total of 22,585 individuals—1891 staff and 4654 students from 59 primary schools and 5852 staff and 10,188 students from 97 secondary schools—participated in at least one survey. Across all survey rounds, staff and student participation rates were 45.2% and 16.4%, respectively, in primary schools and 30% and 15.2%, respectively, in secondary schools. Although primary student participation increased over time, and secondary student participation remained reasonably consistent, staff participation declined across rounds, especially for secondary school staff (3165/7583, 41.7% in round 1 and 2290/10,374, 22.1% in round 6). Although staff participation overall was generally reflective of the eligible staff population, student participation was higher in schools with low absenteeism, a lower proportion of students eligible for free school meals, and from schools in the least deprived locations (in primary schools, 446/4654, 9.6% of participating students were from schools in the least deprived quintile compared with 1262/22,225, 5.7% of eligible students). Conclusions: We outline the study design, methods, and participation, and reflect on the strengths of the SIS study as well as the practical challenges encountered and the strategies implemented to address these challenges. The SIS study, by measuring current and incident infection over time, alongside the implementation of control measures in schools across a range of settings in England, aims to inform national guidance and public health policy for educational settings. International Registered Report Identifier (IRRID): RR1-10.2196/34075
- 24 May 2021
- Published by American Society of Tropical Medicine and Hygiene in The American Journal of Tropical Medicine and Hygiene
- Vol. -1 (aop) , 196-203
A One Health Approach to Defining Animal and Human Helminth Exposure Risks in a Tribal Village in Southern India
The high burden of soil-transmitted helminth infections has been studied in India; however, little data exist on zoonotic helminths, and on animal-associated exposure to soil-transmitted helminths. Our study took place in the Jawadhu Hills, which is a tribal region in Tamil Nadu, India. Using a One Health approach, we included animal and environmental samples and human risk factors to answer questions about the associations among infected household soil, domestic animals, and human risk factors. Helminth eggs were identified by microscopy in animal and soil samples, and a survey about risk factors was administered to the head of the household. Contact with animals was reported in 71% of households. High levels of helminth infections were found across domestic animal species, especially in goats, chickens, and dogs. Helminth eggs were recorded in 44% of household soil (n = 43/97) and separately in 88% of soil near a water source (n = 28/32). Animal contact was associated with 4.05 higher odds of having helminth eggs in the household soil (P = 0.01), and also having a water source at the household was associated with a 0.33 lower odds of having helminth eggs in the household soil (P = 0.04). Soil moisture was a mediator of this association with a significant indirect effect (P < 0.001). The proportion mediated was 0.50. While our work does not examine transmission, these results support consideration of animal-associated exposure to STH and potentially zoonotic helminths in future interventions to reduce helminth burden. Our study provides support for further investigation of the effects of animals and animal fecal matter on human health.
- 24 May 2021
- Published by American Society of Tropical Medicine and Hygiene in The American Journal of Tropical Medicine and Hygiene
- Vol. -1 (aop) , 196-203
A One Health Approach to Defining Animal and Human Helminth Exposure Risks in a Tribal Village in Southern India
The high burden of soil-transmitted helminth infections has been studied in India; however, little data exist on zoonotic helminths, and on animal-associated exposure to soil-transmitted helminths. Our study took place in the Jawadhu Hills, which is a tribal region in Tamil Nadu, India. Using a One Health approach, we included animal and environmental samples and human risk factors to answer questions about the associations among infected household soil, domestic animals, and human risk factors. Helminth eggs were identified by microscopy in animal and soil samples, and a survey about risk factors was administered to the head of the household. Contact with animals was reported in 71% of households. High levels of helminth infections were found across domestic animal species, especially in goats, chickens, and dogs. Helminth eggs were recorded in 44% of household soil (n = 43/97) and separately in 88% of soil near a water source (n = 28/32). Animal contact was associated with 4.05 higher odds of having helminth eggs in the household soil (P = 0.01), and also having a water source at the household was associated with a 0.33 lower odds of having helminth eggs in the household soil (P = 0.04). Soil moisture was a mediator of this association with a significant indirect effect (P < 0.001). The proportion mediated was 0.50. While our work does not examine transmission, these results support consideration of animal-associated exposure to STH and potentially zoonotic helminths in future interventions to reduce helminth burden. Our study provides support for further investigation of the effects of animals and animal fecal matter on human health.
- Open Access
- 12 May 2021
- Published by Public Library of Science (PLoS) in PLOS Neglected Tropical Diseases
- Vol. 15 (5) , e0009292
Epidemiology of soil-transmitted helminths following sustained implementation of routine preventive chemotherapy: Demographics and baseline results of a cluster randomised trial in southern Malawi
Malawi has successfully leveraged multiple delivery platforms to scale-up and sustain the implementation of preventive chemotherapy (PCT) for the control of morbidity caused by soil-transmitted helminths (STH). Sentinel monitoring demonstrates this strategy has been successful in reducing STH infection in school-age children, although our understanding of the contemporary epidemiological profile of STH across the broader community remains limited. As part of a multi-site trial evaluating the feasibility of interrupting STH transmission across three countries, this study aimed to describe the baseline demographics and the prevalence, intensity and associated risk factors of STH infection in Mangochi district, southern Malawi. Between October-December 2017, a community census was conducted across the catchment area of seven primary healthcare facilities, enumerating 131,074 individuals across 124 villages. A cross-sectional parasitological survey was then conducted between March-May 2018 in the censused area as a baseline for a cluster randomised trial. An age-stratified random sample of 6,102 individuals were assessed for helminthiasis by Kato-Katz and completed a detailed risk-factor questionnaire. The age-cluster weighted prevalence of any STH infection was 7.8% (95% C.I. 7.0%-8.6%) comprised predominantly of hookworm species and of entirely low-intensity infections. The presence and intensity of infection was significantly higher in men and in adults. Infection was negatively associated with risk factors that included increasing levels of relative household wealth, higher education levels of any adult household member, current school attendance, or recent deworming. In this setting of relatively high coverage of sanitation facilities, there was no association between hookworm and reported access to sanitation, handwashing facilities, or water facilities. These results describe a setting that has reduced the prevalence of STH to a very low level, and confirms many previously recognised risk-factors for infection. Expanding the delivery of anthelmintics to groups where STH infection persist could enable Malawi to move past the objective of elimination of morbidity, and towards the elimination of STH. Trial registration: NCT03014167.
- 12 May 2021
- Published by Public Library of Science (PLoS) in PLOS Neglected Tropical Diseases
- Vol. 15 (5) , e0009292
Open AccessEpidemiology of soil-transmitted helminths following sustained implementation of routine preventive chemotherapy: Demographics and baseline results of a cluster randomised trial in southern Malawi
Malawi has successfully leveraged multiple delivery platforms to scale-up and sustain the implementation of preventive chemotherapy (PCT) for the control of morbidity caused by soil-transmitted helminths (STH). Sentinel monitoring demonstrates this strategy has been successful in reducing STH infection in school-age children, although our understanding of the contemporary epidemiological profile of STH across the broader community remains limited. As part of a multi-site trial evaluating the feasibility of interrupting STH transmission across three countries, this study aimed to describe the baseline demographics and the prevalence, intensity and associated risk factors of STH infection in Mangochi district, southern Malawi. Between October-December 2017, a community census was conducted across the catchment area of seven primary healthcare facilities, enumerating 131,074 individuals across 124 villages. A cross-sectional parasitological survey was then conducted between March-May 2018 in the censused area as a baseline for a cluster randomised trial. An age-stratified random sample of 6,102 individuals were assessed for helminthiasis by Kato-Katz and completed a detailed risk-factor questionnaire. The age-cluster weighted prevalence of any STH infection was 7.8% (95% C.I. 7.0%-8.6%) comprised predominantly of hookworm species and of entirely low-intensity infections. The presence and intensity of infection was significantly higher in men and in adults. Infection was negatively associated with risk factors that included increasing levels of relative household wealth, higher education levels of any adult household member, current school attendance, or recent deworming. In this setting of relatively high coverage of sanitation facilities, there was no association between hookworm and reported access to sanitation, handwashing facilities, or water facilities. These results describe a setting that has reduced the prevalence of STH to a very low level, and confirms many previously recognised risk-factors for infection. Expanding the delivery of anthelmintics to groups where STH infection persist could enable Malawi to move past the objective of elimination of morbidity, and towards the elimination of STH. Trial registration: NCT03014167.
- Open Access
- 30 April 2021
- Published by Public Library of Science (PLoS) in PLOS Neglected Tropical Diseases
- Vol. 15 (4) , e0009338
Epidemiology of soil transmitted helminths and risk analysis of hookworm infections in the community: Results from the DeWorm3 Trial in southern India
Since 2015, India has coordinated the largest school-based deworming program globally, targeting soil-transmitted helminths (STH) in ~250 million children aged 1 to 19 years twice yearly. Despite substantial progress in reduction of morbidity associated with STH, reinfection rates in endemic communities remain high. We conducted a community based parasitological survey in Tamil Nadu as part of the DeWorm3 Project—a cluster-randomised trial evaluating the feasibility of interrupting STH transmission at three geographically distinct sites in Africa and Asia—allowing the estimation of STH prevalence and analysis of associated factors. In India, following a comprehensive census, enumerating 140,932 individuals in 36,536 households along with geospatial mapping of households, an age-stratified sample of individuals was recruited into a longitudinal monitoring cohort (December 2017-February 2018) to be followed for five years. At enrolment, a total of 6089 consenting individuals across 40 study clusters provided a single adequate stool sample for analysis using the Kato-Katz method, as well as answering a questionnaire covering individual and household level factors. The unweighted STH prevalence was 17.0% (95% confidence interval [95%CI]: 16.0–17.9%), increasing to 21.4% when weighted by age and cluster size. Hookworm was the predominant species, with a weighted infection prevalence of 21.0%, the majority of which (92.9%) were light intensity infections. Factors associated with hookworm infection were modelled using mixed-effects multilevel logistic regression for presence of infection and mixed-effects negative binomial regression for intensity. The prevalence of both Ascaris lumbricoides and Trichuris trichiura infections were rare (<1%) and risk factors were therefore not assessed. Increasing age (multivariable odds ratio [mOR] 21.4, 95%CI: 12.3–37.2, pTrial Registration: NCT03014167.
- 30 April 2021
- Published by Public Library of Science (PLoS) in PLOS Neglected Tropical Diseases
- Vol. 15 (4) , e0009338
Open AccessEpidemiology of soil transmitted helminths and risk analysis of hookworm infections in the community: Results from the DeWorm3 Trial in southern India
Since 2015, India has coordinated the largest school-based deworming program globally, targeting soil-transmitted helminths (STH) in ~250 million children aged 1 to 19 years twice yearly. Despite substantial progress in reduction of morbidity associated with STH, reinfection rates in endemic communities remain high. We conducted a community based parasitological survey in Tamil Nadu as part of the DeWorm3 Project—a cluster-randomised trial evaluating the feasibility of interrupting STH transmission at three geographically distinct sites in Africa and Asia—allowing the estimation of STH prevalence and analysis of associated factors. In India, following a comprehensive census, enumerating 140,932 individuals in 36,536 households along with geospatial mapping of households, an age-stratified sample of individuals was recruited into a longitudinal monitoring cohort (December 2017-February 2018) to be followed for five years. At enrolment, a total of 6089 consenting individuals across 40 study clusters provided a single adequate stool sample for analysis using the Kato-Katz method, as well as answering a questionnaire covering individual and household level factors. The unweighted STH prevalence was 17.0% (95% confidence interval [95%CI]: 16.0–17.9%), increasing to 21.4% when weighted by age and cluster size. Hookworm was the predominant species, with a weighted infection prevalence of 21.0%, the majority of which (92.9%) were light intensity infections. Factors associated with hookworm infection were modelled using mixed-effects multilevel logistic regression for presence of infection and mixed-effects negative binomial regression for intensity. The prevalence of both Ascaris lumbricoides and Trichuris trichiura infections were rare (<1%) and risk factors were therefore not assessed. Increasing age (multivariable odds ratio [mOR] 21.4, 95%CI: 12.3–37.2, pTrial Registration: NCT03014167.