Hand hygiene intervention to optimise soil-transmitted helminth infection control among primary school children: the Mikono Safi cluster randomised controlled trial in northwestern Tanzania

Prevalence, Infection Intensity, and Risk Factors for Soil-transmitted Helminth Infections among School Children in Northwestern Tanzania

Soil-transmitted helminthiases (STH) are among the neglected tropical diseases and infect more than 24% of the world population. The World Health Organization recommends regular monitoring of STH's prevalence and intensity following mass drug administrations to evaluate their effectiveness and inform future control strategies. This study evaluated the prevalence, intensity, and risk factors of STH infections among school children aged 6 to 14 years old in northwestern Tanzania. A cross-sectional study was conducted among 728 school children in the Kagera region in 2021. Participants were selected using a two-stage cluster sampling method. A questionnaire was used to collect data on the risk factors. Stool samples were examined using the Kato-Katz technique. The data were analysed using STATA. The overall prevalence of STH was 56.2% (95% CI: 52.5-59.8, 409/728). About 5.7% and 1.1% of the infected children had moderate-intensity infections with Ascaris lumbricoides and Trichuris trichiura, respectively. Risk factors included the mother's occupation as a farmer (aOR: 1.2, p = 0.002) and not washing hands with water and soap (aOR: 1.4, p = 0.035). Washing one's hands after using the toilet (aOR: 0.6; p = 0.024) is a preventive measure against STH infections. STH was prevalent in the study area. The mother's occupation (farmer) and the lack of handwashing with water and soap influenced STH transmission. Conversely, washing hands after visiting the toilet and after playing with soil reduced the risk of STH infection.

Determination of the Prevalence of Ascaris lumbricoides in Children under the Age of Five Years Attending at Kongowe Health Centre, Kibaha District, Pwani Region

Background

The worldwide distribution and occurrence show that more than 1.8 billion people, accounting for 28% of the global population, are infected with A. lumbricoides infection due to poor hygiene. The World Health Organization aims to eliminate morbidity from A. lumbricoides infection in children by 2030 by at least 75%. Surveys in the Pwani Region of Tanzania have shown poor hygienic risk factors due to high population and lack of sufficient toilets/latrines, poor sewage waste disposal, and insufficient clean drinking water that encourages the reproduction, transmission, and reinfection of A. lumbricoides. No study has been conducted in Pwani Region to determine the extent of A. lumbricoides infection among the population. This research tends to explore more about the status of A. lumbricoides infection in Kibaha District in the Pwani Region, Tanzania.

Methods

A cross-sectional study was done on 400 children (170 males and 230 females) who were under the age of 5 years old at Kongowe Health Centre. Collected data for A. lumbricoides infection measured were analyzed using Microsoft Excel, while data for sociodemographic findings and risk assessment were subjected to bivariate and multivariable analysis using Statistical Package for Social Sciences version 28.0.1.0 software (SPSS Inc., USA) at the level of significance of P < 0.05.

Results

Of the 400 children who participated in the laboratory testing of A. lumbricoides infection, 194 were found positive for A. lumbricoides infection. Amongst the 194 children who were found to be positive, 4.1%, 38.7%, and 57.2% were found to be in the age group of below 1 year old, 1 to 2, and 3 to 4 years old, respectively. The tabulated responses on the social demographic responses showed that 81.8% of the responses at P = 0.041 and 80.6% at P = 0.101 knew that A. lumbricoides infection is acquired from faeces and uncooked food, respectively, as 61.8% at P = 0.132 and 63.2% at P = 0.085 respondents did not accept that soil and dirty water, respectively, were not sources of A. lumbricoides infection. At P = 0.612 and P = 0.022, 64% and 91.2% of the respondents showed the importance of using latrines/toilets and washing fruits, respectively. Further results showed that 69.8% and 37.6% of the respondents reacted with no importance of washing hands with soap after using a toilet/latrine and no need to treat or boil water before drinking, respectively.

Conclusions

A. lumbricoides infection has a high prevalence in infants of the Kibaha District of Tanzania, especially in Kongowe village. The infection is dominant in males compared to female children. The prevalence is due to risk factors such as inadequate sanitation, low level of education, knowledge, and awareness of prevention strategies.

Nongovernmental Organization Practitioners' Perspectives on the Challenges and Solutions to Changing Handwashing Behavior in Older Children: A Qualitative Study

BACKGROUND

Increasing handwashing with soap (HWWS) among older children (aged 5-14 years) can achieve a substantial public health impact. However, HWWS interventions targeting older children have had mixed success. Recent research has attempted to quantitatively identify effective intervention techniques; however, success is likely also influenced by the wider context of implementation. We explore nongovernmental organization (NGO) practitioners' perspectives on the challenges and solutions to HWWS interventions targeting older children to enhance understanding of what is required, beyond intervention content, for them to be effective.

METHODS

We conducted in-depth, semistructured interviews in April-November 2020 with 25 practitioners employed across 11 NGOs and involved in HWWS interventions targeting older children in development and humanitarian settings. We used purposive and snowball sampling to recruit participants in roles at the global, national/regional, and local levels. Interviews were audio-recorded, transcribed, and thematically analyzed to identify challenges and solutions to HWWS interventions targeting older children. Results were organized according to program development cycle stages.

RESULTS

Twelve themes relating to perceived challenges emerged: (1) lack of prioritization, (2) funding inconsistency, (3) insufficient formative research, (4) demand on resources, (5) unengaging intervention content, (6) non-enabling physical environments, (7) availability of skilled implementers, (8) reaching out-of-school children, (9) community mistrust, (10) lack of coordination, (11) lack of evaluation rigor, and (12) failure to assign older children's HWWS as a primary outcome in evaluations of hygiene interventions. Recommended solutions were at the intervention, organization, and sector levels.

CONCLUSION

Intervention design and delivery are important for the success of HWWS interventions for older children, but contextual factors, such as the availability of human and material resources and the level of coordination within and beyond the NGO sector, should also be considered. NGOs need to prioritize HWWS promotion among older children and support programs accordingly.

Monks: A Population at Risk for Liver Fluke and Skin-Penetrating Helminths

Monks cannot cook received raw meat dishes and should walk barefoot while working. This population lacks both a survey of parasitic infection and a proper prevention and control policy. Five hundred and fourteen monks from the Ubolratana, Ban Haet, and Ban Phai Districts of Kh on Kaen Province were enrolled in this study. A stool container and questionnaire were collected from each study participant. Stool samples were processed by formalin ethyl acetate concentration and agar plate culture techniques. We then analyzed the results and risk factors to demonstrate associations. The prevalence of overall parasites, liver flukes, and skin-penetrating helminths were 28.8%, 11.1%, and 19.3%, respectively. Raw fish dish offerings were associated with opisthorchiasis (ORcrude 3.32; 95% CI 1.53–7.20). The risk factors for skin-penetrating helminths were older age (ORcrude 5.02; 95% CI 2.2–11.17), being a long-term ordinate (ORcrude 3.28; 95% CI 1.15–9.34), smoking (ORcrude 2.03; 95% CI 1.23–3.36), and chronic kidney disease with other underlying disease (ORcrude 20.7; 95% CI 2.54–190.1). The protective factors for skin-penetrating helminths were secular education above primary education (ORcrude 0.41; 95% CI 0.25–0.65) and having received health education about parasitic infection (ORcrude 0.47; 95% CI 0.28–0.80). Wearing shoes at times other than alms work does not show a protective effect against skin-penetrating helminths (ORcrude 0.86; 95% CI 0.51–1.46). These findings support the recommendation for a strict Rule of Discipline regarding raw meat ingestion and allowing shoes to be worn for protection against skin-penetrating helminths in high-risk situations.

Interventions to improve water, sanitation, and hygiene for preventing soil-transmitted helminth infection

BACKGROUND

It is estimated that 1.5 billion people are infected with soil-transmitted helminths (STHs) worldwide. Re-infection occurs rapidly following deworming, and interruption of transmission is unlikely without complementary control efforts such as improvements in water, sanitation, and hygiene (WASH) access and behaviours.

OBJECTIVES

To assess the effectiveness of WASH interventions to prevent STH infection.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 19 October 2021.

SELECTION CRITERIA

We included interventions to improve WASH access or practices in communities where STHs are endemic. We included randomized controlled trials (RCTs), as well as trials with an external control group where participants (or clusters) were allocated to different interventions using a non-random method (non-RCTs). We did not include observational study designs. Our primary outcome was prevalence of any STH infection. Prevalence of individual worms was a secondary outcome, including for Ascaris lumbricoides, Trichuris trichiura, hookworm (Ancylostoma duodenale or Necator americanus), or Strongyloides stercoralis. Intensity of infection, measured as a count of eggs per gram of faeces for each species, was another secondary outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed titles and abstracts and full-text records for eligibility, performed data extraction, and assessed risk of bias using the Cochrane risk of bias assessment tool for RCTs and the EPOC tool for non-RCTs. We used a random-effects meta-analysis to pool study estimates. We used Moran's I² statistic to assess heterogeneity and conducted subgroup analyses to explore sources of heterogeneity. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 32 studies (16 RCTs and 16 non-RCTs) involving a total of 52,944 participants in the review. Twenty-two studies (14 RCTs (16 estimates) and eight non-RCTs (11 estimates)) reported on our primary outcome, prevalence of infection with at least one STH species. Twenty-one studies reported on the prevalence of A lumbricoides (12 RCTs and 9 non-RCTs); 17 on the prevalence of T trichiura (9 RCTs and 8 non-RCTs); 18 on the prevalence of hookworm (10 RCTs and 8 non-RCTs); and one on the prevalence of S stercoralis (1 non-RCT). Sixteen studies measured the intensity of infection for an individual STH type. Ten RCTs and five non-RCTs reported on the intensity of infection of A lumbricoides; eight RCTs and five non-RCTs measured the intensity of infection of T trichiura; and eight RCTs and five non-RCTs measured the intensity of hookworm infection. No studies reported on the intensity of infection of S stercoralis. The overall pooled effect estimates showed that the WASH interventions under study may result in a slight reduction of any STH infection, with an odds ratio (OR) of 0.86 amongst RCTs (95% confidence interval (CI) 0.74 to 1.01; moderate-certainty evidence) and an OR of 0.71 amongst non-RCTs (95% CI 0.54 to 0.94; low-certainty evidence). All six of the meta-analyses assessing individual worm infection amongst both RCTs and non-RCTs had pooled estimates in the preventive direction, although all CIs encapsulated the null, leaving the possibility of the null or even harmful effects; the certainty of the evidence ranged from very low to moderate. Individual studies assessing intensity of infection showed mixed evidence supporting WASH. Subgroup analyses focusing on narrow specific subsets of water, sanitation, and hygiene interventions did very little to elucidate which interventions might be better than others. Data on intensity of infection (e.g. faecal egg count) were reported in a variety of ways across studies, precluding the pooling of results for this outcome. We did not find any studies reporting adverse events resulting from the WASH interventions under study or from mass drug administration (MDA).

AUTHORS' CONCLUSIONS

Whilst the available evidence suggests that the WASH interventions under study may slightly protect against STH infection, WASH also serves as a broad preventive measure for many other diseases that have a faecal oral transmission route of transmission. As many of the studies were done in addition to MDA/deworming (i.e. MDA was ongoing in both the intervention and control arm), our data support WHO recommendations for implementation of improvements to basic sanitation and adequate access to safe water alongside MDA. The biological plausibility for improved access to WASH to interrupt transmission of STHs is clear, but WASH interventions as currently delivered have shown impacts that were lower than expected. There is a need for more rigorous and targeted implementation research and process evaluations in order that future WASH interventions can better provide benefit to users. Inconsistent reporting of the intensity of infection underscores the need to define the minimal, standard data that should be collected globally on STHs to enable pooled analyses and comparisons.

Does a school-based intervention to engage parents change opportunity for handwashing with soap at home? Practical experience from the Mikono Safi trial in Northwestern Tanzania

BACKGROUND

School-based de-worming is advocated as a strategy for reducing the burden of soil-transmitted helminth (STH) infections among children. However, re-infection tends to occur rapidly, suggesting that comprehensive water, sanitation, and hygiene (WASH) improvements may be needed to prevent this. We qualitatively assessed the influence of parental engagement activities on parents' motivation to improve WASH infrastructure and hygiene practices at home in the context of a school-based de-worming programme.

METHODOLOGY

We conducted a longitudinal qualitative study nested within the Mikono Safi trial, designed to assess the effect of a WASH intervention on STH infection prevalence in children. Meetings were organized for parents/guardians at schools where they were given information about STH infection, the role of WASH in STH infection prevention, and actionable steps they could take at home. During the meetings, parents/guardians received information about their own child's STH infection status. Twenty purposively selected households were visited and interviewed 3 times over a period of about 8-months. We employed thematic analysis; findings are reported following the Capability-Opportunity-Motivation and Behaviour (COM-B) framework.

PRINCIPAL FINDINGS

The engagement strategy improved parents'/guardians' knowledge and skills about handwashing with soap and its benefits. Parents/guardians reported that the sessions had motivated them to improve WASH infrastructure at home. Of 20 households included in this study, 17 renovated or built new latrines and 18 installed handwashing facilities. However, only 8 households established and maintained handwashing stations with both soap and water at 8 months.

CONCLUSIONS

The engagement of parents/guardians in a school-based WASH education intervention as part of the Mikono Safi trial resulted in increased knowledge and motivation about handwashing and sanitation. This led to improvements in sanitation facilities and handwashing opportunities at home. However, long-term success in provision of water and soap was limited, indicating that sustained engagement may be required to encourage households to ensure these materials are consistently available at home.