Impact of community-based integrated mass drug administration on schistosomiasis and soil-transmitted helminth prevalence in Togo

The impact of community based interventions for the prevention and control of soil-transmitted helminths: A systematic review and meta-analysis

Soil-transmitted helminths (STHs) are among the most common human infections worldwide and a major cause of morbidity. They are caused by different species of parasitic worms and transmitted by eggs released in faeces or when hookworm larvae penetrate the skin. The main control strategy in endemic regions is periodic treatment with deworming medication. In the last 10 years, there has been a scale-up of prevention and control activities with a focus on community-based interventions (CBIs). This review aims to systematically analyse the impact of CBIs on the prevalence and infection intensity of STHs. A systematic review was published on this topic in 2014, but there have subsequently been several new studies published which are included in this review. Electronic database search of MEDLINE (Ovid), Global Health Online (Ovid), Cochrane Library, Embase (Ovid) and Web of Science was conducted. Titles, abstracts, and full texts were screened by two independent reviewers according to predefined eligibility criteria. Data were extracted and a meta-analysis of included studies was conducted. A total of 11,954 de-duplicated titles were screened, and 33 studies were included in the review. 14 focussed on community-wide treatment, 11 studies investigated school-based interventions, and 3 studies investigating both. Results suggest that CBIs are effective in reducing the prevalence of Hookworm, Trichuris trichiura and Ascaris lumbricoides. School-based treatment and community-wide treatment, as well as annual and semi-annual deworming, all reduce STH prevalence significantly. Mass drug administration was effective in reducing the infection intensity of Hookworm (Mean difference: -211.36 [95% CI: -519.12, 96.39]), Trichuris trichiura (-736.69 [-1349.97, -123.42]) and Ascaris lumbricoides (-2723.34 [-5014.85, -431.84]). The results suggest that CBIs are effective in reducing the prevalence and intensity of STH infections. While most studies delivered preventive chemotherapy (PC), few studies explored the impact of interventions such as water, sanitation, and hygiene (WASH) or health education, which may be essential in preventing reinfection after PC.

Control and elimination of Schistosoma mansoni infection in adult individuals on Ukerewe island, northwestern Tanzania: baseline results before implementation of intervention measures

BACKGROUND

Communities living along the shoreline and on the islands of Lake Victoria in northwestern Tanzania remain endemic for schistosomiasis and suffer from the life-threatening morbidities associated with the disease. Nevertheless, the control measures particularly the mass drug administration do not cover the adult population. The current project on Ukerewe island aims to close this gap by involving adult community members in the control program. Here we report the baseline results of S. mansoni infection and associated hepatosplenic morbidities and factors before implementing the project activities.

METHODS

A cross-sectional analytical study was conducted with 4,043 participants aged ≥ 18 years living in 20 villages on Ukerewe island, northwestern Tanzania. Individual stool and urine samples were collected and examined using the Kato-Katz (KK) technique and point-of-care circulating cathodic antigen testing(POC-CCA) to identify S. mansoni eggs and antigens, respectively. All study participants underwent ultrasound evaluation of S. mansoni hepatosplenic morbidities using the Niamey protocol. Rapid diagnostic tests were used to diagnose HIV infection, hepatitis C and chronic hepatitis B. A questionnaire was used to collect demographic data and reported clinical symptoms of study participants.

RESULTS

A total of 4,043 participants took part in the study, of which 49.7% (n = 2,009) and 50.3% (n = 2,035) were male and female, respectively. The overall prevalence of S. mansoni infection was 30.4% (95%CI:29.0-31.9%) and 84.7% (95%CI:83.3-85.9%), respectively, based on the KK technique and the POC-CCA test. The geometrical mean eggs per gram of faeces (GMepg) was 105.3 (95%CI:98.7-112.3% GMepg) with 53.9%, 32.4% and 13.7% of the participants having mild, had moderate and severe intensity of infection. The prevalence of hepatitis C, HIV, and hepatitis B was 0.4%, 2.2% and 4.7%, with 0.2%, 2.2% and 5.4% of the infected individuals coexisting with S. mansoni infection. The prevalence of splenomegaly, periportal fibrosis, hepatomegaly, and portal vein dilatation was 40.5%(95%CI: 38.8-42.1%), 48.1%(95%CI:64.4-49.7%), 66.2%(95%CI:4.6-67.7%) and 67.7%(95%CI:66.2-69.2%), with their prevalence varying depending on the demographic information and infection status of the participants. Other detectable ultrasound-related morbidities included ascites (1.7%), collateral veins (18.3%) and gall bladder wall thickness (40.4%). Age groups, gender, reported clinical characteristics, reported non-use of the drug praziquantel, liver imaging pattern, and place of residence remained independently associated with hepatosplenic morbidities.

CONCLUSION

The current study setting is endemic for S. mansoni infection and the population has a high prevalence of the disease associated hepatosplenic morbidities characterized by hepatomegaly, splenomegaly, ascites, gall bladder wall thickening, periportal fibrosis and portal vein dilatation. Several demographic, clinical and epidemiological circumstances remained independently associated with S. mansoni infection and associated morbidities. These findings call for integrative intervention efforts, starting with whole community MDA that includes all out of schools community members.

Chemical Control of Snail Vectors as an Integrated Part of a Strategy for the Elimination of Schistosomiasis-A Review of the State of Knowledge and Future Needs

WHO promotes the implementation of a comprehensive strategy to control and eliminate schistosomiasis through preventive chemotherapy, snail control, clean water supply, improved sanitation, behaviour change interventions, and environmental management. The transmission of schistosomiasis involves infected definitive hosts (humans or animals) excreting eggs that hatch (miracidia), which infect freshwater snail vectors (also referred to as intermediate snail hosts) living in marshlands, ponds, lakes, rivers, or irrigation canals. Infective larvae (cercariae) develop within the snail, which, when released, may infect humans and/or animals in contact with the water. Snail control aims to interrupt the transmission cycle of the disease by removing the vector snails and, by so doing, indirectly improves the impact of the preventive chemotherapy by reducing reinfection. Snail control was, for many years, the only strategy for the prevention of schistosomiasis before preventive chemotherapy became the primary intervention. Snails can be controlled through various methods: environmental control, biological control, and chemical control. The chemical control of snails has proven to be the most effective method to interrupt the transmission of schistosomiasis. The current review aims to describe the vector snails of human schistosomiasis, present the chemicals and strategies for the control of snails, the challenges with the implementation, and the future needs. Snail control can play a key role in reducing schistosomiasis transmission and, thus, complements other interventions for disease control. There is a need to develop new molluscicide products or new formulations and methods of applications for existing molluscicides that would target snail vectors more specifically.

Extensive transmission and variation in a functional receptor for praziquantel resistance in endemic Schistosoma mansoni

Mass-drug administration (MDA) of human populations using praziquantel monotherapy has become the primary strategy for controlling and potentially eliminating the major neglected tropical disease schistosomiasis. To understand how long-term MDA impacts schistosome populations, we analysed whole-genome sequence data of 570 Schistosoma mansoni samples (and the closely related outgroup species, S. rodhaini) from eight countries incorporating both publicly-available sequence data and new parasite material. This revealed broad-scale genetic structure across countries but with extensive transmission over hundreds of kilometres. We characterised variation across the transient receptor potential melastatin ion channel, TRPMPZQ, a target of praziquantel, which has recently been found to influence praziquantel susceptibility. Functional profiling of TRPMPZQ variants found in endemic populations identified four mutations that reduced channel sensitivity to praziquantel, indicating standing variation for resistance. Analysis of parasite infrapopulations sampled from individuals pre- and post-treatment identified instances of treatment failure, further indicative of potential praziquantel resistance. As schistosomiasis is targeted for elimination as a public health problem by 2030 in all currently endemic countries, and even interruption of transmission in selected African regions, we provide an in-depth genomic characterisation of endemic populations and an approach to identify emerging praziquantel resistance alleles.

Epidemiology of soil-transmitted helminthiasis among school-aged children in pastoralist communities of Kenya: A cross-sectional study

INTRODUCTION

Soil-transmitted helminthiasis (STH) are a major public health problem in Sub-Saharan Africa. In Kenya, the National School Based Deworming Program (NSBDP) was launched in 2012 with a goal of reducing STH prevalence in school-aged children (SAC) to <1%, however monitoring and evaluation results have consistently showed > 20% prevalence in Narok County. We conducted a study to investigate factors associated with STH infections among SAC in Narok County.

METHODOLOGY

A cross-sectional study was conducted among 514 SAC from five schools in Trans Mara West sub-county, Narok County. The sub-county was selected because it had participating schools within the NSBDP with a high prevalence of STH infection. Participants were selected using systematic random sampling. Stool samples collected from participants were examined for STH eggs using Kato-Katz technique. An open data kit questionnaire was used to collect socio-demographics, household, and STH knowledge information from 139 of the 514 SAC. Descriptive statistics was used to summarize the data, prevalence and mean intensity of infections were calculated, and logistic regression used to determine factors associated with STH infections.

RESULTS

The overall prevalence of any STH infection was 24.6% (95%CI: 21.1-28.6). Trichuris trichiura 14.4% (95%CI: 11.7-17.8), Ascaris lumbricoides 12.5% (95%CI: 9.9-15.7) and hookworm 0%. From multivariable analysis the only factors significantly associated with increased risk of STH infection were, children attending Karda and Nkarano schools with aOR = 5.29 (95%CI: 1.45-19.24); p = 0.011 and aOR = 4.53 (95%CI: 1.29-15.97); p = 0.019 respectively. For A. lumbricoides, children attending Nkarano School were associated with a significant risk of infection with aOR = 7.81 (95%CI: 1.81-33.63); p = 0.006.

CONCLUSIONS

Despite the ongoing work of NSBDP, the STH prevalence is still ≥ 20% in Trans Mara West sub-county Narok County, among SAC. This underscores the need for continued annual MDA. Additionally, if possible, drug combinations may effectively manage T. trichiura, the region's most common helminth. The study found a correlation between children attending specific schools and STH infection risk, suggesting the importance of health education and improved water, sanitation, and hygiene practices holistically both in schools and associated catchment areas that can act as STH reservoirs to alleviate the burden of STH.

Health workers' perspectives on school-based mass drug administration control programs for soil-transmitted helminthiasis and schistosomiasis in Ogun State, Nigeria

BACKGROUND

Soil-transmitted helminthiasis (STH) and schistosomiasis (SCH) are among the most prevalent neglected tropical diseases (NTDs), affecting 1.5 billion globally, with a significant burden in sub-Saharan Africa, particularly Nigeria. These diseases impair health and contribute to socio-economic challenges, especially in children, undermining educational and future economic prospects. The 2030 NTD Roadmap highlights Mass Drug Administration (MDA) as a critical strategy for controlling these NTDs, targeting vulnerable populations like school-age children. Despite some successes, challenges persist, indicating the need for deeper insights into program implementation. This study focuses on the perspectives of health workers implementing MDA in selected local government areas (LGAs) of Ogun State, Nigeria, aiming to identify challenges and enablers that align with the broader NTD 2030 goals.

METHODOLOGY/PRINCIPAL FINDINGS

The study used a qualitative research approach involving focus group discussions and in-depth interviews with health workers engaged in neglected tropical disease control programs in Ogun State, Nigeria, between July and September 2022. A semi-structured questionnaire guided the exploration of ideas, and the data were analyzed using the QRS Nvivo 12 software package. The study found that the school-based MDA control program's efficacy largely relies on strong collaborations and partnerships, particularly with educators, community heads, and other stakeholders. These alliances and strategic communication methods, like town announcements and media campaigns, have been pivotal in reaching communities. However, the program does grapple with hurdles such as parental misconceptions, limited funds, insufficient staffing, and misalignment with the Ministry of Education. It is recommended to boost funding, foster early stakeholder involvement, enhance mobilization techniques, and consider introducing a monitoring card system similar to immunization.

CONCLUSIONS/SIGNIFICANCE

The MDA Integrated Control Programs for STH and SCH in Ogun State schools demonstrate a holistic approach, integrating knowledge, collaboration, communication, and feedback. Health workers have shown commitment and adeptness in their roles. However, achieving maximum efficacy requires addressing critical barriers, such as parental misconceptions and funding challenges. Adopting the recommended strategies, including proactive communication, increased remuneration, and introducing a tracking system, can significantly enhance the program's reach and impact. The involvement of all stakeholders, from health workers to community leaders and parents, is essential for the program's sustainability and success.

Effects of paediatric schistosomiasis control programmes in sub-Saharan Africa: A systematic review

Preventive chemotherapy by mass drug administration is globally recommended as the primary method of reaching the elimination of schistosomiasis, especially in the high risk-paediatric population. This systematic review provides a summary of the effects of paediatric schistosomiasis control programs on eliminating schistosomiasis in sub-Saharan Africa. A systematic search was conducted in PubMed, EBSCOhost, and other databases to obtain studies regarding the effects of paediatric schistosomiasis control programmes in sub-Saharan Africa. 3455 studies were screened for eligibility, included articles reported on both paediatrics control programmes and schistosomiasis, and articles were excluded when they did not report on schistosomiasis control programmes in paediatrics exclusively. 40 selected studies were critically appraised using the JBI critical appraisal tools for relevance and 30 studies were included in the study. An in-depth quantitative descriptive analysis was conducted, and a comprehensive narrative summary explained the results within the scope of the review questions. The results show that despite preventive chemotherapy lowering schistosomiasis prevalence, chances of re-infection are high in endemic areas. Preventive chemotherapy without complementary interventions including safe water provision and proper sanitation, snail control and health education on the aetiology of schistosomiasis, transmission pattern and control practices might not eliminate schistosomiasis.

Investigating the effect of a school-based WASH intervention on soil-transmitted helminth and schistosome infections and nutritional status of school children in Ethiopia: a quasi-experimental study

BACKGROUND

The impact of access to improved water, sanitation and hygiene (WASH) and health education on large-scale deworming programs aimed at controlling soil-transmitted helminth (STH) and schistosome (SCH) infections has not been well studied. We assessed the additional impact of improved WASH infrastructure and health education at schools on STH and SCH infections in Ethiopia.

METHODS

The study used a quasi-experimental design under which 30 schools were assigned to either an intervention (15 schools) or control (15 schools) arm. Both arms received a standard deworming treatment and lunch. In the intervention arm, improved WASH and health education were provided. At three consecutive time points (baseline in 2013, 2014 and 2015), the prevalence and intensity of STH and SCH infections and the nutritional status [hemoglobin concentrations and physical growth (height and weight)] were determined. To verify whether interventions were successfully implemented, the WASH status at school and the student knowledge, attitudes and practices related to WASH (WASH-KAP) were recorded. Differences in metrics between arms at baseline (2013) and follow-up (2015) were assessed both within and between the arms.

RESULTS

A significant increase in scores for both the school WASH and student KAP was found in the intervention arm, indicating successful implementation of the intervention. The prevalence of any STH infection was significantly reduced in the intervention arm but not in the control arm (F = 4.486, p = 0.034). There was a significantly greater reduction in the intensity of infection of hookworm and Ascaris lumbricoides compared to baseline in both arms. The intervention did not affect school children's height-for-age z-score (intervention arm * time coef = 0.12, p = 0.400) and body mass index-for-age z-scores (intervention * time coef = - 0.06, p = 0.526). Hemoglobin concentrations increased significantly more in the control than the intervention arm (coef = - 0.16, p = 0.006).

CONCLUSIONS

Although the intervention did increase school WASH and student WASH-KAP, our study found poor evidence of the additional benefit of improved WASH and health education to deworming and school food programs on parasite re-infection and the health outcomes of children.

Mass drug administration campaigns: comparing two approaches for schistosomiasis and soil-transmitted helminths prevention and control in selected Southern Malawi districts

BACKGROUND

Mass drug administration is one of the key interventions recommended by WHO to control certain NTDs. With most support from donors, health workers distribute antihelminthic drugs annually in Malawi. Mean community coverage of MDA from 2018 to 2020 was high at 87% for praziquantel and 82% for albendazole. However, once donor support diminishes sustaining these levels will be challenging. This study intended to compare the use of the community-directed intervention approach with the standard practice of using health workers in delivery of MDA campaigns.

METHODS

This was a controlled implementation study carried out in three districts, where four health centres and 16 villages in each district were selected and randomly assigned to intervention and control arms which implemented MDA campaigns using the CDI approach and the standard practice, respectively. Cross-sectional and mixed methods approach to data collection was used focusing on quantitative data for coverage and knowledge levels and qualitative data to assess perceptions of health providers and beneficiaries at baseline and follow-up assessments. Quantitative and qualitative data were analyzed using IBM SPSS software version 26 and NVivo 12 for Windows, respectively.

RESULTS

At follow-up, knowledge levels increased, majority of the respondents were more knowledgeable about what schistosomiasis was (41%-44%), its causes (41%-44%) and what STH were (48%-64%), while knowledge on intermediate host for schistosomiasis (19%-22%), its types (9%-13%) and what causes STH (15%-16%) were less known both in intervention and control arm communities. High coverage rates for praziquantel were registered in intervention (83%-89%) and control (86%-89%) communities, intervention (59%-79) and control (53%-86%) schools. Costs for implementation of the study indicated that the intervention arm used more resources than the control arm. Health workers and community members perceived the use of the CDI approach as a good initiative and more favorable over the standard practice.

CONCLUSIONS

The use of the CDI in delivery of MDA campaigns against schistosomiasis and STH appears feasible, retains high coverages and is acceptable in intervention communities. Despite the initial high costs incurred, embedding into community delivery platforms could be considered as a possible way forward addressing the sustainability concern when current donor support wanes.

TRIAL REGISTRATION

Pan-African Clinical Trials Registry PACTR202102477794401, date: 25/02/2021.

Progress from morbidity control to elimination as a public health problem of schistosomiasis and the status of soil-transmitted helminth infection in Togo: a second impact assessment after ten rounds of mass drug administration

BACKGROUND

Due to the burden of schistosomiasis (SCH) and soil-transmitted helminths (STH), Togo Ministry of Health launched a program for Preventive Chemotherapy Neglected Tropical Diseases (PC-NTDs) in 2009, initiating integrated mass drug administration (MDA) the following year for the three PC-NTDs: SCH, STH and onchocerciasis. Significant reduction of infection across the country was noted in 2015 during the first impact assessment, following 5 years of high-coverage MDA implemented at the sub-district level for SCH and district level for STH. After another 5 years of effective MDA, a second survey was conducted in 2021 to re-evaluate the situation of SCH and STH.

METHODS

A cross-section of school-aged children was taken across ten districts of Togo. A total of 302 schools in 92 sub-districts were sampled, with 24 school-aged children per school resulting in 7248 children surveyed. Urine samples were tested by haemastix® for Schistosoma haematobium, with urine filtration for the presence of eggs conducted on haematuria-positive samples. Stool samples were collected in a subset of 34 sub-districts in seven out of the ten surveyed districts, where STH and Schistosoma mansoni endemicity was high during the 2015 impact assessment. Duplicate (two) Kato-Katz analysis was performed for each stool sample. Sociodemographic and school-level water, sanitation and hygiene information was also collected.

RESULTS

Overall, SCH prevalence was 5.90% (95% CI: 5.4-6.5), with 5.09% (95% CI: 4.64-5.67) for S. haematobium and 2.56% (95% CI: 1.98-3.29) for S. mansoni. STH prevalence was 19.7% (95% CI: 18.2-21.4), with 19.6% (95% CI: 18.1-21.3) hookworm, 0.08% (95% CI: 2.2-5.8) Trichuris trichiura and 0.04% (95% CI: 0.01-0.33) Ascaris lumbricoides. Compared to baseline, a significant reduction in both SCH (22.2% to 5.90%) and STH (29.2% t0 19.7%) prevalence was observed. Children aged 5-9 years were less infected than older peers aged 10-14 years: 4.76% vs. 7.53% (P < 0.01) for SCH and 17.2% vs. 23.0% (P < 0.01) for STH.

CONCLUSIONS

After 10 years of high coverage integrated MDA, Togo has achieved low prevalence SCH infection through the sub-district MDA implementation with considerable infection heterogeneity within sub-districts. As STH infection has not reached a level where the infections are not a public health problem, the sub-district treatment strategy could also be adopted in addition to improvement of treatment coverage among preschool age children and hygiene and sanitation practices.

The Impact of Targeted Treatment and Mass Drug Administration Delivery Strategies on the Prevalence and Intensity of Schistosomiasis in School Aged Children in Africa: A Systematic Review

Schistosomiasis is a public health problem in more than 78 countries in the world. The disease is most prevalent among children than adults due to their high exposure to infectious water sources. Various interventions such as mass drug administration (MDA), snail control, safe water provision and health education have been implemented independently or jointly to control, reduce and ultimately eliminate Schistosomiasis. This scoping review focused on studies reporting the impact of different delivery strategies of targeted treatment and MDA on the prevalence and intensity of schistosomiasis infection in school aged children in Africa. The review focused on Schistosoma haematobium and Schistosoma mansoni species. A systematic search for eligible literature from peer-reviewed articles was done from Google Scholar, Medline, PubMed and EBSCO host databases. The search yielded twenty-seven peer-reviewed articles. All articles found reported a decrease in the prevalence of schistosomiasis infection. Five studies (18.5%) reported a prevalence change below 40%, eighteen studies (66.7%) reported a change between 40% and 80%, and four studies (14.8%) reported a change above 80%. The infection intensity post-treatment was varied: twenty-four studies reported a decrease, while two studies reported an increase. The review showed that the impact of targeted treatment on the prevalence and intensity of schistosomiasis depended on the frequency at which it was offered, complementary interventions, and its uptake by the target population. Targeted treatment can significantly control the infection burden, but cannot eliminate the disease. Constant MDA programs coupled with preventative and health promotional programs are required to reach the elimination stage.

Empowering local research ethics review of antibacterial mass administration research

BACKGROUND

Recent studies using mass drug administration (MDA) of antibiotics to entire communities have focused global attention on the unique ethical challenges of MDA of antibiotics in research and public health interventions. However, there is no specific guidance for Research Ethics Committees (RECs) or Institutional Review Boards (IRBs) to review such trials. We surveyed the literature to identify the unique ethical challenges and to strengthen the competencies of RECs or IRBs in low- and middle-income countries (LMICs) in their ethical reviews of these trials.

METHODS

We employed a desk review. We searched PubMed, Web of Science, and Google Scholar, combining terms for "mass drug administration" with terms for "research ethics committees," "institutional review boards," and "ethics." We reviewed citations of search results to retrieve additional articles. Only articles published and indexed in the above databases up to 6 January 2022 in English were included. Abstracts (without full articles), books and articles that had exclusive veterinary and environmental focus were excluded. We synthesized the literature to identify particularly challenging ethical issues relevant to antibacterial MDA trials in LMICs.

RESULTS

The most challenging ethical issues can be categorised into four broad domains: determining the social value of MDA, assessing risks and benefits, engaging all stakeholders meaningfully, and study design-related ethical challenges. These four domains interact and impact each other. Together, they reveal the need for RECs/IRBs to review MDA studies through a broader lens than that of clinical trials per se. From our findings, we propose a framework to guide the RECs and IRBs in LMICs to perform the initial and continuing review of antibiotic MDA trials. We also recommend strengthening the competencies of LMIC RECs or IRBs through ongoing training and collaboration with RECs or IRBs from high-income countries.

CONCLUSIONS

REC/IRB review of research using MDA of antibiotics plays a critical role in assuring the ethical conduct of MDA studies. Local RECs/IRBs should be empowered to review MDA studies comprehensively and competently in order to advance scientific knowledge about MDA and promote improved global health.

Ethical challenges in mass drug administration for reducing childhood mortality: a qualitative study

Background

Mass drug administration (MDA) of medications to entire at-risk communities or populations has shown promise in the control and elimination of global infectious diseases. MDA of the broad-spectrum antibiotic azithromycin has demonstrated the potential to reduce childhood mortality in children at risk of premature death in some global settings. However, MDA of antibiotics raises complex ethical challenges, including weighing near-term benefits against longer-term risks—particularly the development of antimicrobial resistance that could diminish antibiotic effectiveness for current or future generations. The aim of this study was to understand how key actors involved in MDA perceive the ethical challenges of MDA.

Methods

We conducted 35 semi-structured interviews from December 2020–February 2022 with investigators, funders, bioethicists, research ethics committee members, industry representatives, and others from both high-income countries (HICs) and low- and middle-income countries (LMICs). Interview participants were identified via one of seven MDA studies purposively chosen to represent diversity in terms of use of the antibiotic azithromycin; use of a primary mortality endpoint; and whether the study occurred in a high child mortality country. Data were analyzed using constructivist grounded theory methodology.

Results

The most frequently discussed ethical challenges related to meaningful community engagement, how to weigh risks and benefits, and the need to target MDA We developed a concept map of how participants considered ethical issues in MDA for child mortality; it emphasizes MDA’s place alongside other public health interventions, empowerment, and equity. Concerns over an ethical double standard in weighing risks and benefits emerged as a unifying theme, albeit one that participants interpreted in radically different ways. Some thought MDA for reducing child mortality was ethically obligatory; others suggested it was impermissible.

Conclusions

Ethical challenges raised by MDA of antibiotics for childhood mortality—which span socio-cultural issues, the environment, and effects on future generations—require consideration beyond traditional clinical trial review. The appropriate role of MDA also requires attention to concerns over ethical double standards and power dynamics in global health that affect how we view antibiotic use in HICs versus LMICs. Our findings suggest the need to develop additional, comprehensive guidance on managing ethical challenges in MDA.

Graphical Abstract

Mapping of schistosomiasis and soil-transmitted helminthiases across 15 provinces of Angola

INTRODUCTION

Schistosomiasis (SCH) and soil transmitted helminthiases (STH) have been historically recognized as a major public health problem in Angola. However, lack of reliable, country wide prevalence data on these diseases has been a major hurdle to plan and implement programme actions to target these diseases. This study aimed to characterize SCH and STH prevalence and distribution in Angola.

METHODS

A country wide mapping was conducted in October 2018 (1 province) and from July to December 2019 (14 provinces) in school aged (SAC) children in 15 (of 18) provinces in Angola, using WHO protocols and procedures. A total of 640 schools and an average of 50 students per school (N = 31,938 children) were sampled. Stool and urine samples were collected and processed using the Kato-Katz method and Urine Filtration. Prevalence estimates for SCH and STH infections were calculated for each province and district with 95% confidence intervals. Factors associated with SCH and STH infection, respectively, were explored using multivariable logistic regression accounting for clustering by school.

RESULTS

Of the 131 districts surveyed, 112 (85.5%) are endemic for STH, 30 (22.9%) have a prevalence above 50%, 24 (18.3%) are at moderate risk (prevalence 20%-50%), and 58 (44.3%) are at low risk (<20% prevalence); similarly, 118 (90,1%) of surveyed districts are endemic for any SCH, 2 (1.5%) are at high risk (>50% prevalence), 59 (45.0%) are at moderate risk (10%-50% prevalence), and 57 (43.5%) are at low risk (<10% prevalence). There were higher STH infection rates in the northern provinces of Malanje and Lunda Norte, and higher SCH infection rates in the southern provinces of Benguela and Huila.

CONCLUSIONS

This mapping exercise provides essential information to Ministry of Health in Angola to accurately plan and implement SCH and STH control activities in the upcoming years. Data also provides a useful baseline contribution for Angola to track its progress towards the 2030 NTD roadmap targets set by WHO.

An assessment of implementation and effectiveness of mass drug administration for prevention and control of schistosomiasis and soil-transmitted helminths in selected southern Malawi districts

Background

Mass drug administration (MDA) is one of the key interventions recommended by WHO for prevention and control of neglected tropical diseases (NTD). In Malawi, MDA is widely carried out annually since 2009 for prevention and control of schistosomiasis and soil-transmitted helminths (STH). No study has been carried out to assess effectiveness of the MDA approach and to document perceptions of health providers and beneficiaries regarding use of MDA. This study was done to understand how well MDA is being implemented and to identify opportunities for improvement in MDA delivery in Malawi.

Methods

Designed as a cross-sectional and multi-methods research, the study was carried out in three southern Malawi districts of Chiradzulu, Mangochi and Zomba. In each district, four health centres and 16 villages were randomly selected to participate. A mixed-methods approach to data collection focusing on quantitative data for coverage and knowledge, attitudes and practices assessments; and qualitative data for assessing perceptions of health providers and beneficiaries regarding MDA was used. Quantitative data were processed and analyzed using IBM SPSS software version 26 while qualitative data were analysed using NVivo 12 for Windows.

Results

Knowledge levels about schistosomiasis and STH in the districts varied according to disease aspects asked about. Majority are more knowledgeable about what schistosomiasis is (78%) and whether STH are treatable with drugs (97%); with least knowledgeable about the organism that transmits schistosomiasis (18%), types of schistosomiasis (11%) and what causes STH (20%). In 2018 and 2019 the districts registered high coverage rates for praziquantel and albendazole using community-based MDA (73–100%) and using school-based MDA (75–91%). Both the health authorities and community members perceived the MDA approach as good because it brings treatment closer to people.

Conclusion

With the high MDA coverage obtained in communities and schools, the effectiveness of MDA in the target districts is satisfactory. There are, however, several challenges including disproportionate knowledge levels, which are hampering progress towards attainment of the 2030 global NTD goals. There is a need for promotion of community participation and partnerships as well as implementation of other recommended interventions for sustainable prevention and control of schistosomiasis and STH.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-07925-3.

Prevalence of Schistosoma mansoni and Associated Risk Factors in Human and Biomphalaria Snails in Ethiopia: A Systematic Review and Meta-analysis

PURPOSE

Schistosomiasis is one of the leading chronic parasitic diseases in Ethiopia. We aimed to summarize the prevalence of S. mansoni in human and Biomphalaria snails as well as risk factors in Ethiopia.

METHODS

Literature search was carried out from Scopus, Google Scholar, Science Direct and PubMed which reported Schistosoma mansoni infection in human and Biomphalaria snails in Ethiopia. The overall prevalence was estimated by a random-effect model and heterogeneities among studies were assessed by I² test.

RESULTS

A total of 178,251 participants and 1,097 snails were tested for the presence of S. mansoni in the eligible studies. The pooled prevalence of S. mansoni was 32.5% (95% CI 28.0-37.0) and 15.9% (95% CI - 5.6-37.5) in human and Biomphalaria snails in Ethiopia, respectively. The highest pooled prevalence was 43.2% (95% CI 27.3-59.1) in South Nations and National Peoples region while the lowest pooled prevalence was 25% (95% CI 19.3-30.7) observed in the Afar region. Interestingly, the pooled prevalence of S. mansoni declined from 40.7% (95% CI 33-48.4) to 22.4% (95% CI 18.5-26.3) after the launching of mass drug administration (MDA). The analysis of risk factors showed that swimming habit (OR, 2.78; 95% CI 2.35-3.21) and participation in irrigation (OR, 2.69; 95% CI 1.45-3.73) were independent predictors for S. mansoni infection.

CONCLUSION

This study revealed that about one-third of human and nearly 16% of Biomphalaria snails were infected with S. mansoni in Ethiopia. This review indicated that the prevalence of S. mansoni declined after the implementation of MDA. This study highlights the importance of further integrated approaches for better control of schistosomiasis in Ethiopia.

How can we better integrate the prevention, treatment, control and elimination of neglected tropical diseases with other health interventions? A systematic review

Background

Globally, about 1.7 billion people living in poverty are affected by one or more of a group of disabling, disfiguring and poverty-promoting conditions known as neglected tropical diseases (NTDs). Major global health actors, like the WHO, have endorsed a shift from vertical to integrated NTD management.

Objective

This systematic review aimed to evaluate how integration is being conducted and how we can improve it.

Methods

PubMed, Medline, Cochrane library, Web of Science, Trip, Embase, Global Health and Google Scholar were searched from 1 April to 22 July 2020. We included peer-reviewed articles published between 1 January 2000 and 22 July 2020 in English.

Results

Database searches produced 24 565 studies, of which 35 articles met the inclusion criteria. Twenty of these articles were conducted in sub-Saharan Africa. Twenty articles were also published between 2015 and 2020. Literature revealed that NTDs have been integrated—among themselves; with water, sanitation and hygiene programmes; with vector control; with primary healthcare; with immunisation programmes; and with malaria management. Integrated mass drug administration for multiple NTDs was the most common method of integration. The three complex, yet common characteristics of successful integration were good governance, adequate financing and total community engagement.

Conclusion

The dataset identified integrated management of NTDs to be cost effective and potentially to increase treatment coverage. However, the identified modes of integration are not exclusive and are limited by the available literature. Nonetheless, integration should urgently be implemented, while considering the programmatic and sociopolitical context.

PROSPERO registration number

The study protocol was registered with PROSPERO number, CRD42020167358.

Whole-genome sequencing of Schistosoma mansoni reveals extensive diversity with limited selection despite mass drug administration

Control and elimination of the parasitic disease schistosomiasis relies on mass administration of praziquantel. Whilst these programmes reduce infection prevalence and intensity, their impact on parasite transmission and evolution is poorly understood. Here we examine the genomic impact of repeated mass drug administration on Schistosoma mansoni populations with documented reduced praziquantel efficacy. We sequenced whole-genomes of 198 S. mansoni larvae from 34 Ugandan children from regions with contrasting praziquantel exposure. Parasites infecting children from Lake Victoria, a transmission hotspot, form a diverse panmictic population. A single round of treatment did not reduce this diversity with no apparent population contraction caused by long-term praziquantel use. We find evidence of positive selection acting on members of gene families previously implicated in praziquantel action, but detect no high frequency functionally impactful variants. As efforts to eliminate schistosomiasis intensify, our study provides a foundation for genomic surveillance of this major human parasite.

Modelling the ability of mass drug administration to interrupt soil-transmitted helminth transmission: Community-based deworming in Kenya as a case study

The World Health Organization has recommended the application of mass drug administration (MDA) in treating high prevalence neglected tropical diseases such as soil-transmitted helminths (STHs), schistosomiasis, lymphatic filariasis, onchocerciasis and trachoma. MDA—which is safe, effective and inexpensive—has been widely applied to eliminate or interrupt the transmission of STHs in particular and has been offered to people in endemic regions without requiring individual diagnosis. We propose two mathematical models to investigate the impact of MDA on the mean number of worms in both treated and untreated human subpopulations. By varying the efficay of drugs, initial conditions of the models, coverage and frequency of MDA (both annual and biannual), we examine the dynamic behaviour of both models and the possibility of interruption of transmission. Both models predict that the interruption of transmission is possible if the drug efficacy is sufficiently high, but STH infection remains endemic if the drug efficacy is sufficiently low. In between these two critical values, the two models produce different predictions. By applying an additional round of biannual and annual MDA, we find that interruption of transmission is likely to happen in both cases with lower drug efficacy. In order to interrupt the transmission of STH or eliminate the infection efficiently and effectively, it is crucial to identify the appropriate efficacy of drug, coverage, frequency, timing and number of rounds of MDA.

We determine the best options for annual and biannual mass drug administration to control soil-transmitted helminths. An additional round of drugs can allow weaker drugs to be used. We apply the results to a community-based deworming project in Kenya.

Mass drug administration for endemic scabies: a systematic review

BACKGROUND

Scabies is an extremely fastidious infestation caused by the Sarcoptes scabiei mite. It causes a persistent itch that can disrupt a person's mental health, sleep, and overall quality of life. In endemic areas, treatment by targeting symptomatic individuals and their contacts is often unsuccessful due to an asymptomatic period and high rates of re-infection. To overcome this, Mass Drug Administration (MDA) is often used to treat the whole community, irrespective of whether individuals presently have scabies. This review summarises the evidence for the effectiveness of MDA in treating scabies.

METHODS

An exhaustive literature review was conducted on MEDLINE, EMBASE, Web of Science and Scopus. All peer-reviewed articles published in English January 1990 to March 2020 were eligible and only if the studies were primary and interventional. Furthermore, the intervention had to be a pharmacological MDA method involving human subjects.

RESULTS

TWELVE articles that qualified for inclusion were identified. MDA for scabies significantly reduced its prevalence in communities at follow up. Some of the drivers of success were communities with low levels of migration, an uptake of MDA of > 85%, the use of oral Ivermectin therapy, the treatment of children and pregnant women within the treated population, and repeated treatment for participants diagnosed with scabies at baseline.

CONCLUSIONS

The average absolute reduction in prevalence of scabies was 22.0% and the relative reduction average was 73.4%. These results suggest MDA is effective in treating scabies in the endemic community. Further evidence is needed surrounding MDA use in urban areas with increased levels of migration. Importantly, MDA should not substitute the tackling of socioeconomic factors which contribute to endemic disease such as good sanitation and hygiene.

Assessment of the usefulness of anti-Wb123 antibody for post-elimination surveillance of lymphatic filariasis

Background

The World Health Organization has targeted lymphatic filariasis (LF) for elimination as a public health problem and recommends, among other measures, post-elimination surveillance of LF. The identification of sensitive and specific surveillance tools is therefore a research priority. The Wuchereria bancrofti-specific antigen Wb123-based enzyme-linked immunosorbent assay (Wb123 ELISA) detects antibodies to the recombinant Wb123 antigen of W. bancrofti and may be useful as a surveillance tool for LF. Six years after stopping mass drug administration to eliminate LF and recording successful results on two post-treatment transmission assessment surveys, a study was conducted in Togo aimed at helping to identify the role of the Wb123 ELISA in post-validation surveillance of LF.

Methods

This was a cross-sectional study in eight previously LF-endemic districts and one non-endemic district in Togo. In each sub-district of these nine districts, two schools were selected and 15 children aged 6 to 9 years old at each school provided finger-stick blood for testing for antibodies to Wb123 using the Filaria Detect™ IgG4 ELISA kit® (InBios, International, Inc., Seattle, WA, USA).

Results

A total of 2654 children aged 6 to 9 years old were tested in 134 schools in the nine districts. Overall, 4.7% (126/2654) children tested positive for antibodies to the Wb123 antigen of W. bancrofti. The prevalence of Wb123 antibodies varied across the eight previously endemic LF districts, from 1.56 to 6.62%. The highest prevalence, 6.99%, was found in the non-endemic district, but this was not significantly different from the average of all the LF districts (4.49%, P = 0.062).

Conclusions

The Wb123 ELISA was positive in 4.7% of Togolese school-age children who were almost certainly unexposed to LF. This apparent lack of specificity in the Togo context makes it difficult to establish a seroprevalence threshold that could serve to signal LF resurgence in the country, precluding the use of this test for post-validation surveillance in Togo. There remains a need to develop a useful and reliable test for post-elimination surveillance for LF in humans.

Prevalence, Intensity, and Correlates of Schistosomiasis and Soil-Transmitted Helminth Infections after Five Rounds of Preventive Chemotherapy among School Children in Southern Ethiopia

Preventive chemotherapy (PC) is a WHO-recommended strategy to control and eliminate schistosomiasis and soil-transmitted helminths (STHs). We assessed the prevalence, intensity, and correlates of schistosomiasis and STH infection after five rounds of PC in southern Ethiopia. A total of 3162 school children from four schools in Wondo Gennet and Hawella Tula districts were screened for Schistosoma mansoni and STHs infection. The overall prevalence of S. mansoni infection was 25.8% (range between schools 11.6% to 54.1%), with light (19.1%), moderate (5.3%), and heavy (1.4%) infection intensities. A total of 61.6% S. mansoni-infected children were STH co-infected. The overall prevalence of STHs infection was 54.7% (range between schools 30.6-71.0%), with moderate-to-heavy intensity infections being 16.3%. Ascaris lumbricoides was the most prevalent 45% (95% CI, 43.5-47) followed by Trichuris trichiura 25.3% (95% CI, 23.8-26.9) and hookworm 6.1% (95% CI, 5.3-7). A total of 33.7% of STHs-infected children had A. lumbricoides and T. trichiura co-infections. S. mansoni infection was significantly associated with school and STHs co-infection (p < 0.001). STH infection was correlated with school and younger age (p < 0.001). Despite repeated PC, S. mansoni and STH infection remain significant health problems, and the WHO target to control schistosomiasis and eliminate STH by 2020 may not be achieved. Intensified control and prevention measures, including drug efficacy surveillance, is recommended.

Intestinal Schistosomiasis and Giardiasis Co-Infection in Sub-Saharan Africa: Can a One Health Approach Improve Control of Each Waterborne Parasite Simultaneously?

Both intestinal schistosomiasis and giardiasis are co-endemic throughout many areas of sub-Saharan Africa, significantly impacting the health of millions of children in endemic areas. While giardiasis is not considered a neglected tropical disease (NTD), intestinal schistosomiasis is formally grouped under the NTD umbrella and receives significant advocacy and financial support for large-scale control. Although there are differences in the epidemiology between these two diseases, there are also key similarities that might be exploited within potential integrated control strategies permitting tandem interventions. In this review, we highlight these similarities and discuss opportunities for integrated control of giardiasis in low and middle-income countries where intestinal schistosomiasis is co-endemic. By applying new, advanced methods of disease surveillance, and by improving the provision of water, sanitation and hygiene (WASH) initiatives, (co)infection with intestinal schistosomiasis and/or giardiasis could not only be more effectively controlled but also better understood. In this light, we appraise the suitability of a One Health approach targeting both intestinal schistosomiasis and giardiasis, for if adopted more broadly, transmission of both diseases could be reduced to gain improvements in health and wellbeing.

Knowledge, Attitude, and Practice of Provincial Dwellers on Prevention and Control of Schistosomiasis: Evidence from a Community-Based Cross-Sectional Study in the Gambia

Background

Socioeconomically disadvantaged and neglected communities were found to be the most affected groups for schistosomiasis as a result of inadequate safe water and sanitation facilities. In order to inform policies and practices, the present study examined the influence of sociodemographic factors and attitudes on the knowledge and practice in the prevention and control of schistosomiasis in eighteen endemic rural communities in the Gambia.

Methods

In January 2019, a community-based cross-sectional study was conducted in which 383 household heads in rural communities across Kuntaur and Janjanbureh Local Government Areas (LGAs) in Central River Region were recruited. A structured interview questionnaire was developed to elicit information regarding residents' knowledge, attitude, and practice on schistosomiasis prevention and control measures. Percentages, chi-square test, and binary and multiple logistic regression models were used to identify sociodemographic factors associated with the KAP variables. The significance level was set at p < 0.05.

Results

Among the 383 participants, only 14.9% had good knowledge, while 54.3% had poor knowledge, 96.9% had positive attitude, and 57.7% had good practice towards prevention and control of schistosomiasis. Older age (≥40 years), compared with residents aged 30-39 years (AOR = 0.331; 95% CI: 0.133, 0.825); ever heard of bilharziasis (AOR = 11.911; 95% CI: 3.452, 41.099); and risks of contact with the polluted river (AOR = 0.101; 95% CI: 0.042, 0.242) were more likely to have good knowledge on schistosomiasis prevention and control in the rural Gambia. Conversely, young people (≤30 years), compared with residents aged ≥40 years (AOR = 2.503; 95% CI = 1.539, 4.071); residents aged 30-39 years (AOR = 2.880; 95% CI = 1.559, 5.320); and male residents (AOR = 2.631; 95% CI = 1.703, 4.067) were more likely to have good practice towards schistosomiasis prevention and control in the rural Gambia.

Conclusion

Despite the low knowledge, rural dwellers' attitudes were found to be positive with slightly good practice towards schistosomiasis prevention and control measures. Thus, while maintaining health system improvement strategies, disease control efforts should focus on these factors as they may influence the knowledge and practices of rural dwellers in a given setting. The findings could prompt appropriate policy responses towards improving the knowledge and practices on schistosomiasis prevention and control in the Gambia.

A prospective risk assessment of the implementation of a schistosomiasis preventive mass drug administration for children aged five years and below in the uMkhanyakude district of KwaZulu-Natal

Background

Schistosomiasis is endemic in the uMkhanyakude district of KwaZulu-Natal, South Africa. The South Africa Department of Health (DoH) has decided to implement a schistosomiasis preventive mass drug administration program in all affected parts of the country. Quality management is part of the strategic objectives of the treatment program. We conducted a risk assessment and developed guidelines for the quality management of a schistosomiasis preventive treatment program for children aged 5 years and below in the uMkhanyakude District of KwaZulu-Natal.

Methods

We conducted a scenario planning exercise by interviewing 10 child health experts from the uMkhanyakude Health District to establish potential risks associated with a planned schistosomiasis preventive control treatment program for children aged 5 years old and below. The risks were analyzed using a modified Failure Mode and Effect Analysis (FMEA). An FMEA table was produced to guide the quality management of the planned schistosomiasis preventive control treatment program for children aged 5 years and below in the uMkhanyakude Health District.

Results

We identified potential risks, failure modes and possible failure corrective/preventive measures in the following activities that would be part of the mass treatment of children aged 5 years and below infected with schistosomiasis in the uMkhanyakude District. These included enrolment of children into the treatment program; general health checks; weight and height measurements; administration of drugs; reporting of side effects and monitoring and evaluation.

Conclusion

We were able to use FMEA guide quality management and identify potential risks associated with the planned schistosomiasis preventive treatment program for children aged 5 years old and below in the uMkhanyakude District of KwaZulu-Natal. The FMEA for this program will be useful to the quality management of schistosomiasis preventive treatment programs for this age group in other similar settings.

Knowledge, attitudes and practices on schistosomiasis and soil-transmitted helminths among caregivers in Ingwavuma area in uMkhanyakude district, South Africa

BACKGROUND

Schistosomiasis and soil-transmitted helminth infections are among the most chronic infections worldwide. Based on their demonstrable impact on human health, the WHO recently recommended the implementation of robust strategies aimed at controlling or eliminating schistosomiasis and soil-transmitted helminths by 2020. The implementation of this strategy, however, warrants a clear understanding of the community's knowledge, attitudes and practices in relation to these infections. This study sought to identify sociocultural gaps that should be addressed to ensure the success of cost-effective community-based schistosomiasis-soil-transmitted helminths control and elimination programs.

METHODS

This was a cross-sectional mixed methodology study. Quantitative data were collected using a structured questionnaire from 442 caregivers of preschool aged children. In-depth interviews and focus group discussions were conducted among caregivers, preschool teachers, traditional authorities and community caregivers. All interviews were captured using an audio recorder to maximize accuracy. Quantitative data were analysed using bivariate and multivariate techniques while qualitative data were analysed thematically.

RESULTS

Findings reflected inadequate knowledge, attitudes and practices in relation to schistosomiasis and soil-transmitted helminths while awareness of schistosomiasis and soil-transmitted helminths was high (87.1 and 79.2% respectively). Correct knowledge on transmission, prevention, signs and symptoms and life cycle was low (below 50%) for both infections among those who had heard of the disease. From multivariate analysis, being aged at least 35 years increased the odds of reporting good practices on schistosomiasis by 65% (COR 1.652, 95% CI: 1.073-2.543) while receiving health information through community meetings (COR 0.072, 95% CI: 0.010-0.548) significantly reduced the odds of having good knowledge on schistosomiasis.

CONCLUSIONS

These findings are valuable in designing behavioural change approaches towards enhancing health outcomes through community-based interventions to ensure effective control and elimination of schistosomiasis and soil-transmitted helminths. There is a critical need for channelling efforts towards making health education the core of schistosomiasis and soil-transmitted helminths programs aimed at achieving intensified control or elimination of these infections by 2020.

Genetic diversity of Ascaris spp. infecting humans and pigs in distinct Brazilian regions, as revealed by mitochondrial DNA

In this study, we assessed the genetic diversity of Ascaris lumbricoides / Ascaris suum circulating in humans and pigs, exploring potential zoonotic cycles in endemic areas in Brazil. We carried out cross-sectional surveys in four municipalities: Santa Isabel do Rio Negro (SIRN-AM) (n = 328); Nossa Senhora de Nazaré (NSN-PI) and Teresina (TER-PI) (n = 605 and n = 297, respectively); and Cachoeiras de Macacu (CAM-RJ) (n = 543). We also studied 61 fecal samples/adult worms obtained from pigs (n = 53 in NSN-PI and n = 8 in TER-PI). A ~450 bp fragment of the Ascaris cytochrome c oxidase subunit 1 (cox1) and ~400 bp of the NADH dehydrogenase subunit 1 (nad1) were amplified and sequenced. Maximum-likelihood (ML) tree and Median-joining (MJ) haplotype network analyses were performed. We also performed scanning electron micrographs of adult specimens. Positivity rates were 93/328 (28.4%) in SIRN-AM, 6/297 (2.0%) in TER-PI, 0/605 (0%) in NSN-PI, and 6/543 (1.1%) in CAM-RJ. In NSN-PI it reached 11/53 (20.7%) in pigs. The MJ network based on cox1 locus (383 bp) revealed three main clusters, one centered around haplotypes H01/H28/H32 and the other around H07/H11. The cox1 haplotypes had a heterogeneous distribution, showing no pattern by geographic region, and high haplotype diversity. The ML trees based on cox1 and nad1 loci showed a similar topology with each other, and with the haplotype networks. Three distinct clusters were observed. Sequences of cox1 and nad1 from humans and animals were distributed throughout the tree and it was not possible to differentiate specimens of human and swine origin. Ascaris populations obtained from humans and swine in different Brazilian regions are not discriminable through the genetic markers used, which indicates the potential for zoonotic transmission and the need for better control of these infections in swine herds, mainly when created in a peridomestic environment.