Productivity Loss Related to Neglected Tropical Diseases Eligible for Preventive Chemotherapy: A Systematic Literature Review

Assessing the knowledge, training and capacity of health workers in the diagnosis and management of soil-transmitted helminths and schistosomiasis in eastern Uganda

BACKGROUND

Neglected tropical diseases (NTDs) affect millions of people in Africa, with Uganda bearing a significant burden. The World Health Organization (WHO) set a goal to reduce NTDs and improve access to diagnosis and management by 2030. However, NTDs have not been well integrated into primary healthcare in many countries, including Uganda, due to limited knowledge and resources among health workers. The study aimed to assess the readiness and capacity of primary healthcare centres to diagnose and manage soil-transmitted helminths (STHs) and schistosomiasis.

METHODS

A cross-sectional quantitative study was conducted among 204 health workers in 20 health facilities in four districts bordering Lake Kyoga. In this study we evaluated health workers' knowledge of symptoms, diagnosis and management of STHs and schistosomiasis as well as the availability of resources and training.

RESULTS

Our findings indicate that health workers have strong knowledge about STHs (86.76%), with lower knowledge levels regarding Schistosoma haematobium (59.72%) and Schistosoma mansoni (71.43%). Regarding resources and training, 95% of health facilities had laboratory services, but the majority lacked diagnostic equipment. Furthermore, only 17% of health workers reported prior training on schistosomiasis and related topics and only 25% had training on surveillance and reporting.

CONCLUSIONS

While health workers in eastern Uganda demonstrated a good knowledge base for some NTDs, there were knowledge gaps and challenges in training on surveillance and reporting mechanisms. Continuously building the capacity of health workers along with investing in diagnostic infrastructure is essential for improved NTD control and ultimately reducing associated morbidity and mortality in the region.

How Does the Proportion of Never Treatment Influence the Success of Mass Drug Administration Programs for the Elimination of Lymphatic Filariasis?

BACKGROUND

Mass drug administration (MDA) is the cornerstone for the elimination of lymphatic filariasis (LF). The proportion of the population that is never treated (NT) is a crucial determinant of whether this goal is achieved within reasonable time frames.

METHODS

Using 2 individual-based stochastic LF transmission models, we assess the maximum permissible level of NT for which the 1% microfilaremia (mf) prevalence threshold can be achieved (with 90% probability) within 10 years under different scenarios of annual MDA coverage, drug combination and transmission setting.

RESULTS

For Anopheles-transmission settings, we find that treating 80% of the eligible population annually with ivermectin + albendazole (IA) can achieve the 1% mf prevalence threshold within 10 years of annual treatment when baseline mf prevalence is 10%, as long as NT <10%. Higher proportions of NT are acceptable when more efficacious treatment regimens are used. For Culex-transmission settings with a low (5%) baseline mf prevalence and diethylcarbamazine + albendazole (DA) or ivermectin + diethylcarbamazine + albendazole (IDA) treatment, elimination can be reached if treatment coverage among eligibles is 80% or higher. For 10% baseline mf prevalence, the target can be achieved when the annual coverage is 80% and NT ≤15%. Higher infection prevalence or levels of NT would make achieving the target more difficult.

CONCLUSIONS

The proportion of people never treated in MDA programmes for LF can strongly influence the achievement of elimination and the impact of NT is greater in high transmission areas. This study provides a starting point for further development of criteria for the evaluation of NT.

Diagnosis of soil-transmitted helminth infections with digital mobile microscopy and artificial intelligence in a resource-limited setting

BACKGROUND

Infections caused by soil-transmitted helminths (STHs) are the most prevalent neglected tropical diseases and result in a major disease burden in low- and middle-income countries, especially in school-aged children. Improved diagnostic methods, especially for light intensity infections, are needed for efficient, control and elimination of STHs as a public health problem, as well as STH management. Image-based artificial intelligence (AI) has shown promise for STH detection in digitized stool samples. However, the diagnostic accuracy of AI-based analysis of entire microscope slides, so called whole-slide images (WSI), has previously not been evaluated on a sample-level in primary healthcare settings in STH endemic countries.

METHODOLOGY/PRINCIPAL FINDINGS

Stool samples (n = 1,335) were collected during 2020 from children attending primary schools in Kwale County, Kenya, prepared according to the Kato-Katz method at a local primary healthcare laboratory and digitized with a portable whole-slide microscopy scanner and uploaded via mobile networks to a cloud environment. The digital samples of adequate quality (n = 1,180) were split into a training (n = 388) and test set (n = 792) and a deep-learning system (DLS) developed for detection of STHs. The DLS findings were compared with expert manual microscopy and additional visual assessment of the digital samples in slides with discordant results between the methods. Manual microscopy detected 15 (1.9%) Ascaris lumbricoides, 172 (21.7%) Tricuris trichiura and 140 (17.7%) hookworm (Ancylostoma duodenale or Necator americanus) infections in the test set. Importantly, more than 90% of all STH positive cases represented light intensity infections. With manual microscopy as the reference standard, the sensitivity of the DLS as the index test for detection of A. lumbricoides, T. trichiura and hookworm was 80%, 92% and 76%, respectively. The corresponding specificity was 98%, 90% and 95%. Notably, in 79 samples (10%) classified as negative by manual microscopy for a specific species, STH eggs were detected by the DLS and confirmed correct by visual inspection of the digital samples.

CONCLUSIONS/SIGNIFICANCE

Analysis of digitally scanned stool samples with the DLS provided high diagnostic accuracy for detection of STHs. Importantly, a substantial number of light intensity infections were missed by manual microscopy but detected by the DLS. Thus, analysis of WSIs with image-based AI may provide a future tool for improved detection of STHs in a primary healthcare setting, which in turn could facilitate monitoring and evaluation of control programs.

Unpacking Immune Modulation as a Site of Therapeutics Innovation for Nematode Parasite Wuchereria bancrofti: A Temporal Quantitative Phosphoproteomics Profiling of Macrophage Migration Inhibitory Factor 2

Nematode infections are common in both humans and livestock, with major adverse planetary health and economic impacts. Wuchereria bancrofti is a parasitic nematode that causes lymphatic filariasis, a neglected tropical disease that can lead to severe disability and deformity worldwide. For the long-term survival of the bancroftian parasites in the host, a complex immune invasion strategy is involved through immunomodulation. Therefore, immunomodulation can serve as a site of research and innovation for molecular targets. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine crucial to the host antimicrobial alarm system and stress response. Interestingly, the nematode parasite W. bancrofti also produces two homologs of MIF (Wba-MIF1 and 2). Using a mass spectrometry-based phosphoproteomics approach, we report new findings on the immunomodulatory effect and signaling mechanism of Wba-MIF2 in macrophage cells. Accordingly, we observed 1201 phosphorylated sites on 467 proteins. Out of the 1201 phosphorylated sites, 1075, 117, and 9 were found on serine (S), threonine (T), and tyrosine (Y) residues, respectively. Our bioinformatics analysis led to identification of major pathways, including spliceosomes, T cell receptor signaling pathway, Th17 differentiation pathway, interleukin-17 signaling pathway, and insulin signaling pathway upon Wba-MIF2 treatment. Wba-MIF2 treatment also enriched CDK4, CDK1, and DNAPK kinases. The comparison of the signaling pathway of Wba-MIF2 with that of human-MIF suggests both share similar signaling pathways. These findings collectively offer new insights into the role and mechanism of Wba-MIF2 as an immunomodulator and inform future diagnostics and drug discovery research for W. bancrofti.

Implementation and Outcomes of a Pilot Collaborative Surgical Hydrocele Training in Côte d'Ivoire

Lymphatic filariasis (LF) is a neglected tropical disease that can cause hydrocele and its associated stigma, loss of economic productivity, and depression. Hydrocele surgery is an essential part of LF morbidity management but can be difficult for national programs to implement. To improve access to hydrocele surgeries in Côte d'Ivoire, we provided a WHO-certified surgical training for six surgical teams from five health districts in Côte d'Ivoire. We then evaluated the surgical outcomes and assessed the impact of hydrocele surgery on quality of life of hydrocelectomy patients. Preoperative and operative records were reviewed to describe baseline hydrocele characteristics and operative details. Postoperative interviews were conducted 4 to 6 months after surgical correction using a standardized questionnaire. Seventeen men underwent surgery during the training and were available for an interview at the 6-month visit. At the time of 6-month follow-up, 11/17 (64.7%) reported improvement in activities of daily living and reduction in difficulties with work, 8/17 (47.1%) reported an improved economic situation, 15/17 (88.2%) reported improved social interactions, and 15/16 (93.8%) reported improved sex life after surgical correction. Three patients (17.6%) had minor postoperative complications, but none required hospitalization. All 17 patients who were available for an interview were satisfied with their surgery. Surgical hydrocelectomy training in Côte d'Ivoire was well received and provided life-altering health improvements for participating patients across multiple domains of life. Support to scale up surgical capacity for this neglected problem is needed.

Solid Lipid Nanoparticles Enhancing the Leishmanicidal Activity of Delamanid

Leishmaniasis, a zoonotic parasitic disease transmitted by infected sandflies, impacts nearly 1 million people yearly and is endemic in many countries across Asia, Africa, the Americas, and the Mediterranean; despite this, it remains a neglected disease with limited effective treatments, particularly in impoverished communities with limited access to healthcare. This study aims to repurpose approved drugs for an affordable leishmaniasis treatment. After the screening of potential drug candidates by reviewing databases and utilizing molecular docking analysis, delamanid was chosen to be incorporated into solid lipid nanoparticles (SLNPs). Both in cellulo and in vivo tests confirmed the successful payload release within macrophages and through the epidermis following topical application on murine skin. The evaluation of macrophages infected with L. infantum amastigotes showed that the encapsulated delamanid exhibited greater leishmanicidal activity compared with the free drug. The process of encapsulating delamanid in SLNPs, as demonstrated in this study, places a strong emphasis on employing minimal technology, ensuring energy efficiency, cost-effectiveness, and reproducibility. It enables consistent, low-cost production of nanomedicines, even on a small scale, offering a promising step toward more accessible and effective leishmaniasis treatments.

Vaccine value profile for Hookworm

Hookworm, a parasitic infection, retains a considerable burden of disease, affecting the most underprivileged segments of the general population in endemic countries and remains one of the leading causes of mild to severe anemia in Low and Middle Income Countries (LMICs), particularly in pregnancy and children under 5. Despite repeated large scale Preventive Chemotherapy (PC) interventions since more than 3 decades, there is broad consensus among scholars that elimination targets set in the newly launched NTD roadmap will require additional tools and interventions. Development of a vaccine could constitute a promising expansion of the existing arsenal against hookworm. Therefore, we have evaluated the biological and implementation feasibility of the vaccine development as well as the added value of such a novel tool. Based on pipeline landscaping and the current knowledge on key biological aspects of the pathogen and its interactions with the host, we found biological feasibility of development of a hookworm vaccine to be moderate. Also, our analysis on manufacturing and regulatory issues as well as potential uptake yielded moderate implementation feasibility. Modelling studies suggest a that introduction of a vaccine in parallel with ongoing integrated interventions (PC, WASH, shoe campaigns), could substantially reduce burden of disease in a cost - saving mode. Finally a set of actions are recommended that might impact positively the likelihood of timely development and introduction of a hookworm vaccine.

Neglected and Emerging Infections of The Kidney

Individuals, societies, and the environment are affected by neglected and emerging diseases. These diseases result in a variety of severe outcomes, including permanent disabilities, chronic diseases such as chronic kidney disease, and even mortality. Consequences include high health care expenditures, loss of means of support, social stigma, and social exclusion. The burden of these diseases is exacerbated in low- and middle-income countries owing to poverty, inadequate fundamental infrastructure, and the absence of health and social protection systems. The World Health Organization is committed to promoting the following public health strategies to prevent and control neglected tropical diseases: preventive chemotherapy; intensive case management; vector control; provision of safe drinkable water, sanitation, and hygiene; and veterinary public health. In addition, it promotes a One Health strategy, which is a collaborative, multisectoral, and interdisciplinary approach to achieving the greatest health outcomes by recognizing the interdependence of human beings, animals, plants, and their shared environment. This article provides knowledge and strategies for the prevention and treatment of neglected and emerging diseases, with a particular concentration on kidney diseases, as part of a comprehensive approach to One Health.

Addressing neglected tropical diseases in Africa: a health equity perspective

Africa accounts for over one-third of the global burden of neglected tropical diseases (NTDs). Although continental efforts have been made to combat these diseases, there still exists a significant gap in the fight, ranging from a lack of data to multisectoral participation and, most critically, health inequity. Here, we assess the effort made to combat challenges caused by health disparities to prevent and control neglected tropical diseases. This article engages a health equity view to addressing the need for inclusion in achieving universal health coverage towards eradicating NTDs and outlines strategies to achieve such. Health disparities exist, and there is substantial and irrefutable evidence for them. Inequitable distribution and limited access to basic and essential life resources such as water, housing, toilets, soap, and literacy continue to facilitate the existence of NTDs such as Schistosomiasis, soil-transmitted helminths, and trachoma, the occurrence of which can be avoided if affected populations have better access to those resources. To eradicate NTDs, health disparities must be addressed to provide excellent health care to all populations and adequate universal health coverage for long-term sustainability. NTD programmes need to be data-driven to ensure better decision-making and ensure the inclusion of diverse population groups including women, children, and youths. This will ensure that no one is left behind, drawing upon the sustainable development goals. Community participation and engagement should also be considered as an essential approach to ensure people are at the centre of health programmes and their implementation.

How well do coverage surveys and programmatically reported mass drug administration coverage match? Results from 214 mass drug administration campaigns in 15 countries, 2008-2017

INTRODUCTION

Delivering preventive chemotherapy through mass drug administration (MDA) is a central approach in controlling or eliminating several neglected tropical diseases (NTDs). Treatment coverage, a primary indicator of MDA performance, can be measured through routinely reported programmatic data or population-based coverage evaluation surveys. Reported coverage is often the easiest and least expensive way to estimate coverage; however, it is prone to inaccuracies due to errors in data compilation and imprecise denominators, and in some cases measures treatments offered as opposed to treatments swallowed.

OBJECTIVE

Analyses presented here aimed to understand (1) how often coverage calculated using routinely reported data and survey data would lead programme managers to make the same programmatic decisions; (2) the magnitude and direction of the difference between these two estimates, and (3) whether there is meaningful variation by region, age group or country.

METHODS

We analysed and compared reported and surveyed treatment coverage data from 214 MDAs implemented between 2008 and 2017 in 15 countries in Africa, Asia and the Caribbean. Routinely reported treatment coverage was compiled using data reported by national NTD programmes to donors, either directly or via NTD implementing partners, following the implementation of a district-level MDA campaign; coverage was calculated by dividing the number of individuals treated by a population value, which is typically based on national census projections and occasionally community registers. Surveyed treatment coverage came from post-MDA community-based coverage evaluation surveys, which were conducted as per standardised WHO recommended methodology.

RESULTS

Coverage estimates using routine reporting and surveys gave the same result in terms of whether the minimum coverage threshold was reached in 72% of the MDAs surveyed in the Africa region and in 52% in the Asia region. The reported coverage value was within ±10 percentage points of the surveyed coverage value in 58/124 of the surveyed MDAs in the Africa region and 19/77 in the Asia region. Concordance between routinely reported and surveyed coverage estimates was 64% for the total population and 72% for school-age children. The study data showed variation across countries in the number of surveys conducted as well as the frequency with which there was concordance between the two coverage estimates.

CONCLUSIONS

Programme managers must grapple with making decisions based on imperfect information, balancing needs for accuracy with cost and available capacity. The study shows that for many of the MDAs surveyed, based on the concordance with respect to reaching the minimum coverage thresholds, the routinely reported data were accurate enough to make programmatic decisions. Where coverage surveys do show a need to improve accuracy of routinely reported results, NTD programme managers should use various tools and approaches to strengthen data quality in order to use data for decision-making to achieve NTD control and elimination goals.

The United States Food and Drug Administration (FDA) regulatory response to combat neglected tropical diseases (NTDs): A review

The availability and accessibility of safe and effective drugs, vaccines, and diagnostics are essential to reducing the immense global burden of neglected tropical diseases (NTDs). National regulatory authorities, such as the United States Food and Drug Administration (FDA), play an essential role in this effort to ensure access to safe and effective medical products by working within a set of legal frameworks and regulatory functions. However, medical product development for NTDs remains neglected, as combating NTDs is not a viable commercial market for pharmaceutical companies. To spur research and development (R&D) of NTD products, the US government has authorized various programs and policies to engage pharmaceutical companies, many of which provide FDA with the legal authority to implement NTD programs and pathways. Thus, this review provides a clear overview of the various regulatory pathways and programs employed by the FDA to increase the availability of NTD drugs, vaccines, and diagnostics. The review assesses the available information on various regulatory considerations and their impact on NTD product development as a first step in estimating the importance of such programs. Next, findings related to currently approved NTD products through these programs are discussed. Lastly, gaps in NTD R&D are identified and suggestions on how to address these are presented. The available data shows that while such incentive programs are factored into companies' decisions to pursue NTD R&D, approved products for NTDs remains vastly insufficient. Most approved products that utilize these NTD regulatory pathways and programs are overwhelmingly for tuberculosis and malaria-both of which are not considered NTDs by the World Health Organization (WHO). Dedicated efforts are needed to facilitate and accelerate NTD product including employing multiple incentive programs, regular assessment of such programs, and leveraging on public-private partnerships.

School water, sanitation, and hygiene (WaSH) intervention to improve malnutrition, dehydration, health literacy, and handwashing: a cluster-randomised controlled trial in Metro Manila, Philippines

BACKGROUND

The impacts of multicomponent school water, sanitation, and hygiene (WaSH) interventions on children's health are unclear. We conducted a cluster-randomized controlled trial to test the effects of a school WaSH intervention on children's malnutrition, dehydration, health literacy (HL), and handwashing (HW) in Metro Manila, Philippines.

METHODS

The trial lasted from June 2017 to March 2018 and included children, in grades 5, 6, 7, and 10, from 15 schools. At baseline 756 children were enrolled. Seventy-eight children in two clusters were purposively assigned to the control group (CG); 13 clusters were randomly assigned to one of three intervention groups: low-intensity health education (LIHE; two schools, n = 116 children), medium-intensity health education (MIHE; seven schools, n = 356 children), and high-intensity health education (HIHE; four schools, n = 206 children). The intervention consisted of health education (HE), WaSH policy workshops, provision of hygiene supplies, and WaSH facilities repairs. Outcomes were: height-for-age and body mass index-for-age Z scores (HAZ, BAZ); stunting, undernutrition, overnutrition, dehydration prevalence; HL and HW scores. We used anthropometry to measure children's physical growth, urine test strips to measure dehydration, questionnaires to measure HL, and observation to measure HW practice. The same measurements were used during baseline and endline. We used multilevel mixed-effects logistic and linear regression models to assess intervention effects.

RESULTS

None of the interventions reduced undernutrition prevalence or improved HAZ, BAZ, or overall HL scores. Low-intensity HE reduced stunting (adjusted odds ratio [aOR] 0.95; 95% CI 0.93 to 0.96), while low- (aOR 0.57; 95% CI 0.34 to 0.96) and high-intensity HE (aOR 0.63; 95% CI 0.42 to 0.93) reduced overnutrition. Medium- (adjusted incidence rate ratio [aIRR] 0.02; 95% CI 0.01 to 0.04) and high-intensity HE (aIRR 0.01; 95% CI 0.00 to 0.16) reduced severe dehydration. Medium- (aOR 3.18; 95% CI 1.34 to 7.55) and high-intensity HE (aOR 3.89; 95% CI 3.74 to 4.05) increased observed HW after using the toilet/urinal.

CONCLUSION

Increasing the intensity of HE reduced prevalence of stunting, overnutrition, and severe dehydration and increased prevalence of observed HW. Data may be relevant for school WaSH interventions in the Global South. Interventions may have been more effective if adherence was higher, exposure to interventions longer, parents/caregivers were more involved, or household WaSH was addressed.

TRIAL REGISTRATION NUMBER

DRKS00021623.

Review of the neglected tropical diseases programme implementation during 2012–2019 in the WHO-Eastern Mediterranean Region

Introduction

The 2012–2020 WHO NTD roadmap set targets for control, elimination, and eradication of neglected tropical diseases (NTDs). It recommends 5 strategies, out of which preventive chemotherapy (PC) and intensified disease management were key to achieve targets. WHO estimated that globally, between 2012 and 2019, the number of persons affected by NTDs decreased from nearly 2.1 to 1.7 billion people. We analysed the situation of NTDs in the WHO Eastern Mediterranean Region (EMR) in 2020 to assess the progress with the 2012–2020 roadmap and to identify gaps.

Methods

We reviewed data repositories of national data sources for 2012 to 2019 including the Global Indicator Data Platform for Sustainable Development Goals, the Global Health Observatory data repository, the WHO PC databank, and the EMR data repository. We allocated countries a Red-Amber-Green (RAG) rating based on standardized criteria, on progress and current situation of each of 11 priority NTDs.

Results

All 22 countries in EMR were affected by 1 or more autochthonous or imported NTDs. In 2019, WHO estimated that in EMR, 78 million people required interventions for NTDs, a 38% decline compared with 2012. Twelve of 22 countries needed priority public health action (i.e., red) for 1 or more NTD. Of these, Sudan needed priority public health action for 6 NTDs and Yemen for 5. Eleven countries also needed priority public health action for cutaneous leishmaniasis, and 5 countries for rabies and trachoma. Visceral leishmaniasis is on the increase in Afghanistan, Libya, Syria, and Yemen.

Conclusion

Since the first roadmap of NTDs in 2012, the EMR has made a substantial progress. Nevertheless, many challenges remain in the prevention and control of NTDs. EMR needs a regional approach to control NTDs in countries most affected and a coordinated strategy to stop the continuing increase of cutaneous leishmaniasis and a possible resurgence of visceral leishmaniasis.

Alternate-day fasting, a high-sucrose/caloric diet and praziquantel treatment influence biochemical and behavioral parameters during Schistosoma mansoni infection in male BALB/c mice

Schistosoma mansoni-induced granulomas result in severe damage to the host's liver, as well as neurological and metabolic disorders. We evaluated the biochemical and behavioral changes during schistosomiasis under three diet protocols: ad libitum (AL), alternate-day fasting (ADF) and a high-sucrose/caloric diet (HSD). Healthy male BALB/c mice were divided into noninfected, matched infected and infected/treated [praziquantel (PZQ)] groups. Caloric intake and energy efficiency coefficients associated with diets were measured. Behavioral (exploratory and locomotor) and biochemical (glucose, triglycerides, total cholesterol, AST, ALT, ALP, and γ-GT) tests and histological analysis were performed. Fifteen weeks postinfection, HSD and PZQ promoted weight gain, with higher caloric consumption than ADF (p < 0.05), reflecting serum glucose levels and lipid profiles. HSD and PZQ prevented liver dysfunction (AST and ALT) and significantly prevented increases in granuloma area (p < 0.05). HSD and PZQ also significantly improved mouse physical performance in exploratory and locomotor behavior (p < 0.05), reversing the impaired motivation caused by infection. These findings showed that ADF worsened the course of S. mansoni infection, while HSD and PZQ, even with synergistic effects, prevented and/or attenuated biochemical and behavioral impairment from infection.

Estimating the financial impact of livestock schistosomiasis on traditional subsistence and transhumance farmers keeping cattle, sheep and goats in northern Senegal

Background

Schistosomiasis is a disease that poses major threats to human and animal health, as well as the economy, especially in sub-Saharan Africa (SSA). Whilst many studies have evaluated the economic impact of schistosomiasis in humans, to date only one has been performed in livestock in SSA and none in Senegal. This study aimed to estimate the financial impact of livestock schistosomiasis in selected regions of Senegal.

Methods

Stochastic partial budget models were developed for traditional ruminant farmers in 12 villages in northern Senegal. The models were parameterised using data from a cross-sectional survey, focus group discussions, scientific literature and available statistics. Two scenarios were defined: scenario 1 modelled a situation in which farmers tested and treated their livestock for schistosomiasis, whilst scenario 2 modelled a situation in which there were no tests or treatment. The model was run with 10,000 iterations for 1 year; results were expressed in West African CFA francs (XOF; 1 XOF was equivalent to 0.0014 GBP at the time of analysis). Sensitivity analyses were conducted to assess the impact of uncertain variables on the disease costs.

Results

Farmers surveyed were aware of schistosomiasis in their ruminant livestock and reported hollowing around the eyes, diarrhoea and weight loss as the most common clinical signs in all species. For scenario 1, the median disease costs per year and head of cattle, sheep and goats were estimated at 13,408 XOF, 27,227 XOF and 27,694 XOF, respectively. For scenario 2, the disease costs per year and head of cattle, sheep and goats were estimated at 49,296 XOF, 70,072 XOF and 70,281 XOF, respectively.

Conclusions

Our findings suggest that the financial impact of livestock schistosomiasis on traditional subsistence and transhumance farmers is substantial. Consequently, treating livestock schistosomiasis has the potential to generate considerable benefits to farmers and their families. Given the dearth of data in this region, our study serves as a foundation for further in-depth studies to provide estimates of disease impact and as a baseline for future economic analyses. This will also enable One Health economic studies where the burden on both humans and animals is estimated and included in cross-sectoral cost–benefit and cost-effectiveness analyses of disease control strategies.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-05147-w.

Safety and efficacy of mass drug administration with a single-dose triple-drug regimen of albendazole + diethylcarbamazine + ivermectin for lymphatic filariasis in Papua New Guinea: An open-label, cluster-randomised trial

Background

Papua New Guinea (PNG) has a high burden of lymphatic filariasis (LF) caused by Wuchereria bancrofti, with an estimated 4.2 million people at risk of infection. A single co-administered dose of ivermectin, diethylcarbamazine and albendazole (IDA) has been shown to have superior efficacy in sustained clearance of microfilariae compared to diethylcarbamazine and albendazole (DA) in small clinical trials. A community-based cluster-randomised trial of DA versus IDA was conducted to compare the safety and efficacy of IDA and DA for LF in a moderately endemic, treatment-naive area in PNG.

Methodology

All consenting, eligible residents of 24 villages in Bogia district, Madang Province, PNG were enrolled, screened for W. bancrofti antigenemia and microfilaria (Mf) and randomised to receive IDA (N = 2382) or DA (N = 2181) according to their village of residence. Adverse events (AE) were assessed by active follow-up for 2 days and passive follow-up for an additional 5 days. Antigen-positive participants were re-tested one year after MDA to assess treatment efficacy.

Principal findings

Of the 4,563 participants enrolled, 96% were assessed for AEs within 2 days after treatment. The overall frequency of AEs were similar after either DA (18%) or IDA (20%) treatment. For those individuals with AEs, 87% were mild (Grade 1), 13% were moderate (Grade 2) and there were no Grade 3, Grade 4, or serious AEs (SAEs). The frequency of AEs was greater in Mf-positive than Mf-negative individuals receiving IDA (39% vs 20% p<0.001) and in Mf-positive participants treated with IDA (39%), compared to those treated with DA (24%, p = 0.023). One year after treatment, 64% (645/1013) of participants who were antigen-positive at baseline were re-screened and 74% of these participants (475/645) remained antigen positive. Clearance of Mf was achieved in 96% (52/54) of infected individuals in the IDA arm versus 84% (56/67) of infected individuals in the DA arm (relative risk (RR) 1.15; 95% CI, 1.02 to 1.30; p = 0.019). Participants receiving DA treatment had a 4-fold higher likelihood of failing to clear Mf (RR 4.67 (95% CI: 1.05 to 20.67; p = 0.043). In the DA arm, a significant predictor of failure to clear was baseline Mf density (RR 1.54; 95% CI, 1.09 to 2.88; p = 0.007).

Conclusion

IDA was well tolerated and more effective than DA for clearing Mf. Widespread use of this regimen could accelerate LF elimination in PNG.

Trial registration

Registration number NCT02899936; https://clinicaltrials.gov/ct2/show/NCT02899936.

Lymphatic filariasis (LF) is a mosquito-transmitted parasitic nematode that can live in human hosts for up to 6–8 years, disrupting the normal functions of the lymphatic system leading to the abnormal enlargement of body parts, causing pain, severe disability, and social stigma. Lymphatic filariasis can be eliminated by stopping the spread of infection through preventive chemotherapy with safe medicine combinations repeated annually. Several small-scale trials demonstrated that a single dose of a triple-drug regimen (ivermectin, diethylcarbamazine, and albendazole or IDA) was more effective at clearing infection than the standard two-drug regimen (diethylcarbamazine and albendazole or DA). This study was conducted to investigate the safety and efficacy of IDA in a large community-randomised trial in a moderate transmission setting. IDA was shown to be as safe as the standard two-drug DA treatment and more effective for clearing microfilariae compared to DA. These results show that IDA is well tolerated in PNG and has the potential to accelerate LF elimination.

The Life Histories of Intermediate Hosts and Parasites of Schistosoma haematobium and Schistosoma mansoni in the White Nile River, Sudan

Background: The epidemiology of schistosomiasis transmission varies depending on the circumstances of the surrounding water bodies and human behaviors. We aimed to explore cercarial emergence patterns from snails that are naturally affected by human schistosomiasis and non-human trematodes. In addition, this study aimed to explore how schistosomiasis infection affects snail survival, reproduction, and growth. Methods: We measured the survival rate, fecundity, and size of Biomphalaria pfeifferi snails and the cercarial rhythmicity of S. haematobium and S. mansoni. The number of egg masses, eggs per egg mass, and snail deaths were counted for 7 weeks. The survival rate and cumulative hazard were assessed for infected and non-infected snails. Results: S. haematobium and S. mansoni cercariae peaked at 9:00–11:00 a.m. Infection significantly reduced the survival rate of B. pfeifferi, which was 35% and 51% for infected and non-infected snails, respectively (p = 0.02), at 7 weeks after infection. The hazard ratio of death for infected snails compared to non-infected snails was 1.65 (95% confidence interval: 1.35–1.99; p = 0.01). Conclusions: An understanding of the dynamics of schistosomiasis transmission will be helpful for formulating schistosomiasis control and elimination strategies. Cercarial rhythmicity can be reflected in health education, and the reproduction and survival rate of infected snails can be used as parameters for developing disease modeling.

Towards global control of parasitic diseases in the Covid-19 era: One Health and the future of multisectoral global health governance

Human parasitic infections—including malaria, and many neglected tropical diseases (NTDs)—have long represented a Gordian knot in global public health: ancient, persistent, and exceedingly difficult to control. With the coronavirus disease (Covid-19) pandemic substantially interrupting control programmes worldwide, there are now mounting fears that decades of progress in controlling global parasitic infections will be undone. With Covid-19 moreover exposing deep vulnerabilities in the global health system, the current moment presents a watershed opportunity to plan future efforts to reduce the global morbidity and mortality associated with human parasitic infections. In this chapter, we first provide a brief epidemiologic overview of the progress that has been made towards the control of parasitic diseases between 1990 and 2019, contrasting these fragile gains with the anticipated losses as a result of Covid-19. We then argue that the complementary aspirations of the United Nations Sustainable Development Goals (SDGs) and the World Health Organization (WHO)’s 2030 targets for parasitic disease control may be achieved by aligning programme objectives within the One Health paradigm, recognizing the interdependence between humans, animals, and the environment. In so doing, we note that while the WHO remains the preeminent international institution to address some of these transdisciplinary concerns, its underlying challenges with funding, authority, and capacity are likely to reverberate if left unaddressed. To this end, we conclude by reimagining how models of multisectoral global health governance—combining the WHO's normative and technical leadership with greater support in allied policy-making areas—can help sustain future malaria and NTD elimination efforts.

The health and economic burden of podoconiosis in Ethiopia

Background

Podoconiosis is one of the leading causes of lymphoedema-related morbidity in low-income settings, but little is known about the scale of its health and economic impact. This information is required to inform control programme planning and policy. In this study, we estimated the health and economic burden of podoconiosis in Ethiopia.

Methods

We developed a model to estimate the health burden attributed to podoconiosis in terms of the number of disability-adjusted life years (DALYs) and the economic burden. We estimated the economic burden by quantifying the treatment and morbidity-management costs incurred by the healthcare system in managing clinical cases, patients' out-of-pocket costs and their productivity costs.

Results

In 2017, there were 1.5 million cases of podoconiosis in Ethiopia, which corresponds to 172 073 DALYs or 182 per 100 000 people. The total economic burden of podoconiosis in Ethiopia is estimated to be US$213.2 million annually and 91.1% of this resulted from productivity costs. The average economic burden per podoconiosis case was US$136.9.

Conclusions

The national cost of podoconiosis is formidable. If control measures are scaled up and the morbidity burden reduced, this will lead to Ethiopia saving millions of dollars. Our estimates provide important benchmark economic costs to programme planners, policymakers and donors for resource allocation and priority setting.

The Impact of Neglected Tropical Diseases (NTDs) on Women's Health and Wellbeing in Sub-Saharan Africa (SSA): A Case Study of Kenya

Neglected Tropical Diseases (NTDs) trap individuals in a cycle of poverty through their devastating effects on health, wellbeing and social–economic capabilities that extend to other axes of inequity such as gender and/or ethnicity. Despite NTDs being regarded as equity tracers, little attention has been paid toward gender dynamics and relationships for gender-equitable access to NTD programs in sub-Saharan Africa (SSA). This paper examines the impact of NTDs on women’s health and wellbeing in SSA using Kenya as a case study. This research is part of a larger research program designed to examine the impact of NTDs on the health and wellbeing of populations in Kenya. Thematic analysis of key informants’ interviews (n = 21) and focus groups (n = 5) reveals first that NTDs disproportionately affect women and girls due to their assigned gender roles and responsibilities. Second, women face financial and time constraints when accessing health care due to diminished economic power and autonomy. Third, women suffer more from the related social consequences of NTDs (that is, stigma, discrimination and/or abandonment), which affects their health-seeking behavior. As such, we strongly suggest a gender lens when addressing NTD specific exposure, socio-economic inequities, and other gender dynamics that may hinder the successful delivery of NTD programs at the local and national levels.

The impact of Neglected Tropical Diseases (NTDs) on health and wellbeing in sub-Saharan Africa (SSA): A case study of Kenya

Neglected Tropical Diseases (NTDs) remain endemic to many regions of sub-Saharan Africa (SSA) left behind by socioeconomic progress. As such, these diseases are markers of extreme poverty and inequity that are propagated by the political, economic, social, and cultural systems that affect health and wellbeing. As countries embrace and work towards achieving the Sustainable Development Goals (SDGs), the needs of such vulnerable populations need to be addressed in local and global arenas. The research uses primary qualitative data collected from five NTD endemic counties of Kenya: interviews key informants (n = 21) involved in NTD implementation programs and focus groups (n = 5) of affected individuals. Informed by theories of political ecology of health, the research focuses on post-devolution Kenya and identifies the political, economic, social, and cultural factors that propagate NTDs and their effects on health and wellbeing. Our findings indicate that structural factors such as competing political interests, health worker strikes, inadequate budgetary allocations, economic opportunity, marginalization, illiteracy, entrenched cultural norms and practices, poor access to water, sanitation and housing, all serve to propagate NTD transmission and subsequently affect the health and wellbeing of populations. As such, we recommend that post-devolution Kenya ensures local political, economic and socio-cultural structures are equitable, sensitive and responsive to the needs of all people. We also propose poverty alleviation through capacity building and empowerment as a means of tackling NTDs for sustained economic opportunity and productivity at the local and national level.

Wellbeing is currently seen as an avenue that shapes, happiness, productivity, environmental awareness, social inclusion, and justice; however, most countries presently adopting wellbeing measures are in the global north. Neglected Tropical Diseases (NTDs) significantly compromise populations’ health and well-being in the global south, causing undesirable effects on the personal, social, and economic capabilities of communities living in endemic regions. As countries work towards achieving the Sustainable Development Goals (SDGs), it is paramount that countries in the global south adopt wellbeing measures and, in doing so, capture the lived experiences of individuals experiencing inequities, particularly as these are shaped by NTDs. In sub-Saharan Africa (SSA), political and economic power manifests across different scales, determining human-environmental interaction, distribution of resources, and the transmission of infectious agents. This paper uses a political ecology of health approach to identify the political, economic, social and cultural factors that contribute to NTDs, which are among the world’s greatest global health problems. The vast majority of people bearing the burden of NTDs reside in low-income countries. Surprisingly, as the economies of the low-income countries improve to middle-income status, NTDs continue to thrive among sub-populations of low socioeconomic status because of the unequal distribution of economic gains. As a result, NTDs are found in environments characterized by poverty and income inequality, and other inequalities in access to health services, housing, safe water, and sanitation. This paper uses political ecology of health in the primarily biomedical field of NTDs to demonstrate that inequities are embedded within the broad political, socio-cultural, and economic systems that exacerbate NTD infection. The study recommends that NTD endemic countries in SSA formulate policies that enhance equity through capacity building and empowerment enhance population wellbeing.

Monetary value of disability-adjusted life years lost from all causes in Mauritius in 2019

Background: The Republic of Mauritius had a total of 422,567 disability-adjusted life years (DALYs) from all causes in 2019. This study aimed to estimate the monetary value of DALYs lost in 2019 from all causes in Mauritius and those projected to be lost in 2030; and to estimate the monetary value of DALYs savings in 2030 if Mauritius were to attain the national targets related to five targets of the United Nations Sustainable Development Goal 3 on good health and well-being. Methods: The human capital approach was used to monetarily value DALYs lost from 157 causes in 2019. The monetary value of DALYs lost in 2019 from each cause was calculated from the product of net gross domestic product (GDP) per capita in Mauritius and the number of DALYs lost from a specific cause. The percentage reductions implied in the SDG3 targets were used to project the monetary values of DALYs expected in 2030. The potential savings equal the monetary value of DALYs lost in 2019 less the monetary value of DALYs expected in 2030. Results:  The DALYs lost in 2019 had a total monetary value of Int$ 9.46 billion and a mean value of Int$ 22,389 per DALY. Of this amount, 84.2% resulted from non-communicable diseases; 8.7% from communicable, maternal, neonatal, and nutritional diseases; and 7.1% from injuries. Full attainment of national targets related to the five SDG3 targets would avert DALYs losses to the value of Int$ 2.4 billion. Conclusions: Diseases and injuries cause a significant annual DALYs loss with substantive monetary value. Fully achieving the five SDG3 targets could save Mauritius nearly 8% of its total GDP in 2019. To achieve such savings, Mauritius needs to strengthen further the national health system, other systems that tackle the social determinants of health, and the national health research system.

Female Genital Schistosomiasis (FGS) in Cameroon: A formative epidemiological and socioeconomic investigation in eleven rural fishing communities

BACKGROUND

Female Genital Schistosomiasis (FGS) is most often caused by presence of Schistosoma haematobium eggs lodged in the female reproductive tract which results in chronic fibrosis and scarring. In Cameroon, despite high community prevalences of urine-patent S. haematobium infections, FGS has yet to be studied in depth. To shed light on the clinical prevalence and socioeconomic effects of FGS, we undertook a formative community-based epidemiological and qualitative survey.

METHOD

A cross sectional multidisciplinary study of 304 girls and women from 11 remote rural fishing communities in Cameroon was undertaken using parasitological sampling, clinical colposcopy, and interviews. The lived experiences of those with FGS were documented using a process of ethnography with participant observation and in-depth interviews.

RESULT

Amongst 304 women and girls aged >5 years (Median age: 18; Interquartile range: 9.6-28), 198 females were eligible for FGS testing and 58 adult women were examined by clinical colposcopy. Of these, 34 were positive for FGS (proportion: 58.6%; 95% CI: 45.8-70.4), younger girls showing a higher FGS prevalence, and older women not shedding eggs showing a pattern for cervical lesions from earlier infection. In a subset of women with FGS selected purposively (12/58), in-depth interviews with participant observation revealed out-of-pocket expenditures of up to 500USD related health spending for repeated diagnosis and treatment of gynecological illnesses, and 9 hours daily lost reproductive labour. Psychosocial unrest, loss in social capital, and despair were linked with sub-fertility and persistent vaginal itch.

CONCLUSION

With our first formative evidence on prevalence, socioeconomic effects and experiences of FGS amongst women and girls in Cameroon, we have clarified to a new level of detail the deficit in provision of and access to peripheral health services in remote areas of Cameroon. Using this information, there is now strong evidence for national programs and services on women's health and schistosomiasis to update and revise policies targeted on prevention and management of FGS. We therefore stress the need for regular provision of Praziquantel treatment to adolescent girls and women in S. haematobium endemic areas, alongside better access to tailored diagnostic services that can detect FGS and appropriately triage care at primary health level.

A systematic review and meta-analysis quantifying schistosomiasis infection burden in pre-school aged children (PreSAC) in sub-Saharan Africa for the period 2000-2020

INTRODUCTION

Following the adoption of the World Health Assembly Resolution WHA 65.21 and Neglected Tropical Diseases road map 2021-2030, schistosomiasis control programmes have shifted from morbidity control to disease elimination. However, several gaps continue to be observed in the implementation of control programmes with certain age groups omitted from these campaigns increasing health inequalities and risks of reinfections to previously treated groups. We used the Inverse Variance Heterogeneity (IVhet) model to estimate the prevalence of schistosomiasis infection among preschool-aged children.

METHODS

We did a systematic review of peer-reviewed literature on schistosomiasis in sub-Saharan Africa for the period January 1, 2000 to November 30, 2020. Quantitative data for cases of schistosomiasis infection were extracted, including country and region where the studies were done, year of publication and specific schistosome species observed. The IVhet model was used to estimate the pooled prevalence estimate (PPE), the heterogeneity and publication bias.

RESULTS

We screened 2601 articles to obtain 47 eligible studies containing quantitative data on preschool-aged children. Of the selected studies, 44.7% (n = 22) were from East Africa while the least number of studies obtained (2.1%, n = 1) was from Central Africa. 21712 subjects were screened for infection due to Schistosoma spp; 13924 for S. mansoni and 7788 for S. haematobium. The PPE for schistosomiasis among PreSAC was 19% (95% CI: 11-28). Infection due to S. mansoni (IVhet PPE: 22% (95% CI: 9-36) was higher than that due to S. haematobium (15%; 95% CI: 6-25). A Luis Furuya-Kanamori index of 1.83 indicated a lack of publication bias. High level of heterogeneity was observed (I2 > 90%) and this could not be reduced through subgroup analysis.

CONCLUSION

Schistosomiasis infection among pre-school aged children 6 years old and below is high. This indicates the importance of including this age group in treatment programmes to reduce infection prevalence and long-term morbidities associated with prolonged schistosome infection.

Health economic analyses of the Global Programme to Eliminate Lymphatic Filariasis

The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was established by the WHO in 2000. It aims to eliminate lymphatic filariasis as a public health problem. This paper summarises the key estimates of the cost-effectiveness and economic benefits related to the mass drug administration (MDA) provided by the GPELF. Several studies have investigated the cost-effectiveness of this MDA, estimating the cost per disability-adjusted life year (DALY) averted. These cost-effectiveness estimates have consistently classed the intervention as cost-effective and as favourable compared with other public health interventions conducted in low- and middle-income countries. Studies have also found that the MDA used for lymphatic filariasis control generates significant economic benefits. Although these studies are positive, there are still important gaps that warrant further health economic research (particularly, the evaluation of alternative interventions, further evaluation of morbidity management strategies and evaluation of interventions for settings coendemic with Loa loa). To conclude, health economic studies for a programme as large as the GPELF are subject to uncertainty. That said, the GPELF has consistently been estimated to be cost-effective and to generate notable economic benefits by a number of independent studies.

Maternal Hookworm Infection and Its Effects on Maternal Health: A Systematic Review and Meta-Analysis

Hookworm is an intestinal parasite that infects nearly 230 million people, with another 5.1 billion at risk, especially in poverty-stricken tropical and subtropical regions. Pregnancy is an especially vulnerable time for hookworm infection because of its effect on both maternal and subsequently fetal health. A systematic review and meta-analysis was conducted. The meta-analysis was performed on the association between maternal hookworm and maternal anemia, as well as maternal hookworm coinfection with malaria. The prevalence of hookworm ranged from 1% to 78% in pregnant women, whereas malaria prevalence ranged from 11% to 81%. Pregnant women with hookworm infection were more likely to have anemia (combined odds ratio [cOR] 2.55 [2.20, 2.96], P < 0.001). In addition, pregnant woman with hookworm were more likely to have malaria coinfection (cOR 1.60 [1.38, 1.86], P < 0.001). Other effects on maternal and child health were investigated and summarized without systematic review or meta-analysis because of the limited study numbers. Despite current deworming recommendations in pregnant women, heavy hookworm burden, coinfection with malaria, and subsequent anemia persist. Although this is likely due, in part, to a lack of implementation of preventive chemotherapy, additional interventions such as health education, proper waste management, or linking malaria and soil-transmitted helminth treatment and prevention programs may also be needed. Further investigations on maternal-child outcomes as a result of hookworm infection during pregnancy will highlight public health interventional targets to reduce morbidity in pregnant women and children globally.

Elimination of Lymphatic Filariasis in Shandong Province, China, 1957-2015

China used to be one of the most heavily endemic countries for lymphatic filariasis (LF) in the world. Bancroftian filariasis, which is caused by the filarioid nematode Wuchereria bancrofti, is the only filariasis in Shandong Province. A total of 864 endemic counties (cities) in 16 provinces/autonomous regions/municipalities with a total population of 330 million people were at risk of infection. Shandong Province was a highly LF-endemic area in the 1950s, the epidemiological investigation of LF conducted in 1957 indicated that the disease was endemic in 74 counties and the highest microfilaria rate was up to 26%. There were ∼5 million people in the province infected with LF; among which almost 2.5 million people had lymphedema, elephantiasis, or hydrocele. Through vigorous prevention and scientific research, Shandong Province was the first to propose to treat LF with fortified diethylcarbamazine salt, more than 25 million people in the province had taken the salt, and more than 3 million people took intermittent medication. After more than 50 years of unremitting efforts, Shandong Province basically eliminated LF in 1983 and became the first province in China that successfully eradicated LF in 2004, which has played an important role in accelerating the elimination of filariasis in the country in 2007 and has made tremendous contributions to social and economic development of China. Since 1980, Shandong Province has carried out extensive international cooperation as the WHO Collaborating Center for Lymphatic Filariasis. This article is intended to share the experience in eliminating LF to other parts of the world and improve public health capacity in regions such as Africa and Oceania where the disease is still endemic for interest.

Economic evaluations of human schistosomiasis interventions: a systematic review and identification of associated research needs

Background: Schistosomiasis is one of the most prevalent neglected tropical diseases (NTDs) with an estimated 229 million people requiring preventive treatment worldwide. Recommendations for preventive chemotherapy strategies have been made by the World Health Organization (WHO) whereby the frequency of treatment is determined by the settings prevalence. Despite recent progress, many countries still need to scale up treatment and important questions remain regarding optimal control strategies. This paper presents a systematic review of the economic evaluations of human schistosomiasis interventions. Methods: A systematic review of the literature was conducted on 22nd August 2019 using the PubMed (MEDLINE) and ISI Web of Science electronic databases. The focus was economic evaluations of schistosomiasis interventions, such as cost-effectiveness and cost-benefit analyses. No date or language stipulations were applied to the searches. Results: We identified 53 relevant health economic analyses of schistosomiasis interventions. Most studies related to Schistosoma japonicum followed by S. haematobium. Several studies also included other NTDs. In Africa, most studies evaluated preventive chemotherapy, whereas in China they mostly evaluated programmes using a combination of interventions (such as chemotherapy, snail control and health education). There was wide variation in the methodology and epidemiological settings investigated. A range of effectiveness metrics were used by the different studies. Conclusions: Due to the variation across the identified studies, it was not possible to make definitive policy recommendations. Although, in general, the current WHO recommended preventive chemotherapy approach to control schistosomiasis was found to be cost-effective. This finding has important implications for policymakers, advocacy groups and potential funders. However, there are several important inconsistencies and research gaps (such as how the health benefits of interventions are quantified) that need to be addressed to identify the resources required to achieve schistosomiasis control and elimination.

Mapping the burden of onchocercal skin disease

Onchocerciasis is a neglected tropical disease caused by a nematode parasite, Onchocerca volvulus, and transmitted by bites of Simulium blackflies which breed near fast-flowing rivers. In humans, thousands of microfilariae (immature worms) migrate to the skin and eyes where they cause pathology. Historically, much research was devoted to the serious effect of blindness, from which the disease earns its alternative name of 'river blindness'. Mapping the burden of onchocercal skin disease (OSD) was expedited by the development of a clinical classification and grading system that facilitated comparison of data from different countries. After successful field testing in Nigeria, the classification scheme was used in a multicountry study in seven endemic sites, to estimate the true burden of OSD across Africa. High levels of OSD were found, affecting 28% of the population. A new control programme, the African Programme for Onchocerciasis Control (APOC) was launched in 20 countries using annual doses of ivermectin, donated by Merck & Co., Inc. The multicountry study also found a close correlation between the levels of itching and OSD with the level of endemicity, as determined by the prevalence of onchocercal nodules. This enabled APOC to use Rapid Epidemiological Mapping of Onchocerciasis, which entailed identifying likely vector breeding sites near rivers, then sampling 50 adult males in nearby villages to determine the prevalence of nodules and delineate which villages required treatment. Onchocerciasis is now targeted for elimination in Africa, and the challenge is to complete Onchocerciasis Elimination Mapping of hypoendemic areas using serology.

The Health and Economic Burdens of Lymphatic Filariasis Prior to Mass Drug Administration Programs

BACKGROUND

The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was launched in 2000 with the goal of eliminating lymphatic filariasis (LF) as a public health problem by 2020. Despite considerable progress, the current prevalence is around 60% of the 2000 figure, with the deadline looming a year away. Consequently, there is a continued need for investment in both the mass drug administration (MDA) and morbidity management programs, and this paper aims to demonstrate that need by estimating the health and economic burdens of LF prior to MDA programs starting in GPELF areas.

METHODS

A previously developed model was used to estimate the numbers of individuals infected and individuals with symptomatic disease, along with the attributable number of disability-adjusted life years (DALYs). The economic burden was calculated by quantifying the costs incurred by the health-care system in managing clinical cases, the patients' out-of-pocket costs, and their productivity costs.

RESULTS

Prior to the MDA program, approximately 129 million people were infected with LF, of which 43 million had clinical disease, corresponding to a DALY burden of 5.25 million. The average annual economic burden per chronic case was US $115, the majority of which resulted from productivity costs. The total economic burden of LF was estimated at US $5.8 billion annually.

CONCLUSIONS

These results demonstrate the magnitude of the LF burden and highlight the continued need to support the GPELF. Patients with clinical disease bore the majority of the economic burden, but will not benefit much from the current MDA program, which is aimed at reducing transmission. This assessment further highlights the need to scale up morbidity management programs.

Whipworm and roundworm infections

Trichuriasis and ascariasis are neglected tropical diseases caused by the gastrointestinal dwelling nematodes Trichuris trichiura (a whipworm) and Ascaris lumbricoides (a roundworm), respectively. Both parasites are staggeringly prevalent, particularly in tropical and subtropical areas, and are associated with substantial morbidity. Infection is initiated by ingestion of infective eggs, which hatch in the intestine. Thereafter, T. trichiura larvae moult within intestinal epithelial cells, with adult worms embedded in a partially intracellular niche in the large intestine, whereas A. lumbricoides larvae penetrate the gut mucosa and migrate through the liver and lungs before returning to the lumen of the small intestine, where adult worms dwell. Both species elicit type 2 anti-parasite immunity. Diagnosis is typically based on clinical presentation (gastrointestinal symptoms and inflammation) and the detection of eggs or parasite DNA in the faeces. Prevention and treatment strategies rely on periodic mass drug administration (generally with albendazole or mebendazole) to at-risk populations and improvements in water, sanitation and hygiene. The effectiveness of drug treatment is very high for A. lumbricoides infections, whereas cure rates for T. trichiura infections are low. Novel anthelminthic drugs are needed, together with vaccine development and tools for diagnosis and assessment of parasite control in the field.

Change in schistosomiasis-related liver disease with repeated praziquantel treatment in school children in rural Zambia

Repeated praziquantel treatment for schistosomiasis is an effective method to reduce disease burden. Ultrasonographic methods were used to assess the severity of schistosoma mansoni-related liver disease and demonstrate improvement following treatment. We compared data from 733 children in 2010 and 972 children in 2018 to determine the effect of repeated praziquantel treatment on prevalence of liver disease. Three age groups were compared across three liver disease classifications (normal, mild, severe). From 2010 to 2018, there was a significant reduction in prevalence of severe liver disease in all age groups (P = 0.03 for 5-10 years, P < 0.001 for 11-15 years and 16-20 years). In both male and female students, the proportion having a normal liver significantly increased (P < 0.001) from 2010 to 2018, in the 11-15-year-olds and 16-20-year-olds, demonstrating that liver disease significantly reduced in these age groups. This study demonstrates a reduction in schistosomiasis-related morbidity with repeated praziquantel treatment.

Economic evaluations of human schistosomiasis interventions: a systematic review and identification of associated research needs

Background: Schistosomiasis is one of the most prevalent neglected tropical diseases (NTDs) with an estimated 229 million people requiring preventive treatment worldwide. Recommendations for preventive chemotherapy strategies have been made by the World Health Organization (WHO) whereby the frequency of treatment is determined by the settings prevalence. Despite recent progress, many countries still need to scale up treatment and important questions remain regarding optimal control strategies. This paper presents a systematic review of the economic evaluations of human schistosomiasis interventions. Methods: A systematic review of the literature was conducted on 22nd August 2019 using the PubMed (MEDLINE) and ISI Web of Science electronic databases. The focus was economic evaluations of schistosomiasis interventions, such as cost-effectiveness and cost-benefit analyses. No date or language stipulations were applied to the searches. Results: We identified 53 relevant health economic analyses of schistosomiasis interventions. Most studies related to Schistosoma japonicum followed by S. haematobium. Several studies also included other NTDs. In Africa, most studies evaluated preventive chemotherapy, whereas in China they mostly evaluated programmes using a combination of interventions (such as chemotherapy, snail control and health education). There was wide variation in the methodology and epidemiological settings investigated. A range of effectiveness metrics were used by the different studies. Conclusions: Due to the variation across the identified studies, it was not possible to make definitive policy recommendations. Although, in general, the current WHO recommended preventive chemotherapy approach to control schistosomiasis was found to be cost-effective. This finding has important implications for policymakers, advocacy groups and potential funders. However, there are several important inconsistencies and research gaps (such as how the health benefits of interventions are quantified) that need to be addressed to identify the resources required to achieve schistosomiasis control and elimination.

Schistosomiasis and hookworm infection in humans: Disease burden, pathobiology and anthelmintic vaccines

Helminth diseases are the ancient scourges of humans and their damages are 'silent and insidious'. Of the helminth infections, schistosomiasis and hookworm infection have a great impact. This review covers information regarding vaccine candidates against schistosomiasis and hookworms that reached at least up to the phase-1 trial and literatures regarding other vaccine candidates have been excluded. For clinical manifestations, all available literatures were included, and for epidemiology and global burden of the diseases (GBD), literatures only within 2000-2019 were included. Literatures were searched surfing various databases including PubMED, Google Scholar, and Science Direct and overall over 150 literatures were identified. Globally ~250 million people are suffering from schistosomiasis, resulting 1430 thousand DALY (disability adjusted life year) per year. On the other hand, about 1.3 billion people are infected with hookworm (HW), and according to WHO, ~878 million school-age children (SAC) are at risk. HW is estimated to cause 65,000 deaths annually, accounts for 845 thousand DALYs as well as to cause 6-35.3% loss in productivity. Despite tremendous efforts, very few anthelmintic vaccine candidates such as Na-GST-1, Na-APR-1 and Na-ASP-2 against HW, and Sm28GST/Sh28GST, Sm-p80, Sm14 and Sm-TSP-1/SmTSP-2 against schistosomiasis reached up to the clinical trials. More efforts are needed to achieve the WHO targets taken against the maladies.

Are Alternative Strategies Required to Accelerate the Global Elimination of Lymphatic Filariasis? Insights From Mathematical Models

Background

With the 2020 target year for elimination of lymphatic filariasis (LF) approaching, there is an urgent need to assess how long mass drug administration (MDA) programs with annual ivermectin + albendazole (IA) or diethylcarbamazine + albendazole (DA) would still have to be continued, and how elimination can be accelerated. We addressed this using mathematical modeling.

Methods

We used 3 structurally different mathematical models for LF transmission (EPIFIL, LYMFASIM, TRANSFIL) to simulate trends in microfilariae (mf) prevalence for a range of endemic settings, both for the current annual MDA strategy and alternative strategies, assessing the required duration to bring mf prevalence below the critical threshold of 1%.

Results

Three annual MDA rounds with IA or DA and good coverage (≥65%) are sufficient to reach the threshold in settings that are currently at mf prevalence <4%, but the required duration increases with increasing mf prevalence. Switching to biannual MDA or employing triple-drug therapy (ivermectin, diethylcarbamazine, and albendazole [IDA]) could reduce program duration by about one-third. Optimization of coverage reduces the time to elimination and is particularly important for settings with a history of poorly implemented MDA (low coverage, high systematic noncompliance).

Conclusions

Modeling suggests that, in several settings, current annual MDA strategies will be insufficient to achieve the 2020 LF elimination targets, and programs could consider policy adjustment to accelerate, guided by recent monitoring and evaluation data. Biannual treatment and IDA hold promise in reducing program duration, provided that coverage is good, but their efficacy remains to be confirmed by more extensive field studies.

Whatever happened to China's neglected tropical diseases?

Before the founding of the People's Republic of China 70 years ago, both extreme poverty and parasitic infections and other neglected tropical diseases were highly prevalent. Owing to social development, particularly economic reforms since the 1980s, poverty has since been dramatically reduced, and China became increasingly urbanized and industrialized. In parallel, China's economic transformation translated into similar and remarkable reductions in neglected tropical diseases. Qian and colleagues report in their review published in Infectious Diseases of Poverty, the elimination or near elimination as a public health problem of lymphatic filariasis, trachoma, soil-transmitted helminth infections, schistosomiasis and other neglected tropical diseases. Of note, neglected tropical disease control and poverty reduction each appear to reinforce the other. China's formula for success in parasitic and neglected tropical disease control might translate to other parts of the world, such as in sub-Saharan Africa through China's new Belt and Road Initiative.

Unavoidable Risks: Local Perspectives on Water Contact Behavior and Implications for Schistosomiasis Control in an Agricultural Region of Northern Senegal

Human schistosomiasis is a snail-borne parasitic disease affecting more than 200 million people worldwide. Direct contact with snail-infested freshwater is the primary route of exposure. Water management infrastructure, including dams and irrigation schemes, expands snail habitat, increasing the risk across the landscape. The Diama Dam, built on the lower basin of the Senegal River to prevent saltwater intrusion and promote year-round agriculture in the drought-prone Sahel, is a paradigmatic case. Since dam completion in 1986, the rural population-whose livelihoods rely mostly on agriculture-has suffered high rates of schistosome infection. The region remains one of the most hyperendemic regions in the world. Because of the convergence between livelihoods and environmental conditions favorable to transmission, schistosomiasis is considered an illustrative case of a disease-driven poverty trap (DDPT). The literature to date on the topic, however, remains largely theoretical. With qualitative data generated from 12 focus groups in four villages, we conducted team-based theme analysis to investigate how perception of schistosomiasis risk and reported preventive behaviors may suggest the presence of a DDPT. Our analysis reveals three key findings: 1) rural villagers understand schistosomiasis risk (i.e., where and when infections occur), 2) accordingly, they adopt some preventive behaviors, but ultimately, 3) exposure persists, because of circumstances characteristic of rural livelihoods. These findings highlight the capacity of local populations to participate actively in schistosomiasis control programs and the limitations of widespread drug treatment campaigns. Interventions that target the environmental reservoir of disease may provide opportunities to reduce exposure while maintaining resource-dependent livelihoods.

Economic evaluations of onchocerciasis interventions: a systematic review and research needs

OBJECTIVE

To provide a systematic review of economic evaluations that has been conducted for onchocerciasis interventions, to summarise current key knowledge and to identify research gaps.

METHOD

A systematic review of the literature was conducted on the 8th of August 2018 using the PubMed (MEDLINE) and ISI Web of Science electronic databases. No date or language stipulations were applied to the searches.

RESULTS

We identified 14 primary studies reporting the results of economic evaluations of onchocerciasis interventions, seven of which were cost-effectiveness analyses. The studies identified used a variety of different approaches to estimate the costs of the investigated interventions/programmes. Originally, the studies only quantified the benefits associated with preventing blindness. Gradually, methods improved and also captured onchocerciasis-associated skin disease. Studies found that eliminating onchocerciasis would generate billions in economic benefits. The majority of the cost-effectiveness analyses evaluated annual mass drug administration (MDA). The estimated cost per disability-adjusted life year (DALY) averted of annual MDA varies between US$3 and US$30 (cost year variable).

CONCLUSIONS

The cost benefit and cost effectiveness of onchocerciasis interventions have consistently been found to be very favourable. This finding provides strong evidential support for the ongoing efforts to eliminate onchocerciasis from endemic areas. Although these results are very promising, there are several important research gaps that need to be addressed as we move towards the 2020 milestones and beyond.

Cyanobacterial peptides as a tour de force in the chemical space of antiparasitic agents

Parasites are scarcely addressed target for antimicrobial peptides despite their big impact in health and global economy. The notion of antimicrobial peptides is frequently associated to the innate immune defense of vertebrates and invertebrate vectors, as the ultimate recipients of the parasite infection. These antiparasite peptides are produced by ribosomal synthesis, with few post-translational modifications, and their diversity come mostly from their amino acid sequence. For many of them permeabilization of the cell membrane of the targeted pathogen is crucial for their microbicidal mechanism. In contrast, cyanobacterial peptides are produced either by ribosomal or non-ribosomal biosynthesis. Quite often, they undergo heavy modifications, such as the inclusion of non-proteinogenic amino acids, lipid acylation, cyclation, N^α-methylation, or heterocyclic rings. Furthermore, the few targets identified for cyanobacterial peptides in parasites are intracellular. Some cyanobacterial antiparasite peptides are active at picomolar concentrations, whereas those from higher eukaryotes usually work in the micromolar range. In all, cyanobacterial peptides are an appealing target to develop new antiparasite therapies and a challenge in the invention of new synthetic methods for peptides. This review aims to provide an updated appraisal of antiparasite cyanobacterial peptides and to establish a side-by -side comparison with those antiparasite peptides from higher eukaryotes.

Molecular Identification of Trichuris suis and Trichuris trichiura Eggs in Human Populations from Thailand, Lao PDR, and Myanmar

Trichuris trichiura is a soil-transmitted helminth infecting human populations globally. Human cases caused by Trichuris suis and Trichuris vulpis have also been reported. Molecular identifications of Trichuris species infecting human populations in Lao PDR and Myanmar are lacking. Here, we explored molecular data obtained from Trichuris eggs recovered from human fecal samples from these countries and compared these with new and existing data from Thailand. Nuclear ribosomal DNA (18S and ITS2) sequences were amplified from Trichuris eggs and sequenced. Forty-one samples showed 99-100% similarity in their 18S sequences to published sequences of T. trichiura and one sample showed 99% similarity to a sequence of T. suis. Similarly, 41 samples showed 92-100% similarity in their ITS2 sequences to published sequences of T. trichiura and one sample showed 94-97% similarity to sequences of T. suis. This study is the first molecular confirmation of human infection with T. suis in northeast Thailand and the first molecular confirmation of the species of Trichuris infecting humans in Lao PDR and Myanmar.

Health, financial, and education gains of investing in preventive chemotherapy for schistosomiasis, soil-transmitted helminthiases, and lymphatic filariasis in Madagascar: A modeling study

BACKGROUND

Neglected tropical diseases (NTDs) account for a large disease burden in sub-Saharan Africa. While the general cost-effectiveness of NTD interventions to improve health outcomes has been assessed, few studies have also accounted for the financial and education gains of investing in NTD control.

METHODS

We built on extended cost-effectiveness analysis (ECEA) methods to assess the health gains (e.g. infections, disability-adjusted life years or DALYs averted), household financial gains (out-of-pocket expenditures averted), and education gains (cases of school absenteeism averted) for five NTD interventions that the government of Madagascar aims to roll out nationally. The five NTDs considered were schistosomiasis, lymphatic filariasis, and three soil-transmitted helminthiases (Ascaris lumbricoides, Trichuris trichiura, and hookworm infections).

RESULTS

The estimated incremental cost-effectiveness for the roll-out of preventive chemotherapy for all NTDs jointly was USD125 per DALY averted (95% uncertainty range: 65-231), and its benefit-cost ratio could vary between 5 and 31. Our analysis estimated that, per dollar spent, schistosomiasis preventive chemotherapy, in particular, could avert a large number of infections (176,000 infections averted per $100,000 spent), DALYs (2,000 averted per $100,000 spent), and cases of school absenteeism (27,000 school years gained per $100,000 spent).

CONCLUSION

This analysis incorporates financial and education gains into the economic evaluation of health interventions, and therefore provides information about the efficiency of attainment of three Sustainable Development Goals (SDGs). Our findings reveal how the national scale-up of NTD control in Madagascar can help address health (SDG3), economic (SDG1), and education (SDG4) goals. This study further highlights the potentially large societal benefits of investing in NTD control in low-resource settings.

Imported onchocerciasis in migrants and travelers

PURPOSE OF REVIEW

With increasing international travel and mass global population migration, clinicians in nonendemic countries must be familiar with imported neglected tropical diseases including onchocerciasis, which is commonly known as 'river blindness'.

RECENT FINDINGS

Imported onchocerciasis manifests differently in travelers compared with migrants from endemic areas and is likely underdiagnosed in both groups. Recent clinical studies confirm that eosinophilia is not a sensitive marker for Onchocerca volvulus, with one-third of patients having a normal eosinophil count. Novel diagnostics measuring antibodies to multiple recombinant O. volvulus antigens maintain a high sensitivity while improving specificity compared with conventional pan-filarial serologic testing. A 6-week course of doxycycline has macrofilaricidal activity through Wolbachia depletion and may be useful in nonendemic areas in addition to standard serial ivermectin.

SUMMARY

Recent studies characterizing distinct clinical presentations in travelers and migrants may enable clinicians to better recognize imported onchocerciasis. Although novel diagnostics have improved specificity, most remain restricted to tropical disease reference laboratories and to date there is no marker of cure. Prolonged doxycycline treatment may reduce the need for serial ivermectin, though more potent short-course macrofilaricidal drugs are being developed.

The Skin-A Common Pathway for Integrating Diagnosis and Management of NTDs

Many of the neglected tropical diseases (NTDs) have major skin manifestations. These skin-related NTDs or ‘skin NTDs’ cause significant morbidity and economic hardship in some of the poorest communities worldwide. We draw attention to the collective burden of skin disease and suggest that the skin be used as a platform for the integration of control activities for NTDs. The opportunities for integration are numerous, ranging from diagnosis and disease mapping to mass drug administration and morbidity management. The dermatology community has an important role to play, and will be expected to support research and control activities globally.

Onchodermatitis: Where Are We Now?

Onchocerciasis causes debilitating pruritus and rashes as well as visual impairment and blindness. Prior to control measures, eye disease was particularly prominent in savanna areas of sub-Saharan Africa whilst skin disease was more common across rainforest regions of tropical Africa. Mass drug distribution with ivermectin is changing the global scene of onchocerciasis. There has been successful progressive elimination in Central and Southern American countries and the World Health Organization has set a target for elimination in Africa of 2025. This literature review was conducted to examine progress regarding onchocercal skin disease. PubMed searches were performed using keywords 'onchocerciasis', 'onchodermatitis' and 'onchocercal skin disease' over the past eight years. Articles in English, or with an English abstract, were assessed for relevance, including any pertinent references within the articles. Recent progress in awareness of, understanding and treatment of onchocercal skin disease is reviewed with particular emphasis on publications within the past five years. The global burden of onchodermatitis is progressively reducing and is no longer seen in children in many formerly endemic foci.

Equity and efficiency in the scaled-up implementation of integrated neglected tropical disease control: the health economics protocol of the COUNTDOWN multicountry observational study in Ghana, Cameroon and Liberia

INTRODUCTION

Worldwide, millions of individuals are affected by neglected tropical diseases (NTDs). They are frequently the poorest and most marginalised members of society. Their living conditions, among other things, make them susceptible to such diseases. Historically, several large-scale treatment programmes providing mass drug administrations (MDAs) were carried out per single disease but over the last decade there has been an increasing trend towards co-implementation of MDA activities given the resources used for such programmes are often the same. The COUNTDOWN multicountry studies focus on scaled-up implementation of integrated control strategies against four diseases: lymphatic filariasis, onchocerciasis, schistosomiasis and soil-transmitted helminthiasis. The objective of the COUNTDOWN economic study is to assess the multicountry implementation of control interventions in terms of equity, impact and efficiency.

METHODS

The health economic study uses different analytical methods to assess the relationship between NTDs and poverty and the cost-effectiveness of different large-scale intervention options. Regression analysis will be used to study the determinants of NTD occurrence, the impact of NTDs on poverty, factors that hinder access to MDAs and the effect of NTDs on quality-of-life of those affected, including disability. Cost-effectiveness analyses of various integration methods will be performed using health economic modelling to estimate the cost and programme impact of different integration options. Here, cost-effectiveness ratios will be calculated, including multivariate sensitivity analyses, using Bayesian analysis.

ETHICS AND DISSEMINATION

Ethics approval has been received both at the Liverpool School of Tropical Medicine and in all participating countries. Results of the various substudies will be presented for publication in peer-reviewed journals.

STUDY DATES

1 July 2016 to 30 June-October 2019.

Should we be treating animal schistosomiasis in Africa? The need for a One Health economic evaluation of schistosomiasis control in people and their livestock

A One Health economic perspective allows informed decisions to be made regarding control priorities and/or implementation strategies for infectious diseases. Schistosomiasis is a major and highly resilient disease of both humans and livestock. The zoonotic component of transmission in sub-Saharan Africa appears to be more significant than previously assumed, and may thereby affect the recently revised WHO vision to eliminate schistosomiasis as a public health problem by 2025. Moreover, animal schistosomiasis is likely to be a significant cost to affected communities due to its direct and indirect impact on livelihoods. We argue here for a comprehensive evaluation of the economic burden of livestock and zoonotic schistosomiasis in sub-Saharan Africa in order to determine if extending treatment to include animal hosts in a One Health approach is economically, as well as epidemiologically, desirable.

Socioeconomic benefit to individuals of achieving 2020 targets for four neglected tropical diseases controlled/eliminated by innovative and intensified disease management: Human African trypanosomiasis, leprosy, visceral leishmaniasis, Chagas disease

BACKGROUND

The control or elimination of neglected tropical diseases (NTDs) has targets defined by the WHO for 2020, reinforced by the 2012 London Declaration. We estimated the economic impact to individuals of meeting these targets for human African trypanosomiasis, leprosy, visceral leishmaniasis and Chagas disease, NTDs controlled or eliminated by innovative and intensified disease management (IDM).

METHODS

A systematic literature review identified information on productivity loss and out-of-pocket payments (OPPs) related to these NTDs, which were combined with projections of the number of people suffering from each NTD, country and year for 2011-2020 and 2021-2030. The ideal scenario in which the WHO's 2020 targets are met was compared with a counterfactual scenario that assumed the situation of 1990 stayed unaltered. Economic benefit equaled the difference between the two scenarios. Values are reported in 2005 US$, purchasing power parity-adjusted, discounted at 3% per annum from 2010. Probabilistic sensitivity analyses were used to quantify the degree of uncertainty around the base-case impact estimate.

RESULTS

The total global productivity gained for the four IDM-NTDs was I$ 23.1 (I$ 15.9 -I$ 34.0) billion in 2011-2020 and I$ 35.9 (I$ 25.0 -I$ 51.9) billion in 2021-2030 (2.5th and 97.5th percentiles in brackets), corresponding to US$ 10.7 billion (US$ 7.4 -US$ 15.7) and US$ 16.6 billion (US$ 11.6 -US$ 24.0). Reduction in OPPs was I$ 14 billion (US$ 6.7 billion) and I$ 18 billion (US$ 10.4 billion) for the same periods.

CONCLUSIONS

We faced important limitations to our work, such as finding no OPPs for leprosy. We had to combine limited data from various sources, heterogeneous background, and of variable quality. Nevertheless, based on conservative assumptions and subsequent uncertainty analyses, we estimate that the benefits of achieving the targets are considerable. Under plausible scenarios, the economic benefits far exceed the necessary investments by endemic country governments and their development partners. Given the higher frequency of NTDs among the poorest households, these investments represent good value for money in the effort to improve well-being, distribute the world's prosperity more equitably and reduce inequity.

Economic evaluations of lymphatic filariasis interventions: a systematic review and research needs

In 2000, the World Health Organization established the Global Programme to Eliminate Lymphatic Filariasis (GPELF), with the goal of eliminating the disease as a public health problem by 2020. Since the start of the programme, a cumulative total of 6.2 billion treatments have been delivered to affected populations - with more than 556 million people treated in 2015 alone. In this paper, we perform a rigorous systematic review of the economic evaluations of lymphatic filariasis interventions have been conducted. We demonstrate that the standard interventions to control lymphatic filariasis are consistently found to be highly cost-effective. This finding has important implications for advocacy groups and potential funders. However, there are several important inconsistencies and research gaps that need to be addressed as we move forward towards the 2020 elimination goals. One of the most important identified research gaps was a lack of evaluation of new interventions specifically targeting areas co-endemic with onchocerciasis and Loa loa - which could become a major barrier to achieving elimination.

Prospects for elimination of soil-transmitted helminths

Purpose of review

Soil-transmitted helminths (STH) are endemic in 120 countries and are associated with substantial morbidity and loss of economic productivity. Although current WHO guidelines focus on morbidity control through mass drug administration (MDA), there is global interest in whether a strategy targeting disease elimination might be feasible in some settings. This review summarizes the prospects for switching from control to an elimination strategy.

Recent findings

STH control efforts have reduced the intensity of infections in targeted populations with associated reductions in morbidity. However, adults are not frequently targeted and remain important reservoirs for reinfection of treated children. Recent modeling suggests that transmission interruption may be possible through expanded community-wide delivery of MDA, the feasibility of which has been demonstrated by other programs. However, these models suggest that high levels of coverage and compliance must be achieved. Potential challenges include the risk of prematurely dismantling STH programs and the potential increased risk of antihelminthic resistance.

Summary

Elimination of STH may offer an opportunity to eliminate substantial STH-related morbidity while reducing resource needs of neglected tropical disease programs. Evidence from large community trials is needed to determine the feasibility of interrupting the transmission of STH in some geographic settings.