Using Passive Surveillance to Maintain Elimination as a Public Health Problem for Neglected Tropical Diseases: A Model-Based Exploration.

BACKGROUND: Great progress is being made toward the goal of elimination as a public health problem for neglected tropical diseases such as leprosy, human African trypanosomiasis, Buruli ulcer, and visceral leishmaniasis, which relies on intensified disease management and case finding. However, strategies for maintaining this goal are still under discussion. Passive surveillance is a core pillar of a long-term, sustainable surveillance program. METHODS: We use a generic model of disease transmission with slow epidemic growth rates and cases detected through severe symptoms and passive detection to evaluate under what circumstances passive detection alone can keep transmission under control. RESULTS: Reducing the period of infectiousness due to decreasing time to treatment has a small effect on reducing transmission. Therefore, to prevent resurgence, passive surveillance needs to be very efficient. For some diseases, the treatment time and level of passive detection needed to prevent resurgence is unlikely to be obtainable. CONCLUSIONS: The success of a passive surveillance program crucially depends on what proportion of cases are detected, how much of their infectious period is reduced, and the underlying reproduction number of the disease. Modeling suggests that relying on passive detection alone is unlikely to be enough to maintain elimination goals.

New Tools and Nuanced Interventions to Accelerate Achievement of the 2030 Roadmap for Neglected Tropical Diseases.

The World Health Organization roadmap for neglected tropical diseases (NTDs) sets out ambitious targets for disease control and elimination by 2030, including 90% fewer people requiring interventions against NTDs and the elimination of at least 1 NTD in 100 countries. Mathematical models are an important tool for understanding NTD dynamics, optimizing interventions, assessing the efficacy of new tools, and estimating the economic costs associated with control programs. As NTD control shifts to increased country ownership and programs progress toward disease elimination, tailored models that better incorporate local context and can help to address questions that are important for decision-making at the national level are gaining importance. In this introduction to the supplement, New Tools and Nuanced Interventions to Accelerate Achievement of the 2030 Roadmap for Neglected Tropical Diseases, we discuss current challenges in generating more locally relevant models and summarize how the articles in this supplement present novel ways in which NTD modeling can help to accelerate achievement and sustainability of the 2030 targets.

Accelerating Progress Towards the 2030 Neglected Tropical Diseases Targets: How Can Quantitative Modeling Support Programmatic Decisions?

Over the past decade, considerable progress has been made in the control, elimination, and eradication of neglected tropical diseases (NTDs). Despite these advances, most NTD programs have recently experienced important setbacks; for example, NTD interventions were some of the most frequently and severely impacted by service disruptions due to the coronavirus disease 2019 (COVID-19) pandemic. Mathematical modeling can help inform selection of interventions to meet the targets set out in the NTD road map 2021-2030, and such studies should prioritize questions that are relevant for decision-makers, especially those designing, implementing, and evaluating national and subnational programs. In September 2022, the World Health Organization hosted a stakeholder meeting to identify such priority modeling questions across a range of NTDs and to consider how modeling could inform local decision making. Here, we summarize the outputs of the meeting, highlight common themes in the questions being asked, and discuss how quantitative modeling can support programmatic decisions that may accelerate progress towards the 2030 targets.

The effects of selected neglected tropical diseases on economic performance at the macrolevel in Africa.

BACKGROUND: Neglected tropical diseases (NTDs) such as leprosy, lymphatic filariasis (LF), schistosomiasis and onchocerciasis are endemic in several African countries. These diseases can lead to severe pain and permanent disability, which can negatively affect the economic productivity of the affected person(s), and hence resulting into low economic performance at the macrolevel. Nonetheless, empirical evidence of the effects of these NTDs on economic performance at the macrolevel is sparse. This study therefore investigates the effects of the above-mentioned NTDs on economic performance at the macrolevel in Africa. METHODS: The study employs a panel design with data comprising 24 to 45 African countries depending on the NTD in question, over the period, 2002 to 2019. Gross domestic product (GDP) is used as the proxy for economic performance (Dependent variable) and the prevalence of the above-mentioned NTDs are used as the main independent variables. The random effects (RE), fixed effects (FE) and the instrumental variable fixed effects (IVFE) panel data regressions are used as estimation techniques. RESULTS: We find that, an increase in the prevalence of the selected NTDs is associated with a fall in economic performance in the selected African countries, irrespective of the estimation technique used. Specifically, using the IVFE regression estimates, we find that a percentage increase in the prevalence of leprosy, LF, schistosomiasis and onchocerciasis is associated with a reduction in economic performance by 0.43%, 0.24%, 0.28% and 0.36% respectively, at either 1% or 5% level of significance. CONCLUSION: The findings highlight the need to increase attention and bolster integrated efforts or measures towards tackling these diseases in order to curb their deleterious effects on economic performance. Such measures can include effective mass drug administration (MDA), enhancing access to basic drinking water and sanitation among others.

Challenges and recent progress in drug discovery for tropical diseases.

Infectious tropical diseases have a huge effect in terms of mortality and morbidity, and impose a heavy economic burden on affected countries. These diseases predominantly affect the world's poorest people. Currently available drugs are inadequate for the majority of these diseases, and there is an urgent need for new treatments. This Review discusses some of the challenges involved in developing new drugs to treat these diseases and highlights recent progress. While there have been notable successes, there is still a long way to go.

Evaluating the World Health Organization's SkinNTDs App as a Training Tool for Skin Neglected Tropical Diseases in Ghana and Kenya: Cross-Sectional Study.

BACKGROUND: Neglected tropical diseases (NTDs) affect over 1.5 billion people worldwide, primarily impoverished populations in low- and middle-income countries. Skin NTDs, a significant subgroup, manifest primarily as skin lesions and require extensive diagnosis and treatment resources, including trained personnel and financial backing. The World Health Organization has introduced the SkinNTDs app, a mobile health tool designed to train and be used as a decision support tool for frontline health care workers. As most digital health guidelines prioritize the thorough evaluation of mobile health interventions, it is essential to conduct a rigorous and validated assessment of this app. OBJECTIVE: This study aims to assess the usability and user experience of World Health Organization SkinNTDs app (version 3) as a capacity-building tool and decision-support tool for frontline health care workers. METHODS: A cross-sectional study was conducted in Ghana and Kenya. Frontline health care workers dealing with skin NTDs were recruited through snowball sampling. They used the SkinNTDs app for at least 5 days before completing a web-based survey containing demographic variables and the user version of the Mobile Application Rating Scale (uMARS), a validated scale for assessing health apps. A smaller group of participants took part in semistructured interviews and one focus group. Quantitative data were analyzed using SPSS with a 95% CI and P≤.05 for statistical significance and qualitative data using ATLAS.ti to identify attributes, cluster themes, and code various dimensions that were explored. RESULTS: Overall, 60 participants participated in the quantitative phase and 17 in the qualitative phase. The SkinNTDs app scored highly on the uMARS questionnaire, with an app quality mean score of 4.02 (SD 0.47) of 5, a subjective quality score of 3.82 (SD 0.61) of 5, and a perceived impact of 4.47 (SD 0.56) of 5. There was no significant association between the app quality mean score and any of the categorical variables examined, according to Pearson correlation analysis; app quality mean score vs age (P=.37), sex (P=.70), type of health worker (P=.35), country (P=.94), work context (P=.17), frequency of dealing with skin NTDs (P=.09), and dermatology experience (P=.63). Qualitative results echoed the quantitative outcomes, highlighting the ease of use, the offline functionality, and the potential utility for frontline health care workers in remote and resource-constrained settings. Areas for improvement were identified, such as enhancing the signs and symptoms section. CONCLUSIONS: The SkinNTDs app demonstrates notable usability and user-friendliness. The results indicate that the app could play a crucial role in improving capacity building of frontline health care workers dealing with skin NTDs. It could be improved in the future by including new features such as epidemiological context and direct contact with experts. The possibility of using the app as a diagnostic tool should be considered. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/39393.

Actives from MMV Open Access Boxes? A suggested way forward.

It is estimated that more than 1 billion people across the world are affected by a neglected tropical disease (NTD) that requires medical intervention. These diseases tend to afflict people in areas with high rates of poverty and cost economies billions of dollars every year. Collaborative drug discovery efforts are required to reduce the burden of these diseases in endemic regions. The release of "Open Access Boxes" is an initiative launched by Medicines for Malaria Venture (MMV) in collaboration with its partners to catalyze new drug discovery in neglected diseases. These boxes are mainly requested by biology researchers across the globe who may not otherwise have access to compounds to screen nor knowledge of the workflow that needs to be followed after identification of actives from their screening campaigns. Here, we present guidelines on how to move such actives beyond the hit identification stage, to help in capacity strengthening and enable a greater impact of the initiative.

Unpacking the impact of integrating the neglected tropical disease supply chain into the national supply chain system: illustrative evidence from Liberia.

Effective supply chain management is a critical pillar of well-functioning health systems ensuring that medical commodities reach those in need. In Liberia, the national neglected tropical disease (NTD) programme supports health systems strengthening for case management of NTDs. Integration of NTD commodities into the national health system supply chain is central to the integrated approach; however, there is minimal evidence on enablers and barriers. Drawing on qualitative evaluation data, we illustrate that perceived benefits and strengths to integrating NTD commodities into the supply chain include leveraged storage and management capacities capitalized at lower system levels; the political will to integrate based on cost-saving and capacity strengthening potential and positive progress integrating paper-based reporting tools. Challenges remain, specifically the risk of reliance on donor funding; difficulty in accessing commodities due to bureaucratic bottlenecks; lack of inclusion of NTD commodities within electronic data tools and poor coordination leading to an inability to meet demand. Collectively, the negative consequences of ineffective integration of NTD commodities into the supply chain has a detrimental impact on health workers (including community health workers) unable to deliver the quality of care to patients. Trust between affected populations and the health system is compromised when treatments are unavailable.

Neglected Tropical Diseases in Italy: introducing IN-NTD, the Italian network for NTDs.

The World Health Organization (WHO) defines neglected tropical diseases (NTDs) as a diverse group of primarily infectious diseases, which disproportionately affect poor and marginalized populations worldwide. In this context, NTDs are responsible for important morbidity and mortality and justify a global response. Moreover, NTDs are relatively neglected by research and development as well as by funding, if compared with the magnitude of the public health problem they represent. This happens even though, unlike other infectious diseases, they can be prevented, controlled and eliminated by targeted public health interventions. NTDs are mainly prevalent in communities from low-income countries in tropical and sub-tropical areas but are also present in upper­middle-income countries, including several in Europe. Here, we provide an update on the most relevant parasitic endemic or imported NTDs in Italy and illustrate the rationale for the establishment of the Italian network on NTDs, an alliance of scientific societies, institutes, foundations, universities and non-profit organizations united to fight NTDs.

Applicability of working abroad for physicians with a specialization in Global Health and Tropical Medicine.

BACKGROUND: In The Netherlands, physicians specialized in global health and tropical medicine (Ps-GHTM) are trained to work in low-resource settings (LRS) after their training program of 27 months. After working for a period of time in LRS, many Ps-GHTM continue their careers in the Dutch healthcare system. While there is limited evidence regarding the value of international health experience for medical students and residents, it is unknown to what extent this applies to Ps-GHTM and to their clinical practice in the Netherlands. METHODS: In this qualitative study we conducted semi-structured interviews and focus group discussions (FGDs) with Ps-GHTM to explore the perceived applicability of their experience abroad for their subsequent return to the Netherlands. Topic guides were developed using literature about the applicability of working abroad. Findings from the interviews served as a starting point for FGDs. The interviews and FGDs were analysed using directed content analysis. RESULTS: 15 themes are described relating experience abroad to healthcare delivery in The Netherlands: broad medical perspective, holistic perspective, adaptive communication skills, creativity, flexibility, cultural awareness, self-reliance, clinical competence, cost awareness, public health, leadership, open-mindedness, organization of care, self-development, and teamwork. Highlighting the variety in competencies and the complexity of the topic, not all themes were recognized by all respondents in the FGDs nor deemed equally relevant. Flexibility, cultural awareness and holistic perspective are examples of important benefits to work experience in LRS. CONCLUSION: Ps-GHTM bring their competencies to LRS and return to the Netherlands with additionally developed skills and knowledge. These may contribute to healthcare delivery in the Netherlands. This reciprocal value is an important factor for the sustainable development of global health. Identifying the competencies derived from work experience in LRS could give stakeholders insight into the added value of Ps-GHTM and partly help in refining the specialization program.

Assessing the cost-effectiveness of integrated case management of Neglected Tropical Diseases in Liberia.

BACKGROUND: In 2017, Liberia became one of the first countries in the African region to develop and implement a national strategy for integrated case management of Neglected Tropical Diseases (CM-NTDs), specifically Buruli ulcer, leprosy, lymphatic filariasis morbidities, and yaws. Implementing this plan moves the NTD program from many countries' fragmented (vertical) disease management. This study explores to what extent an integrated approach offers a cost-effective investment for national health systems. METHODS: This study is a mixed-method economic evaluation that explores the cost-effectiveness of the integrated CM-NTDs approach compared to the fragmented (vertical) disease management. Primary data were collected from two integrated intervention counties and two non-intervention counties to determine the relative cost-effectiveness of the integrated program model vs. fragmented (vertical) care. Data was sourced from the NTDs program annual budgets and financial reports for integrated CM-NTDs and Mass Drug Administration (MDA) to determine cost drivers and effectiveness. RESULTS: The total cost incurred by the integrated CM-NTD approach from 2017 to 2019 was US$ 789,856.30, with the highest percentage of costs for program staffing and motivation (41.8%), followed by operating costs (24.8%). In the two counties implementing fragmented (vertical) disease management, approximately US$ 325,000 was spent on the diagnosis of 84 persons and the treatment of twenty-four persons suffering from NTDs. While 2.5 times as much was spent in integrated counties, 9-10 times more patients were diagnosed and treated. CONCLUSIONS: The cost of a patient being diagnosed under the fragmented (vertical) implementation is five times higher than integrated CM-NTDs, and providing treatment is ten times as costly. Findings indicate that the integrated CM-NTDs strategy has achieved its primary objective of improved access to NTD services. The success of implementing an integrated CM-NTDs approach in Liberia, presented in this paper, demonstrates that NTD integration is a cost-minimizing solution.

A health-systems journey towards more people-centred care: lessons from neglected tropical disease programme integration in Liberia.

BACKGROUND: Neglected tropical diseases (NTDs) are associated with high levels of morbidity and disability as a result of stigma and social exclusion. To date, the management of NTDs has been largely biomedical. Consequently, ongoing policy and programme reform within the NTD community is demanding the development of more holistic disease management, disability and inclusion (DMDI) approaches. Simultaneously, integrated, people-centred health systems are increasingly viewed as essential to ensure the efficient, effective and sustainable attainment of Universal Health Coverage. Currently, there has been minimal consideration of the extent to which the development of holistic DMDI strategies are aligned to and can support the development of people-centred health systems. The Liberian NTD programme is at the forefront of trying to establish a more integrated, person-centred approach to the management of NTDs and provides a unique learning site for health systems decision makers to consider how shifts in vertical programme delivery can support overarching systems strengthening efforts that are designed to promote the attainment of health equity. METHODS: We use a qualitative case study approach to explore how policy and programme reform of the NTD programme in Liberia supports systems change to enable the development of integrated people-centred services. RESULTS: A cumulation of factors, catalysed by the shock to the health system presented by the Ebola epidemic, created a window of opportunity for policy change. However, programmatic change aimed at achieving person-centred practice was more challenging. Deep reliance on donor funding for health service delivery in Liberia limits the availability of flexible funding, and the ongoing funding prioritization towards specific disease conditions limits flexibility in health systems design that can shape more person-centred care. CONCLUSION: Sheikh et al.'s four key aspects of people centred health systems, that is, (1) putting peoples voices and needs first; (2) people centredness in service delivery; (3) relationships matter: health systems as social institutions; and (4) values drive people centred health systems, enable the illumination of varying push and pull factors that can facilitate or hinder the alignment of DMDI interventions with the development of people-centred health systems to support disease programme integration and the attainment of health equity.

Key Contributions by the Swiss Tropical and Public Health Institute Towards New and Better Drugs for Tropical Diseases.

Thanks to its expertise in clinical research, epidemiology, infectious diseases, microbiology, parasitology, public health, translational research and tropical medicine, coupled with deeply rooted partnerships with institutions in low- and middle-income countries (LMICs), the Swiss Tropical and Public Health Institute (Swiss TPH) has been a key contributor in many drug research and development consortia involving academia, pharma and product development partnerships. Our know-how of the maintenance of parasites and their life-cycles in the laboratory, plus our strong ties to research centres and disease control programme managers in LMICs with access to field sites and laboratories, have enabled systems for drug efficacy testing in vitro and in vivo, clinical research, and modelling to support the experimental approaches. Thus, Swiss TPH has made fundamental contributions towards the development of new drugs - and the better use of old drugs - for neglected tropical diseases and infectious diseases of poverty, such as Buruli ulcer, Chagas disease, food-borne trematodiasis (e.g. clonorchiasis, fascioliasis and opisthorchiasis), human African trypanosomiasis, leishmaniasis, malaria, schistosomiasis, soil-transmitted helminthiasis and tuberculosis. In this article, we show case the success stories of molecules to which Swiss TPH has made a substantial contribution regarding their use as anti-infective compounds with the ultimate aim to improve people's health and well-being.

A century of the Journal of Helminthology.

The Journal of Helminthology (JHL) was first published in 1923 and was originally created as a house journal of the London School of Hygiene and Tropical Medicine. The JHL was devised by its first Editor, Robert Leiper, to allow for rapid publication of results from the Department of Helminthology and its offshoot the Institute of Agricultural Parasitology. From this initial narrow focus the JHL has subsequently become not only internationally recognized but also retained its original emphasis on morphological, taxonomic and life cycle studies while embracing the emergence of new fields and technological advancements. The present review covers the historical development of the JHL over the last century from 1923 to 2023.

Membrane Technology for Rapid Point-of-Care Diagnostics for Parasitic Neglected Tropical Diseases.

Parasitic neglected tropical diseases (NTDs) affect over one billion people worldwide, with individuals from communities in low-socioeconomic areas being most at risk and suffering the most. Disease management programs are hindered by the lack of infrastructure and resources for clinical sample collection, storage, and transport and a dearth of sensitive diagnostic methods that are inexpensive as well as accurate. Many diagnostic tests and tools have been developed for the parasitic NTDs, but the collection and storage of clinical samples for molecular and immunological diagnosis can be expensive due to storage, transport, and reagent costs, making these procedures untenable in most areas of endemicity. The application of membrane technology, which involves the use of specific membranes for either sample collection and storage or diagnostic procedures, can streamline this process, allowing for long-term sample storage at room temperature. Membrane technology can be used in serology-based diagnostic assays and for nucleic acid purification prior to molecular analysis. This facilitates the development of relatively simple and rapid procedures, although some of these methods, mainly due to costs, lack accessibility in low-socioeconomic regions of endemicity. New immunological procedures and nucleic acid storage, purification, and diagnostics protocols that are simple, rapid, accurate, and cost-effective must be developed as countries progress control efforts toward the elimination of the parasitic NTDs.

Human Filariasis in Travelers and Migrants: A Retrospective 25-year Analysis at the Institute of Tropical Medicine, Antwerp, Belgium.

BACKGROUND: Information on human filariasis in international travelers is scarce. We describe the epidemiology, clinical presentation, and outcome of these infections in a reference travel clinic over the past decades. METHODS: We reviewed all cases of filariasis diagnosed at the Institute of Tropical Medicine, Antwerp, Belgium, from 1994 to 2018. Diagnosis was obtained by either parasitological methods (confirmed) or strict clinical case definitions (probable). We assessed the characteristics of cases at diagnosis and response to therapy within 3-12 months. RESULTS: A total of 320 patients (median age: 41 years; 71% males) were diagnosed with 327 filarial infections (Wuchereria bancrofti = 6, Onchocerca volvulus = 33, Loa loa = 150, Mansonella perstans = 130, unspecified species = 8). Diagnosis was confirmed in 213/320 (67%) patients. European long-term travelers accounted for 166 patients (52%) and visitors/migrants from tropical countries for another 110 (34%). Central Africa was the likely region of acquisition for 294 (92%) patients. The number of filariasis cases decreased from 21.5/year on average in the 1990s to 6.3/year in the past decade, when loiasis became predominant. Cases reported symptoms in >80% of all filarial infections but mansonellosis (45/123 single infections; 37%). Lymphatic filariasis and onchocerciasis cases responded well to conventional therapy. However, 30% of patients with loiasis and mansonellosis experienced treatment failure (with diethylcarbamazine and levamisole-mebendazole, respectively). CONCLUSIONS: The burden and species distribution of filariasis in travelers evolved in the past decades. Most presentations were symptomatic. Case management would benefit from more effective therapies for loiasis and mansonellosis.

Quantifying Population Burden and Effectiveness of Decentralized Surveillance Strategies for Skin-Presenting Neglected Tropical Diseases, Liberia.

We evaluated programmatic approaches for skin neglected tropical disease (NTD) surveillance and completed a robust estimation of the burden of skin NTDs endemic to West Africa (Buruli ulcer, leprosy, lymphatic filariasis morbidity, and yaws). In Maryland, Liberia, exhaustive case finding by community health workers of 56,285 persons across 92 clusters identified 3,241 suspected cases. A total of 236 skin NTDs (34.0 [95% CI 29.1-38.9]/10,000 persons) were confirmed by midlevel healthcare workers trained using a tailored program. Cases showed a focal and spatially heterogeneous distribution. This community health worker‒led approach showed a higher skin NTD burden than prevailing surveillance mechanisms, but also showed high (95.1%) and equitable population coverage. Specialized training and task-shifting of diagnoses to midlevel health workers led to reliable identification of skin NTDs, but reliability of individual diagnoses varied. This multifaceted evaluation of skin NTD surveillance strategies quantifies benefits and limitations of key approaches promoted by the 2030 NTD roadmap of the World Health Organization.

Uche Amazigo: neglected tropical diseases in the pandemic.

Uche Amazigo talks to Andreia Azevedo Soares about the impact of the pandemic on NTD-related activities and the prospects for regaining momentum on the global NTD agenda.

A framework for assessing the impact of disease treatment.

OBJECTIVES: To address ongoing pandemics and epidemics, policy makers need good data not only on the need for treatments but also on new interventions' impacts. We present a mathematical model of medicines' health consequences using disease surveillance data to inform health policy and scientific research that can be extended to address the current public health crisis. METHODS: The Global Health Impact index calculates the amount of mortality and morbidity averted by key medicines for malaria, TB, HIV/AIDS and several Neglected Tropical Diseases (NTDs) using data on outcomes in the absence of treatment, treatment effectiveness and access to needed treatment. Country-level data were extracted from data repositories maintained by the Global Burden of Disease study, Global Health Observatory, WHO, UNICEF and a review of the scientific literature. RESULTS: The index aggregates drug impact by country, disease, company and treatment regimen to identify the spatial and temporal patterns of treatment impact and can be extended across multiple diseases. Approximately 62 million life-years were saved by key drugs that target malaria, TB, HIV/AIDS and NTDs in our latest model year. Malaria and TB medicines together were responsible for alleviating 95% of this burden, while HIV/AIDS and NTD medicines contribute 4% and 1%, respectively. However, the burden of disease in the absence of treatment was nearly evenly distributed among malaria, TB and HIV/AIDS. CONCLUSIONS: A common framework that standardises health impact across diseases and their interventions can aid in identifying current shortcomings on a global scale.

Training and capacity building in medical statistics in Sub-Saharan Africa: Impact of the London School of Hygiene & Tropical Medicine MSc in Medical Statistics, 1969 to 2021.

Since its inception in 1969, the MSc in medical statistics program has placed a high priority on training students from Africa. In this article, we review how the program has shaped, and in turn been shaped by, two substantial capacity building initiatives: (a) a fellowship program, funded by the UK Medical Research Council, and run through the International Statistical Epidemiology Group at the LSHTM, and (b) the Sub-Saharan capacity building in Biostatistics (SSACAB) initiative, administered through the Developing Excellence in Leadership, Training and Science in Africa (DELTAS) program of the African Academy of Sciences. We reflect on the impact of both initiatives, and the implications for future work in this area.