Toward an open-access global database for mapping, control, and surveillance of neglected tropical diseases

Background

After many years of general neglect, interest has grown and efforts came under way for the mapping, control, surveillance, and eventual elimination of neglected tropical diseases (NTDs). Disease risk estimates are a key feature to target control interventions, and serve as a benchmark for monitoring and evaluation. What is currently missing is a georeferenced global database for NTDs providing open-access to the available survey data that is constantly updated and can be utilized by researchers and disease control managers to support other relevant stakeholders. We describe the steps taken toward the development of such a database that can be employed for spatial disease risk modeling and control of NTDs.

Methodology

With an emphasis on schistosomiasis in Africa, we systematically searched the literature (peer-reviewed journals and ‘grey literature’), contacted Ministries of Health and research institutions in schistosomiasis-endemic countries for location-specific prevalence data and survey details (e.g., study population, year of survey and diagnostic techniques). The data were extracted, georeferenced, and stored in a MySQL database with a web interface allowing free database access and data management.

Principal Findings

At the beginning of 2011, our database contained more than 12,000 georeferenced schistosomiasis survey locations from 35 African countries available under http://www.gntd.org. Currently, the database is expanded to a global repository, including a host of other NTDs, e.g. soil-transmitted helminthiasis and leishmaniasis.

Conclusions

An open-access, spatially explicit NTD database offers unique opportunities for disease risk modeling, targeting control interventions, disease monitoring, and surveillance. Moreover, it allows for detailed geostatistical analyses of disease distribution in space and time. With an initial focus on schistosomiasis in Africa, we demonstrate the proof-of-concept that the establishment and running of a global NTD database is feasible and should be expanded without delay.     

Community perceptions and acceptability of mass drug administration for the control of neglected tropical diseases in Asia-Pacific countries: A systematic scoping review of qualitative research

BackgroundPreventative chemotherapy and mass drug administration have been identified as effective strategies for the prevention, treatment, control and elimination of several NTDs in the Asia-Pacific region. Qualitative research can provide in-depth insight into the social dynamics and processes underlying effective implementation of and adherence to mass drug administration programs. This scoping review examines published qualitative literature to examine factors influencing community perceptions and acceptability of mass drug administration approaches to control NTDs in the Asia-Pacific region.MethodologyTwenty-four peer reviewed published papers reporting qualitative data from community members and stakeholders engaged in the implementation of mass drug administration programs were identified as eligible for inclusion.FindingsThis systematic scoping review presents available data from studies focussing on lymphatic filariasis, soil-transmitted helminths and scabies in eight national settings (India, Indonesia, Philippines, Bangladesh, Laos, American Samoa, Papua New Guinea, Fiji). The review highlights the profoundly social nature of individual, interpersonal and institutional influences on community perceptions of willingness to participate in mass drug administration programs for control of neglected tropical diseases (NTD). Future NTD research and control efforts would benefit from a stronger qualitative social science lens to mass drug administration implementation, a commitment to understanding and addressing the social and structural determinants of NTDs and NTD control in complex settings, and efforts to engage local communities as equal partners and experts in the co-design of mass drug administration and other efforts to prevent, treat, control and eliminate NTDs.ConclusionFor many countries in the Asia-Pacific region, the “low hanging fruit has been picked” in terms of where mass drug administration has worked and transmission has been stopped. The settings that remain–such as remote areas of Fiji and Papua New Guinea, or large, highly populated, multi-cultural urban settings in India and Indonesia–present huge challenges going forward.     

Modeling transmission dynamics and control of vector-borne neglected tropical diseases

Neglected tropical diseases affect more than one billion people worldwide. The populations most impacted by such diseases are typically the most resource-limited. Mathematical modeling of disease transmission and cost-effectiveness analyses can play a central role in maximizing the utility of limited resources for neglected tropical diseases. We review the contributions that mathematical modeling has made to optimizing intervention strategies of vector-borne neglected diseases. We propose directions forward in the modeling of these diseases, including integrating new knowledge of vector and pathogen ecology, incorporating evolutionary responses to interventions, and expanding the scope of sensitivity analysis in order to achieve robust results.     

One Health and surveillance of zoonotic tuberculosis in selected low-income,middle-income and high-income countries: A systematic review

BackgroundLittle is known about zoonotic tuberculosis (zTB) due to Mycobacterium bovis burden across the globe. The aim of this study was to describe zTB surveillance programs in selected WHO signatory countries and to assess the relationship of the disease with the country’s income level and the risk of M. bovis transmission.MethodsWe searched the main articles databases and grey literature for guide documents published between 1980 and 2019. For inclusion, the articles and guide documents had to be in English, French, Portuguese, Spanish, or Italian. Only original articles and narrative and systematic reviews were accepted and the guide documents were required to be available on official websites. We excluded articles that did not focus on epidemiology, control and surveillance. We used bovine TB cases in livestock and wildlife populations as a proxy for the country’s risk of zTB using data from the World Organization for Animal Health (OIE) published from 2015 to 2018. Countries were classified according to income level (World Bank’s classification) and strength of zTB surveillance. The study was registered in PROSPERO under number CRD42018090603.FindingsWe included 13 articles and 208 guide documents including data from 119/194 countries (61.3%). We found a lack of surveillance data about zTB in over half (89.9%) of the 119 WHO signatory countries. Most surveillance systems perform passive surveillance and are not integrated into the One Health perspective, which was operating in 4/119 (3.4%) countries, all high-income. Many of these countries (71/119, 59.7%) have M. bovis circulating in their cattle herds, but only ~10% of them have implemented zTB surveillance activities.InterpretationOur findings highlight weaknesses in zTB surveillance worldwide, with a consequent lack of information that could support an adequate understanding of disease burden, especially in countries at major risk for M. bovis transmission. To meet this challenge, efforts will be needed to promote intersectoral policies, implementing the One Health strategy.     

Nudge strategies for behavior-based prevention and control of neglected tropical diseases: A scoping review and ethical assessment

BackgroundNudging, a strategy that uses subtle stimuli to direct people’s behavior, has recently been included as an effective and low-cost behavior change strategy in low- and middle- income countries (LMIC), targeting behavior-based prevention and control of neglected tropical diseases (NTDs). The present scoping review aims to provide a timely overview of how nudge interventions have been applied within this field. In addition, the review proposes a framework for the ethical consideration of nudges for NTD prevention and control, or more broadly global health promotion.MethodsA comprehensive search was performed in several databases: MEDLINE, PsycINFO, and Embase (Ovid), Web of Science Core Collection, CINAHL, ERIC and Econ.Lit (EBSCO), as well as registered trials and reviews in CENTRAL and PROSPERO to identify ongoing or unpublished studies. Additionally, studies were included through a handpicked search on websites of governmental nudge units and global health or development organizations.ResultsThis scoping review identified 33 relevant studies, with only two studies targeting NTDs in particular, resulting in a total of 67 nudge strategies. Most nudges targeted handwashing behavior and were focused on general health practices rather than targeting a specific disease. The most common nudge strategies were those targeting decision assistance, such as facilitating commitment and reminder actions. The majority of nudges were of moderate to high ethical standards, with the highest standards being those that had the most immediate and significant health benefits, and those implemented by agents in a trust relationship with the target audience.ConclusionThree key recommendations should inform research investigating nudge strategies in global health promotion in general. Firstly, future efforts should investigate the different opportunities that nudges present for targeting NTDs in particular, rather than relying solely on integrated health promotion approaches. Secondly, to apply robust study designs including rigorous process and impact evaluation which allow for a better understanding of ‘what works’ and ‘how it works’. Finally, to consider the ethical implications of implementing nudge strategies, specifically in LMIC.     

Rickettsial infections: A blind spot in our view of neglected tropical diseases

Rickettsial diseases are a group of vector-borne bacterial infections that cause acute febrile illness with potentially severe or fatal complications. These vector-borne diseases are prevalent in tropical and subtropical regions worldwide and disproportionately affect poorer communities but are scientifically underrecognized. Despite this, they are not included in the World Health Organization’s list of neglected tropical diseases nor were they mentioned in Peter Hotez’s recent reflections on “What constitutes a neglected tropical disease?” in PLOS Neglected Tropical Diseases [1]. Here we present the case that rickettsial infections, as an overlooked cause of morbidity, mortality, and economic losses in marginalized populations, should be recognized as neglected tropical diseases. We describe how this oversight is the result of a number of factors and how it negatively impacts patient outcomes. We then propose measures to address the neglect of rickettsial infections in both scientific research and public health interventions.     

A blueprint for success: integration of neglected tropical disease control programmes

The rapid expansion of chemotherapy-based control programmes for neglected tropical diseases has been catalysed by funding from the Bill and Melinda Gates Foundation, donations of several drugs from pharmaceutical manufacturers, and the reduced price of the drug praziquantel. Focussing on lymphatic filariasis, schistosomiasis and soil-transmitted helminthiasis, we review here the progress made to date with the implementation and integration of large-scale control programmes. Unresolved issues include a means for rapid identification of communities at highest risk of co-morbidity, cost-effective approaches for integrating the technical interventions into setting-specific packages, and determination of the most appropriate and sustainable delivery systems.     

Resisting control of neglected tropical diseases: dilemmas in the mass treatment of schistosomiasis and soil-transmitted helminths in north-west Uganda

A strong case has recently been made by academics and policymakers to develop national programmes for the integrated control of Africa's 'neglected tropical diseases'. Uganda was the first country to develop a programme for the integrated control of two of these diseases: schistosomiasis and soil-transmitted helminths. This paper discusses social responses to the programme in Panyimur, north-west Uganda. It shows that adults are increasingly rejecting free treatment. Resistance is attributed to a subjective fear of side-effects; divergence between biomedical and local understandings of schistosomiasis/bilharzia; as well as inappropriate and inadequate health education. In addition, the current procedures for distributing drugs at a district level are problematic. Additional research was carried out in neighbouring areas to explore the generalizability of findings. Comparable problems have arisen. It is concluded that the national programme will not fulfil its stated objectives of establishing a local demand for mass treatment unless it can establish more effective delivery strategies and promote behavioural change in socially appropriate ways. To do so will require new approaches to social, economic and political aspects of distribution. There are reasons why populations infected with the 'neglected tropical diseases' are themselves neglected. Those reasons cannot just be wished away.     

A research agenda for helminth diseases of humans: health research and capacity building in disease-endemic countries for helminthiases control

Capacity building in health research generally, and helminthiasis research particularly, is pivotal to the implementation of the research and development agenda for the control and elimination of human helminthiases that has been proposed thematically in the preceding reviews of this collection. Since helminth infections affect human populations particularly in marginalised and low-income regions of the world, they belong to the group of poverty-related infectious diseases, and their alleviation through research, policy, and practice is a sine qua non condition for the achievement of the United Nations Millennium Development Goals. Current efforts supporting research capacity building specifically for the control of helminthiases have been devised and funded, almost in their entirety, by international donor agencies, major funding bodies, and academic institutions from the developed world, contributing to the creation of (not always equitable) North-South "partnerships". There is an urgent need to shift this paradigm in disease-endemic countries (DECs) by refocusing political will, and harnessing unshakeable commitment by the countries' governments, towards health research and capacity building policies to ensure long-term investment in combating and sustaining the control and eventual elimination of infectious diseases of poverty. The Disease Reference Group on Helminth Infections (DRG4), established in 2009 by the Special Programme for Research and Training in Tropical Diseases (TDR), was given the mandate to review helminthiases research and identify research priorities and gaps. This paper discusses the challenges confronting capacity building for parasitic disease research in DECs, describes current capacity building strategies with particular reference to neglected tropical diseases and human helminthiases, and outlines recommendations to redress the balance of alliances and partnerships for health research between the developed countries of the "North" and the developing countries of the "South". We argue that investing in South-South collaborative research policies and capacity is as important as their North-South counterparts and is essential for scaled-up and improved control of helminthic diseases and ultimately for regional elimination.