Ten failings in global neglected tropical diseases control

Scabies in the Amhara region of northern Ethiopia: a cross-sectional study of prevalence, determinants, clinical presentation and community knowledge

BACKGROUND

The WHO aims to prevent, eliminate or control neglected tropical diseases, including scabies, by 2030. However, limited epidemiological data presented a challenge to control efforts, especially in high burden countries. There was a major scabies outbreak in northern Ethiopia starting in 2015 and prevalence has since increased across much of the country.

OBJECTIVE

To estimate scabies prevalence, identify its predictors, and assess community perception of, and knowledge about, the infestation.

DESIGN

Population-based cross-sectional study.

STUDY SETTING

Ayu Guagusa district, Amhara region, northern Ethiopia.

PARTICIPANTS

1437 people who were members of 381 randomly selected households participated in the study. Five trained mid-level health workers clinically diagnosed people with scabies.

OUTCOME MEASURES

Clinically diagnosed scabies infestation.

DATA ANALYSIS

Multi-level logistic regression models were fitted to adjust for individual and household-level confounding variables, and identify predictors of scabies infestation.

RESULTS

Scabies prevalence was 13.4% (95% CI 11.8 to 15.5). Households of more than five people (adjusted OR (aOR)=3.5, 95% CI 1.2 to 10.2) were associated with increased odds of developing scabies, however, females had lower odds (aOR=0.5 95% CI 0.3 to 0.8). Scabietic lesions most frequently involved the trunk (62.0%), and vesicles were the most common types of lesions (67.7%). Two-thirds of adult study participants had heard about scabies and most obtained scabies related information from informal sources. Only 32% of cases sought care for scabies from any source.

CONCLUSION

Scabies prevalence was high, signifying the need for community-based control interventions. Host density and sex were important predictors of scabies. Despite the favourable attitude toward the effectiveness of scabies treatment, healthcare seeking was low.

Global burden and trends of the Entamoeba infection-associated diseases from 1990 to 2019: An observational trend study

BACKGROUND

Entamoeba infection-associated diseases (EIADs) in humans are a worldwide public health problem, but there is a lack of a global picture of EIADs, which is vital to prevention and control.

METHODS

We applied 2019 Global Burden of Disease (GBD) data collected from multiple sources at global, national and regional levels. The disability-adjusted life years (DALYs) with corresponding 95% uncertainty intervals (95% UIs) were extracted as the main measure of the burden of EIADs. The Joinpoint regression model was used to estimate the trends of age-standardised DALY rates by age, sex, geographical region, and sociodemographic index (SDI). Besides, a generalized linear model was conducted to analyze the influence of sociodemographic factors on the DALY rate of EIADs.

RESULTS

In 2019, there were 2,539,799 (95% UI 850,865-6,186,972) DALY cases attributable to Entamoeba infection, and the global age-standardised DALY rate of EIADs was 36.77/100,000 (95% UI: 12.03-90.49). Although over the past 30 years, the age-standardised DALY rate of EIADs presented significantly declining trends [average annual percent change (AAPC) = -3.79%, 95% CI: -4.05% - -3.53%], it has remained a heavy burden among the age group of <5 years (257.43/100,000, 95% UI: 67.73-676.78) and the low SDI regions (100.47/100,000, 95% UI: 32.27-249.09). The age-standardized DALY rate in high-income North America and Australia had an increasing trend (AAPC = 0.38%, 95% CI: 0.47% - 0.28% and 0.38%, 95% CI: 0.46% - 0.29%, respectively). Furthermore, the DALY rates in high SDI regions showed statistically significant increasing trends among the age groups of 14-49, 50-69 years and 70+ years, with AAPCs of 1.01% (95% CI: 0.87% - 1.15%), 1.58% (95% CI: 1.43% - 1.73%), and 2.93% (95% CI: 2.58% - 3.29%), respectively.

CONCLUSIONS

Over the past 30 years, the burden of EIADs has declined significantly. However, it has still caused a high burden in the low SDI regions and the age group of <5 years. At the same time, in adults and the elderly of the high SDI regions, the increasing trends of Entamoeba infection-associated burden should also be given more attention.

Centrin-deficient Leishmania mexicana confers protection against New World cutaneous leishmaniasis

Leishmaniasis is a neglected protozoan disease affecting over 12 million people globally with no approved vaccines for human use. New World cutaneous leishmaniasis (CL) caused by L. mexicana is characterized by the development of chronic non-healing skin lesions. Using the CRISPR/Cas9 technique, we have generated live attenuated centrin knockout L. mexicana (LmexCen^-/-) parasites. Centrin is a cytoskeletal protein important for cellular division in eukaryotes and, in Leishmania, is required only for intracellular amastigote replication. We have investigated the safety and immunogenicity characteristics of LmexCen^-/- parasites by evaluating their survival and the cytokine production in bone-marrow-derived macrophages (BMDMs) and dendritic cells (BMDCs) in vitro. Our data shows that LmexCen^-/- amastigotes present a growth defect, which results in significantly lower parasitic burdens and increased protective cytokine production in infected BMDMs and BMDCs, compared to the wild type (WT) parasites. We have also determined the safety and efficacy of LmexCen^-/- in vivo using experimental murine models of L. mexicana. We demonstrate that LmexCen^-/- parasites are safe and do not cause lesions in susceptible mouse models. Immunization with LmexCen^-/- is also efficacious against challenge with WT L. mexicana parasites in genetically different BALB/c and C57BL/6 mouse models. Vaccinated mice did not develop cutaneous lesions, displayed protective immunity, and showed significantly lower parasitic burdens at the infection site and draining lymph nodes compared to the control group. Overall, we demonstrate that LmexCen^-/- parasites are safe and efficacious against New World cutaneous leishmaniasis in pre-clinical models.

From infection to vaccination: reviewing the global burden, history of vaccine development, and recurring challenges in global leishmaniasis protection

INTRODUCTION

Leishmaniasis is a major public health problem and the second most lethal parasitic disease in the world due to the lack of effective treatments and vaccines. Even when not lethal, leishmaniasis significantly affects individuals and communities through life-long disabilities, psycho-sociological trauma, poverty, and gender disparity in treatment.

AREAS COVERED

This review discusses the most relevant and recent research available on Pubmed and GoogleScholar highlighting leishmaniasis' global impact, pathogenesis, treatment options, and lack of effective control strategies. An effective vaccine is necessary to prevent morbidity and mortality, lower health care costs, and reduce the economic burden of leishmaniasis for endemic low- and middle-income countries. Since there are several forms of leishmaniasis, a pan-Leishmania vaccine without geographical restrictions is needed. This review also focuses on recent advances and common challenges in developing prophylactic strategies against leishmaniasis.

EXPERT OPINION

Despite advances in pre-clinical vaccine research, approval of a human leishmaniasis vaccine still faces major challenges - including manufacturing of candidate vaccines under Good Manufacturing Practices, developing well-designed clinical trials suitable in endemic countries, and defined correlates of protection. In addition, there is a need to explore Challenge Human Infection Model to avoid large trials because of fluctuating incidence and prevalence of leishmanasis.

​US Tropical Disease Priority Review Vouchers: Lessons In Promoting Drug Development And Access

The COVID-19 global pandemic has devastated lives and economies. It has served as a reminder of how critical it is to invest in preventing and treating infectious diseases. Until the COVID-19 pandemic, the largest US government-sponsored reward for infectious disease drug and vaccine development was the Tropical Disease Priority Review Voucher program. Under this program, the Food and Drug Administration awards a priority review voucher to the sponsor of a new drug or vaccine for tropical infectious diseases. The voucher then can be exchanged for the faster review of one drug. We provide case studies for tropical disease voucher recipients between 2007 and 2018, examine the effects of the voucher program on product innovation and access, and recommend that policy makers protect the voucher program while creating complementary incentives.

An Overview on Target-Based Drug Design against Kinetoplastid Protozoan Infections: Human African Trypanosomiasis, Chagas Disease and Leishmaniases

The protozoan diseases Human African Trypanosomiasis (HAT), Chagas disease (CD), and leishmaniases span worldwide and therefore their impact is a universal concern. The present regimen against kinetoplastid protozoan infections is poor and insufficient. Target-based design expands the horizon of drug design and development and offers novel chemical entities and potential drug candidates to the therapeutic arsenal against the aforementioned neglected diseases. In this review, we report the most promising targets of the main kinetoplastid parasites, as well as their corresponding inhibitors. This overview is part of the Special Issue, entitled "Advances of Medicinal Chemistry against Kinetoplastid Protozoa (Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp.) Infections: Drug Design, Synthesis and Pharmacology".

Implications of global environmental change for the burden of snakebite

Snakebite envenoming is a set of intoxication diseases that disproportionately affect people of poor socioeconomic backgrounds in tropical countries. As it is highly dependent on the environment its burden is expected to shift spatially with global anthropogenic environmental (climate, land use) and demographic change. The mechanisms underlying the changes to snakebite epidemiology are related to factors of snakes and humans. The distribution and abundance of snakes are expected to change with global warming via their thermal tolerance, while rainfall may affect the timing of key activities like feeding and reproduction. Human population growth is the primary cause of land-use change, which may impact snakes at smaller spatial scales than climate via habitat and biodiversity loss (e.g. prey availability). Human populations, on the other hand, could experience novel patterns and morbidity of snakebite envenoming, both as a result of snake responses to environmental change and due to the development of agricultural adaptations to climate change, socioeconomic and cultural changes, development and availability of better antivenoms, personal protective equipment, and mechanization of agriculture that mediate risk of encounters with snakes and their outcomes. The likely global effects of environmental and demographic change are thus context-dependent and could encompass both increasing and or snakebite burden (incidence, number of cases or morbidity), exposing new populations to snakes in temperate areas due to “tropicalization”, or by land use change-induced snake biodiversity loss, respectively. Tackling global change requires drastic measures to ensure large-scale ecosystem functionality. However, as ecosystems represent the main source of venomous snakes their conservation should be accompanied by comprehensive public health campaigns. The challenges associated with the joint efforts of biodiversity conservation and public health professionals should be considered in the global sustainability agenda in a wider context that applies to neglected tropical and zoonotic and emerging diseases.

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Distribution and abundance of snakes are expected to be affected by climate change.

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Land-use change may also impact snakes but at smaller spatial scales than climate.

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Human populations could experience novel patterns and morbidity of snakebite.

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Reducing snakebite should be accompanied by actions that protect snake diversity.

The process of building the priority of neglected tropical diseases: A global policy analysis

The global burden attributed to Neglected Tropical Diseases (NTDs) is 47.9 million Disability-Adjusted Life Years (DALYs). These diseases predominantly affect disadvantaged populations. Priority for NTDs has grown in recent years, which is observed by their inclusion in the sustainable development goals (SDGs). This study analyzed the process that allowed these diseases to be included on the global health policy agenda. This global policy analysis used the Shiffman and Smith framework to understand the determinants of global health political priority for NTDs. The framework comprises four categories: actor power, ideas, political contexts, and issue characteristics. Global documents and World Health Assembly (WHA) resolutions were examined, key-informant interviews were conducted, and academic publications were reviewed to understand the four categories that comprise the framework. A total of 37 global policy documents, 15 WHA resolutions, and 38 academic publications were examined. Twelve semi-structured interviews were conducted with individuals representing different sectors within the NTD community who have been involved in raising the priority of these diseases. This study found that several factors helped better position NTDs in the global health agenda. These include the leadership of actors that mobilized the global health community, the creation of a label combining these diseases as a group to represent a larger disease burden, the presence of mechanisms aligning the NTD community, and the agreement on ways to present the NTD burden and potential solutions. The process of building the priority of NTDs in the global health agenda shows that several determinants led to positive outcomes, but these diseases continue to have low priority at the global level which requires the implementation of actions to increase their global priority. These include sustaining the commitment of current actors and engaging new ones; increasing the attention given to diseases formerly categorized as "tool-deficient", including zoonotic NTDs; continue leveraging on policy windows and creating favorable policy moments to sustain commitment, as well as setting realistic targets. Findings from this study can help develop strategies to build the momentum and drive actions to implement the goals of the new Roadmap for NTDs in the pathway to universal health coverage (UHC) and sustainable development.

Computer-Aided Design, Synthesis, and Antiviral Evaluation of Novel Acrylamides as Potential Inhibitors of E3-E2-E1 Glycoproteins Complex from Chikungunya Virus

Chikungunya virus (CHIKV) causes an infectious disease characterized by inflammation and pain of the musculoskeletal tissues accompanied by swelling in the joints and cartilage damage. Currently, there are no licensed vaccines or chemotherapeutic agents to prevent or treat CHIKV infections. In this context, our research aimed to explore the potential in vitro anti-CHIKV activity of acrylamide derivatives. In silico methods were applied to 132 Michael's acceptors toward the six most important biological targets from CHIKV. Subsequently, the ten most promising acrylamides were selected and synthesized. From the cytotoxicity MTT assay, we verified that LQM330, 334, and 336 demonstrate high cell viability at 40 µM. Moreover, these derivatives exhibited anti-CHIKV activities, highlighting the compound LQM334 which exhibited an inhibition value of 81%. Thus, docking simulations were performed to suggest a potential CHIKV-target for LQM334. It was observed that the LQM334 has a high affinity towards the E3-E2-E1 glycoproteins complex. Moreover, LQM334 reduced the percentage of CHIKV-positive cells from 74.07 to 0.88%, 48h post-treatment on intracellular flow cytometry staining. In conclusion, all virtual simulations corroborated with experimental results, and LQM334 could be used as a promising anti-CHIKV scaffold for designing new drugs in the future.

Social marketing interventions for the prevention and control of neglected tropical diseases: A systematic review

BACKGROUND

Social marketing is an approach to behavior change that contributes to disease prevention and control. This study aimed to understand how social marketing interventions have addressed neglected tropical diseases (NTDs). It examined the characteristics, breadth of coverage, and outcomes of social marketing interventions focused on the prevention and control of these diseases.

METHODOLOGY/PRINCIPAL FINDINGS

Studies published in any language between January 1971 and April 2017, targeting at least one of the 17 NTDs prioritized in the World Health Organization (WHO) NTD Roadmap were considered. Included studies had interventions that applied both, at least one core social marketing concept, "social behavioral influence", and one social marketing technique, "integrated intervention mix", described in the Hierarchical Model of Social Marketing. This review is registered with PROSPERO CRD42017063858. Twenty interventions, addressing eight NTDs, met the inclusion criteria. They focused on behaviors related to four of the five WHO public health strategies for NTDs. Most interventions incorporated the concepts "relationship building" and "public / people orientation focus", and the technique "insight-driven segmentation". All the interventions reported changing behavioral determinants such as knowledge, 19 reported behavior change, and four influenced health outcomes.

CONCLUSION/SIGNIFICANCE

Evidence from this study shows that social marketing has been successfully used to address behaviors related to most of the five public health strategic interventions for NTDs recommended by the WHO. It is suggested that social marketing interventions for the prevention and control of NTDs be grounded on an understanding of the audience and adapted to the contexts intervened. Building stakeholder relationships as early as possible, and involving the publics could help in reaching NTD outcomes. Elements of the intervention mix should be integrated and mutually supportive. Incorporating health education and capacity building, as well as being culturally appropriate, is also relevant. It is recommended that ongoing discussions to formulate the targets and milestones of the new global Roadmap for NTDs integrate social marketing as an approach to overcome these diseases.

Case Report: Lower Gastrointestinal Bleeding due to Entamoeba histolytica Detected Early by Multiplex PCR: Case Report and Review of the Laboratory Diagnosis of Amebiasis

We report a case of Entamoeba histolytica infection in a young man who presented with cerebral infarction and shortly after admission developed bloody diarrhea with fever. A rapid diagnosis of severe E. histolytica colitis was established through the use of a multiplex polymerase chain reaction enteropathogen stool panel. This result was unexpected in a patient native to the United States without known risk factors for amebiasis and negative stool microscopy examination for ova and parasites. Rapid diagnosis allowed prompt initiation of appropriate anti-amebic therapy and ultimately a good outcome in a condition that otherwise carries high morbidity and fatality.

Drug discovery technologies: Caenorhabditis elegans as a model for anthelmintic therapeutics

Helminthiasis is one of the gravest problems worldwide. There is a growing concern on less available anthelmintics and the emergence of resistance creating a major threat to human and livestock health resources. Novel and broad-spectrum anthelmintics are urgently needed. The free-living nematode Caenorhabditis elegans could address this issue through automated high-throughput technologies for the screening of large chemical libraries. This review discusses the strong advantages and limitations for using C elegans as a screening method for anthelmintic drug discovery. C elegans is the best model available for the validation of novel effective drugs in treating most, if not all, helminth infections, and for the elucidation the mode of action of anthelmintic candidates. This review also focuses on available technologies in the discovery of anthelmintics published over the last 15 years with particular attention to high-throughput technologies over conventional screens. On the other hand, this review highlights how combinatorial and nanomedicine strategies could prolong the use of anthelmintics and control resistance problems.

Nanocarriers for effective delivery of benznidazole and nifurtimox in the treatment of chagas disease: A review

Neglected tropical diseases (NTDs) constitute a group of infectious diseases prevalent in countries with tropical and subtropical climate that affect the poorest individuals and produce high chronic disability associated with serious problems for the health system and socioeconomic development. Chagas disease or American trypanosomiasis is included on the NTDs list. However, even though this disease affects more than 10 million people, mostly in Latin America, causing the death of over 10,000 people every year, only two drugs are approved for its treatment, benznidazole and nifurtimox. These antiparasitic agents were developed almost half a century ago and present several biopharmaceutical disadvantages such as low aqueous solubility and permeability limiting their bioavailability. In addition, both therapeutic agents are available only as tablets and a liquid pediatric formulation is still lacking. Therefore, novel pharmaceutical strategies to optimize the pharmacotherapy of Chagas disease are urgently required. In this regard, nanotechnological approaches may be a crucial alternative for the delivery of both drugs ensuring an effective pharmacotherapy although the successful bench-to-bedside translation remains a major challenge. The present work reviews in detail the formulation and in-vitro/in-vivo analysis of different nanoformulations of nifurtimox and benznidazole in order to enhance their solubility, dissolution, bioavailability and trypanocidal activity.

Home improvement and system-based health promotion for sustainable prevention of Chagas disease: A qualitative study

BACKGROUND

Human transmission of Chagas disease (CD) most commonly occurs in domiciliary spaces where triatomines remain hidden to feed on blood sources during inhabitants' sleep. Similar to other neglected tropical diseases (NTDs), sustainable control of CD requires attention to the structural conditions of life of populations at risk, in this case, the conditions of their living environments. Considering socio-cultural and political dynamics involved in dwellings' construction, this study aimed to explore social factors that contribute or limit sustainability of CD's prevention models focused on home improvement.

METHODS AND MAIN FINDINGS

Using Healthy Homes for Healthy Living (HHHL)-a health promotion strategy focused on improvement of living environments and system-based health promotion-as a reference, a qualitative study was conducted. Research participants were selected from three rural communities of a CD endemic region in southern Ecuador involved in HHHL's refurbishment and reconstruction interventions between 2013 and 2016. Folowing an ethnographic approach, data were collected through interviews, participant observation, informal conversations and document analysis. Our results indicate that the HHHL model addressed risk factors for CD at the household level, while simultaneously promoting wellbeing at emotional, economic and social levels in local communities. We argue that sustainability of the CD prevention model proposed by HHHL is enhanced by the confluence of three factors: systemic improvement of families' quality of life, perceived usefulness of control measures, and flexibility to adapt to emerging dynamics of the context.

CONCLUSION

HHHL's proposed home improvement, facilitated through system-based rather than disease specific health promotion processes, enhances agency in populations at risk and facilitates community partnerships forged around CD prevention. Although an independent analysis of cost-effectiveness is recommended, structural poverty experienced by local families is still the most important factor to consider when evaluating the sustainability and scalability of this model.

Emerging Resistance of Neglected Tropical Diseases: A Scoping Review of the Literature

Background: Antimicrobial resistance (AMR) is a global public health threat with the potential to cause millions of deaths. There has been a tremendous increase in the use of antimicrobials, stemming from preventive chemotherapy elimination and control programs addressing neglected tropical diseases (NTDs). This study aims to identify the frequency of drug resistance for 11 major NTDs and 20 treatment drugs within a specific period by systematically analyzing the study design, socio-demographic factors, resistance, and countries of relevant studies. Methods: Adhering to PRISMA guidelines, we performed systematic reviews of the major 11 NTDs to identify publications on drug resistance between 2000 and 2016. A quality assessment tool adapted for evaluating observational and experimental studies was applied to assess the quality of eligible studies. Results: One of the major findings is that six NTDs have information on drug resistance, namely human African trypanosomiasis, leishmaniasis, onchocerciasis, schistosomiasis, soil-transmitted helminths, and trachoma. Many studies recorded resistance due to diagnostic tests, and few studies indicated clinical resistance. Although most studies were performed in Africa where there is the occurrence of several NTDs, there was no link between disease burden and locations of study. Conclusions: Based on this study we deduce that monitoring and surveillance systems need to be strengthened to enable the early detection of AMR and the mitigation of its global spread.

Nanoparticulate drug delivery systems for the treatment of neglected tropical protozoan diseases

Neglected Tropical Diseases (NTDs) comprise of a group of seventeen infectious conditions endemic in many developing countries. Among these diseases are three of protozoan origin, namely leishmaniasis, Chagas disease, and African trypanosomiasis, caused by the parasites Leishmania spp., Trypanosoma cruzi, and Trypanosoma brucei respectively. These diseases have their own unique challenges which are associated with the development of effective prevention and treatment methods. Collectively, these parasitic diseases cause more deaths worldwide than all other NTDs combined. Moreover, many current therapies for these diseases are limited in their efficacy, possessing harmful or potentially fatal side effects at therapeutic doses. It is therefore imperative that new treatment strategies for these parasitic diseases are developed. Nanoparticulate drug delivery systems have emerged as a promising area of research in the therapy and prevention of NTDs. These delivery systems provide novel mechanisms for targeted drug delivery within the host, maximizing therapeutic effects while minimizing systemic side effects. Currently approved drugs may also be repackaged using these delivery systems, allowing for their potential use in NTDs of protozoan origin. Current research on these novel delivery systems has provided insight into possible indications, with evidence demonstrating their improved ability to specifically target pathogens, penetrate barriers within the host, and reduce toxicity with lower dose regimens. In this review, we will examine current research on these delivery systems, focusing on applications in the treatment of leishmaniasis, Chagas disease, and African trypanosomiasis. Nanoparticulate systems present a unique therapeutic alternative through the repositioning of existing medications and directed drug delivery.

High Throughput and Computational Repurposing for Neglected Diseases

Purpose

Neglected tropical diseases (NTDs) represent are a heterogeneous group of communicable diseases that are found within the poorest populations of the world. There are 23 NTDs that have been prioritized by the World Health Organization, which are endemic in 149 countries and affect more than 1.4 billion people, costing these developing economies billions of dollars annually. The NTDs result from four different causative pathogens: protozoa, bacteria, helminth and virus. The majority of the diseases lack effective treatments. Therefore, new therapeutics for NTDs are desperately needed.

Methods

We describe various high throughput screening and computational approaches that have been performed in recent years. We have collated the molecules identified in these studies and calculated molecular properties.

Results

Numerous global repurposing efforts have yielded some promising compounds for various neglected tropical diseases. These compounds when analyzed as one would expect appear drug-like. Several large datasets are also now in the public domain and this enables machine learning models to be constructed that then facilitate the discovery of new molecules for these pathogens.

Conclusions

In the space of a few years many groups have either performed experimental or computational repurposing high throughput screens against neglected diseases. These have identified compounds which in many cases are already approved drugs. Such approaches perhaps offer a more efficient way to develop treatments which are generally not a focus for global pharmaceutical companies because of the economics or the lack of a viable market. Other diseases could perhaps benefit from these repurposing approaches.

Electronic supplementary material

The online version of this article (10.1007/s11095-018-2558-3) contains supplementary material, which is available to authorized users.

Modeling liver fluke transmission in northeast Thailand: Impacts of development, hydrology, and control

Human infection with the Southeast Asian liver fluke Opisthorchis viverrini and liver fluke-associated cholangiocarcinoma cause significant disease burden in Southeast Asia. While there has been considerable work to understand liver fluke pathology and to reduce infection prevalence, there remains a limited understanding of the environmental determinants of parasite transmission dynamics to inform treatment and control programs. A particular setting where targeted control efforts have taken place is the Lawa Lake complex in northeast Thailand. Here, we describe the recent history of host infections, as well as the hydrologic characteristics of this floodplain ecosystem that influence the extent of snail habitat and fish mobility and the transport of human waste and parasite cercariae. Using mathematical modeling, we outline a framework for reconstructing environmental transmission of O. viverrini over the course of the Lawa Project control program from its inception in 2008 until 2016, using locally acquired but fragmentary longitudinal infection data for both humans and environmental hosts. The role of water flow in facilitating movement between snail, fish, human, and reservoir hosts is a particular focus with respect to its relevant scales and its impact on success of interventions. In this setting, we argue that an understanding of the key environmental drivers of disease transmission processes is central to the effectiveness of any environmental intervention.

Host-Directed Drug Therapies for Neglected Tropical Diseases Caused by Protozoan Parasites

The neglected tropical diseases (NTDs) caused by protozoan parasites are responsible for significant morbidity and mortality worldwide. Current treatments using anti-parasitic drugs are toxic and prolonged with poor patient compliance. In addition, emergence of drug-resistant parasites is increasing worldwide. Hence, there is a need for safer and better therapeutics for these infections. Host-directed therapy using drugs that target host pathways required for pathogen survival or its clearance is a promising approach for treating infections. This review will give a summary of the current status and advances of host-targeted therapies for treating NTDs caused by protozoa.

The global fight to develop antipoverty vaccines in the anti-vaccine era

Antipoverty vaccines are the vaccines targeting a group of approximately 20 neglected tropical diseases (NTDs), as currently defined by the World Health Organization (WHO). The “antipoverty” moniker refers to the fact that NTDs trap populations in poverty due to their chronic and deleterious effects on child intellect and worker productivity. Therefore, NTD vaccines can be expected to promote both global health and economic advancement. Unfortunately, antipoverty vaccine development has lagged behind vaccines for major childhood infections and pandemic threats, despite evidence for their cost-effectiveness and cost-savings. Currently, the only licensed vaccines for NTDs include those for yellow fever, dengue, and rabies, although several other NTD vaccines for hookworm disease, schistosomiasis, leishmaniasis, and Zika and Ebola virus infections are in different stages of clinical development, while others are at the preclinical development stage. With the exception of the viral NTD vaccines there so far has been minimal industry interest in the antipoverty vaccines, leaving their development to a handful of non-profit product development partnerships. The major scientific and geopolitical hurdles to antipoverty vaccine development are discussed, including a rising antivaccine (“antivax”) movement now entering highly populated low- and middle-income countries.

Global epidemiology of podoconiosis: A systematic review

Background

Podoconiosis is one of the few diseases that could potentially be eliminated within one generation. Nonetheless, the global distribution of the disease remains largely unknown. The global atlas of podoconiosis was conceived to define the epidemiology and distribution of podoconiosis through dedicated surveys and assembling the available epidemiological data.

Methods

We have synthesized the published literature on the epidemiology of podoconiosis. Through systematic searches in SCOPUS and MEDLINE from inception to February 14, 2018, we identified observational and population-based studies reporting podoconiosis. To establish existence of podoconiosis, we used case reports and presence data. For a study to be included in the prevalence synthesis, it needed to be a population-based survey that involved all residents within a specific area. Studies that did not report original data were excluded. We undertook descriptive analyses of the extracted data. This study is registered with PROSPERO, number CRD42018084959.

Results

We identified 3,260 records, of which 27 studies met the inclusion criteria. Podoconiosis was described to exist or be endemic in 32 countries, 18 from the African Region, 3 from Asia and 11 from Latin America. Overall, podoconiosis prevalence ranged from 0·10% to 8.08%, was highest in the African region, and was substantially higher in adults than in children and adolescents. The highest reported prevalence values were in Africa (8.08% in Cameroon, 7.45% in Ethiopia, 4.52% in Uganda, 3.87% in Kenya and 2.51% in Tanzania). In India, a single prevalence of 0.21% was recorded from Manipur, Mizoram and Rajasthan states. None of the Latin American countries reported prevalence data.

Conclusion

Our data suggest that podoconiosis is more widespread in the African Region than in the rest of the regions, although this could be related to the fact that most podoconiosis epidemiological research has been focused in the African continent. The assembled dataset confirms that comprehensive podoconiosis control strategies such as promotion of footwear and personal hygiene are urgently needed in endemic parts of Africa. Mapping, active surveillance and a systematic approach to the monitoring of disease burden must accompany the implementation of podoconiosis control activities.

Podoconiosis is one of the Neglected Tropical Diseases, and causes painful and massive swelling of the lower legs. Despite the importance of the disease, its global distribution and epidemiology are poorly understood. We conducted a systematic review to assess the global epidemiology of podoconiosis. We found that podoconiosis was described to exist or be endemic in 32 countries, 18 from Africa, 3 from Asia and 11 from Latin America. Almost all prevalence data recorded corresponded to the African region. None of the Latin American countries reported prevalence data, although some countries are suspected to be endemic. We recommend that comprehensive podoconiosis control strategies such as promotion of footwear and personal hygiene are urgently needed in endemic countries in the African Region. Mapping, active surveillance and a systematic approach to the monitoring of disease burden must accompany the implementation of podoconiosis control activities.