Assessing urogenital schistosomiasis and female genital schistosomiasis (FGS) among adolescents in Anaocha, Anambra State, Nigeria: implications for ongoing control efforts

BACKGROUND

Urogenital schistosomiasis (UgS) remains a persistent health challenge among adolescents in Anambra State, Nigeria, despite ongoing control efforts. Mass praziquantel treatment programs, initiated in 2013, primarily target primary school-aged children (5-14 years old), leaving adolescents (10-19 years old) enrolled in secondary schools vulnerable to urogenital schistosomiaisis. Additionally, the extent of female genital schistosomiasis (FGS), a neglected gynaecological manifestation of UgS remains unclear.

METHODOLOGY

To address these gaps, a cross-sectional study was conducted in Anaocha Local Government Area from February to May 2023. Four hundred and seventy consenting adolescents aged 10-19 years were enrolled. Urinalysis including urine filtration was employed to confirm haematuria and detect urogenital schistosomiasis (UGS) among the participants. For females with heavy infections (≥ 50 eggs/10 ml urine), a gynaecologist performed colposcopy examinations, complemented by acetic acid and Lugol's iodine staining to assess for female genital schistosomiasis (FGS) lesions or other related reproductive health conditions. Socio-demographic data, including information on potential risk factors, were systematically collected using the Kobo ToolBox software, following gender-sensitive data collection guidelines. Data were analysed using SPSS version 25, incorporating descriptive statistics, multinomial logistic regression, odds ratios, and significance testing.

RESULTS

Among the 470 adolescents (52.8% females, 47.2% males) examined, an overall UgS prevalence of 14.5% was observed, with an average of 5.25 eggs per 10 ml of urine. Females had a slightly higher prevalence (16.1%), and 7.5% had heavy infections. Although gender differences in infection rates were not statistically significant, males had slightly higher odds of infection (OR: 1.332; 95% CI: 0.791-2.244; p-value: 0.280). Adolescents aged 10-14 had the highest prevalence, with significantly increased odds of infection (OR: 1.720; 95% CI: 1.012-2.923; p-value: 0.045). Colposcopy examinations of females with heavy infections revealed FGS lesions and co-infections with Trichomonas vaginalis. Haematuria, though prevalent (24.6%), was not the sole indicator, as those without it faced significantly higher odds of infection (OR: 2.924; 95% CI: 1.731-4.941; p-value: 0.000). Dysuria and genital itching/burning sensation were other UgS and FGS associated symptoms. Direct water contact was associated with higher infection odds (OR: 2.601; 95% CI: 1.007-6.716; p-value: 0.048). Various risk factors were associated with UgS.

CONCLUSION

The study highlights the need for a comprehensive Urogenital Schistosomiasis (UGS) control strategy that includes secondary school adolescents, emphasizes risk factor management, promotes safe water practices, and raises awareness about UGS and Female Genital Schistosomiasis (FGS) among adolescents, thus improving control efforts and mitigating this health challenge in the region.

Control, elimination, and eradication efforts for neglected tropical diseases in the World Health Organization African region over the last 30 years: A scoping review

OBJECTIVES

NTDs historically receive less attention than other diseases in the same regions. Recent gap analyses revealed notable shortcomings despite NTD elimination progress. This systematic scoping review was conducted to understand NTD control, elimination, and eradication efforts in the WHO African region over the last 30 years.

METHODS

Peer-reviewed publications from PubMed, Web of Science, and Cochrane databases related to NTD control, elimination, and eradication in the WHO African Region from 1990 to 2022 were reviewed. Included articles were categorized based on NTD; study location, type, and period; and topic areas. Technical and guidance documents from WHO, UN, partner, and academic/research institutions were reviewed. Country-specific multi-year NTD master plans were documented.

RESULTS

Four hundred eighty peer-reviewed articles, six Cochrane reviews, and 134 technical reports were included. MDA and non-interventional/survey-related studies were common topics. Lymphatic filariasis, trachoma, schistosomiasis, and onchocerciasis were the most frequently studied NTDs. Tanzania, Ethiopia, and Nigeria were the most represented countries; multi-country studies were limited.

CONCLUSION

The review highlights progress made in NTD control, elimination, and eradication efforts in the WHO African Region and can inform national/regional strategies. Disease and geographical disparities were evident, warranting focus and research in certain countries. A standardized approach to NTD control programs is needed for sustained progress.

FUNDING

There was no funding source for this study.

A 14-year review (2007-2020) of helminthiasis epidemiology in a hospital in Southern Madrid, Spain

PURPOSE

Vast majority of helminth diseases remain neglected tropical diseases (NTDs), causing significant morbidity. The widespread and periodic distribution of antiparasitic drugs, remains the cornerstone for controlling these diseases. In Spain, most helminthiasis cases are imported, and suspicion and diagnosis have become increasingly important. Our primary objective is to present the epidemiological landscape of helminthiasis diagnoses within our facility, while also detailing the demographic characteristics of the affected population.

METHODS

A retrospective study was conducted at the Hospital Universitario Severo Ochoa (HUSO) from January 1, 2007, to December 31, 2020, encompassing all diagnosed cases of helminthiasis during this period. Comprehensive epidemiological, clinical, and microbiological data were gathered for all diagnosed patients. The study population comprised patients receiving treatment at the HUSO, as well as those receiving treatment at the Leganés and Fuenlabrada Primary Care Units. Subsequently, descriptive and comparative statistics were performed, comparing Spanish and foreign patients.

RESULTS

During this period, a total of 952 patients were diagnosed with some form of helminthiasis. Among them, 495 were Spanish, and 457 were foreign. The total number of helminths identified, including patients with multiple infections, was 1,010. Significant differences were observed between Africans and Americans in terms of age distribution, with a higher prevalence among Africans in the 0-15 age range and among Americans in the 31-60 age range. Variations were noted in the distribution of helminths, with S. stercoralis significantly affecting Americans. For Spanish patients, the presence of Trichuris trichiura and S. stercoralis was significantly associated with eosinophilia, whereas among foreign patients, it was associated with Trichuris trichiura, Ascaris lumbricoides among others. Regarding symptoms, skin manifestations were more frequent among Spanish, while digestive were more common among foreigners.

CONCLUSIONS

This study offers crucial epidemiological insights into helminth infections observed over time in a Madrid hospital. Although the prevalence of helminth infections has been decreasing, there is still a need for screening and diagnosing foreign patients.

Computational investigation of turmeric phytochemicals targeting PTR1 enzyme of Leishmania species

In this study, we used in silico techniques to identify available parasite treatments, representing a promising therapeutic avenue. Building upon our computational initiatives aimed at discovering natural inhibitors for various target enzymes from parasites causing neglected tropical diseases (NTDs), we present novel findings on three turmeric-derived phytochemicals as inhibitors of Leishmania pteridine reductase I (PTR1) through in silico methodologies. PTR1, a crucial enzyme in the unique folate metabolism of trypanosomatid parasites, holds established therapeutic significance. Employing MOE software, a molecular docking analysis assesses the efficacy of turmeric phytochemicals against Leishmania PTR1. Validation of the docking protocol is confirmed with an RMSD value of 2. Post-docking, compounds displaying notable interactions with critical residues and binding affinities ranging between -6 and -8 kcal/mol are selected for interaction pattern exploration. Testing twelve turmeric phytochemicals, including curcumin, zingiberene, curcumol, curcumenol, eugenol, bisdemethoxycurcumin, tetrahydrocurcumin, tryethylcurcumin, turmerones, turmerin, demethoxycurcumin, and turmeronols, revealed binding affinities ranging from -5.5 to -8 kcal/mol. Notably, curcumin, demethoxycurcumin, and bisdemethoxycurcumin exhibit binding affinities within -6.5 to -8 kcal/mol and establish substantial interactions with catalytic residues. These phytochemicals hold promise as lead structures for rational drug design targeting Leishmania spp. PTR in future applications. This work underscores the potential of these identified phytochemicals in the development of more effective inhibitors, demonstrating their relevance in addressing neglected tropical diseases caused by parasites.

Exploring microalgal and cyanobacterial metabolites with antiprotozoal activity against Leishmania and Trypanosoma parasites

Neglected tropical diseases (NTD) like Leishmaniasis and trypanosomiasis affect millions of people annually, while currently used antiprotozoal drugs have serious side effects. Drug research based on natural products has shown that microalgae and cyanobacteria are a promising platform of biochemically active compounds with antiprotozoal activity. These unicellular photosynthetic organisms are rich in polyunsaturated fatty acids, pigments including phycocyanin, chlorophylls and carotenoids, polyphenols, bioactive peptides, terpenes, alkaloids, which have proven antioxidant, antimicrobial, antiviral, antiplasmodial and antiprotozoal properties. This review provides up-to-date information regarding ongoing studies on substances synthesized by microalgae and cyanobacteria with notable activity against Leishmania spp., Trypanosoma cruzi, and Trypanosoma brucei, the causative agents of Leishmaniasis, Chagas disease, and human African trypanosomiasis, respectively. Extracts of several freshwater or marine microalgae have been tested on different strains of Leishmania and Trypanosoma parasites. For instance, ethanolic extract of Chlamydomonas reinhardtii and Tetraselmis suecica have biological activity against T. cruzi, due to their high content of carotenoids, chlorophylls, phenolic compounds and flavonoids that are associated with trypanocidal activity. Halophilic Dunaliella salina showed moderate antileishmanial activity that may be attributed to the high β-carotene content in this microalga. Peptides such as almiramides, dragonamides, and herbamide that are biosynthesized by marine cyanobacteria Lyngbya majuscula were found to have increased activity in micromolar scale IC50 against L. donovani, T. Cruzi, and T. brucei parasites. The cyanobacterial peptides symplocamide and venturamide isolated from Symploca and Oscillatoria species, respectively, and the alkaloid nostocarbonile isolated from Nostoc have shown promising antiprotozoal properties and are being explored for pharmaceutical and medicinal purposes. The discovery of new molecules from microalgae and cyanobacteria with therapeutic potential against Leishmaniasis and trypanosomiasis may address an urgent medical need: effective and safe treatments of NTDs.

Situation of onchocerciasis transmission in 2020 in the Cascades region of Burkina Faso

Faced with the focal resurgence of onchocerciasis reported since 2004 in the South-West of Burkina Faso, the Neglected Tropical Diseases Control Program adopted a resumption of biannual community-directed treatment with ivermectin, since 2011 in the Cascades region and since 2013 in the South West region. The objective of this study was to assess the situation of onchocerciasis transmission in the Cascades region, nine years after the resumption of mass drug administration. This cross-sectional and descriptive survey concerned people over 5. The traditional method of skin snip on both iliac crests was performed for the parasitological diagnosis of onchocerciasis. The Ov-16 serological test was carried out in children aged 5 to 9 years. In 22 surveyed villages, the overall prevalence of microfilariae was 0.11% and below the tolerable threshold of 5%. It was less than 5% in all the villages (n = 22), less than 1% in 21 villages (99%) and zero in 19 villages (86.36%). The community microfilarial loads varied from 0.01 to 0.05 mf/b. Out of 946 children tested for OV-16, only one 9-year-old was positive and whose skin snip examination was negative. All the positive cases came from endemical areas in Côte d'Ivoire. Population migration is a risk factor for introducing the parasite into Burkina Faso; it also is risk factor for the effective elimination of onchocerciasis which requires the joint development of a control strategy between neighboring countries.

Neglected tropical disease (NTD) diagnostics: current development and operations to advance control

Neglected tropical diseases (NTDs) have become important public health threats that require multi-faceted control interventions. As late treatment and management of NTDs contribute significantly to the associated burdens, early diagnosis becomes an important component for surveillance and planning effective interventions. This review identifies common NTDs and highlights the progress in the development of diagnostics for these NTDs. Leveraging existing technologies to improve NTD diagnosis and improving current operational approaches for deployment of developed diagnostics are crucial to achieving the 2030 NTD elimination target. Point-of-care NTD (POC-NTD) diagnostic tools are recommended preferred diagnostic options in resource-constrained areas for mapping risk zones and monitoring treatment efficacy. However, few are currently available commercially. Technical training of remote health care workers on the use of POC-NTD diagnostics, and training of health workers on the psychosocial consequences of these diagnostics are critical in harnessing POC-NTD diagnostic potential. While the COVID-19 pandemic has challenged the possibility of achieving NTD elimination in 2030 due to the disruption of healthcare services and dwindling financial support for NTDs, the possible contribution of NTDs in exacerbating COVID-19 pandemic should motivate NTD health system strengthening.

Musculoskeletal involvement in neglected tropical diseases: a comprehensive review

Neglected tropical diseases (NTDs) encompass a group of diseases predominantly found in tropical regions, with origins dating back to their inclusion in the United Nations Millennium Development Goals in 2000. This initiative aimed to raise awareness and global funding to combat these diseases, which thrive in areas with limited sanitation, healthcare, and education. NTDs are caused by various pathogens such as bacteria, fungi, parasites, and viruses and affect over two billion individuals in resource-poor communities, leading to preventable deaths and devastating consequences. While the musculoskeletal system is only occasionally affected, the resulting chronic disabilities prevent individuals from working, posing a significant socioeconomic burden in this region of the world. Some NTDs exhibit distinct imaging features, and radiologists need to be aware of these characteristics to facilitate early treatment. In this review, we delve into musculoskeletal NTDs, focusing on clinical features and imaging findings, differential diagnosis, and clinical management.

Reduced efficacy of single-dose albendazole against Ascaris lumbricoides, and Trichuris trichiura, and high reinfection rate after cure among school children in southern Ethiopia: a prospective cohort study

BACKGROUND

Mass drug administration (MDA) program of albendazole to at-risk populations as preventive chemotherapy is the core public health intervention to control soil-transmitted helminths (STHs). Achieving this goal relies on drug effectiveness in reducing the parasite reservoirs in the community and preventing reinfection. We assessed the efficacy of albendazole against STH parasite infection and reinfection status after cure.

METHODS

A total of 984 schoolchildren infected with at least one type of STH parasite (hookworm, Ascaris lumbricoides, Trichuris trichiura) in southern Ethiopia were enrolled and received albendazole and praziquantel in MDA campaign conducted from January to March 2019. Stool exams at week-4 and at week-8 of post-MDA were done using Kato Katz technique. The primary outcome was efficacy assessed by cure rate (CR) and fecal egg reduction rates (ERRs) at four weeks of post-MDA. The secondary outcome was reinfection status defined as parasite egg positivity at eight weeks among those who were cured at 4 weeks of post-MDA. Group comparisons in CR and related factors were assessed with chi-square or Fisher's exact tests. Predictors of CR were examined through univariate and multivariate regression analyses.

RESULTS

The overall CR and ERR for hookworm infection were 97.2% (95% CI 94.6-99.4) and 97.02%, respectively. The overall CR and ERR for A. lumbricoides were 71.5% (95% CI 68.3-74.6) and 84.5% respectively. The overall CR and ERR and for T. trichiura were 49.5% (95% CI 44.8-54.2) and 68.3%, respectively. The CR among moderate T. trichiura infection intensity was 28.6%. Among children cured of hookworm, A. lumbricoides and T. trichiura at week 4 post-MDA, 4.6%, 18.3% and 52.4% became reinfected at week-8 post-MDA, respectively. Significantly lower CR (36.6%) and higher reinfection after cure (60.6%) among A. lumbricoides and T. trichiura coinfected children than A. lumbricoides only (CR = 69.6%, reinfection rate = 15.1%) or T. trichiura only infected children (CR = 55.6%, reinfection rate = 47.1%) was observed. Pre-treatment coinfection with ≥ two types of STH parasites was significantly associated with re-infection after cure.

CONCLUSION

Albendazole MDA is efficacious against hookworm but has reduced efficacy against A. lumbricoides and is not effective against T. trichiura. The low drug efficacy and high reinfection rate after cure underscore the need for alternative treatment and integration of other preventive measures to achieve the target of eliminating STHs as a public health problem by 2030.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION

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

Protective efficacy of the oral vaccine Tc24:Co1 produced in Schizochytrium sp. against Trypanosoma cruzi infection in a mouse model

Trypanosoma cruzi parasite - causal Chagas disease agent - affects about 7 million people; no vaccine is available, and current medications have not been entirely effective. Multidisciplinary efforts are necessary for developing clinical vaccine prototypes. Thus, this research study aims to assess the expressed and whole-cell administration protection of the oral vaccine prototype Tc24:Co1 using Schizochytrium sp. microalga. High recombinant protein expression yields (675 μg/L) of algal culture were obtained. Additionally, Schizochytrium sp.-Tc24:Co1 resulted stable at 4 °C for up to six months and at 25 °C for three months. After receiving four oral doses of the vaccine, the mice showed a significant humoral immune response and a parasitemia reduction associated with a lack of heart inflammatory damage compared with the unvaccinated controls. The Schizochytrium sp.-Tc24:Co1 vaccine demonstrates to be promising as a prototype for further development showing protective effects against a T. cruzi challenge in a mouse model.

Original algorithms for the detection of cardiovascular involvement of neglected tropical diseases

INTRODUCTION

Neglected tropical diseases (NTDs) introduce considerable morbidity and mortality on a global scale, directly impacting over 1 billion individuals as well as their families and communities. Afflicted individuals may have limited access to resources and care in these regions, contributing to a high proportion of chronic, progressive, and systemic disease. The cardiovascular system is at particular risk of demise for several NTDs, yet remains largely unstudied due in part to the lack of robust data collection mechanisms in the most impacted regions.

AREAS COVERED

The present review is a part of the Neglected Tropical Diseases and other Infectious Diseases affecting the Heart (NET-Heart) Project, aiming at summarizing the current knowledge on cardiovascular implications of NTDs and providing diagnostic as well as management recommendations which can be tailored to low-resource settings. The diagnostic and management algorithms of 13 unique NTDs are presented and summarized.

EXPERT OPINION

Recognizing cardiac manifestations of NTDs can significantly alter disease trajectory and all physicians benefit from improved knowledge about NTDs. Great potential exists to advance patient care by improving data collection, communication, and international collaboration.

Five years of post-validation surveillance of lymphatic filariasis in Thailand

BACKGROUND

The World Health Organization (WHO) validated Thailand in 2017 as having eliminated lymphatic filariasis (LF) as a public health problem with recommendations for continued surveillance. This article describes measures and progress made in Thailand with post-validation surveillance (PVS) of LF from 2018 until 2022.

METHODS

The implementation unit (IU) is a sub-village in 11 former LF endemic provinces. Human blood surveys are targeted in 10% of IUs each year. In Wuchereria bancrofti areas, filaria antigen test strips (FTS) are used, and in Brugia malayi areas, antibody test kits (Filaria DIAG RAPID) are used. Positive cases are confirmed by thick blood film (TBF) and polymerase chain reaction (PCR). Vector surveys for mosquito species identification and dissection for microfilaria (Mf)/filarial larvae are done in 1% of IUs where human blood surveys are conducted. Human blood surveys using FTS are conducted among migrants in five provinces. Surveillance of cats is done in areas that previously recorded > 1.0% Mf rate among cats. Morbidity management and disability prevention (MMDP) are done every 2 years in LF-endemic areas where chronic disease patients reside.

RESULTS

From 2018 to 2022, in a total of 357 IUs in 11 provinces, human blood surveys were conducted in 145 IUs (41%) with an average population coverage of 81%. A total of 22,468 FTS and 27,741 FilariaDIAG RAPID were performed. 27 cases were detected: 3 cases of W. bancrofti in Kanchanaburi province and 24 cases of B. malayi in Narathiwat province. 4 cases of W. bancrofti were detected in two provinces through routine public health surveillance. Vector surveys in 47 IUs detected B. malayi Mf filarial larvae only in Narathiwat province. Chronic LF patients reduced from 114 in 2017 to 76 in 2022. Surveys among 7633 unregistered migrants yielded 12 cases of W. bancrofti. Mf rate among cats in Narathiwat province declined from 1.9% in 2018 to 0.7% in 2022. MMDP assessments revealed gaps in healthcare provider's management of chronic cases due to staff turnover.

CONCLUSIONS

In 2022, after 5 years of PVS, Thailand re-surveyed 41% of its previously endemic IUs and demonstrated ongoing transmission in only one province of Narathiwat, where Mf prevalence is below the WHO provisional transmission threshold of 1%. This study highlights the importance of continued disease surveillance measures and vigilance among health care providers in LF receptive areas.

Optimal control analysis of a transmission interruption model for the soil-transmitted helminth infections in Kenya

Kenya is among the countries endemic for soil-transmitted helminthiasis (STH) with over 66 subcounties and over 6 million individuals being at-risk of infection. Currently, the country is implementing mass drug administration (MDA) to all the at-risk groups as the mainstay control strategy. This study aimed to develop and analyze an optimal control (OC) model, from a transmission interruption model, to obtain an optimal control strategy from a mix of three strategies evaluated. The study used the Pontryagin's maximum principle to solve, numerically, the OC model. The analysis results clearly demonstrated that water and sanitation when implemented together with the MDA programme offer the best chances of eliminating these tenacious and damaging parasites. Thus, we advocate for optimal implementation of the combined mix of the two interventions in order to achieve STH elimination in Kenya, and globally, in a short implementation period of less than eight years.

Buruli ulcer in Africa: Geographical distribution, ecology, risk factors, diagnosis, and indigenous plant treatment options - A comprehensive review

Buruli ulcer (BU), a neglected tropical disease (NTD), is an infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. The disease has been documented in many South American, Asian, and Western Pacific countries and is widespread throughout much of Africa, especially in West and Central Africa. In rural areas with scarce medical care, BU is a devastating disease that can leave patients permanently disabled and socially stigmatized. Mycobacterium ulcerans is thought to produce a mycolactone toxin, which results in necrosis of the afflicted tissue and may be involved in the etiology of BU. Initially, patients may notice a painless nodule or plaque on their skin; as the disease progresses, however, it may spread to other parts of the body, including the muscles and bones. Clinical signs, microbial culture, and histological analysis of afflicted tissue all contribute to a diagnosis of BU. Though antibiotic treatment and surgical removal of infected tissue are necessary for BU management, plant-derived medicine could be an alternative in areas with limited access to conventional medicine. Herein we reviewed the geographical distribution, socioeconomic, risk factors, diagnosis, biology and ecology of the pathogen. Complex environmental, socioeconomic, and genetic factors that influence BU are discussed. Further, our review highlights future research areas needed to develop strategies to manage the disease through the use of indigenous African plants.

Botanicals against some important nematodal diseases: Ascariasis and hookworm infections

Ascariasis and intestinal parasitic nematodes are the leading cause of mass mortality infecting many people across the globe. In light of the various deleterious side effects of modern chemical-based allopathic drugs, our preferences have currently shifted towards the use of traditional plant-based drugs or botanicals for treating diseases. The defensive propensities in the botanicals against parasites have probably evolved during their co-habitation with parasites, humans and plants in nature and hence their combative interference in one another's defensive mechanisms has occurred naturally ultimately being very effective in treating diseases. This article broadly outlines the utility of plant-based compounds or botanicals prepared from various medicinal herbs that have the potential to be developed as effective therapies against the important parasites causing ascariasis and intestinal hookworm infections leading to ascariasis & infections and thereby human mortality, wherein allopathic treatments are less effective and causes enormous side-effects.

Safety and infectivity of female cercariae in Schistosoma-naïve, healthy participants: a controlled human Schistosoma mansoni infection study

BACKGROUND

A controlled human infection model for schistosomiasis (CHI-S) can speed up vaccine development and provides insight into early immune responses following schistosome exposure. Recently, we established CHI-S model using single-sex male-only Schistosoma mansoni (Sm) cercariae in Schistosoma-naïve individuals. Given important differences in antigenic profile and human immune responses to schistosomes of different sex, we pioneered a single-sex female-only CHI-S model for future use in vaccine development.

METHODS

We exposed 13 healthy, Schistosoma-naïve adult participants to 10 (n = 3) or 20 (n = 10) female cercariae and followed for 20 weeks, receiving treatment with praziquantel (PZQ) 60 mg/kg at week 8 and 12 after exposure.

FINDINGS

The majority (11/13) participants reported rash and/or itch at the site of exposure, 5/13 had transient symptoms of acute schistosomiasis. Exposure to 20 cercariae led to detectable infection, defined as serum circulating anodic antigen levels >1.0 pg/mL, in 6/10 participants. Despite two rounds of PZQ treatment, 4/13 participants showed signs of persistent infection. Additional one- or three-day PZQ treatment (1 × 60 mg/kg and 3 × 60 mg/kg) or artemether did not result in cure, but over time three participants self-cured. Antibody, cellular, and cytokine responses peaked at week 4 post infection, with a mixed Th1, Th2, and regulatory profile. Cellular responses were (most) discriminative for symptoms.

INTERPRETATION

Female-only infections exhibit similar clinical and immunological profiles as male-only infections but are more resistant to PZQ treatment. This limits future use of this model and may have important implications for disease control programs.

FUNDING

European Union's Horizon 2020 (grant no. 81564).

microRNA silencing in a whole worm cestode model provides insight into miR-71 function

Parasites belonging to the class Cestoda include zoonotic species such as Echinococcus spp. and Taenia spp. that cause morbidity and mortality in endemic areas, mainly affecting pastoral and rural communities in low income countries but also upper middle income countries. Cestodes show remarkable developmental plasticity, implying tight regulation of gene expression throughout their complex life cycles. Despite the recent availability of genomic data for cestodes, little progress was made on postgenomic functional studies. MicroRNAs (miRNAs) are key components of gene regulatory systems that guide diverse developmental processes in multicellular organisms. miR-71 is a highly expressed miRNA in cestodes, which is absent in vertebrates and targets essential parasite genes, representing a potential key player in understanding the role of miRNAs in cestodes biology. Here we used transfection with antisense oligonucleotides to perform whole worm miRNA knockdown in tetrathyridia of Mesocestoides vogae (syn. Mesocestoides corti), a laboratory model of cestodes. We believe this is the first report of miRNA knockdown at the organism level in these parasites. Our results showed that M. vogae miR-71 is involved in the control of strobilation in vitro and in the establishment of murine infection. In addition, we identified miR-71 targets in M. vogae, several of them being de-repressed upon miR-71 knockdown. This study provides new knowledge on gene expression regulation in cestodes and suggests that miRNAs could be evaluated as new selective therapeutic targets for treating Neglected Tropical Diseases prioritised by the World Health Organization.

Finishing the task of eliminating neglected tropical diseases (NTDs) in WHO South-East Asia Region: promises kept, challenges, and the way forward

Globally 20 Neglected tropical diseases (NTDs) are prioritized by World Health Organization (WHO), of which 15 are present in the South-East Asia Region (SEAR) with all 11 countries being affected. As the region bears 54% of the global burden, "Finishing the task of eliminating neglected tropical diseases and other diseases on the verge of elimination" was identified as a regional flagship priority in 2014 with focus on lymphatic filariasis (LF), kala-azar, yaws, trachoma, and leprosy. Intensified efforts have been made to raise and sustain political commitment and momentum among partners innovate tools, interventions and strategies to accelerate elimination, and establish the process and support countries to accelerate and validate achievement of elimination targets. Seven countries have verified or validated for having eliminated at least one NTD since 2016, including yaws, LF and trachoma. Between 2010 and 2020, the number of people requiring interventions against NTDs in the South-East Asia Region reduced by 20%. The priorities in the next decade are to strengthen last-mile efforts to eliminate identified NTDs, sustain it and to use the lessons learnt to eliminate other NTDs.

Funding

None.

Diagnosis and management of complicated urogenital schistosomiasis: a systematic review of the literature

BACKGROUND

Currently, there are no standardized guidelines for the diagnosis or management of the complications of urogenital schistosomiasis (UGS). This systematic review of the literature aims to investigate the state of the art in reference to diagnostic approaches and the clinical management of this condition.

METHODS

A systematic review of literature published between January 1990 and January 2021 was conducted in the MEDLINE database, scoping for articles regarding diagnostic means or therapeutic options for the complications of UGS, namely obstructive uropathy, bladder cancer, abortion, ectopic pregnancy, infertility, kidney failure, urolithiasis and the need for invasive procedures. Relevant data were then extracted from the articles deemed eligible according to the inclusion criteria.

MAIN RESULTS

In total, 3052 articles were identified by the research query, of which 167 articles fulfilling inclusion criteria after title/abstract screening and full-text evaluation were included, 35% on both diagnostic and therapeutic aspects, and 51% on diagnosis and 14% on therapy. Ultrasound was the most frequently tool employed for the diagnosis of UGS complications showing a good performance. Concerning the management of hydronephrosis, the majority of available evidences came from community-based studies where universal treatment with praziquantel was used leading to decrease of prevalence of obstructive uropathy. Concerning studies on surgical procedures, laser endoureterotomy followed by stenting was mostly employed in adult patients leading to a crude cure rate of 60% (43 of 71 patients). In the case of severe hydronephrosis, surgery consisting of ureteral re-implantation showed excellent results with a crude cure rate of 98% (157 cured patients of 160 treated). Concerning bladder cancer, data on 93 patients with a clear diagnosis of UGS-related bladder were available reporting a variable and sometime combined approach based on disease stage. Available data on diagnosis and management of abortion, ectopic pregnancy, infertility, kidney failure, urolithiasis and the need for invasive procedures due to UGS are also presented.

CONCLUSIONS

The review produced a complete picture of the diagnostic and therapeutic options currently available for complicated UGS. These results can be useful both for guiding clinicians towards correct management and for tracing the direction of future research.

Editorial : Swiss TPH: 30 Years of R&D Towards New Drugs for Tropical Diseases

The year 2023 marks the 80th anniversary of the Swiss Tropical and Public Health Institute (Swiss TPH). Associated with the University of Basel, Swiss TPH combines research, education and services, working across a value chain from innovation and validation to application to improve people's health and well-being. Around 700 staff and students work in Swiss TPH's new headquarters in an emerging life-science cluster in Allschwil, Switzerland, focusing on infectious and non-communicable diseases, environment, society and health as well as health systems and interventions. In this special issue of Chimia, we highlight 30 years of research and development (R&D) at Swiss TPH, deeply grounded in partnership, towards new drugs for tropical diseases.

Repurposing Know-how for Drug Development: Case Studies from the Swiss Tropical and Public Health Institute

In pursuing novel therapeutic solutions, drug discovery and development rely on efficiently utilising existing knowledge and resources. Repurposing know-how, a strategy that capitalises on previously acquired information and expertise, has emerged as a powerful approach to accelerate drug discovery and development processes, often at a fraction of the costs of de novo developments. For 80 years, collaborating within a network of partnerships, the Swiss Tropical and Public Health Institute (Swiss TPH) has been working along a value chain from innovation to validation and application to combat poverty-related diseases. This article presents an overview of selected know-how repurposing initiatives conducted at Swiss TPH with a particular emphasis on the exploration of drug development pathways in the context of neglected tropical diseases and other infectious diseases of poverty, such as schistosomiasis, malaria and human African trypanosomiasis.

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.

Basel: A Hotspot for Drug Discovery and Development Against Poverty-Related Diseases

In discussion with Lukas Meier from the Swiss Tropical and Public Health Institute (Swiss TPH), Lutz Hegemann, Head of Novartis Global Health and Sustainability and Marcel Tanner, President of the Swiss Academies of Arts and Sciences, give their opinions on the changes that occurred in drug discovery and development for poverty-related diseases over the past 30 years. They emphasise the power of public-private partnerships and provide their points of views on what needs to be done in the future to ensure that the poorest of the poor also have access to important therapies.

National prevalence and risk factors for tungiasis in Kenya

BACKGROUND

Tungiasis is a highly neglected tropical skin disease caused by the sand flea, Tunga penetrans, the female of which burrows into the skin, causing pain and itching. The disease occurs throughout South America and sub-Saharan Africa but there are few systematic data on national disease burdens. The tungiasis research community is keen to develop survey methods to fill this gap. Here we used a school-based, thorough examination method to determine the prevalence and risk factors for tungiasis in Kenya.

METHODS

We conducted the first nationally representative survey of tungiasis, including nine counties covering the major ecological zones of Kenya. A stratified multistage random sampling was used to select 22 primary schools from each of the nine counties and to select up to 114 pupils aged 8 to 14 years in each school. Pupils were examined thoroughly for tungiasis. Two surveys were conducted, the first between May and July 2021 and the second between October 2021 and April 2023 when pupils were also interviewed for risk factors. Mixed effect logistic regression models were used to test associations of independent variables with tungiasis using the school as a random effect.

RESULTS

The overall prevalence of tungiasis in the first survey was 1.35% [95% confidence interval (CI): 1.15-1.59%], and 0.89% in the second survey. The prevalence ranged from 0.08% (95% CI: 0.01-0.59%) in Taita Taveta county to 3.24% (95% CI: 2.35-4.44%) in Kajiado county. Tungiasis infection was associated with county of residence, male sex [adjusted odds ratio (aOR) = 2.01, 95% CI: 1.52-2.67], and lower age (aOR = 0.81, 95% CI: 0.75-0.88). For the first time we demonstrate an association with attending public schools rather than private schools (aOR = 5.62, 95% CI: 1.20-26.22) and lower socioeconomic status (aOR = 0.10, 95% CI: 0.03-0.33). Using a rapid screening method of the top of feet only, would have missed 62.9% of all cases, 78.9% of mild cases and 20.0% of severe cases.

CONCLUSIONS

Tungiasis is widely but heterogeneously distributed across Kenya. School-based surveys offer an efficient strategy for mapping tungiasis distribution.

Multiple Stool Sampling and Specific Parasitological Technique are Crucial to Diagnose Strongyloidiasis in Alcoholic Patients

PURPOSE

Chronic alcoholism is a well-known risk factor for strongyloidiasis, in these patients the disease is potentially more severe, probably due to the breakdown of local protective barriers and immunosuppression caused by alcohol, which can lead to autoinfection and dissemination. The aim of this study was to evaluate multiple stool sampling and a specific parasitological assay agar plate culture (APC) for the diagnosis of Strongyloides stercoralis in alcoholics.

METHODS

APC was compared to sedimentation technique (HPJ; Hoffman, Pons and Janer), as parasitological methods to detect S. stercoralis infection in alcoholic individuals. Three stool samples from 60 alcoholic and 60 non-alcoholic individuals were analyzed.

RESULTS

S. stercoralis larvae were observed in 11 (18.3%) alcoholic individuals and 1 (1.7%) nonalcoholic individual (P = 0.0042). In view of the combined results, sensitivity for the APC method was 63.6% (CI 31.6-87.6%) with the first sample reaching 100% (CI 67.8-100%) after analyzing three fecal samples. The HPJ sensitivity was 36.4% (CI 12.4-68.4) in the first sample, reaching 72.7% (CI 39.3-92.7) after three samples analyzed.

CONCLUSION

The present results suggest that in alcoholic patients, it is important to repeat stool sampling with specific techniques, especially using the APC method, to avoid misdiagnosis in cases that could evolve to disseminated strongyloidiasis.

Prototyping of a lateral flow assay based on monoclonal antibodies for detection of Bothrops venoms

BACKGROUND

Brazil is home to a multitude of venomous snakes; perhaps the most medically relevant of which belong to the Bothrops genus. Bothrops spp. are responsible for roughly 70% of all snakebites in Brazil, and envenomings caused by their bites can be treated with three types of antivenom: bothropic antivenom, bothro-lachetic antivenom, and bothro-crotalic antivenom. The choice to administer antivenom depends on the severity of the envenoming, while the choice of antivenom depends on availability and on how certain the treating physician is that the patient was bitten by a bothropic snake. The diagnosis of a bothropic envenoming can be made based on expert identification of the dead snake or a photo thereof or based on a syndromic approach wherein the clinician examines the patient for characteristic manifestations of envenoming. This approach can be very effective but requires staff that has been trained in clinical snakebite management, which, unfortunately, far from all relevant staff has.

RESULTS

In this article, we describe a prototype of the first lateral flow assay (LFA) capable of detecting venoms from Brazilian Bothrops spp. The monoclonal antibodies for the assay were generated using hybridoma technology and screened in sandwich enzyme-linked immunosorbent assays (ELISAs) to identify Bothrops spp.-specific antibody sandwich pairs. The prototype LFA is able to detect venom from several Bothrops spp. The LFA has a limit of detection (LoD) of 9.5 ng/mL in urine, when read with a commercial reader, and a visual LoD of approximately 25 ng/mL.

SIGNIFICANCE

The work presented here serves as a proof of concept for a genus-specific venom detection kit that could support physicians in diagnosing Bothrops envenomings. Although further optimisation and testing is needed before the LFA can find clinical use, such a device could aid in decentralising antivenoms in the Brazilian Amazon and help ensure optimal snakebite management for even more victims of this highly neglected disease.

Broadening the research landscape in the field of snakebite envenoming: Towards a holistic perspective

Snakebite envenoming (SBE) is a neglected tropical disease that kills and maims hundreds of thousands of people yearly, particularly in impoverished rural settings of the Global South. Understanding the complexity of SBE and tackling this disease demands a transdisciplinary, One Health approach. There is a long-standing research tradition on SBE in toxinology and human medicine. In contrast, other disciplines, such as veterinary medicine or social sciences, still need to be better developed in this field, especially in countries with a high incidence of SBE. Broadening the disciplinary landscape, connecting various research approaches, methods, and data across disciplines and sectors, and engaging with communities affected by SBE in implementing evidence-based solutions are needed. This review summarizes areas that require strengthening to better understand the complexity of SBE and to generate a robust body of knowledge to be translated into effective public health interventions.

Motile microfilaria captured by fluorescent microscopy and the unmasking of eosinophilia following treatment

A 24-year-old patient from Cameroon presented to our hospital because of a foreign structure in her left eye. To our knowledge, for the first time, fluorescent microscopy revealed motile microfilariae, and the diagnosis of loiasis was established. Despite substantial microfilaremia, eosinophilia only unmasked after the initiation of antiparasitic therapy.

Burden of neglected tropical diseases and access to medicine and diagnostics in Ethiopia: a scoping review

BACKGROUND

More than 1.7 billion people are affected by neglected tropical diseases (NTDs) worldwide. Forty percent of the NTD-affected people live in Africa with the poorest, most vulnerable, and hard to reach geographical areas. The NTDs cause significant social and economic burden and deepen marginalization and stigmatization. The World Health Organization's current roadmap for NTD aims to prevent, control, eliminate, or eradicate 20 tropical diseases. Ethiopia experiences a high burden of these diseases, but current access to diagnostics, medicine, and/or care has been little explored to inform the country's NTD strategic plan. The overall purpose of the scoping review was to map and characterize the burden of NTDs and challenges in access to diagnostics, medicine, and/or care in Ethiopia.

METHODS

A systematic search of evidence was conducted in PubMed, Cochrane Library, and Google Scholar from January 2000 until May 2022, without restrictions of language or study design. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Review was followed for screening of studies. Key findings were extracted and narrated qualitatively.

RESULTS

The search resulted in 4532 articles, of which 105 met the inclusion criteria and were included in the scoping review under three themes: burden of NTDs, access to diagnostics, medicine and/or care, and key barriers. Although gains have been made in the prevention and control of NTDs in Ethiopia, the burden remains high, and progress in access to diagnostics, medicine/drugs, and/or care is very slow. Poverty, poor quality of life, and underfunding of NTD programs decelerate the process of NTD elimination program in the country.

CONCLUSIONS

The scoping review identified a considerable number of studies on the burden of NTDs in Ethiopia and strategies for diagnosis, treatment, and/or care; however, there is a paucity of evidence on the suitability and potential benefits of novel diagnostic technologies and medicines in the country. A regular review and analysis of such country-level evidence is important to inform the country NTDs roadmap and local implementation strategies.

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.

The oral repellent - science fiction or common sense? Insects, vector-borne diseases, failing strategies, and a bold proposition

Over the last decades, unimaginable amounts of money have gone into research and development of vector control measures, repellents, treatment, and vaccines for vector borne diseases. Technological progress and scientific breakthroughs allowed for ever more sophisticated and futuristic strategies. Yet, each year, millions of people still die or suffer from potentially serious consequences of malaria or dengue to more recent infections, such as zika or chikungunya, or of debilitating consequences of neglected tropical diseases. This does not seem value for money. In addition, all current vector control strategies and personal protection methods have shortcomings, some serious, that are either destructive to non-target species or unsatisfactory in their effectiveness. On the other hand, the rapid decline in insect populations and their predators reflects decades-long aggressive and indiscriminate vector control. This major disruption of biodiversity has an impact on human life not anticipated by the well-meaning killing of invertebrates. The objective of this paper is to re-examine current control methods, their effectiveness, their impact on biodiversity, human and animal health, and to call for scientific courage in the pursuit of fresh ideas. This paper brings together topics that are usually presented in isolation, thereby missing important links that offer potential solutions to long-standing problems in global health. First, it serves as a reminder of the importance of insects to human life and discusses the few that play a role in transmitting disease. Next, it examines critically the many currently employed vector control strategies and personal protection methods. Finally, based on new insights into insect chemo-sensation and attractants, this perspective makes a case for revisiting a previously abandoned idea, the oral repellent, and its use via currently successful methods of mass-application. The call is out for focused research to provide a powerful tool for public health, tropical medicine, and travel medicine.

Incidence and mortality trends of neglected tropical diseases and malaria in China and ASEAN countries from 1990 to 2019 and its association with the socio-demographic index

BACKGROUND

People in China and the countries in the Association of Southeast Asian Nations (ASEAN) are affected by neglected tropical diseases and malaria (NTDM). In this study, we aimed to assess the current status and trends of NTDM burden from 1990 to 2019 in China and ASEAN countries, and also explore the association of NTDM burden with socio-demographic index (SDI).

METHODS

The data from the Global Burden of Diseases Study 2019 (GBD 2019) results were used. Absolute incidence and death number, and age-standardized incidence and mortality rate (ASIR and ASMR) of NTDM in China and ASEAN were extracted. The estimated annual percentage change (EAPC) and join-point regression in the rates quantified the trends. Nonlinear regression (second order polynomial) was used to explore the association between SDI and ASRs.

RESULTS

The ASIR of NTDM increased in China, Philippines, Singapore and Brunei, at a speed of an average 4.15% (95% CI 3.83-4.47%), 2.15% (1.68-2.63%), 1.03% (0.63-1.43%), and 0.88% (0.60-1.17%) per year. Uptrends of ASIR of NTDM in recent years were found in China (2014-2017, APC = 10.4%), Laos (2005-2013, APC = 3.9%), Malaysia (2010-2015, APC = 4.3%), Philippines (2015-2019, APC = 4.2%), Thailand (2015-2019, APC = 2.4%), and Vietnam (2014-2017, APC = 3.2%, all P < 0.05). Children < 5 had relatively low incidences but unexpectedly high mortality rates of NTDM in most ASEAN countries. Both incidence and mortality rates of NTDM were higher in older people. ASIR and ASMR of NTDM had a U-shaped association with SDI.

CONCLUSIONS

The burden of NTDM in China and ASEAN countries was still huge and affects vulnerable and impoverished populations' livelihoods, including children under the age of 5 and people aged 60 and older. Facing with the large burden and complex situation of NTDM in China and ASEAN countries, regional cooperating strategies are needed to reduce the burden of NTDM, so as to achieve the goal of elimination in the world.

Evaluation of the Antiparasitic and Antifungal Activities of Synthetic Piperlongumine-Type Cinnamide Derivatives: Booster Effect by Halogen Substituents

A series of synthetic N-acylpyrrolidone and -piperidone derivatives of the natural alkaloid piperlongumine were prepared and tested for their activities against Leishmania major and Toxoplasma gondii parasites. Replacement of one of the aryl meta-methoxy groups by halogens such as chlorine, bromine and iodine led to distinctly increased antiparasitic activities. For instance, the new bromo- and iodo-substituted compounds 3 b/c and 4 b/c showed strong activity against L. major promastigotes (IC50 =4.5-5.8 μM). Their activities against L. major amastigotes were moderate. In addition, the new compounds 3 b, 3 c, and 4 a-c exhibited high activity against T. gondii parasites (IC50 =2.0-3.5 μM) with considerable selectivities when taking their effects on non-malignant Vero cells into account. Notable antitrypanosomal activity against Trypanosoma brucei was also found for 4 b. Antifungal activity against Madurella mycetomatis was observed for compound 4 c at higher doses. Quantitative structure-activity relationship (QSAR) studies were carried out, and docking calculations of test compounds bound to tubulin revealed binding differences between the 2-pyrrolidone and 2-piperidone derivatives. Microtubules-destabilizing effects were observed for 4 b in T. b. brucei cells.

Formulation of benznidazole-lipid nanocapsules: Drug release, permeability, biocompatibility, and stability studies

Benznidazole, a poorly soluble in water drug, is the first-line medication for the treatment of Chagas disease, but long treatment periods at high dosages cause several adverse effects with insufficient activity in the chronic phase. According to these facts, there is a serious need for novel benznidazole formulations for improving the chemotherapy of Chagas disease. Thus, this work aimed to incorporate benznidazole into lipid nanocapsules for improving its solubility, dissolution rate in different media, and permeability. Lipid nanocapsules were prepared by the phase inversion technique and were fully characterized. Three formulations were obtained with a diameter of 30, 50, and 100 nm and monomodal size distribution with a low polydispersity index and almost neutral zeta potential. Drug encapsulation efficiency was between 83 and 92% and the drug loading was between 0.66 and 1.04%. Loaded formulations were stable under storage for one year at 4 °C. Lipid nanocapsules were found to protect benznidazole in simulated gastric fluid and provide a sustained release platform for the drug in a simulated intestinal fluid containing pancreatic enzymes. The small size and the almost neutral surface charge of these lipid nanocarriers improved their penetration through mucus and such formulations showed a reduced chemical interaction with gastric mucin glycoproteins. LNCs. The incorporation of benznidazole in lipid nanocapsules improved the drug permeability across intestinal epithelium by 10-fold compared with the non-encapsulated drug while the exposure of the cell monolayers to these nanoformulations did not affect the integrity of the epithelium.

Exploring N-myristoyltransferase as a promising drug target against parasitic neglected tropical diseases

Neglected tropical diseases (NTDs) constitute a group of approximately 20 infectious diseases that mainly affect the impoverished population without basic sanitation in tropical countries. These diseases are responsible for many deaths worldwide, costing billions of dollars in public health investment to treat and control these infections. Among them are the diseases caused by protozoa of the Trypanosomatid family, which constitute Trypanosoma cruzi (Chagas disease), Trypanosoma brucei (sleeping sickness), and Leishmaniasis. In addition, there is a classification of other diseases, called the big three, AIDS, tuberculosis, and malaria, which are endemic in countries with tropical conditions. Despite the high mortality rates, there is still a gap in the treatment. The drugs have a high incidence of side effects and protozoan resistance, justifying the investment in developing new alternatives. In fact, the Target-Based Drug Design (TBDD) approach is responsible for identifying several promising compounds, and among the targets explored through this approach, N-myristoyltransferase (NMT) stands out. It is an enzyme related to the co-translational myristoylation of N-terminal glycine in various peptides. The myristoylation process is a co-translation that occurs after removing the initiator methionine. This process regulates the assembly of protein complexes and stability, which justifies its potential as a drug target. In order to propose NMT as a potential target for parasitic diseases, this review will address the entire structure and function of this enzyme and the primary studies demonstrating its promising potential against Leishmaniasis, T. cruzi, T. brucei, and malaria. We hope our information can help researchers worldwide search for potential drugs against these diseases that have been threatening the health of the world's population.

Public-Private Partnerships and the Landscape of Neglected Tropical Disease Research: The Shifting Logic and Spaces of Knowledge Production

Until the recent spread of public-private partnerships, pharmaceutical firms had avoided research and development into neglected tropical diseases (NTDs). Because these are diseases that affect the poorest populations in developing regions, research and development initiatives have for the most part depended on the resources and expertise drawn from academia, international organizations, and intermittent state interventions in disease-endemic countries. Over the last few decades, however, public-private product development partnerships (PDPs) have been introducing new collaborative agreements in which the existing resources and expertise combine with the those traditionally withheld by the pharmaceutical industry and global health NGOs. This paper explores recent transformations in the representation of NTDs by examining the shifting logic and spaces of knowledge production which the advent of PDPs has enabled. An analysis of two case studies focused on Chagas disease-related initiatives addresses recurring preoccupations in Science, Technology and Society studies as well as in critical analyses of PDPs: that is, the back-and-forth movement of the disease from being an object of scientific inquiry to a public health concern, and the legitimacy risks and material asymmetries entailed in global health PDPs. Both cases show that it is major global health stakeholders and experts in non-endemic countries, rather than transnational pharmaceutical firms, that exert the greatest influence upon these changing representations: PDPs attempt to expand the preexisting biomedical focus on NTDs by means of incorporating "real world" drug development preoccupations (which I term epistemic shifts), but they also combine their stated global humanitarian aim with security concerns about the diseases spreading to non-endemic, industrialized countries (which I term geographical shifts).

Green Synthesis of Molecules for the Treatment of Neglected Diseases

Neglected tropical diseases (NTDs) affect mainly poor and marginalized populations of tropical and subtropical areas in 150 countries. Many of the chemical processes involved in the synthesis of active pharmaceutical ingredients (APIs) are highly polluting and inefficient, both in terms of materials and energy-consuming. In this review, we present the green protocols developed in the last 10 years to access new small molecules with potential applications in the treatment of leishmania, tuberculosis, malaria, and Chagas disease. The use of alternative and efficient energy sources, like microwaves and ultrasound, as well as reactions using green solvents and solvent-free protocols, are discussed in this review.

High-risk spatiotemporal patterns of cutaneous leishmaniasis: a nationwide study in Iran from 2011 to 2020

BACKGROUND

Cutaneous leishmaniasis (CL) is a wide-reaching infection of major public health concern. Iran is one of the six most endemic countries in the world. This study aims to provide a spatiotemporal visualization of CL cases in Iran at the county level from 2011 to 2020, detecting high-risk zones, while also noting the movement of high-risk clusters.

METHODS

On the basis of clinical observations and parasitological tests, data of 154,378 diagnosed patients were obtained from the Iran Ministry of Health and Medical Education. Utilizing spatial scan statistics, we investigated the disease's purely temporal, purely spatial, spatial variation in temporal trends and spatiotemporal patterns. At P = 0.05 level, the null hypothesis was rejected in every instance.

RESULTS

In general, the number of new CL cases decreased over the course of the 9-year research period. From 2011 to 2020, a regular seasonal pattern, with peaks in the fall and troughs in the spring, was found. The period of September-February of 2014-2015 was found to hold the highest risk in terms of CL incidence rate in the whole country [relative risk (RR) = 2.24, P < 0.001)]. In terms of location, six significant high-risk CL clusters covering 40.6% of the total area of the country were observed, with the RR ranging from 1.87 to 9.69. In addition, spatial variation in the temporal trend analysis found 11 clusters as potential high-risk areas that highlighted certain regions with an increasing tendency. Finally, five space-time clusters were found. The geographical displacement and spread of the disease followed a moving pattern over the 9-year study period affecting many regions of the country.

CONCLUSIONS

Our study has revealed significant regional, temporal, and spatiotemporal patterns of CL distribution in Iran. Over the years, there have been multiple shifts in spatiotemporal clusters, encompassing many different parts of the country from 2011 to 2020. The results reveal the formation of clusters across counties that cover certain parts of provinces, indicating the importance of conducting spatiotemporal analyses at the county level for studies that encompass entire countries. Such analyses, at a finer geographical scale, such as county level, might provide more precise results than analyses at the scale of the province.

Discovery and structure-activity relationship of Morita-Baylis-Hillman adducts as larvicides against dengue mosquito vector, Aedes aegypti (Diptera: Culicidae)

Neglected tropical diseases (NTDs) have become a significant public health problem worldwide, notably the life-threatening dengue hemorrhagic fever borne by the Aedes aegypti mosquito. Thus, mosquito vector control measures remain essential in public health vector surveillance and control to combat Aedes-borne infections. Therefore, a series of MBH adducts were synthesized and assessed towards the fourth instar mosquito larvae, Aedes aegypti, along with the preliminary structure-activity relationship (SAR). Noteworthy, this compound class might be synthetized by an efficient eco-friendly synthesismethod and a rapid route for the synthesis of commercial larvicide through a single synthetic step. The bioassays showed that this compound class is a promising larvicide to control Aedes aegypti mosquito larvae, mainly 3g, with an LC₅₀ of 41.35 µg/mL, which was higher than evaluated positive controls. Nevertheless, it is a viable larvicidalhit candidate for further hit-to-leadproperties optimization of its biphenyl backbone scaffold with enhanced insecticidalbioactivity. Moreover, scanning electron microscopy analysis suggested a disruption of the osmoregulatory/ionoregulatory functions by the complete deterioration of the terminal exoskeleton hindgut and anal papillae. Therefore, this new study shows the larvicidal efficacy of the tested compounds against the Aedes aegypti larvae.

Influence of amino acid size at the P3 position of N-Cbz-tripeptide Michael acceptors targeting falcipain-2 and rhodesain for the treatment of malaria and human african trypanosomiasis

In recent decades, several structure-activity relationship (SAR) studies provided potent inhibitors of the cysteine proteases falcipain-2 (FP-2) and rhodesain (RD) from Plasmodium falciparum and Trypanosoma brucei rhodesiense, respectively. Whilst the roles of the warhead and residues targeting the P1 and P2 pockets of the proteases were extensively investigated, the roles of the amino acids occupying the S3 pocket were not widely assessed. Herein we report the synthesis and biological evaluation of a set of novel Michael acceptors bearing amino acids of increasing size at the P3 site (1a-g/2a-g, SPR20-SPR33) against FP-2, RD, P. falciparum, and T. brucei. Overall, the Michael acceptors bearing small amino acids at the P3 site exhibited the most potent inhibitory properties towards FP-2. In contrast, analogues with bulky residues at the P3 position were very potent rhodesain inhibitors. In cell based assays, single-digit micromolar EC₅₀ values against the two protozoa were observed. These findings can be a starting point for the development of peptide-based FP-2 and RD inhibitors.

Morbidity hotspot surveillance: A novel approach to detect lymphatic filariasis transmission in non-endemic areas of the Tillabéry region of Niger

The Niger Lymphatic Filariasis (LF) Programme is making good progress towards the elimination goal and scaling up morbidity management and disability prevention (MMDP) activities. Clinical case mapping and the increased availability of services has prompted patients to come forward in both endemic and non-endemic districts. The latter included Filingué, Baleyara and Abala districts of the Tillabéry region, and in 2019, 315 patients were found during a follow-up active case finding activity, suggesting it may have low transmission. The aim of this study was to assess the endemicity status in areas reporting clinical cases, 'morbidity hotspots', in three non-endemic districts of the Tillabéry region. A cross-sectional survey was conducted in 12 villages in June 2021. Filarial antigen was detected using the rapid Filariasis Test Strip (FTS) diagnostic, and information obtained on gender, age, residency length, bed net ownership and usage, and presence of hydrocoele and/or lymphoedema. Data were summarised and mapped using QGIS software. A total of 4058 participants between 5 and 105 years old were surveyed, with 29 (0.7%) participants found to be FTS positive. Baleyara district had significantly higher FTS positive rates than the other districts. No significant differences were found by gender (male 0.8%; female 0.6%), age group (<26 years 0.7%; ≥26 years 0. 7%), and residency length (<5 years 0.7%; ≥5 years 0.7%). Three villages reported no infections; seven villages <1%, one village 1.1% and one village 4.1%, which was on the border of an endemic district. Bed net ownership (99.2%) and usage (92.6%) was very high and there was no significant difference between FTS infection rates. The results indicate that there are low levels of transmission in populations, including children, living in districts previously classified as non-endemic. This has implications for the Niger LF programme in terms of delivering targeted mass drug administration (MDA) in transmission hotspots, and MMDP services, including hydrocoele surgery to patients. The use of morbidity data may be a practical proxy to trigger mapping of ongoing transmission in low endemic areas. Continued efforts to study morbidity hotspots, post-validation transmission, cross-border and cross-district endemicity are needed to meet the WHO NTD 2030 roadmap targets.

Rapid ethnography and participatory techniques increase onchocerciasis mass drug administration treatment coverage in Benin: a difference-in-differences analysis

BACKGROUND

Onchocerciasis, a neglected tropical disease (NTD) that causes blindness, is controlled via mass drug administration (MDA) where entire endemic communities are targeted with preventative chemotherapeutic treatment. However, in many settings, MDA coverage remains low. The purpose of this project was to determine if engaging communities in the development of implementation strategies improves MDA coverage.

METHODS

This study took place in an intervention and a control commune in Benin, West Africa. We conducted rapid ethnography in each commune to learn about community member perceptions of onchocerciasis, MDA, and opportunities to increase MDA coverage. Findings were shared with key stakeholders and a structured nominal group technique was used to derive implementation strategies most likely to increase treatment coverage. The implementation strategies were delivered prior to and during onchocerciasis MDA. We conducted a coverage survey within 2 weeks of MDA to determine treatment coverage in each commune. A difference-in-differences design was used to determine if the implementation package effectively increased coverage. A dissemination meeting was held with the NTD program and partners to share findings and determine the perceived acceptability, appropriateness, and feasibility of implementing rapid ethnography as part of routine program improvement.

RESULTS

During rapid ethnography, key barriers to MDA participation included trust in community drug distributors, poor penetration of MDA programs in rural or geographically isolated areas, and low demand for MDA among specific sub-populations driven by religious or socio-cultural beliefs. Stakeholders developed a five-component implementation strategy package, including making drug distributor trainings dynamic, redesigning distributor job aids, tailoring community sensitization messages, formalizing supervision, and preparing local champions. After implementing the strategy package, MDA coverage increased by 13% (95% CI: 11.0-15.9%) in the intervention commune relative to the control commune. Ministry of Health and implementing partners found the approach to be largely acceptable and appropriate; however, there was mixed feedback regarding the feasibility of future implementation of rapid ethnography.

CONCLUSIONS

Implementation research conducted in Benin, and indeed throughout sub-Saharan Africa, is often implemented in a top-down manner, with both implementation determinants and strategies derived in the global North. This project demonstrates the importance of participatory action research involving community members and implementers to optimize program delivery.

Recent advancements in snake antivenom production

Snakebite envenoming (SBE), a neglected tropical disease, claims lives of about 138,000 people globally, and antivenom is the only approved treatment worldwide. However, this century-old therapy has serious limitations, including limited efficacy and some side effects. Although alternative and adjunct therapies are being developed, their commercialization will take time. Hence, improving existing antivenom therapy is crucial for immediate reduction in the global SBE burden. The neutralization potential and immunogenicity of antivenoms depend primarily on the venom pool used for animal immunization and the production host, along with antivenom purification procedure and quality control. Enhancing antivenom quality and production capacity are also critical actions of the World Health Organization (WHO) roadmap 2021 against SBE. The present review details the latest developments in antivenom production, such as immunogen preparation, production host, antibody purification methods, antivenom testing-including alternative animal models, in vitro assays, and proteomics and in silico methodologies, and storage, reported from 2018 to 2022. Based on these reports, we propose that production of broadly specific, affordable, safe, and effective (BASE) antivenoms is fundamental to realizing the WHO roadmap and reducing the global SBE burden. This concept can also be applied during the designing of alternative antivenoms.

Spatial and temporal distribution of Taenia solium and its risk factors in Uganda

OBJECTIVES

The lack of subnational mapping of the zoonotic cestode Taenia solium in endemic countries presents a major challenge to achieving intensified T. solium control milestones, as outlined in the "World Health Organization neglected tropical disease roadmap by 2030". We conducted a mapping study in Uganda, considered to be endemic, to identify subnational high-risk areas.

METHODS

T. solium prevalence data, adjusted for diagnostic sensitivity and specificity in a Bayesian framework, were identified through a systematic review. Spatial autocorrelation and interpolation techniques were used to transform demographic and health survey cluster-level sanitation and poverty indicators, overlaid onto a pig density map for Uganda into modelled  porcine cysticercosis (PCC) risk maps.

RESULTS

A total of 16 articles (n = 11 PCC and n = 5 human cysticercosis (HCC) and/or human taeniasis) were included in the final analysis. The observed HCC prevalence ranged from 0.01% to 6.0% (confidence interval range: 0.004-11.4%), whereas the adjusted PCC ranged from 0.3 to 93.9% (uncertainty interval range: 0-99.8%). There was substantial variation in the modelled  PCC risk factors and prevalence across Uganda and over time.

CONCLUSION

The high PCC prevalence and moderate HCC exposure estimates indicate the need for urgent implementation of T. solium control efforts in Uganda.

Efficacy and safety of antiparasitic therapy for neurocysticercosis in rural Tanzania: a prospective cohort study

PURPOSE

Neurocysticercosis is common in regions endemic for Taenia solium. Active-stage neurocysticercosis can be treated with antiparasitic medication, but so far no study on efficacy and safety has been conducted in Africa.

METHODS

We conducted a prospective cohort study on treatment of neurocysticercosis in Tanzania between August 2018 and January 2022. Patients were initially treated with albendazole (15 mg/kg/d) for 10 days and followed up for 6 months. Additionally in July 2021, all participants who then still had cysts were offered a combination therapy consisting of albendazole (15 mg/kg/d) and praziquantel (50 mg/kg/d). Antiparasitic treatment was accompanied by corticosteroid medication and anti-seizure medication if the patient had experienced epileptic seizures before treatment.

RESULTS

Sixty-three patients were recruited for this study, of whom 17 had a complete follow-up after albendazole monotherapy. These patients had a total of 138 cysts at baseline, of which 58 (42%) had disappeared or calcified by the end of follow-up. The median cyst reduction was 40% (interquartile range 11-63%). Frequency of epileptic seizures reduced considerably (p < 0.001). Three patients had all active cysts resolved or calcified and of the remaining 14, eight received the combination therapy which resolved 63 of 66 cysts (95%). Adverse events were infrequent and mild to moderate during both treatment cycles.

CONCLUSION

Cyst resolution was unsatisfactory with albendazole monotherapy but was very high when it was followed by a combination of albendazole and praziquantel.

Characterization of tungiasis infection and morbidity using thermography in Kenya revealed higher disease burden during COVID-19 school closures

BACKGROUND

Tungiasis is a neglected tropical skin disease caused by the sand flea Tunga penetrans. Female fleas penetrate the skin, particularly at the feet, and cause severe inflammation. This study aimed to characterize disease burden in two highly affected regions in Kenya, to test the use of thermography to detect tungiasis-associated inflammation and to create a new two-level classification of disease severity suitable for mapping, targeting, and monitoring interventions.

METHODS

From February 2020 to April 2021, 3532 pupils age 8-14 years were quasi-randomly selected in 35 public primary schools and examined for tungiasis and associated symptoms. Of the infected pupils, 266 were quasi-randomly selected and their households visited, where an additional 1138 family members were examined. Inflammation was assessed using infra-red thermography. A Clinical score was created combining the number of locations on the feet with acute and chronic symptoms and infra-red hotspots.

RESULTS

The overall prevalence of tungiasis among all the school pupils who were randomly selected during survey rounds 1 and 3 was 9.3% [95% confidence interval (CI): 8.4-10.3]. Based on mixed effects logistic models, the odds of infection with tungiasis among school pupils was three times higher in Kwale (coastal Kenya) than in Siaya [western Kenya; adjusted odds ratio (aOR) = 0.36, 95% CI: 0.18-0.74]; three times higher in males than in females (aOR = 3.0, 95% CI: 2.32-3.91) and three times lower among pupils sleeping in a house with a concrete floor (aOR = 0.32, 95% CI: 0.24-0.44). The odds of finding an infected person among the household population during surveys before the COVID-19 pandemic was a third (aOR = 0.32, 95% CI: 0.19-0.53) of that when schools were closed due to COVID-19 restrictions and approximately half (aOR = 0.44, 95% CI: 0.29-0.68) in surveys done after school re-opening (round 3). Infection intensity was positively correlated with inflammation as measured by thermography (Spearman's rho = 0.68, P < 0.001) and with the clinical score (rho = 0.86, P < 0.001). Based on the two-level classification, severe cases were associated with a threefold higher level of pain (OR = 2.99, 95% CI: 2.02-4.43) and itching (OR = 3.31, 95% CI: 2.24-4.89) than mild cases.

CONCLUSIONS

Thermography was a valuable addition for assessing morbidity and the proposed two-level classification of disease severity clearly separated patients with mild and severe impacts. The burden of tungiasis was considerably higher in households surveyed during COVID-19 restrictions suggesting underlying risks are found in the home environment more than in school.