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1.
Molecules ; 29(9)2024 Apr 23.
Article En | MEDLINE | ID: mdl-38731401

The burden of human schistosomiasis, a known but neglected tropical disease in Sub-Saharan Africa, has been worrisome in recent years. It is becoming increasingly difficult to tackle schistosomiasis with praziquantel, a drug known to be effective against all Schistosoma species, due to reports of reduced efficacy and resistance. Therefore, this study seeks to investigate the antischistosomal potential of phytochemicals from Azadirachta indica against proteins that have been implicated as druggable targets for the treatment of schistosomiasis using computational techniques. In this study, sixty-three (63) previously isolated and characterized phytochemicals from A. indica were identified from the literature and retrieved from the PubChem database. In silico screening was conducted to assess the inhibitory potential of these phytochemicals against three receptors (Schistosoma mansoni Thioredoxin glutathione reductase, dihydroorotate dehydrogenase, and Arginase) that may serve as therapeutic targets for schistosomiasis treatment. Molecular docking, ADMET prediction, ligand interaction, MMGBSA, and molecular dynamics simulation of the hit compounds were conducted using the Schrodinger molecular drug discovery suite. The results show that Andrographolide possesses a satisfactory pharmacokinetic profile, does not violate the Lipinski rule of five, binds with favourable affinity with the receptors, and interacts with key amino acids at the active site. Importantly, its interaction with dihydroorotate dehydrogenase, an enzyme responsible for the catalysis of the de novo pyrimidine nucleotide biosynthetic pathway rate-limiting step, shows a glide score and MMGBSA of -10.19 and -45.75 Kcal/mol, respectively. In addition, the MD simulation shows its stability at the active site of the receptor. Overall, this study revealed that Andrographolide from Azadirachta indica could serve as a potential lead compound for the development of an anti-schistosomal drug.


Azadirachta , Dihydroorotate Dehydrogenase , Molecular Docking Simulation , Oxidoreductases Acting on CH-CH Group Donors , Schistosomiasis , Azadirachta/chemistry , Animals , Schistosomiasis/drug therapy , Oxidoreductases Acting on CH-CH Group Donors/antagonists & inhibitors , Oxidoreductases Acting on CH-CH Group Donors/metabolism , Humans , Phytochemicals/pharmacology , Phytochemicals/chemistry , Molecular Dynamics Simulation , Schistosoma mansoni/drug effects , Schistosoma mansoni/enzymology , NADH, NADPH Oxidoreductases/antagonists & inhibitors , NADH, NADPH Oxidoreductases/metabolism , Plant Extracts/chemistry , Plant Extracts/pharmacology , Computer Simulation , Schistosomicides/pharmacology , Schistosomicides/chemistry , Schistosomicides/therapeutic use , Multienzyme Complexes/antagonists & inhibitors , Multienzyme Complexes/metabolism , Praziquantel/pharmacology , Praziquantel/chemistry , Praziquantel/therapeutic use
3.
PLoS One ; 19(5): e0300384, 2024.
Article En | MEDLINE | ID: mdl-38758736

BACKGROUND: Hundreds of millions of doses of Praziquantel (PZQ) have been administered to persons with and without schistosomiasis living in schistosomiasis endemic settings, through the mass drug administration (MDA) strategy which started in the early 2000s. A recent publication suggested high risk of PZQ-related visual disorders, raising public health concerns. We aim to systematically synthesize evidence on the magnitude of PZQ-related visual disorders. METHODS: We will search PubMed, Google Scholar, CINAHL, SCOPUS, CENTRAL and LILACS from 1977 (when the first human clinical trials on PZQ started) to 31st May 2024, with no language restrictions. The key search terms will include "Praziquantel", "PZQ", "visual disorder", "adverse events", "side effects", "blurry vision" and "visual impairment" together with alternative terms and synonyms. All the countries endemic for schistosomiasis will be included as search terms. We will also search HINARI, Africa Journals Online, Thesis Databases and Preprint Repositories. Where necessary, we will contact expert researchers working in the field of schistosomiasis, UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR), pharmaceutical industries, country-specific Food and Drug Authorities (FDAs) and the European Medicines Agency databases. We will search Conference Proceedings and reference lists of relevant studies for additional studies. At least two authors will independently select studies, extract data and assess risk of bias in the included studies. Any disagreements or discrepancies will be resolved through discussion between the reviewers. Heterogeneity will be explored graphically, and statistically using the I2-statistic. We will conduct random-effects meta-analysis when heterogeneity is appreciable, and express dichotomous outcomes (visual adverse events including excessive lacrimation, blurry vision and visual impairments) as risk ratio (RR) or Odds Ratio (OR) with their 95% confidence interval (CI). We will perform subgroup analysis to assess the impact of heterogeneity, and sensitivity analyses to test the robustness of the effect estimates. The overall level of evidence will be assessed using GRADE. EXPECTED OUTCOMES: The present review expects to identify and categorize visual disorders occurring after administration of PZQ, alone or in combination with other drugs. By synthesizing the data from multiple studies, the review aims to present a quantitative assessment of the risk or odds of experiencing a visual disorder in different populations after ingesting PZQ. The review will also generate insights into whether PZQ in combination with other drugs are associated with increased odds of visual disorders and whether the occurrence of visual disorders correlates with dosage or treatment duration. Policymakers, public health experts and stakeholders could rely on the review findings to deliver context-sensitive preventive chemotherapy programs by adjusting drug combinations or dosing schedules to reduce risk of visual adverse effects in populations treated with PZQ. The review aims to identify gaps in the current evidence regarding visual disorders following PZQ administration in schistosomiasis endemic settings which can serve as the basis for future research on important but unanswered questions. DISSEMINATION AND PROTOCOL REGISTRATION: The findings of this study will be disseminated through stakeholder forums, conferences, and peer-review publications. The review protocol has been registered in the International Prospective Register for Systematic Reviews (PROSPERO)- CRD42023417963.


Mass Drug Administration , Praziquantel , Schistosomiasis , Systematic Reviews as Topic , Vision Disorders , Humans , Schistosomiasis/epidemiology , Schistosomiasis/prevention & control , Schistosomiasis/drug therapy , Praziquantel/therapeutic use , Praziquantel/adverse effects , Praziquantel/administration & dosage , Vision Disorders/epidemiology , Vision Disorders/chemically induced , Meta-Analysis as Topic , Endemic Diseases/prevention & control , Anthelmintics/therapeutic use , Anthelmintics/administration & dosage , Anthelmintics/adverse effects
4.
PLoS One ; 19(5): e0302509, 2024.
Article En | MEDLINE | ID: mdl-38718082

BACKGROUND: Soil-transmitted helminthiasis (STH) and schistosomiasis (SCH) are among the most prevalent neglected tropical diseases (NTDs), affecting 1.5 billion globally, with a significant burden in sub-Saharan Africa, particularly Nigeria. These diseases impair health and contribute to socio-economic challenges, especially in children, undermining educational and future economic prospects. The 2030 NTD Roadmap highlights Mass Drug Administration (MDA) as a critical strategy for controlling these NTDs, targeting vulnerable populations like school-age children. Despite some successes, challenges persist, indicating the need for deeper insights into program implementation. This study focuses on the perspectives of health workers implementing MDA in selected local government areas (LGAs) of Ogun State, Nigeria, aiming to identify challenges and enablers that align with the broader NTD 2030 goals. METHODOLOGY/PRINCIPAL FINDINGS: The study used a qualitative research approach involving focus group discussions and in-depth interviews with health workers engaged in neglected tropical disease control programs in Ogun State, Nigeria, between July and September 2022. A semi-structured questionnaire guided the exploration of ideas, and the data were analyzed using the QRS Nvivo 12 software package. The study found that the school-based MDA control program's efficacy largely relies on strong collaborations and partnerships, particularly with educators, community heads, and other stakeholders. These alliances and strategic communication methods, like town announcements and media campaigns, have been pivotal in reaching communities. However, the program does grapple with hurdles such as parental misconceptions, limited funds, insufficient staffing, and misalignment with the Ministry of Education. It is recommended to boost funding, foster early stakeholder involvement, enhance mobilization techniques, and consider introducing a monitoring card system similar to immunization. CONCLUSIONS/SIGNIFICANCE: The MDA Integrated Control Programs for STH and SCH in Ogun State schools demonstrate a holistic approach, integrating knowledge, collaboration, communication, and feedback. Health workers have shown commitment and adeptness in their roles. However, achieving maximum efficacy requires addressing critical barriers, such as parental misconceptions and funding challenges. Adopting the recommended strategies, including proactive communication, increased remuneration, and introducing a tracking system, can significantly enhance the program's reach and impact. The involvement of all stakeholders, from health workers to community leaders and parents, is essential for the program's sustainability and success.


Health Personnel , Helminthiasis , Mass Drug Administration , Schistosomiasis , Soil , Humans , Nigeria/epidemiology , Schistosomiasis/prevention & control , Schistosomiasis/epidemiology , Schistosomiasis/drug therapy , Helminthiasis/prevention & control , Helminthiasis/epidemiology , Helminthiasis/drug therapy , Soil/parasitology , Male , Female , Schools , Adult , Neglected Diseases/prevention & control , Neglected Diseases/epidemiology , Child , Anthelmintics/therapeutic use , Anthelmintics/administration & dosage , Focus Groups
5.
Clin Infect Dis ; 78(Supplement_2): S153-S159, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38662699

BACKGROUND: Control of schistosomiasis (SCH) relies on the regular distribution of preventive chemotherapy (PC) over many years. For the sake of sustainable SCH control, a decision must be made at some stage to scale down or stop PC. These "stopping decisions" are based on population surveys that assess whether infection levels are sufficiently low. However, the limited sensitivity of the currently used diagnostic (Kato-Katz [KK]) to detect low-intensity infections is a concern. Therefore, the use of new, more sensitive, molecular diagnostics has been proposed. METHODS: Through statistical analysis of Schistosoma mansoni egg counts collected from Burundi and a simulation study using an established transmission model for schistosomiasis, we investigated the extent to which more sensitive diagnostics can improve decision making regarding stopping or continuing PC for the control of S. mansoni. RESULTS: We found that KK-based strategies perform reasonably well for determining when to stop PC at a local scale. Use of more sensitive diagnostics leads to a marginally improved health impact (person-years lived with heavy infection) and comes at a cost of continuing PC for longer (up to around 3 years), unless the decision threshold for stopping PC is adapted upward. However, if this threshold is set too high, PC may be stopped prematurely, resulting in a rebound of infection levels and disease burden (+45% person-years of heavy infection). CONCLUSIONS: We conclude that the potential value of more sensitive diagnostics lies more in the reduction of survey-related costs than in the direct health impact of improved parasite control.


Cost-Benefit Analysis , Parasite Egg Count , Schistosoma mansoni , Schistosomiasis mansoni , Humans , Animals , Schistosoma mansoni/isolation & purification , Schistosomiasis mansoni/diagnosis , Schistosomiasis mansoni/prevention & control , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/epidemiology , Anthelmintics/therapeutic use , Anthelmintics/economics , Female , Male , Schistosomiasis/diagnosis , Schistosomiasis/prevention & control , Schistosomiasis/drug therapy , Schistosomiasis/epidemiology , Adult , Adolescent , Child , Chemoprevention/economics , Chemoprevention/methods , Young Adult , Sensitivity and Specificity
6.
Bull World Health Organ ; 102(4): 265-275, 2024 Apr 01.
Article En | MEDLINE | ID: mdl-38562204

Objective: To determine if the prevalence of schistosomiasis in children aged 9-12 years is associated with the prevalence in 5-8-year-olds and adults after preventive chemotherapy in schools or the community. Methods: We combined data from four community-randomized, preventive chemotherapy trials in treatment-naïve populations in Côte d'Ivoire, Kenya and the United Republic of Tanzania during 2010-2016 according to the number of praziquantel treatments and the delivery method. Schistosoma mansoni infection was sought on two slides prepared from each participant's first stool using the Kato-Katz technique. We assessed associations between S. mansoni prevalence in 9-12-year-olds and 5-8-year-olds and adults in the community before and after treatment using Bayesian regression models. Findings: Stool samples from 47 985 5-8-year-olds, 81 077 9-12-year-olds and 20 492 adults were analysed. We found associations between the prevalence in 9-12-year-olds and that in 5-8-year-olds and adults after preventive treatment, even when only school-age children were treated. When the prevalence in 9-12-year-olds was under 10%, the prevalence in 5-8-year-olds was consistently under 10%. When the prevalence in 9-12-year-olds was under 50%, the prevalence in adults after two or four rounds of preventive chemotherapy was 10%-15% lower than before chemotherapy. Post-chemotherapy age-group associations were consistent with pre-chemotherapy associations in this analysis and previous studies. Conclusion: The prevalence of S. mansoni infection in 9-12-year-olds was associated with the prevalence in other age groups and could be used to guide community treatment decisions.


Schistosomiasis , Child , Adult , Humans , Cote d'Ivoire/epidemiology , Prevalence , Bayes Theorem , Kenya/epidemiology , Tanzania/epidemiology , Schistosomiasis/drug therapy , Schistosomiasis/epidemiology , Feces
7.
Int Marit Health ; 75(1): 49-54, 2024.
Article En | MEDLINE | ID: mdl-38647059

Schistosomiasis, caused by Schistosoma trematode worms, represents a significant global health challenge. This review offers a thorough examination of the disease's epidemiology, transmission dynamics, diagnostic modalities, and treatment options. Diagnostic techniques encompass direct parasitological methods, immunological assays, DNA/RNA detection, and biomarker utilization, each with distinct advantages and limitations. There is an urgent need for improved diagnostic tools with enhanced sensitivity and specificity. Praziquantel remains the cornerstone of treatment, exhibiting efficacy against all Schistosoma species, while the potential of artemisin derivatives in combination therapy is also explored. In this review, we focus on the importance of praziquantel administration as the central aspect of schistosomiasis treatment, highlighting ongoing efforts to optimize its utilization for improved patient outcomes.


Anthelmintics , Praziquantel , Schistosomiasis , Praziquantel/therapeutic use , Humans , Schistosomiasis/drug therapy , Schistosomiasis/diagnosis , Anthelmintics/therapeutic use , Animals , Schistosoma/drug effects
8.
ACS Infect Dis ; 10(5): 1520-1535, 2024 May 10.
Article En | MEDLINE | ID: mdl-38669567

The term "zoonosis" denotes diseases transmissible among vertebrate animals and humans. These diseases constitute a significant public health challenge, comprising 61% of human pathogens and causing an estimated 2.7 million deaths annually. Zoonoses not only affect human health but also impact animal welfare and economic stability, particularly in low- and middle-income nations. Leishmaniasis and schistosomiasis are two important neglected tropical diseases with a high prevalence in tropical and subtropical areas, imposing significant burdens on affected regions. Schistosomiasis, particularly rampant in sub-Saharan Africa, lacks alternative treatments to praziquantel, prompting concerns regarding parasite resistance. Similarly, leishmaniasis poses challenges with unsatisfactory treatments, urging the development of novel therapeutic strategies. Effective prevention demands a One Health approach, integrating diverse disciplines to enhance diagnostics and develop safer drugs. Metalloenzymes, involved in parasite biology and critical in different biological pathways, emerged in the last few years as useful drug targets for the treatment of human diseases. Herein we have reviewed recent reports on the discovery of inhibitors of metalloenzymes associated with zoonotic diseases like histone deacetylases (HDACs), carbonic anhydrase (CA), arginase, and heme-dependent enzymes.


Leishmania , Leishmaniasis , Schistosoma , Schistosomiasis , Zoonoses , Animals , Humans , Leishmaniasis/drug therapy , Leishmaniasis/parasitology , Schistosoma/drug effects , Schistosoma/enzymology , Zoonoses/drug therapy , Schistosomiasis/drug therapy , Leishmania/drug effects , Leishmania/enzymology , Carbonic Anhydrases/metabolism , Histone Deacetylases/metabolism , Enzyme Inhibitors/pharmacology
9.
Parasitol Res ; 123(4): 180, 2024 Apr 09.
Article En | MEDLINE | ID: mdl-38592544

Because of recent reports of praziquantel resistance in schistosome infections, there have been suggestions to employ ivermectin as a possible alternative, especially as its chemical composition is different from that of praziquantel, so cross-resistance is not expected. In order to ascertain possible damage and elimination of worms, we used ivermectin by oral gavage in infected mice, at a high dose (30.1 mg/kg, bordering toxicity). We also tested the efficacy of the drug at various times postinfection (PI), to check on possible effect on young and mature stages of the parasites. Thus, we treated mice on days 21 and 22 or on days 41 and 42 and even on days 21, 22, 41, and 42 PI. None of the treatment regimens resulted in cure rates or signs of lessened pathology in the mice. We also compared the effect of ivermectin to that of artemisone, an artemisinin derivative which had served us in the past as an effective anti-schistosome drug, and there was a stark difference in the artemisone's efficacy compared to that of ivermectin; while ivermectin was not effective, artemisone eliminated most of the worms, prevented egg production and granulomatous inflammatory response. We assume that the reported lack of activity of ivermectin, in comparison with praziquantel and artemisinins, originates from the difference in their mode of action. In wake of our results, we suggest that ivermectin is not a suitable drug for treatment of schistosomiasis.


Artemisinins , Schistosomatidae , Schistosomiasis , Animals , Mice , Praziquantel/therapeutic use , Ivermectin/therapeutic use , Schistosomiasis/drug therapy
10.
PLoS Negl Trop Dis ; 18(4): e0011766, 2024 Apr.
Article En | MEDLINE | ID: mdl-38626192

INTRODUCTION: Schistosomiasis is a parasitic infection highly prevalent in sub-Saharan Africa (SSA) with Madagascar being among the countries with highest burden of the disease worldwide. Despite WHO recommendations, suggesting treatment of pregnant women after the first trimester, this group is still excluded from Mass Drug Administration programs. Our study, had the objective to measure the prevalence of schistosome infection among pregnant women in Madagascar in order to inform public health policies for treatment in this vulnerable population. METHODS: Women were recruited for this cross-sectional study between April 2019 and February 2020 when attending Antenatal Care Services (ANCs) at one of 42 included Primary Health Care Centers. The urine-based upconverting reporter particle, lateral flow (UCP-LF) test detecting circulating anodic antigen was used for the detection of schistosome infections. To identify factors associated with the prevalence of schistosome infection crude and adjusted prevalence ratios and 95% CIs were estimated using mixed-effect Poisson regression. RESULTS: Among 4,448 participating women aged between 16 and 47 years, the majority (70.4%, 38 n = 3,133) resided in rural settings. Overall, the prevalence of schistosome infection was 55.9% (n = 2486, CI 95%: 53.3-58.5). A statistically significant association was found with age group (increased prevalence in 31-47 years old, compared to 16-20 years old (aPR = 1.15, CI 95%: 1.02-1.29) and with uptake of antimalaria preventive treatment (decreased prevalence, aPR = 0.85, CI 95%: 0.77-0.95). No other associations of any personal characteristics or contextual factors with schistosome infection were found in our multivariate regression analysis. DISCUSSION AND CONCLUSION: The high prevalence of schistosome infection in pregnant women supports the consideration of preventive schistosomiasis treatment in ANCs of the Malagasy highlands. We strongly advocate for adapting schistosomiasis programs in highly endemic contexts. This, would contribute to both the WHO and SDGs agendas overall to improving the well-being of women and consequently breaking the vicious cycle of poverty perpetuated by schistosomiasis.


Pregnancy Complications, Parasitic , Rural Population , Schistosomiasis , Vulnerable Populations , Humans , Female , Madagascar/epidemiology , Pregnancy , Cross-Sectional Studies , Adult , Young Adult , Adolescent , Middle Aged , Prevalence , Schistosomiasis/epidemiology , Schistosomiasis/drug therapy , Schistosomiasis/prevention & control , Pregnancy Complications, Parasitic/epidemiology , Pregnancy Complications, Parasitic/prevention & control , Pregnancy Complications, Parasitic/drug therapy , Public Health , Prenatal Care
11.
Parasitol Int ; 101: 102878, 2024 Aug.
Article En | MEDLINE | ID: mdl-38452972

OBJECTIVE: A case description of a rare occurrence of female genital schistosomiasis affecting the upper genital tract that presented with features mimicking an ovarian neoplasm. CASE REPORT: Female genital schistosomiasis is a neglected clinical manifestation of the water-born parasitic disease which occurs due to the presence of schistosome eggs in the genitalia of women. A 23-year-old nulliparous woman presented with progressive abdominal distension. An abdominopelvic CT scan revealed a multilobulated right adnexal mass with gross ascites. Diagnosis of schistosomiasis was made by histology of biopsied specimens following laparotomy. Cervical colposcopic findings were consistent with female genital schistosomiasis. She was successfully treated with praziquantel. CONCLUSION: Female genital schistosomiasis of the upper genital tract can mimic an ovarian malignancy. Hence there is a need for its consideration as a differential diagnosis in patients with non-classical presentations of pelvic tumours in schistosomiasis-endemic areas.


Ovarian Neoplasms , Praziquantel , Female , Humans , Ovarian Neoplasms/diagnosis , Ovarian Neoplasms/pathology , Ovarian Neoplasms/drug therapy , Praziquantel/therapeutic use , Diagnosis, Differential , Young Adult , Anthelmintics/therapeutic use , Schistosomiasis haematobia/diagnosis , Schistosomiasis haematobia/drug therapy , Schistosomiasis/diagnosis , Schistosomiasis/drug therapy , Animals
12.
Expert Opin Pharmacother ; 25(4): 409-420, 2024 Mar.
Article En | MEDLINE | ID: mdl-38511392

INTRODUCTION: Schistosomiasis, one of the current Neglected Tropical Diseases (NTDs) affects over 230 million people globally, with nearly 700 million at risk in more than 74 countries. Praziquantel (PZQ) has served as the primary treatment for the past four decades; however, its effectiveness is limited as it solely eliminates adult worms. In regions where infections are frequent, PZQ exhibits only temporary efficacy and has restricted potential to disrupt the prolonged transmission of the disease. AREAS COVERED: A comprehensive exploration using the PubMed database was conducted to review current pharmacotherapy approaches for schistosomiasis. This review also encompasses recent research findings related to potential novel therapeutics and the repurposing of existing drugs. EXPERT OPINION: Current schistosoma treatment strategies, primarily relying on PZQ, face challenges like temporary effectiveness and limited impact on disease transmission. Drug repurposing, due to economic constraints, is decisive for NTDs. Despite PZQ's efficacy, its failure to prevent reinfection highlights the need for complementary strategies, especially in regions with persistent environmental foci. Integrating therapies against diverse schistosome stages boosts efficacy and impedes resistance. Uncovering novel agents is essential to address resistance concerns in tackling this neglected tropical disease. Integrated strategies present a comprehensive approach to navigate the complex challenges.


Drug Repositioning , Neglected Diseases , Praziquantel , Schistosomiasis , Schistosomicides , Humans , Schistosomiasis/drug therapy , Animals , Praziquantel/therapeutic use , Neglected Diseases/drug therapy , Neglected Diseases/prevention & control , Schistosomicides/therapeutic use , Drug Resistance , Schistosoma/drug effects
13.
PLoS Negl Trop Dis ; 18(2): e0011992, 2024 Feb.
Article En | MEDLINE | ID: mdl-38416775

Schistosomiasis is a major neglected parasitic disease that affects more than 240 million people worldwide caused by Platyhelminthes of the genus Schistosoma. The treatment of schistosomiasis relies on the long-term application of a single safe drug, praziquantel (PZQ). Unfortunately, PZQ is very effective on adult parasites and poorly on larval stage and immature juvenile worms; this can partially explain the re-infection in endemic areas where patients are likely to host parasites at different developmental stages concurrently. Moreover, the risk of development of drug resistance because of the widespread use of a single drug in a large population is nowadays a serious threat. Hence, research aimed at identifying novel drugs to be used alone or in combination with PZQ is needed. Schistosomes display morphologically distinct stages during their life cycle and epigenetic mechanisms are known to play important roles in parasite growth, survival, and development. Histone deacetylase (HDAC) enzymes, particularly HDAC8, are considered valuable for therapeutic intervention for the treatment of schistosomiasis. Herein, we report the phenotypic screening on both larvae and adult Schistosoma mansoni stages of structurally different HDAC inhibitors selected from the in-house Siena library. All molecules have previously shown inhibition profiles on human HDAC6 and/or HDAC8 enzymes. Among them we identified a quinolone-based HDAC inhibitor, NF2839, that impacts larval and adult parasites as well as egg viability and maturation in vitro. Importantly, this quinolone-based compound also increases histone and tubulin acetylation in S. mansoni parasites, thus representing a leading candidate for the development of new generation anti-Schistosoma chemotherapeutics.


Anthelmintics , Histone Deacetylase Inhibitors , Quinolones , Schistosomiasis mansoni , Schistosomiasis , Animals , Humans , Anthelmintics/pharmacology , Anthelmintics/therapeutic use , Histone Deacetylase 6/antagonists & inhibitors , Larva , Praziquantel/pharmacology , Praziquantel/therapeutic use , Quinolones/pharmacology , Repressor Proteins , Schistosoma mansoni , Schistosomiasis/drug therapy , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/parasitology , Histone Deacetylase Inhibitors/chemistry , Histone Deacetylase Inhibitors/pharmacology , Histone Deacetylase Inhibitors/therapeutic use
14.
Acta Trop ; 252: 107141, 2024 Apr.
Article En | MEDLINE | ID: mdl-38342286

The impact of diet composition and energy content on schistosomiasis evolution and treatment efficacy is still controversial. This study compared the impact of sucrose-rich diet and intermittent fasting on Schistosoma mansoni infection and praziquantel (PZQ)-based chemotherapy response in mice. BALB/c mice were infected with S. mansoni and followed for 15 weeks. The animals were randomized into nine groups receiving high glycemic load (high-sucrose diet - HSD), low caloric load (standard chow alternate-day fasting - ADF), and standard chow ad libitum (AL). Eight weeks after S. mansoni infection, these groups remained untreated or were treated with PZQ (300 mg/kg/day) for 3 days. Our results indicated that parasite load (S. mansoni eggs and parasite DNA levels), granulomatous inflammation (granulomas number and size), and liver microstructural damage (reduction in hepatocytes number, increase in nucleus-cytoplasm ratio, connective stroma expansion and fibrosis) were increased in ADF-treated animals. These animals also showed decreased eggs retention, granulomatous inflammation and collagen accumulation in the small intestine. Conversely, HSD diet and PZQ treatment attenuated all these parameters and stimulated hepatic regenerative response. PZQ also stimulated fibrosis resolution in HSD-treated mice, effect that was limited ADF-exposed mice. Our findings indicate that dietary glycemic and energy load can modulate schistosomiasis progression and the severity of hepatic and intestinal granulomatous inflammation in untreated and PZQ-treated mice. Thus, lower intestinal eggs retention may potentially be linked to worsening liver disease in ADF, while attenuation of hepatic and intestinal granulomatous inflammation is consistent with reduced parasite load in HSD- and PZQ-treated animals.


Anthelmintics , Liver Diseases , Schistosomiasis mansoni , Schistosomiasis , Animals , Mice , Schistosoma mansoni , Antiparasitic Agents/therapeutic use , Praziquantel/pharmacology , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/parasitology , Liver/parasitology , Schistosomiasis/drug therapy , Inflammation/drug therapy , Fibrosis , Diet , Sucrose/pharmacology , Sucrose/therapeutic use , Anthelmintics/therapeutic use
15.
Br Med Bull ; 149(1): 45-59, 2024 Mar 13.
Article En | MEDLINE | ID: mdl-38220571

BACKGROUND: Female genital schistosomiasis (FGS) is a chronic gynaecological disease affecting girls and women in sub-Saharan Africa (SSA), caused by the parasite Schistosoma (S.) haematobium. FGS is associated with sexual dysfunction, reproductive tract morbidity and increased prevalence of HIV and cervical precancer lesions. SOURCE OF DATA: Key peer-reviewed published literature. AREAS OF AGREEMENT: FGS screening and diagnosis require costly equipment and specialized training, seldom available in resource-limited settings. FGS surveillance is not included in wider schistosomiasis control strategies. The interplay of FGS with other SRH infections is not fully understood. Integration of FGS within sexual and reproductive health (SRH) control programmes needs to be explored. AREAS OF CONTROVERSY: There are no standardized methods for individual or population-based FGS screening and diagnosis, hindering accurate disease burden estimates and targeted resource allocation. Treatment recommendations rely on public health guidelines, without rigorous clinical evidence on efficacy. GROWING POINTS: Integrating FGS screening with SRH programmes offers an opportunity to reach at-risk women with limited access to healthcare services. Home-based self-sampling coupled with handheld colposcopes operated by primary healthcare workers show promise for FGS diagnosis and surveillance at scale. AREAS TIMELY FOR DEVELOPING RESEARCH: There is growing interest in decentralizing strategies for FGS screening and diagnosis. The accurate predictions on the 'cost-effectiveness' of these approaches will determine their affordability and feasibility within the overburdened health systems in SSA. Clinical trials are needed to optimize FGS treatment. Longitudinal studies can expand on the epidemiological knowledge on co-morbidities and integration within other SRH interventions.


Genital Diseases, Female , Schistosomiasis , Female , Humans , Schistosomiasis/drug therapy , Genitalia, Female/parasitology , Genital Diseases, Female/diagnosis , Genital Diseases, Female/epidemiology , Genital Diseases, Female/parasitology , Specimen Handling , Prevalence
16.
Chem Biodivers ; 21(3): e202301929, 2024 Mar.
Article En | MEDLINE | ID: mdl-38278761

Schistosomiasis is a major neglected disease that imposes a substantial worldwide health burden, affecting approximately 250 million people globally. As praziquantel is the only available drug to treat schistosomiasis, there is a critical need to identify new anthelmintic compounds, particularly from natural sources. To enhance the activity of different natural products, one potential avenue involves its combination with silver nanoparticles (AgNP). Based on this approach, a one-step green method for the in situ preparation of dehydrodieugenol (DHDG) by oxidation coupling reaction using silver and natural eugenol is presented. AgNP formation was confirmed by UV-Vis spectroscopy due to the appearance of the surface plasmon resonance (SPR) band at 430 nm which is characteristic of silver nanoparticles. The nanoparticles were spherical with sizes in the range of 40 to 50 nm. Bioassays demonstrated that the silver nanoparticles loaded with DHDG exhibited significant anthelmintic activity against Schistosoma mansoni adult worms without toxicity to mammalian cells and an in vivo animal model (Caenorhabditis elegans), contributing to the development of new prototypes based on natural products for the treatment of schistosomiasis.


Anthelmintics , Anti-Infective Agents , Biological Products , Eugenol/analogs & derivatives , Lignans , Metal Nanoparticles , Schistosomiasis , Animals , Humans , Silver/pharmacology , Silver/chemistry , Metal Nanoparticles/chemistry , Anthelmintics/pharmacology , Anthelmintics/therapeutic use , Schistosomiasis/drug therapy , Anti-Infective Agents/therapeutic use , Schistosoma mansoni , Biological Products/therapeutic use , Mammals
17.
Sci Rep ; 14(1): 1582, 2024 01 18.
Article En | MEDLINE | ID: mdl-38238498

Schistosomiasis is caused by parasites of the genus Schistosoma, which infect more than 200 million people. Praziquantel (PZQ) has been the main drug for controlling schistosomiasis for over four decades, but despite that it is ineffective against juvenile worms and size and taste issues with its pharmaceutical forms impose challenges for treating school-aged children. It is also important to note that PZQ resistant strains can be generated in laboratory conditions and observed in the field, hence its extensive use in mass drug administration programs raises concerns about resistance, highlighting the need to search for new schistosomicidal drugs. Schistosomes survival relies on the redox enzyme thioredoxin glutathione reductase (TGR), a validated target for the development of new anti-schistosomal drugs. Here we report a high-throughput fragment screening campaign of 768 compounds against S. mansoni TGR (SmTGR) using X-ray crystallography. We observed 49 binding events involving 35 distinct molecular fragments which were found to be distributed across 16 binding sites. Most sites are described for the first time within SmTGR, a noteworthy exception being the "doorstop pocket" near the NADPH binding site. We have compared results from hotspots and pocket druggability analysis of SmTGR with the experimental binding sites found in this work, with our results indicating only limited coincidence between experimental and computational results. Finally, we discuss that binding sites at the doorstop/NADPH binding site and in the SmTGR dimer interface, should be prioritized for developing SmTGR inhibitors as new antischistosomal drugs.


Multienzyme Complexes , NADH, NADPH Oxidoreductases , Schistosomiasis mansoni , Schistosomiasis , Animals , Child , Humans , Schistosoma mansoni , Crystallography, X-Ray , NADP/metabolism , Schistosomiasis/drug therapy , Binding Sites , Schistosomiasis mansoni/parasitology
18.
PLoS Negl Trop Dis ; 18(1): e0011886, 2024 Jan.
Article En | MEDLINE | ID: mdl-38265982

Malaria and schistosomiasis are two important parasitic diseases that are a particular threat to young children and pregnant women in sub-Saharan Africa. Malaria and schistosomiasis prevention and control strategies primarily focus on the distribution of long-lasting insecticidal nets and the delivery of praziquantel tablets to at-risk populations in high burden settings through mass drug administration, respectively. The objective of this scoping review was to identify previous efforts to integrate malaria and schistosomiasis prevention and control programs in the literature and to summarize the strategies and approaches used in these programs following the PRISMA-ScR guidelines. We reviewed published and grey literature using a combination of keywords and search terms following themes surrounding "malaria", "Plasmodium falciparum", "Anopheles", "schistosomiasis", "Schistosoma haematobium", "Schistosoma mansoni", and "snails". Neither a date limit nor relevant terms for prevention and control were used. Out of 6374, eight articles were included in the scoping review-three articles investigated the integration of mass drug administration for schistosomiasis with the administration of antimalarials, four articles investigated the effect of administering antimalarials on malaria, schistosomiasis, and their co-infection, and one article assessed the impact of an educational intervention on malaria and schistosomiasis knowledge and preventative behaviors. Our findings suggest that there is an opportunity to link disease control programs to increase access and coverage of interventions to improve outcomes for malaria, schistosomiasis, and their co-infection. Further research is needed on the potential benefits, feasibility, and cost-effectiveness of integrating malaria and schistosomiasis prevention and control programs.


Antimalarials , Coinfection , Malaria , Schistosomiasis , Pregnancy , Child , Animals , Humans , Female , Child, Preschool , Antimalarials/therapeutic use , Malaria/drug therapy , Malaria/prevention & control , Schistosomiasis/drug therapy , Schistosomiasis/prevention & control , Schistosoma haematobium
19.
BMC Health Serv Res ; 24(1): 11, 2024 Jan 03.
Article En | MEDLINE | ID: mdl-38172854

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.


Helminths , Schistosomiasis , Animals , Humans , Cross-Sectional Studies , Malawi/epidemiology , Mass Drug Administration , Praziquantel/therapeutic use , Prevalence , Schistosomiasis/drug therapy , Schistosomiasis/epidemiology , Schistosomiasis/prevention & control , Soil/parasitology
20.
Proc Natl Acad Sci U S A ; 121(2): e2315463120, 2024 Jan 09.
Article En | MEDLINE | ID: mdl-38181058

Schistosomiasis is a neglected tropical disease affecting over 150 million people. Hotspots of Schistosoma transmission-communities where infection prevalence does not decline adequately with mass drug administration-present a key challenge in eliminating schistosomiasis. Current approaches to identify hotspots require evaluation 2-5 y after a baseline survey and subsequent mass drug administration. Here, we develop statistical models to predict hotspots at baseline prior to treatment comparing three common hotspot definitions, using epidemiologic, survey-based, and remote sensing data. In a reanalysis of randomized trials in 589 communities in five endemic countries, a regression model predicts whether Schistosoma mansoni infection prevalence will exceed the WHO threshold of 10% in year 5 ("prevalence hotspot") with 86% sensitivity, 74% specificity, and 93% negative predictive value (NPV; assuming 30% hotspot prevalence), and a regression model for Schistosoma haematobium achieves 90% sensitivity, 90% specificity, and 96% NPV. A random forest model predicts whether S. mansoni moderate and heavy infection prevalence will exceed a public health goal of 1% in year 5 ("intensity hotspot") with 92% sensitivity, 79% specificity, and 96% NPV, and a boosted trees model for S. haematobium achieves 77% sensitivity, 95% specificity, and 91% NPV. Baseline prevalence is a top predictor in all models. Prediction is less accurate in countries not represented in training data and for a third hotspot definition based on relative prevalence reduction over time ("persistent hotspot"). These models may be a tool to prioritize high-risk communities for more frequent surveillance or intervention against schistosomiasis, but prediction of hotspots remains a challenge.


Schistosomiasis mansoni , Schistosomiasis , Humans , Animals , Mass Drug Administration , Schistosomiasis/drug therapy , Schistosomiasis/epidemiology , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/epidemiology , Schistosoma haematobium , Models, Statistical
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