Efficacy and safety of praziquantel 40 mg/kg in preschool-aged and school-aged children: a meta-analysis

In vitro and in vivo efficacy of the amiodarone and praziquantel combination against the blood fluke Schistosoma mansoni

Schistosomiasis, a widespread parasitic disease caused by the blood fluke of the genus Schistosoma, affects over 230 million people, primarily in developing countries. Praziquantel, the sole drug currently approved for schistosomiasis treatment, demonstrates effectiveness against patent infections. A recent study highlighted the antiparasitic properties of amiodarone, an anti-arrhythmic drug, exhibiting higher efficacy than praziquantel against prepatent infections. This study assessed the efficacy of amiodarone and praziquantel, both individually and in combination, against Schistosoma mansoni through comprehensive in vitro and in vivo experiments. In vitro experiments demonstrated synergistic activity (fractional inhibitory concentration index ≤0.5) for combinations of amiodarone with praziquantel. In a murine model of schistosomiasis featuring prepatent infections, treatments involving amiodarone (200 or 400 mg/kg) followed by praziquantel (200 or 400 mg/kg) yielded a substantial reduction in worm burden (60%-70%). Given the low efficacy of praziquantel in prepatent infections, combinations of amiodarone with praziquantel may offer clinical utility in the treatment of schistosomiasis.

Praziquantel-related visual disorders among recipients in mass drug administration campaigns in schistosomiasis endemic settings: Systematic review and meta-analysis protocol

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.

Threshold dynamics of a reaction-advection-diffusion schistosomiasis epidemic model with seasonality and spatial heterogeneity

Most water-borne disease models ignore the advection of water flows in order to simplify the mathematical analysis and numerical computation. However, advection can play an important role in determining the disease transmission dynamics. In this paper, we investigate the long-term dynamics of a periodic reaction-advection-diffusion schistosomiasis model and explore the joint impact of advection, seasonality and spatial heterogeneity on the transmission of the disease. We derive the basic reproduction number R 0 and show that the disease-free periodic solution is globally attractive whenR 0 < 1 whereas there is a positive endemic periodic solution and the system is uniformly persistent in a special case whenR 0 > 1 . Moreover, we find that R 0 is a decreasing function of the advection coefficients which offers insights into why schistosomiasis is more serious in regions with slow water flows.

Advances in the study of the interaction between schistosome infections and the host's intestinal microorganisms

Schistosomiasis, also called bilharziasis, is a neglected tropical disease induced by schistosomes that infects hundreds of millions of people worldwide. In the life cycle of schistosomiasis, eggs are regarded as the main pathogenic factor, causing granuloma formation in the tissues and organs of hosts, which can cause severe gastrointestinal and liver granulomatous immune responses and irreversible fibrosis. Increasing evidence suggests that the gut microbiome influences the progression of schistosomiasis and plays a central role in liver disease via the gut-liver axis. When used as pharmaceutical supplements or adjunctive therapy, probiotics have shown promising results in preventing, mitigating, and even treating schistosomiasis. This review elucidates the potential mechanisms of this three-way parasite-host-microbiome interaction by summarizing schistosome-mediated intestinal flora disorders, local immune changes, and host metabolic changes, and elaborates the important role of the gut microbiome in liver disease after schistosome infection through the gut-liver axis. Understanding the mechanisms behind this interaction may aid in the discovery of probiotics as novel therapeutic targets and sustainable control strategies for schistosomiasis.

Consensus definitions in imported human schistosomiasis: a GeoSentinel and TropNet Delphi study

Terminology in schistosomiasis is not harmonised, generating misunderstanding in data interpretation and clinical descriptions. This study aimed to achieve consensus on definitions of clinical aspects of schistosomiasis in migrants and returning travellers. We applied the Delphi method. Experts from institutions affiliated with GeoSentinel and TropNet, identified through clinical and scientific criteria, were invited to participate. Five external reviewers revised and pilot-tested the statements. Statements focusing on the definitions of acute or chronic; possible, probable, or confirmed; active; and complicated schistosomiasis were managed through REDCap and replies managed in a blinded manner. Round 1 mapped the definitions used by experts; subsequent rounds were done to reach consensus, or quantify disagreement, on the proposed statements. Data were analysed with percentages, medians, and IQRs of a 5-point Likert scale. The study was terminated on the basis of consensus or stability-related and time-related criteria. 28 clinicians and scientists met the criteria for experts. 25 (89%) of 28 experts replied to Round 1, 18 (64%) of 28 to Round 2, 19 (68%) of 28 to Round 3, and 21 (75%) of 28 to at least two rounds. High-level consensus (79-100% agreement and IQRs ≤1) was reached for all definitions. Consensus definitions will foster harmonised scientific and clinical communication and support future research and development of management guidelines for schistosomiasis.

Efficacy and safety of prazequantel for the treatment of Schistosoma mansoni infection across different transmission settings in Amhara Regional State, northwest Ethiopia

BACKGROUND

Schistosoma mansoni and S. haematobium infections have been public health problems in Ethiopia, S. mansoni being more prevalent. To reduce the burden of schistosomiasis, a national school-based prazequantel (PZQ) mass drug administration (MDA) program has been implemented since November 2015. Nevertheless, S. mansoni infection is still a major public health problem throughout the country. Reduced efficacy of PZQ is reported by a few studies in Ethiopia, but adequate data in different geographical settings is lacking. Hence, this study aimed to assess the efficacy and safety of PZQ for the treatment of S. mansoni infection across different transmission settings in Amhara Regional State, northwest Ethiopia.

METHODS

A school-based single-arm prospective cohort study was conducted from February to June, 2023 among 130 S. mansoni-infected school-aged children (SAC). Forty-two, 37, and 51 S. mansoni-infected SAC were recruited from purposely selected schools located in low, moderate, and high transmission districts, respectively. School-aged children who were tested positive both by Kato Katz (KK) using stool samples and by the point of care circulating cathodic antigen (POC-CCA) test using urine samples at baseline were treated with a standard dose of PZQ and followed for 21 days for the occurrence of adverse events. After three weeks post-treatment, stool and urine samples were re-tested using KK and POC-CCA. Then the cure rate (CR), egg reduction rate (ERR), and treatment-associated adverse events were determined. The data were analyzed using SPSS version 21.

RESULTS

Out of the total 130 study participants, 110 completed the follow-up. The CR and ERR of PZQ treatment were 88.2% (95%CI: 82.7-93.6) and 93.5% (95%CI: 85.4-98.5), respectively, by KK. The CR of PZQ based on the POC-CCA test was 70.9% (95%CI: 62.7-79.1) and 75.5% (95%CI: 67.3-83.6) depending on whether the interpretation of 'trace' results was made as positive or negative, respectively. After treatment on the 21st day, 78 and 83 participants tested negative both by KK and POC-CCA, with respective interpretations of 'trace' POC-CCA test results as positive or negative. The CR in low, moderate and high transmission settings was 91.7%, 91.2% and 82.5%, respectively (p = 0.377) when evaluated by KK. The CR among SAC with a light infection at baseline (95.7%) by KK was higher than that of moderate (81.5%) and heavy (64.3%) infections (χ2 = 12.53, p = 0.002). Twenty-six (23.6%) participants manifested at least one adverse event. Eleven (10.0%), eight (7.3%), six (5.5%), and three (2.7%) participants complained about abdominal pain, nausea, headache, and anorexia, respectively. All adverse events were mild, needing no intervention. Occurrence of adverse events was slightly higher in high endemic areas (32.5%) than moderate (23.5%) and low endemic areas (p = 0.279).

CONCLUSIONS

A single dose of 40 mg/kg PZQ was efficacious and safe for the treatment of S. mansoni infection when it was evaluated by the KK test, but a lower efficacy was recorded when it was evaluated by the POC-CCA test. However, the POC-CCA test's specificity, clearance time of CCA from urine after treatment, and interpretation of weakly reactive (trace) test results need further research.

Current drug strategies for the treatment and control of schistosomiasis

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.

Development of subunit selective proteasome substrates for Schistosoma species

Schistosomiasis, or bilharzia, is a neglected tropical disease caused by Schistosoma spp. blood flukes that infects over 200 million people worldwide. Just one partially effective drug is available, and new drugs and drug targets would be welcome. The 20S proteasome is a validated drug target for many parasitic infections, including those caused by Plasmodium and Leishmania. We previously showed that anticancer proteasome inhibitors that act through the Schistosoma mansoni 20S proteasome (Sm20S) kill the parasite in vitro. To advance these initial findings, we employed Multiplex Substrate Profiling by Mass Spectrometry (MSP-MS) to define the substrate cleavage specificities of the three catalytic β subunits of purified Sm20S. The profiles in turn were used to design and synthesize subunit-specific optimized substrates that performed two to eight fold better than the equivalent substrates used to measure the activity of the constitutive human proteasome (c20S). These specific substrates also eliminated the need to purify Sm20S from parasite extracts - a single step enrichment was sufficient to accurately measure substrate hydrolysis and its inhibition with proteasome inhibitors. Finally, we show that the substrate and inhibition profiles for the 20S proteasome from the three medically important schistosome species are similar, suggesting that data arising from an inhibitor development campaign that focuses on Sm20S can be extrapolated to the other two targets with consequent time and cost savings.

Antimalarial artesunate-mefloquine versus praziquantel in African children with schistosomiasis: an open-label, randomized controlled trial

Schistosomiasis treatment entirely relies on a single drug, praziquantel, prompting research into alternative therapeutics. Here we evaluated the efficacy and safety of the antimalarial combination artesunate-mefloquine for the treatment of schistosomiasis in a proof-of-concept, pragmatic, open-label, randomized controlled trial in primary schools of six villages endemic for schistosomiasis in northern Senegal. Children (6-14 years) were eligible if Schistosoma eggs were detected by microscopy in urine and/or stool. In total, 726 children were randomized 1:1 to praziquantel (standard care: 40 mg kg-1 single dose; n = 364) or to artesunate-mefloquine (antimalarial dosage: artesunate 4 mg kg-1 and mefloquine 8 mg kg-1 daily for three consecutive days; n = 362). Eight children not meeting the inclusion criteria were excluded from efficacy analysis. Median age of the remaining 718 participants was 9 years; 399 (55.6%) were male, and 319 (44.4%) female; 99.3% were infected with Schistosoma haematobium and 15.2% with S. mansoni. Primary outcomes were cure rate, assessed by microscopy, and frequency of drug-related adverse effects of artesunate-mefloquine versus praziquantel at 4 weeks after treatment. Cure rate was 59.6% (208/349) in the artesunate-mefloquine arm versus 62.1% (211/340) in the praziquantel arm. The difference of -2.5% (95% confidence interval (CI) -9.8 to 4.8) met the predefined criteria of noninferiority (margin set at 10%). All drug-related adverse events were mild or moderate, and reported in 28/361 children receiving artesunate-mefloquine (7.8%; 95% CI 5.4 to 11.0) versus 8/363 (2.2%; 95% CI 1.1 to 4.3) receiving praziquantel (P < 0.001). Artesunate-mefloquine at antimalarial dosage was moderately safe and noninferior to standard-care praziquantel for the treatment of schistosomiasis, predominantly due to S. haematobium. Multicentric trials in different populations and epidemiological settings are needed to confirm these findings. ClinicalTrials.gov identifier: NCT03893097 .

Anthelmintic efficacy evaluation and mechanism of N-methylbenzo[d]oxazol-2-amine

Parasitic roundworms cause significant sickness and mortality in animals and humans. In livestock, these nematodes have severe economic impact and result in losses in food production on a global scale. None of the currently available drugs ideally suit all treatment circumstances, and the development of drug-resistant nematode strains has become a challenge to control the infection. There is an urgent need to develop novel anthelmintic compounds. According to our previous report, N-methylbenzo[d]oxazol-2-amine (1) showed anthelmintic activity and lowest cytotoxicity. In this study, in vivo anthelmintic properties were evaluated using Trichinella spiralis infected mice. Toxicity was evaluated using the rats and mode of action using molecular docking and metabolomics approaches. The in vivo results demonstrate that a dose of 250 mg/kg reduced the T. spiralis abundance in the digestive tract by 49%. The 250 mg/kg Albendazole was served as control. The relatively low acute toxicity was categorized into chemical category 5, with an LD50 greater than 2000 mg/kg body. Molecular docking analysis showed the T. spiralis tubulin beta chain and glutamate-gated channels might not be the main targets of compound 1. Metabolomics analysis was used to explain the effects of compound 1 on the T. spiralis adult worm. The results demonstrated that compound 1 significantly up-regulated the metabolism of purine, pyrimidine and down-regulated sphingolipid metabolism. In conclusion, compound 1 could be a potential molecule for anthelmintic development. The bioavailability, pharmacokinetics, and absorption of this compound should be studied further to provide information for its future efficacy improvement.

Efficacy and safety of praziquantel treatment against Schistosoma mansoni infection among pre-school age children in southern Ethiopia

BACKGROUND

Preventive chemotherapy with a single dose of praziquantel given to an all-at-risk population through mass drug administration is the cornerstone intervention to control and eliminate schistosomiasis as a public health problem. This intervention mainly targets school age children, and pre-school age children (pre-SAC) are excluded from receiving preventive chemotherapy, partly due to scarcity of data on praziquantel treatment outcomes.

METHODS

We conducted active efficacy and safety surveillance of praziquantel treatment among 240 Schistosoma mansoni-infected pre-SAC who received a single dose of praziquantel (40 mg/kg) in southern Ethiopia. The study outcomes were egg reduction rates (ERR) and cure rates (CRs) four weeks after treatment using the Kato-Katz technique and treatment-associated adverse events (AEs) that occurred within 8 days post-treatment.

RESULTS

The overall ERR was 93.3% (WHO reference threshold ≥ 90%), while the CR was 85.2% (95% CI = 80.0-89.5%). Baseline S. mansoni infection intensity was significantly associated with CRs, 100% among light infected than moderate (83.4%) or heavy (29.4%) infected children. An increase of 100 in baseline S. mansoni egg count per gram of stool resulted in a 26% (95% CI: 17%, 34%) reduction in the odds of cure. The incidence of experiencing at least one type of AE was 23.1% (95% CI: 18.0%, 29.0%). Stomachache, diarrhea, and nausea were the most common AEs. AEs were mild-to-moderate grade and transient. Pre-treatment moderate (ARR = 3.2, 95% CI: 1.69, 6.14) or heavy infection intensity (ARR = 6.5, 95% CI: 3.62, 11.52) was a significant predictor of AEs (p < 0.001). Sex, age, or soil-transmitted helminth coinfections were not significant predictors of CR or AEs.

CONCLUSIONS

Single-dose praziquantel is tolerable and effective against S. mansoni infection among pre-SAC, and associated AEs are mostly mild-to-moderate and transient. However, the reduced CR in heavily infected and AEs in one-fourth of S. mansoni-infected pre-SAC underscores the need for safety and efficacy monitoring, especially in moderate-to-high infection settings. Integrating pre-SACs in the national deworming programs is recommended to accelerate the elimination of schistosomiasis as a public health problem.

Metabolism of (R)-Praziquantel versus the Activation of a Parasite Transient Receptor Potential Melastatin Ion Channel

Praziquantel (PZQ) is an essential anthelmintic drug recently established to be an activator of a Transient Receptor Potential Melastatin (TRPMPZQ ) ion channel in trematode worms. Bioinformatic, mutagenesis and drug metabolism work indicate that the cyclohexyl ring of PZQ is a key pharmacophore for activation of trematode TRPMPZQ , as well as serving as the primary site of oxidative metabolism which results in PZQ being a short-lived drug. Based on our recent findings, the hydrophobic cleft in schistosome TRPMPZQ defined by three hydrophobic residues surrounding the cyclohexyl ring has little tolerance for polarity. Here we evaluate the in vitro and in vivo activities of PZQ analogues with improved metabolic stability relative to the challenge of maintaining activity on the channel. Finally, an estimation of the respective contribution to the overall activity of both the parent and the main metabolite of PZQ in humans is reported.

Efficacy, safety, and palatability of arpraziquantel (L-praziquantel) orodispersible tablets in children aged 3 months to 6 years infected with Schistosoma in Côte d'Ivoire and Kenya: an open-label, partly randomised, phase 3 trial

BACKGROUND

WHO has underlined the need for a child-friendly treatment for schistosomiasis, a prevalent parasitic disease in low-income and middle-income countries. After successful phase 1 and 2 trials, we aimed to evaluate the efficacy, safety, palatability, and pharmacokinetics of arpraziquantel (L-praziquantel) orodispersible tablets for preschool-aged children.

METHODS

This open-label, partly randomised, phase 3 study was conducted at two hospitals in Côte d'Ivoire and Kenya. Children with a minimum bodyweight of 5 kg in those aged 3 months to 2 years and 8 kg in those aged 2-6 years were eligible. In cohort 1, participants aged 4-6 years infected with Schistosoma mansoni were randomly assigned (2:1) to receive a single dose of oral arpraziquantel 50 mg/kg (cohort 1a) or oral praziquantel 40 mg/kg (cohort 1b) using a computer-generated randomisation list. Cohorts 2 (aged 2-3 years) and 3 (aged 3 months to 2 years) infected with S mansoni, and the first 30 participants in cohort 4a (aged 3 months to 6 years) infected with Schistosoma haematobium, received a single dose of oral arpraziquantel 50 mg/kg. After follow-up assessments, arpraziquantel was increased to 60 mg/kg (cohort 4b). Laboratory personnel were masked to the treatment group, screening, and baseline values. S mansoni was detected using a point-of-care circulating cathodic antigen urine cassette test and confirmed using the Kato-Katz method. The primary efficacy endpoint was clinical cure rate at 17-21 days after treatment in cohorts 1a and 1b, measured in the modified intention-to-treat population and calculated using the Clopper-Pearson method. This study is registered with ClinicalTrials.gov, NCT03845140.

FINDINGS

Between Sept 2, 2019, and Aug 7, 2021, 2663 participants were prescreened and 326 were diagnosed with S mansoni or S haematobium. 288 were enrolled (n=100 in cohort 1a, n=50 in cohort 1b, n=30 in cohort 2, n=18 in cohort 3, n=30 in cohort 4a, and n=60 in cohort 4b), but eight participants received antimalarial drugs and were excluded from the efficacy analyses. The median age was 5·1 years (IQR 4·1-6·0) and 132 (47%) of 280 participants were female and 148 (53%) were male. Cure rates with arpraziquantel were similar to those with praziquantel (87·8% [95% CI 79·6-93·5] in cohort 1a vs 81·3% [67·4-91·1] in cohort 1b). No safety concerns were identified during the study. The most common drug-related treatment-emergent adverse events were abdominal pain (41 [14%] of 288 participants), diarrhoea (27 [9%]), vomiting (16 [6%]), and somnolence (21 [7%]).

INTERPRETATION

Arpraziquantel, a first-line orodispersible tablet, showed high efficacy and favourable safety in preschool-aged children with schistosomiasis.

FUNDING

The Global Health Innovative Technology Fund, the European and Developing Countries Clinical Trials Partnership, and the healthcare business of Merck KGaA, Darmstadt, Germany (CrossRef Funder ID: 10.13039/100009945).

Perspective on Schistosomiasis Drug Discovery: Highlights from a Schistosomiasis Drug Discovery Workshop at Wellcome Collection, London, September 2022

In September 2022, the Drug Discovery Unit at the University of Dundee, UK, organised an international meeting at the Wellcome Collection in London to explore the current clinical situation and challenges associated with treating schistosomiasis. The aim of this meeting was to discuss the need for new treatments in view of the clinical situation and to ascertain what the key requirements would be for any potential new anti-schistosomals. This information will be essential to inform ongoing drug discovery efforts for schistosomiasis. We also discussed the potential drug discovery pathway and associated criteria for progressing compounds to the clinic. To date, praziquantel (PZQ) is the only drug available to treat all species causing schistosomiasis, but it is often unable to completely clear parasites from an infected patient, partially due to its inactivity against juvenile worms. PZQ-mediated mass drug administration campaigns conducted in endemic areas (e.g., sub-Saharan Africa, where schistosomiasis is primarily prevalent) have contributed to reducing the burden of disease but will not eliminate the disease as a public health problem. The potential for Schistosoma to develop resistance towards PZQ, as the sole treatment available, could become a concern. Consequently, new anthelmintic medications are urgently needed, and this Perspective aims to capture some of the learnings from our discussions on the key criteria for new treatments.

Enhancing the antischistosomal activity of carvacryl acetate using nanoemulsion

Aim: To formulate a carvacryl acetate nanoemulsion (CANE) and test its antischistosomal activity. Materials & methods: CANE was prepared and tested in vitro on Schistosoma mansoni adult worms and both human and animal cell lines. Next, CANE was administered orally to mice infected with either a prepatent infection or a patent infection of S. mansoni. Results: CANE was stable during 90 days of analysis. CANE showed in vitro anthelmintic activity, and no cytotoxic effects were observed. In vivo, CANE was more effective than the free compounds in reducing worm burden and egg production. Treatment with CANE was more effective for prepatent infections than praziquantel. Conclusion: CANE improves antiparasitic properties and may be a promising delivery system for schistosomiasis treatment.

Presumptive treatment or serological screening for schistosomiasis in migrants from Sub-Saharan Africa could save both lives and money for the Italian National Health System: results of an economic evaluation

BACKGROUND

Schistosomiasis can lead to severe irreversible complications and death if left untreated. Italian and European guidelines recommend serological screening for this infection in migrants from Sub-Saharan Africa (SSA). However, studies on clinical and economic impact of this strategy in the Italian and European settings are lacking. This study aims to compare benefits and costs of different strategies to manage schistosomiasis in migrants from SSA to Italy.

METHODS

A decision tree and a Markov model were developed to assess the health and economic impacts of three interventions: (i) passive diagnosis for symptomatic patients (current practice in Italy); (ii) serological screening of all migrants and treating those found positive and (iii) presumptive treatment for all migrants with praziquantel in a single dose. The time horizon of analysis was one year to determine the exact expenses, and 28 years to consider possible sequelae, in the Italian health-care perspective. Data input was derived from available literature; costs were taken from the price list of Careggi University Hospital, Florence, and from National Hospitals Records.

RESULTS

Assuming a population of 100 000 migrants with schistosomiasis prevalence of 21·2%, the presumptive treatment has a greater clinical impact with 86.3% of the affected being cured (75.2% in screening programme and 44.9% in a passive diagnosis strategy). In the first year, the presumptive treatment and the screening strategy compared with passive diagnosis prove cost-effective (299 and 595 cost/QALY, respectively). In the 28-year horizon, the two strategies (screening and presumptive treatment) compared with passive diagnosis become dominant (less expensive with more QALYs) and cost-saving.

CONCLUSION

The results of the model suggest that presumptive treatment and screening strategies are more favourable than the current passive diagnosis in the public health management of schistosomiasis in SSA migrants, especially in a longer period analysis.

Efficacy of Single-Dose Albendazole for the Treatment of Soil-Transmitted Helminthic Infections among School Children in Rwanda-A Prospective Cohort Study

Mass drug administration (MDA) of single-dose albendazole to all at-risk populations as preventive chemotherapy (deworming) is recommended by WHO to halt transmission of soil-transmitted helminth (STH) in endemic countries. We assessed the effectiveness of single-dose albendazole against STH infection in the western province of Rwanda, where STH prevalence remains high despite the implementation of preventive chemotherapy for over a decade. Two weeks before the scheduled MDA, 4998 school children (5-15 years old) were screened for STH infections (Ascaris lumbricoides, Trichuris trichiura, and hookworm), and 1526 children who tested positive for at least one type of STH parasite were enrolled and received single-dose albendazole (400 mg) through MDA. A follow-up stool exam was performed at three weeks post-treatment using Kato-Katz. Efficacy was assessed by cure rate (CR), defined as the proportion of children who became egg-free, and egg reduction rates (ERRs) at three weeks post-treatment. The CR and ERR for hookworms (CR = 96.7%, ERR = 97.4%) was above, and for Ascaris lumbricoides (CR = 95.1%, ERR = 94.6%) was borderline compared with the WHO efficacy threshold (CR and ERR ≥ 95%). However, the CR and ERR for T. trichiura (CR = 17.6% ERR = 40.3%) were below the WHO threshold for efficacy (CR and ERR ≥ 50%). Having moderate-to-heavy infection intensity and coinfection with another type of STH parasites were independent risk factors for lower CR and ERR against Trichirus trichiura (p < 0.001). Single-dose albendazole used in the MDA program is efficacious for the treatment and control for hookworms and Ascaris lumbricoides infections but not effective for Trichirus trichiura. An alternative treatment regimen is urgently needed to prevent, control, and eliminate STH as a public health problem.

Efficacy and safety of praziquantel preventive chemotherapy in Schistosoma mansoni infected school children in Southern Ethiopia: A prospective cohort study

Background: The World Health Organization recommends efficacy and safety surveillance of anti-helminths used in mass drug administration campaigns. We evaluated the effectiveness of single-dose praziquantel against Schistosoma mansoni infection, and the safety of praziquantel plus albendazole preventive chemotherapy (PC) in Schistosoma mansoni infected school children (n = 512) in Southern Ethiopia. Method: Stool examinations were done using thick smear Kato-Katz at baseline, week-4, and week-8 of post-Mass drug administration (MDA) to assess praziquantel efficacy. Participants were followed for MDA-associated adverse events up to day 7 of post-MDA. The primary and secondary study outcomes were praziquantel efficacy (parasitological cure and egg reduction rates) and MDA-associated adverse events (AEs), respectively. Result: The overall cure rates at week-4 and week-8 were 89.1% (95%CI = 86.1-91.7) and 87.5% (95%CI = 83.6-90.8), respectively. Cure rates among moderate-to-heavily infected children were significantly lower (p = 0.001) compared to those with light infection at week-4 (84.4% vs. 91.1%, p = 0.03) and week-8 (78.6% vs. 91.9%, respectively). Older children had a higher cure rate than younger ones at week-8 (90.1% vs. 79.5%, p = 0.01). Among those who were Schistosoma egg-free (cured) at week 4, 7.8% became egg-positive at week 8. The overall egg reduction rate (ERR) at week-4 and week-8 were 93.5% and 91.3%, respectively, being lower among the 5-9 years old age groups (p = 0.01) at week-8. The proportion of children who remained schistosoma egg-positive throughout the study follow-up period was 4.6%, and their ERR at week-4 and week-8 was 50% and 51%, respectively, which is below the 90% World Health Organization threshold for efficacy. The incidence of experiencing at least one type of MDA-associated AEs were 17.0% (95%CI = 13.8%-20.5%); abdominal pain, headache, and vomiting were the most common. The proportion of mild, moderate, and severe AEs was 63.2%, 26.3%, and 10.5%, respectively. Females experienced more AEs than males (p = 0.03). Conclusion: Single-dose praziquantel is still effective for the treatment of intestinal schistosomiasis. Praziquantel and albendazole preventive chemotherapy is safe and tolerable, and associated AEs are mostly mild-to-moderate and transient. However, the reduced PZQ effectiveness in moderate-to-heavy infection and observed AEs in about one-fifth of infected children underscores the need for better treatment strategies and surveillance for early detection of parasite resistance and management of AEs.

Neolignans isolated from Saururus cernuus L. (Saururaceae) exhibit efficacy against Schistosoma mansoni

Schistosomiasis, a parasitic disease caused by the blood fluke of the genus Schistosoma, affects over 230 million people, especially in developing countries. Despite the significant economic and public health consequences, only one drug is currently available for treatment of schistosomiasis, praziquantel. Thus, there is an urgent demand for new anthelmintic agents. Based on our continuous studies involving the chemical prospection of floristic biodiversity aiming to discover new bioactive compounds, this work reports the in vitro antiparasitic activity against Schistosoma mansoni adult worms of neolignans threo-austrobailignan-6 and verrucosin, both isolated from Saururus cernuus L. (Saururaceae). These neolignans showed a significant in vitro schistosomicidal activity, with EC₅₀ values of 12.6-28.1 µM. Further analysis revealed a pronounced reduction in the number of S. mansoni eggs. Scanning electron microscopy analysis revealed morphological alterations when schistosomes were exposed to either threo-austrobailignan-6 or verrucosin. These relevant antischistosomal properties were accompanied by low cytotoxicity potential against the animal (Vero) and human (HaCaT) cell lines, resulting in a high selectivity index. Considering the promising chemical and biological properties of threo-austrobailignan-6 and verrucosin, this research should be of interest to those in the area of neglected diseases and in particular antischistosomal drug discovery.

Safety Surveillance of Mass Praziquantel and Albendazole Co-Administration in School Children from Southern Ethiopia: An Active Cohort Event Monitoring

Preventive chemotherapy (PC) with praziquantel and albendazole co-administration to all at-risk populations is the global intervention strategy to eliminate schistosomiasis and soil-transmitted helminth (STH) from being public health problems. Due to weak pharmacovigilance systems, safety monitoring during a mass drug administration (MDA) is lacking, especially in sub-Saharan Africa. We conducted large-scale active safety surveillance to identify the incidence, types, severity, and associated risk factors of adverse events (AEs) following praziquantel and albendazole MDA in 5848 school children (5−15 years old). Before MDA, 1484 (25.4%) children were prescreened for S. mansoni and STH infections, of whom 71.8% were infected with at least one parasite; 34.5% (512/1484) had S. mansoni and 853 (57.5%) had an STH infection. After collecting the baseline socio-demographic, clinical, and medical data, including any pre-existing clinical symptoms, participants received single dose praziquantel and albendazole MDA. Treatment-associated AEs were actively monitored on days 1 and 7 of the MDA. The events reported before and after the MDA were cross-checked and verified to identify MDA-associated AEs. The cumulative incidence of experiencing at least one type of MDA-associated AE was 13.3% (95% CI = 12.5−14.2%); 85.5%, 12.4%, and 1.8% of reported AEs were mild, moderate, and severe, respectively. The proportion of experiencing one, two, or ≥ three types of AEs was 57.7%, 34.1%, and 8.2%, respectively. The cumulative incidence of AEs in S. mansoni- and (17.0%) and STH (14.1%)-infected children was significantly higher (p < 0.001, χ2 = 15.0) than in non-infected children (8.4%). Headache, abdominal pain, vomiting, dizziness, and nausea were the most common AEs. Being female, older age, having S. mansoni or STH infection were significant predictors of MDA-associated AEs. In summary, praziquantel and albendazole co-administration is generally safe and tolerable. MDA-associated AEs are mostly mild-to-moderately severe and transient. The finding of few severe AEs and significantly high rates of AEs in helminth-infected children underscores the need to integrate pharmacovigilance in MDA programs, especially in high schistosomiasis and STH endemic areas.

Adverse drug effects among students following mass de-worming exercise involving administration of Praziquantel and Albendazole in KEEA Municipality, Ghana

Background

To manage the deleterious effects of parasitic infections such as lymphatic filariasis (LF) and schistosomiasis among school children, most countries including Ghana make use of mass drug administration (MDA). Although MDA has proven effective in reducing worm burden, unfortunately adverse drug effects (ADEs) post-MDA are derailing the gains and also remain poorly monitored. The study assessed incidence and factors associated with ADEs among students following a school-based mass de-worming exercise involving administration of Praziquantel (PZQT) and Albendazole (ADZ) against LF and SCH at Komenda-Edina-Eguafo-Abirem (KEEA) Municipal.

Methodology

After fulfilling all ethical obligations, a total of 598 students aged 5–20 years who received PZQT or ADZ monotherapy or a combination of the two (PZQT + ADZ) as part of the mass de-worming exercise were recruited through quota and random sampling. Bodyweight and height of students were measured and body mass index (BMI) calculated. Students were orally interviewed to obtain information such as age, sex, intake of diet before taking drugs. Subsequently, students were monitored over 24 hours post-MDA for cases of ADEs. Descriptive statistics and logistic regression analysis using SPSS version 26 was used to describe data collected and to determine associations between incidence of ADEs and predictor variables.

Principal findings

Out of the 598 students, 243 (40.64%) represented by 124 males (51.03%) and 119 females (48.97%) with mean (SD) age of 13.43 (2.74) years experienced one or more forms of ADE. In decreasing order, the detected ADEs included headache (64.6%), Abdominal pain (48.6%), fever (30.0%), diarrhea (21.4%) and itching (12.8%). Multivariable statistical analysis showed that age 5–9 years (OR: 2.01, p = 0.041) and underweight (OR: 2.02, p = 0.038) were associated with incidence of ADEs. Compared with students who received combination therapy, students who received ADZ only (OR: 0.05, p < 0.001) and PZQT only (OR: 0.26, p < 0.001) had low cases of ADEs. Gender and diet intake before MDA were not associated with ADE incidence.

Conclusion

ADE incidence was common among students in the KEEA municipality. Age, underweight, and double dosing were associated with increase in ADE incidence, while gender and food intake were not associated with increase in ADE incidence. The Disease Control Unit of the Ghana Health Service should incorporate stringent ADE monitoring in post-MDA surveillance in the National MDA program in order to be able to detect, manage and report ADEs to inform planning for future MDA programs. Such initiatives will help not only in improving effectiveness of MDA programs but also identify high risk groups and exact strategies to reduce negative influence of ADE on MDA coverage and anthelminthic drug compliance.

Type 2 immunity: a two-edged sword in schistosomiasis immunopathology

Schistosomiasis is the second most debilitating neglected tropical disease globally after malaria, with no available therapy to control disease-driven immunopathology. Although schistosomiasis induces a markedly heterogenous immune response, type 2 immunity is the dominating immune response following oviposition. While type 2 immunity has a crucial role in granuloma formation and host survival during the acute stage of disease, its chronic activation can result in tissue scarring, fibrosis, and organ impairment. Here, we discuss recent advances in schistosomiasis, demonstrating how different immune and non-immune cells and signaling pathways are involved in the induction, maintenance, and regulation of type 2 immunity. A better understanding of these immune responses during schistosomiasis is essential to inform the potential development of candidate therapeutic strategies that fine-tune type 2 immunity to ideally modulate schistosomiasis immunopathology.

Safety of Praziquantel and Albendazole Coadministration for the Control and Elimination of Schistosomiasis and Soil-Transmitted Helminths Among Children in Rwanda: An Active Surveillance Study

Introduction

School-based preventive chemotherapy (Deworming) with praziquantel and albendazole to control and eliminate schistosomiasis and soil-transmitted helminths as public health problems is recommended by the World Health Organization (WHO). Safety monitoring during mass drug administration (MDA) is imperative but data from sub-Saharan Africa are scarce.

Objective

The aim of this active safety surveillance study was to identify the incidence, type, severity, and risk factors for adverse events (AEs) following mass administration of praziquantel and albendazole.

Methods

Overall, 8037 school children aged 5–15 years in Rwanda were enrolled. Baseline sociodemographic, medical history and any pre-existing clinical symptoms were recorded. Participants received a single dose of praziquantel and albendazole during MDA. AEs were actively monitored on days 1, 2, and 7 post MDA.

Results

Overall, 3196 AEs were reported by 1658 children; 91.3%, 8.4%, and 0.3% of the AEs were mild, moderate, and severe, respectively, and most resolved within 3 days. Headache (21%), dizziness or fainting (15.2 %), nausea (12.8%) and stomach pain (12.2%) were the most common AEs. The overall cumulative incidence of experiencing at least one type of AE was 20.6% (95% confidence interval [CI] 19.7–21.5%), being significantly higher (p < 0.001) in children with pre-MDA clinical events (27.5%, 95% CI 25.4–29.6%) than those without (18.7%, 95% CI 17.7–19.7%). Females, older age, having pre-MDA events, types of food taken before MDA and taking two or more praziquantel tablets were significant predictors of AEs.

Conclusions

Praziquantel and albendazole MDA is safe and well-tolerated; however, one in five children experience transient mild to moderate, and in few cases severe, AEs. The incidence of AEs varies significantly between sex and age groups. Pharmacovigilance in the MDA program is recommended for timely detection and management of AEs.

Research on Schistosomiasis in the Era of the COVID-19 Pandemic: A Bibliometric Analysis

The objectives of this work are to check whether the COVID-19 pandemic affected the research on schistosomiasis, to provide an insight into the most productive countries and journals and the most cited publications, and to analyse any association between the total publications of countries and a set of socio-economic and demographic factors. Based on PRISMA methodology, we used the Scopus database to search for articles published between 1 January 2020 and 26 March 2022. VOSviewer was used to generate the co-authorship and the co-occurrence networks, and Spearman’s rank correlation was applied to study associations. A total of 1988 articles were included in the study. Although we found that the year-wise distribution of publications suggests no impact on schistosomiasis research, many resources have been devoted to research on COVID-19, and the Global Schistosomiasis Alliance revealed the main activities for eradication of schistosomiasis had been affected. The most productive country was the United States of America. The articles were mainly published in PLoS Neglected Tropical Diseases. The most prolific funding institution was the National Natural Science Foundation of China. The total publications per country were significantly correlated with population, GERD, and researchers per million inhabitants, but not with GDP per capita and MPM.

Therapeutic Efficacy of Carvacrol-Loaded Nanoemulsion in a Mouse Model of Schistosomiasis

Since praziquantel is the only drug available to treat schistosomiasis, a neglected parasitic disease that affects more than 240 million people worldwide, there is an urgent demand for new antischistosomal agents. Natural compound-loaded nanoparticles have recently emerged as a promising alternative for the treatment of schistosomiasis. Carvacrol is an antimicrobial monoterpene present in the essential oil extracted from several plants, especially oregano (Origanum vulgare). In this study, a carvacrol nanoemulsion (CVNE) was prepared, characterized, and administered orally (200 mg/kg) in a mouse infected with either immature (prepatent infection) or adult (patent infection) Schistosoma mansoni. For comparison, data obtained with an unloaded nanoemulsion (blank formulation), free carvacrol, and the drug of reference praziquantel are also presented. CVNE was more effective than free carvacrol in reducing the worm burden and egg production in both patent and prepatent infections. Favorably, CVNE had a high effect in terms of reducing the number of worms and eggs (85%–90%) compared with praziquantel (∼30%) in prepatent infection. In tandem, carvacrol-loaded nanoemulsion markedly improved antischistosomal activity, showing efficiency in reducing worm and egg burden, and thus it may be a promising delivery system for the treatment of schistosomiasis.

Moxidectin: heartworm disease prevention in dogs in the face of emerging macrocyclic lactone resistance

Heartworm (Dirofilaria immitis) disease continues to increase and spread, remaining one of the most important and pathogenic parasitic diseases of dogs, despite the regular use of macrocyclic lactones (MLs) in preventive products. Dogs harboring strains of D. immitis resistant to MLs, the only drug class available for heartworm prevention in the United States, have been documented and proven. As no new products are available utilizing a novel drug class for the prevention of this disease, the only options for combating ML resistance include increasing the dose and/or changing the dosage regime of current MLs, or by optimizing the formulations of MLs currently available. Moxidectin provides a unique opportunity for optimization of the dose and formulation, which may provide improved efficacy against ML-resistant strains. Currently there are oral, topical, and injectable moxidectin products approved for heartworm prevention in the USA. Two new products (ProHeart^® 12 and Simparica Trio^®), available in many countries around the world including the USA, take advantage of the unique attributes of moxidectin for providing robust heartworm prevention against the strains of heartworm to which most dogs in the USA will likely be exposed. Both products have demonstrated 100% preventive efficacy in laboratory studies against recently collected field strains of heartworm, and also in large field studies, where the majority of dogs were living in the southern USA in areas where ML resistance has been confirmed to occur, therefore under elevated heartworm challenge. Based on the data summarized here, these products offer important advances in heartworm prevention and provide additional options for veterinarians and pet owners to protect their dogs from developing heartworm disease.

Recent trends in praziquantel nanoformulations for helminthiasis treatment

INTRODUCTION

Infections caused by parasitic flatworms impose a considerable worldwide health burden. Recently, World Health Organization launched its roadmap for neglected diseases for the period 2021 to 2030 and oral treatment with praziquantel (PZQ) in tablet form is the main drug therapy for combating these diseases, but its use is limited by many drawbacks, including the high therapeutic dose due to the drug's low solubility and bioavailability. Among the strategies to improve PZQ performance, the use of drug nanocarriers has been cited as an interesting approach to overcome these pharmacological issues.

AREAS COVERED

This review focuses on the various types of nanomaterials (polymeric, lipidic, inorganic nanoparticles, and nanocrystals) which have been recently used to improve PZQ therapy. In addition, recent advances in PZQ nanoformulations, developed to overcome the barriers of the conventional drug are described.

EXPERT OPINION

Considering the poor rate of discovery in the anthelmintic segment observed in recent decades, the effective management of existing drugs has become essential. The application of new strategies based on nanotechnology can extend the useful life of PZQ in new and more effective formulations. Pharmaceutical nanotechnology can solve the pharmacokinetic challenges characteristic of PZQ and improve its solubility and bioavailability.

Efficacy of Praziquantel for the Treatment of Human Schistosomiasis in Ethiopia: A Systematic Review and Meta-Analysis

Background

Schistosomiasis is one of the neglected tropical diseases causing a serious human health problem in Ethiopia. Praziquantel is the only drug that has been used for the treatment of human schistosomiasis in the country. In line with this, the efficacy of praziquantel has been evaluated in a few interventional studies in the country, but there is a lack in systematically gathered and analyzed information for policymakers. The aim of this systematic review and meta-analysis was to provide a summary of the efficacy of praziquantel for the treatment of human schistosomiasis in Ethiopia.

Methods

We conducted a literature search from ScienceDirect, PubMed/Medlin, and Google Scholar databases. A total of 140 articles published in English from 1980 to June 2021 were accessed and 15 of them were eligible for this meta-analysis. The meta-analysis was conducted using Stata 14 software, "metan command." The heterogeneities among studies were evaluated using I ² test.

Results

A total of 140 articles were reviewed, but only 15 of them fulfilled the inclusion criteria. The polled cure rate of 40 mg/kg praziquantel was 89.2% (95% CI: 85.4-93.1) and 93.6% (95% CI: 80.6-106) among Schistosoma mansoni and S. haematobium, respectively. Similarly, the mean egg reduction rates of 40 mg/kg praziquantel were 90.2% and 85% among S. mansoni and S. haematobium infected subjects, respectively. The common adverse events observed after receiving praziquantel include abdominal pain, vomiting, headache, diarrhea, and bloody stool.

Conclusion

This systematic review and meta-analysis has indicated that praziquantel is still an appropriate drug for the treatment of human schistosomiasis in Ethiopia.

Genetic analysis of praziquantel response in schistosome parasites implicates a transient receptor potential channel

[Figure: see text].

Pathogenicity of Salmonella During Schistosoma-Salmonella Co-infections and the Importance of the Gut Microbiota

Antibiotic inefficacy in treating bacterial infections is largely studied in the context of developing resistance mechanisms. However, little attention has been paid to combined diseases mechanisms, interspecies pathogenesis and the resulting impact on antimicrobial treatment. This review will consider the co-infections of Salmonella and Schistosoma mansoni. It summarises the protective mechanisms that the pathophysiology of the two infections confer, which leads to an antibiotic protection phenomenon. This review will elucidate the functional characteristics of the gut microbiota in the context of these co-infections, the pathogenicity of these infections in infected mice, and the efficacy of the antibiotics used in treatment of these co-infections over time. Salmonella-Schistosoma interactions and the mechanism for antibiotic protection are not well established. However, antimicrobial drug inefficacy is an existing phenomenon in these co-infections. The treatment of schistosomiasis to ensure the efficacy of antibiotic therapy for bacterial infections should be considered in co-infected patients.

Praziquantel Treatment of Schistosoma mansoni Infected Mice Renders Them Less Susceptible to Reinfection

Beyond transient control of the infection, additional benefits of mass drug administration of praziquantel in endemic communities have been suggested in communities but not mechanistically investigated experimentally. The present study sought to evaluate the additional and hitherto unreported benefits of repeated mass drug administration of praziquantel. We used a tractable mouse model of Schistosoma mansoni infection to assess the effects of repeated infection-treatment cycles on the host susceptibility to reinfection. Parasitaemia was assessed by quantification of Schistosoma egg burden in liver tissues and morbidity was followed up by histological observation of liver lesions by microscopy and using biochemical measurement of liver transaminases. Immune responses were further determined by serum probing of schistosoma-specific antibodies, cytokines and quantification of liver cellular and soluble mediator responses by flow cytometry and ELISA, respectively. At similar ages and comparable gender distribution, groups of mice undergoing higher number of infections treatment cycles over a longer period, remained susceptible to reinfection by the parasite, as judged by the presence of eggs and the associated increasing pathology in the liver tissues. However, notably, there was a clear and significantly higher propensity to lower egg burden upon reinfection when compared to counterparts undergoing a lower number of infection-treatment cycles. This relative reduction of susceptibility to infection was paralleled by a more robust humoral response against parasite antigens, elevated serum IL-4 and liver cytokines. Of note, praziquantel treatment of infected mice left them at a higher baseline of serum IL-4, IgE and liver cytokines but lower CD4+ T cell -derived cytokines when compared to infected non-treated mice supporting an immunological treatment-induced advantage of previously infected mice over naïve mice and infected/not treated mice. Notably, repeated infection-treatment cycles did not preclude the infection-driven aggravation of collagen deposition in the livers over time and was corroborated by a more robust local production of inflammatory cytokines in the most exposed livers. Taken together, our data reveal that treatment of S. mansoni-infected hosts with praziquantel rewires the immune system to a conformation less permissive to subsequent reinfection in mice. Provided the data are translatable from mouse to human, our findings may provide mechanistic support to the potential benefits of more frequent MDAs in high transmission areas to allow rapid acquisition of protective immunity against reinfection.

Transmission Dynamics of Schistosoma haematobium among School-Aged Children: A Cohort Study on Prevalence, Reinfection and Incidence after Mass Drug Administration in the White Nile State of Sudan

The reinfection rate of schistosomiasis after mass drug administration (MDA) has not been documented in Sudan. We aimed to explore the transmission dynamics of urogenital schistosomiasis after MDA, targeting school-aged children in the White Nile State of Sudan, assessing the prevalence, reinfection rate, and incidence. A single dose of praziquantel (40 mg/kg) was administered to 1951 students in five primary schools from January to February 2018 immediately after a baseline survey, and follow-up surveys were performed at 2 weeks and 6 months after treatment. We examined Schistosoma haematobium eggs by centrifugation methods. The overall reinfection rate at 6 months after treatment was 9.8% (95% confidence interval: 0.5-17.4%). By school, the reinfection rate was highest in the Al Hidaib school, whose prevalence was highest at baseline. The reinfection rate was significantly higher in high-infection areas than low-infection areas (p = 0.02). Of the prevalence at 6 months in high-infection areas, 41% of cases were due to reinfection. MDA interventions are decided upon and undertaken at the district level. A more targeted treatment strategy should be developed with a particular focus on tracking high-risk groups, even within a school or a community.

Effect of Pharmacogenetics Variations on Praziquantel Plasma Concentrations and Schistosomiasis Treatment Outcomes Among Infected School-Aged Children in Tanzania

Studies on pharmacogenetics of praziquantel (PZQ) and its relevance on plasma drug concentrations and schistosomiasis treatment outcomes are lacking. We investigated the effect of pharmacogenetics variations of PZQ on plasma drug levels and schistosomiasis treatment outcomes among infected Tanzanian school-aged children. A total of 340 Schistosoma mansoni infected children were enrolled and treated with single-dose PZQ. Stool samples analysis was done by thick smear Kato-Katz technique, and treatment efficacy was assessed at 3-weeks post-treatment. Safety was assessed within 4 h after PZQ intake. Plasma samples were collected at 4 h post-dose, and PZQ and trans-4-OH-PZQ concentrations were quantified using UPLCMS/MS. Genotyping for CYP3A4*1B, CYP3A5 (*3, *6, *7), CYP2C19 (*2, *3, *17), and CYP2C9 (*2, *3) were done by Real-Time PCR. The median age (range) of the study participants was 12 years (7-17). There was a significant association of CYP2C19 genotypes with PZQ concentrations and its metabolic ratio (trans-4-OH-PZQ/PZQ). PZQ concentration was significantly higher among CYP2C19 (*2, *3) carriers than CYP2C19 *1/*1 and CYP2C19 *17 carriers (ultra-rapid metabolizers) (p = 0.04). The metabolic ratio was significantly higher among CYP2C19*17 carriers than CYP2C19 (*2, *3) carriers (p = 0.01). No significant effect of CYP3A4, CYP3A5, CYP2C19, and CYP2C9 genotypes on treatment efficacy or adverse events were observed. Baseline infection intensity and CYP3A5 genotype were significant predictors of treatment associated-adverse events. In conclusion, CYP2C19 genotype significantly affects plasma PZQ concentration and its metabolic ratio. For the first time, we report the importance of pharmacogenetic variation for the treatment of schistosomiasis, a neglected tropical disease.

Evaluation of mass drug administration for schistosomiasis and soil-transmitted helminths in school-aged children in Bankass, Mali

BACKGROUND

In 2004, Mali implemented mass drug administration (MDA) aimed at controlling schistosomiasis and soil-transmitted helminths. Despite several rounds of MDA, the health district of Bankass reported low coverage (64.8%) for praziquantel and albendazole in 2017, meaning that this district was still facing challenges in accomplishing the targeted 75% coverage. This study aimed to explore the barriers and gaps that hindered MDA implementation in Bankass.

METHODS

A cross-sectional study was performed. Questionnaires were administrated to all school-aged children in randomly selected villages. Technical directors of community health centers and community drug distributors in the selected villages were included in the interviews.

RESULTS

A total of 2128 children and 52 health workers were interviewed. Coverage rates were 93.51% (1990/2128) for praziquantel and 95.25% (2027/2128) for albendazole. Among the untreated children, 31.63% (31/98) reported being unaware of the campaign and 26.53% (26/98) were unable to reach the distribution points. Most of the health workers suggested increasing incentives.

CONCLUSION

The data showed satisfactory coverage >90%, in contrast with lower rates initially reported by the district health information system. These results raise concerns about the reliability of programmatic data and highlight the importance of population-based surveys for the evaluation of control interventions.

Antioxidants resveratrol and SkQ1 attenuate praziquantel adverse effects on the liver in Opisthorchis felineus infected hamsters

Anthelmintic praziquantel (PZQ) is the drug of the choice for opisthorchiasis, schistosomiasis and other trematodiases therapy for several decades. Despite its good therapeutic performance and effective control of trematode infections, PZQ has some shortcomings; its inability to counteract disease sequelae necessitates novel therapeutic strategies. Testing of antioxidants that have proven themselves in clinical practice, in combination with this anthelmintic drug, offers new opportunities for developing alternatives to PZQ monotherapy. The effects of two antioxidants combined with PZQ on histological parameters of liver tissue were evaluated in a hamster model of opisthorchiasis felinea. Liver pathology including the parenchyma state, accumulation of neutral lipids and 4-Hydroxy-2-nonenal as a lipid peroxidation product, biochemical characteristics of hamster blood serum, and mRNA expression of inflammation- and fibrogenesis-associated genes were determined. PZQ and opisthorchiasis caused liver accumulation of lipids and glycogen. The combination of PZQ with resveratrol (RSV) or 10-(6'-plastoquinonyl)decyltriphenylphosphonium (SkQ1) significantly reduced hepatocyte changes (P = 0.009 and P = 0.009, respectively, Mann-Whitney U test) as compared with infected hamsters treated only with PZQ. RSV and SkQ1 significantly reduced cholangiocyte hyperplasia, bile duct proliferation, fibrosis, and lipid droplet and glycogen granule accumulation. The downregulation of 4-hydroxynonenal was also observed. The combinations of the anthelmintic drug with antioxidants RSV and SkQ1 ameliorate host oxidative stress and mitigate adverse effects of PZQ on hepatic parenchyma. The use of drug combinations may improve the action of standard anthelmintic agents, such as PZQ, which still remains the most effective agent against adult trematodes.

The discovery of a novel series of compounds with single-dose efficacy against juvenile and adult Schistosoma species

Treatment and control of schistosomiasis depends on a single drug, praziquantel, but this is not ideal for several reasons including lack of potency against the juvenile stage of the parasite, dose size, and risk of resistance. We have optimised the properties of a series of compounds we discovered through high throughput screening and have designed candidates for clinical development. The best compounds demonstrate clearance of both juvenile and adult S. mansoni worms in a mouse model of infection from a single oral dose of < 10 mg/kg. Several compounds in the series are predicted to treat schistosomiasis in humans across a range of species with a single oral dose of less than 5 mg/kg.

A 12-year follow-up of intestinal schistosomiasis in pre-school-aged children in Assoni Village, Eastern Senegal

Background

To monitor the prevalence of schistosomiasis in school-aged children (SAC), the National Bilharzia Control Program (PNLB) was set up by the Senegalese authorities; however, geographically isolated Bedik ethnic groups that did not benefit from this program were found to be heavily infected with Schistosoma mansoni. This observation led us to implement a new schistosomiasis control program in 2008 under the aegis of the non-governmental organization “Le Kaïcedrat” and in partnership with the PNLB/WHO to monitor the prevalence of schistosomiasis in this area. In the village of Assoni, where 100% of SAC were infected, analysis of the stools of pre-school-aged children (PSAC) showed that they were massively infected, so we decided to focus our program on them.

Methods

From 2008 to 2020, we (i) monitored the prevalence of S. mansoni in PSAC in Assoni using double-stool smear preparation, (ii) treated the infected PSAC with a standard dose of praziquantel 40 mg/kg, (iii) ran educational campaigns each year in the village, and (iv) built latrines to improve sanitation and reduce schistosomiasis transmission. Linear regression was used to examine the trend in the annual schistosomiasis prevalence and a two-sided of Chi-squared test was used to compare prevalence between the different age groups of PSAC.

Results

We observed an extremely high prevalence of schistosomiasis (78%) in PSAC before implementation of the program in 2008. Contamination occurred in very young children, as 64.3% of children under 2 years old were infected. Moreover, prevalence increased with age and reached 96.8% in children 4 to < 6 years old. Our annual interventions in Assoni Village raised awareness among villagers that water bodies were areas of significant infestation, allowed the building of 88 latrines and led to a decrease in prevalence in PSAC as only 11% of these children were infected in 2020.

Conclusion

Our study allowed Assoni to be the first village in Senegal to treat PSAC since 2014, but only on an individual basis. It also shows that schistosomiasis is difficult to eradicate and that multi-sectorial actions are required to keep its prevalence at a low level.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-021-00867-8.

Evaluation of Artesunate-mefloquine as a Novel Alternative Treatment for Schistosomiasis in African Children (SchistoSAM): protocol of a proof-of-concept, open-label, two-arm, individually-randomised controlled trial

INTRODUCTION

Alternative drugs and diagnostics are needed for the treatment and control of schistosomiasis. The exclusive use of praziquantel (PZQ) in mass drug administration programmes may result in the emergence of drug resistance. PZQ has little activity against Schistosoma larvae, thus reinfection remains a problem in high-risk communities. Furthermore, the insufficient sensitivity of conventional microscopy hinders therapeutic response assessment. Evaluation of artesunate-mefloquine (AM) as a Novel Alternative Treatment for Schistosomiasis in African Children (SchistoSAM) aims to evaluate the safety and efficacy of the antimalarial combination artesunate-mefloquine, re-purposed for the treatment of schistosomiasis, and to assess the performance of highly sensitive novel antigen-based and DNA-based assays as tools for monitoring treatment response.

METHODS AND ANALYSIS

The SchistoSAM study is an open-label, two-arm, individually randomised controlled non-inferiority trial, with a follow-up of 48 weeks. Primary school-aged children from the Richard Toll district in northern Senegal, an area endemic for Schistosoma mansoni and Schistosoma haematobium, are allocated to the AM intervention arm (3-day courses at 6-week intervals) or the PZQ control arm (single dose of 40 mg/kg). The trial's primary endpoints are the efficacy (cure rate (CR), assessed by microscopy) and safety (frequency and pattern of drug-related adverse events) of one AM course versus PZQ at 4 weeks after treatment. Secondary endpoints include (1) cumulative CR, egg reduction rate and safety after each additional course of AM, and at weeks 24 and 48, (2) prevalence and severity of schistosomiasis-related morbidity and (3) malaria prevalence, incidence and morbidity, both after 24 and 48 weeks. CRs and intensity reduction rates are also assessed by antigen-based and DNA-based diagnostic assays, for which performance for treatment monitoring is evaluated.

ETHICS AND DISSEMINATION

Ethics approval was obtained both in Belgium and Senegal. Oral assent from the children and signed informed consent from their legal representatives was obtained, prior to enrolment. The results will be disseminated in peer-reviewed journals and at international conferences.

TRIAL REGISTRATION NUMBER

NCT03893097; pre-results.

Schistosomiasis Drug Discovery in the Era of Automation and Artificial Intelligence

Schistosomiasis is a parasitic disease caused by trematode worms of the genus Schistosoma and affects over 200 million people worldwide. The control and treatment of this neglected tropical disease is based on a single drug, praziquantel, which raises concerns about the development of drug resistance. This, and the lack of efficacy of praziquantel against juvenile worms, highlights the urgency for new antischistosomal therapies. In this review we focus on innovative approaches to the identification of antischistosomal drug candidates, including the use of automated assays, fragment-based screening, computer-aided and artificial intelligence-based computational methods. We highlight the current developments that may contribute to optimizing research outputs and lead to more effective drugs for this highly prevalent disease, in a more cost-effective drug discovery endeavor.

Optimization of Benzothiazole and Thiazole Hydrazones as Inhibitors of Schistosome BCL-2

Limited therapeutic options are available for the treatment of human schistosomiasis caused by the parasitic Schistosoma flatworm. The B cell lymphoma-2 (BCL-2)-regulated apoptotic cell death pathway in schistosomes was recently characterized and shown to share similarities with the intrinsic apoptosis pathway in humans. Here, we exploit structural differences in the human and schistosome BCL-2 (sBCL-2) pro-survival proteins toward a novel treatment strategy for schistosomiasis. The benzothiazole hydrazone scaffold previously employed to target human BCL-XL was repurposed as a starting point to target sBCL-2. We utilized X-ray structural data to inform optimization and then applied a scaffold-hop strategy to identify the 5-carboxamide thiazole hydrazone scaffold (43) with potent sBCL-2 activity (IC₅₀ 30 nM). Human BCL-XL potency (IC₅₀ 13 nM) was inadvertently preserved during the optimization process. The lead analogues from this study exhibit on-target activity in model fibroblast cell lines dependent on either sBCL-2 or human BCL-XL for survival. Further optimization of the thiazole hydrazone class is required to exhibit activity in schistosomes and enhance the potential of this strategy for treating schistosomiasis.

Alternatives to Praziquantel for the Prevention and Control of Schistosomiasis

Schistosomiasis, a neglected tropical disease provoked by infection with parasitic blood flukes of the genus Schistosoma, affects almost 240 million people worldwide, and more than 700 million people live in endemic areas. However, 40 years after the approval of praziquantel as an anthelmintic drug, the pipeline is nearly empty, and no other therapeutic alternative has reached the market. In its roadmap to "eliminate Schistosomiasis as a public health problem by 2030", the World Health Organization calls for the development of new therapeutic interventions. A viewpoint on the learnings from praziquantel research as well as shaping the next generation of drugs is shared.

New evidence for tamoxifen as an antischistosomal agent: in vitro, in vivo and target fishing studies

Background: Praziquantel is the only drug available to treat schistosomiasis, and there is an urgent demand for new anthelmintic agents. Methodology & results: We conducted in-depth in vitro and in vivo studies and report a target fishing investigation. In vitro, tamoxifen was active against adult and immature worms at low concentrations (<5 μM). Tamoxifen at a single dose (400 mg/kg) or once daily for five consecutive days (100 mg/kg/day) in mice harboring either adult (patent infection) or juvenile (prepatent infection) significantly reduced worm burden (30-70%) and egg production (70-90%). Target fishing studies revealed propionyl-CoA carboxylase as a potential target for tamoxifen in Schistosoma mansoni and glucose uptake by S. mansoni was also significantly reduced. Conclusion: Our results provide news evidence of antiparasitic effect of tamoxifen and reveal propionyl-CoA carboxylase as a potential target.

Prevalence and risk factors of Schistosoma mansoni infection among preschool-aged children from Panamasso village, Burkina Faso

Background

Schistosomiasis remains a major public health concern in sub-Saharan Africa. Although schistosomiasis is well documented in school-aged children in Burkina Faso, prevalence data among preschool-aged children (PSAC) are limited and outdated, and its risk factors in this group remain poorly documented. The main objective of this study was to assess the prevalence and risk factors associated with Schistosoma (S.) mansoni infection among PSAC from Panamasso village, western Burkina Faso.

Methodology

A cross-sectional study was carried out among 228 children under 6 years old from Panamasso village. Sociodemographic and water contact data were collected using a structured questionnaire. Kato-Katz and formol-ether concentration techniques were used to detect S. mansoni eggs in stool samples. Urine samples were subjected to a point-of-care circulating cathodic antigen (POC-CCA) cassette test and a centrifugation method to check for both S. mansoni and S. haematobium infection, respectively. Potential risk factors for S. mansoni infection were explored using multivariable logistic regression.

Results

The mean age of children was 40.2 ± 15.0 months. The prevalence of S. mansoni infection as determined by Kato-Katz, formol-ether concentration and POC-CCA was 42.1%, 39.5% and 80.7%, respectively. Based on the combined results of the three methods, the overall prevalence of S. mansoni infection was 81.1%. No case of S. haematobium infection was found. The geometric mean intensity of S. mansoni infection was 107.2 eggs per gram of feces with 54.2%, 33.3% and 12.5% of the children having light, moderate and heavy infections, respectively. Girls (AOR = 2.9, 95% CI 1.3–6.1), a household located within 500 m from the pond (AOR = 3.0, 95% CI 1.0–8.6) or between 500 and 1000 m from the pond (AOR = 3.0, 95% CI 1.2–7.2), and the child’s history of going to the pond (AOR = 5.0, 95% CI 1.7–14.3) were the variables significantly associated with S. mansoni infection.

Conclusion

S. mansoni was the sole species infecting a high proportion of PSAC in the study area. A mass drug administration program with praziquantel is therefore urgently required for those below 6 years old. Other control strategies should include increased community-awareness and provision of safe water.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-04692-8.

Land use impacts on parasitic infection: a cross-sectional epidemiological study on the role of irrigated agriculture in schistosome infection in a dammed landscape

Background

Water resources development promotes agricultural expansion and food security. But are these benefits offset by increased infectious disease risk? Dam construction on the Senegal River in 1986 was followed by agricultural expansion and increased transmission of human schistosomes. Yet the mechanisms linking these two processes at the individual and household levels remain unclear. We investigated the association between household land use and schistosome infection in children.

Methods

We analyzed cross-sectional household survey data (n = 655) collected in 16 rural villages in August 2016  across demographic, socio-economic and land use dimensions, which were matched to Schistosoma haematobium (n = 1232) and S. mansoni (n = 1222) infection data collected from school-aged children. Mixed effects regression determined the relationship between irrigated area and schistosome infection presence and intensity.

Results

Controlling for socio-economic and demographic risk factors, irrigated area cultivated by a household was associated with an increase in the presence of S. haematobium infection (odds ratio [OR] = 1.14; 95% confidence interval [95% CI]: 1.03–1.28) but not S. mansoni infection (OR = 1.02; 95% CI: 0.93–1.11). Associations between infection intensity and irrigated area were positive but imprecise (S. haematobium: rate ratio [RR] = 1.05; 95% CI: 0.98–1.13, S. mansoni: RR = 1.09; 95% CI: 0.89–1.32).

Conclusions

Household engagement in irrigated agriculture increases individual risk of S. haematobium but not S. mansoni infection. Increased contact with irrigated landscapes likely drives exposure, with greater impacts on households relying on agricultural livelihoods.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-021-00816-5.

Evaluation of Praziquantel Effectivenss After Decades of Prolonged Use in an Endemic Area in Egypt

PURPOSE

Praziquantel (PZQ) is the preferred drug for schistomiasis treatment because of its safety. As PZQ is used for mass drug administration (MDA) in schistosomiasis endemic areas, the effectiveness of the drug, used solely for decades, should be continuously monitored to detect drug resistance. We aimed to assess the effectiveness of PZQ to cure Schistosoma mansoni infection and to reduce the intensity of infection in an endemic area by estimating the cure rate (CR), egg reduction rate (ERR), and comparing these estimates to the levels recommended by the World Health Organization (WHO).

METHODS

A total of 342 children aged 5-15 years living in Kafr-El-Sheikh were screened for S. mansoni infection. Stool samples were examined microscopically using Kato-Katz (KK) technique. Among the screened children, 106 children had S. mansoni ova in stool, 100 of them received the first dose of PZQ (40 mg/kg). Four weeks later, 96 of 100 children received the second dose of PZQ. Stool samples, collected 4 weeks after each dose of PZQ, were examined using KK. The effectiveness of PZQ was assessed based on ERR and CR.

RESULTS

CR after the first dose of PZQ was 66.7%, increased to 79.12% after second dose (X² = 3.05, P = 0.08). Median egg count before treatment was 30.00 (6.00-744), that significantly decreased after two doses of PZQ to 0.00 (0.00-221.33) (Z = 8.29, P = 0.001). Children aged 10-15 years showed higher CR (91.3%) than those aged 5-9 years (OR = 5.25, CI 1.58-17.40).

CONCLUSIONS

PZQ is still an effective agent against S. mansoni in endemic areas, achieving a high CR and ERR with predominantly low intensity of infection. Age is a main predictor of response to PZQ.

Efficacy of praziquantel has been maintained over four decades (from 1977 to 2018): A systematic review and meta-analysis of factors influence its efficacy

BACKGROUND

The antihelminthic drug praziquantel has been used as the drug of choice for treating schistosome infection for more than 40 years. Although some epidemiological studies have reported low praziquantel efficacy in cure rate (CR) and/or egg reduction rate (ERR), there is no consistent robust evidence of the development of schistosome resistance to praziquantel (PZQ). There is need to determine factors that lead to variable treatment CR and/or ERR. Therefore, we conducted a systematic review and meta-analysis to review CR and ERR as well as identify their predictors.

METHODOLOGY/PRINCIPAL FINDINGS

In this systematic review and meta-analysis, a literature review was conducted using Biosis Citation Index, Data Citation Index, MEDLINE, and Web of Science Core Collection all of which were provided through Web of Science. Alongside these, EMBASE, and CAB abstracts were searched to identify relevant articles. Random effect meta-regression models were used to identify the factors that influence CR and/or ERR by considering differences in host characteristics and drug dose. In total, 12,127 potential articles were screened and 146 eligible articles (published from 1979 to 2020) were identified and included for the meta-analysis. We found that there has been no significant reduction in CR or ERR over the study period. The results showed more variability in CR, compared with ERR which was more consistent and remained high. The results showed a positive effect of "PZQ treatment dose" with the current recommended dose of 40 mg/kg body weight achieving 57% to 88% CR depending on schistosome species, age of participants, and number of parasitological samples used for diagnosis, and ERR of 95%.

CONCLUSIONS/SIGNIFICANCE

Based on a review of over 40 years of research there is no evidence to support concerns about schistosomes developing resistance to PZQ. These results indicate that PZQ remains effective in treating schistosomiasis.

Parasitological Observation in Schoolchildren with Urogenital Schistosomiasis Following Treatment with Three Different Brands of Praziquantel

This study compared the anthelminthic effects of three different brands of praziquantel being used in Sudan against Schistosoma haematobium (S. haematobium) infection. We enrolled 1,286 schoolchildren from six primary schools and examined their urine samples for eggs of S. haematobium at the baseline survey and follow-up two weeks after administering the medication. The schoolchildren were divided into three groups based on the three brands of praziquantel (different material production), with two school children for one brand. The overall baseline prevalence of S. haematobium infection was 15.5%. Two weeks after treatment with brands A, B, and C of praziquantel, cure rates were 87.1%, 82.4% and 83.8% respectively, and the egg-reduction rates were 69.0%, 81.0% and 70.6% respectively. There was no statistically significant difference in cure rates and egg-reduction rates between the three brands. We conclude that the three different commercial brands of praziquantel used in Sudan have similar anthelminthic effects on S. haematobium.

Evaluation of the therapeutic efficacy of praziquantel against schistosomes in seven countries with ongoing large-scale deworming programs

The World Health Organization (WHO) recommends periodic assessment of the therapeutic efficacy of praziquantel (PZQ) to detect reduced efficacy that may arise from drug resistance in schistosomes. In this multi-country study (2014), we assessed the therapeutic efficacy of a single oral dose of PZQ (40 mg/kg) against Schistosoma mansoni (Brazil, Cameroon, Ethiopia, Mali, Madagascar and Tanzania), S. haematobium (Cameroon, Ethiopia, Mali, Tanzania and Zanzibar) and S. japonicum (the Philippines) infections in school-aged children, across a total of 12 different trials. Each trial was performed according to the standardized methodology for evaluating PZQ efficacy as described by the WHO. Overall, therapeutic efficacy, measured as the reduction in arithmetic mean of schistosome egg counts following drug administration (egg reduction rate; ERR), was high for all three schistosome species (S. mansoni: 93.4% (95%CI: 88.8–96.8); S. haematobium: 97.7% (95%CI: 96.5–98.7) and S. japonicum: 90.0% (95%CI: 68.4–99.3). At the trial level, therapeutic efficacy was satisfactory (point estimate ERR ≥90%) for all three Schistosoma species with the exception of S. mansoni in Cameroon where the ERR was 88.5% (95%CI: 79.0–95.1). Furthermore, we observed that in some trials individual drug response could vary significantly (wide 95%CI) and that few non-responsive individuals could significantly impact ERR point estimates. In conclusion, these results do not suggest any established reduced efficacy of the standard PZQ treatment to any of the three schistosome species within these countries. Nevertheless, the substantial degree of variation in individual responses to treatment in some countries underpins the need for future monitoring. The reported ERR values serve as reference values to compare with outcomes of future PZQ efficacy studies to ensure early detection of reduced efficacies that could occur as drug pressure continues increase. Finally, this study highlights that 95%CI should be considered in WHO guidelines to classify the therapeutic efficacy of PZQ.

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PZQ efficacy against schistosomes was assessed in school-aged-children in seven countries.

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There was no overall sign of reduced PZQ efficacy against any schistosome species.

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Notable variation in individual responses to treatment does require future monitoring.

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It is recommended to include reporting of the 95%CI in future WHO guidelines.

Co-grinding with surfactants as a new approach to enhance in vitro dissolution of praziquantel

This paper evaluates the process of co-grinding with a surfactant as a new approach to enhance physicochemical and biopharmaceutical properties of praziquantel (PZQ), a poorly soluble drug that is essential for the treatment of schistosomiasis, a neglected tropical disease. Surfactants used in this study were poloxamer F-127 and sucrose stearate (C-1816), selected based on their well-documented biocompatibility and solubilizing activity. A series of products were prepared by mechanochemical activation using vibrational ball-mill at different drug to surfactant ratio and milling times. The obtained products were characterised in terms of drug recovery, solubility and in vitro dissolution rates. The obtained results were correlated to solid-state properties of the products analysed by differential scanning calorimetry, powder X-ray diffraction and particle size analysis. Results of UPLC-MS analysis and ¹H-NMR spectroscopy showed that the used surfactants and applied grinding procedures caused no chemical degradation of the PZQ. The physicochemical properties, solubility and the in vitro dissolution enhancement of the co-ground products were related to the drug to surfactant ratio and the grinding protocol applied. The highest enhancement of the in vitro dissolution rate was achieved at the drug to surfactant ratio of 10:3 and 10:2 for F-127 and C-1816, respectively with the milling time of 30 min. The MTT assay on Caco-2 cell line demonstrated the biocompatibility of both co-ground products. Furthermore, the surfactants used did not change intrinsically high intestinal permeability of PZQ (Papp ∼ 4.00 × 10^-5 cm s^-1). The presented results confirmed that the co-grinding with surfactant is a promising new approach in enhancing in vitro dissolution of poorly soluble drugs like PZQ.