The cost of a disease targeted for elimination in Brazil: the case of schistosomiasis mansoni

Unveiling potent inhibitors for schistosomiasis through ligand-based drug design, molecular docking, molecular dynamics simulations and pharmacokinetics predictions

Schistosomiasis is a neglected tropical disease which imposes a considerable and enduring impact on affected regions, leading to persistent morbidity, hindering child development, diminishing productivity, and imposing economic burdens. Due to the emergence of drug resistance and limited management options, there is need to develop additional effective inhibitors for schistosomiasis. In view of this, quantitative structure-activity relationship studies, molecular docking, molecular dynamics simulations, drug-likeness and pharmacokinetics predictions were applied to 39 Schistosoma mansoni Thioredoxin Glutathione Reductase (SmTGR) inhibitors. The chosen QSAR model demonstrated robust statistical parameters, including an R2 of 0.798, R2adj of 0.767, Q2cv of 0.681, LOF of 0.930, R2test of 0.776, and cR2p of 0.746, confirming its reliability. The most active derivative (compound 40) was identified as a lead candidate for the development of new potential non-covalent inhibitors through ligand-based design. Subsequently, 12 novel compounds (40a-40l) were designed with enhanced anti-schistosomiasis activity and binding affinity. Molecular docking studies revealed strong and stable interactions, including hydrogen bonding, between the designed compounds and the target receptor. Molecular dynamics simulations over 100 nanoseconds and MM-PBSA free binding energy (ΔGbind) calculations validated the stability of the two best-designed molecules. Furthermore, drug-likeness and pharmacokinetics prediction analyses affirmed the potential of these designed compounds, suggesting their promise as innovative agents for the treatment of schistosomiasis.

Dietary glycemic and energy load differentially modulates Schistosoma mansoni-induced granulomatous inflammation and response to antiparasitic chemotherapy

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.

Nanotechnological approaches in the treatment of schistosomiasis: an overview

Schistosomiasis causes over 200,000 deaths annually. The current treatment option, praziquantel, presents limitations, including low bioavailability and resistance. In this context, nanoparticles have emerged as a promising option for improving schistosomiasis treatment. Several narrative reviews have been published on this topic. Unfortunately, the lack of clear methodologies presented in these reviews leads to the exclusion of many important studies without apparent justification. This integrative review aims to examine works published in this area with a precise and reproducible method. To achieve this, three databases (i.e., Pubmed, Web of Science, and Scopus) were searched from March 31, 2022, to March 31, 2023. The search results included only original research articles that used nanoparticles smaller than 1 µm in the treatment context. Additionally, a search was conducted in the references of the identified articles to retrieve works that could not be found solely using the original search formula. As a result, 65 articles that met the established criteria were identified. Inorganic and polymeric nanoparticles were the most prevalent nanosystems used. Gold was the primary material used to produce inorganic nanoparticles, while poly(lactic-co-glycolic acid) and chitosan were commonly used to produce polymeric nanoparticles. None of these identified works presented results in the clinical phase. Finally, based on our findings, the outlook appears favorable, as there is a significant diversity of new substances with schistosomicidal potential. However, financial efforts are required to advance these nanoformulations.

Assessment of the accuracy of 11 different diagnostic tests for the detection of Schistosomiasis mansoni in individuals from a Brazilian area of low endemicity using latent class analysis

Background

Schistosomiasis is a parasitic disease associated with poverty. It is estimated that 7.1 million people are infected with Schistosoma mansoni in Latin America, with 95% of them living in Brazil. Accurate diagnosis and timely treatment are important measures to control and eliminate schistosomiasis, but diagnostic improvements are needed to detect infections, especially in areas of low endemicity.

Methodology

This research aimed to evaluate the performance of 11 diagnostic tests using latent class analysis (LCA). A cross-sectional survey was undertaken in a low endemicity area of the municipality of Malacacheta, Minas Gerais, Brazil. Feces, urine, and blood samples were collected from 400 residents older than 6 years of age, who had not been treated with praziquantel in the 12 months previous to the collection of their samples. The collected samples were examined using parasitological (Helm Test® kit Kato-Katz), nucleic acid amplification tests -NAATs (PCR, qPCR and LAMP on urine; PCR-ELISA, qPCR and LAMP on stool), and immunological (POC-CCA, the commercial anti-Schistosoma mansoni IgG ELISA kit from Euroimmun, and two in-house ELISA assays using either the recombinant antigen PPE or the synthetic peptide Smp150390.1) tests.

Results

The positivity rate of the 11 tests evaluated ranged from 5% (qPCR on urine) to 40.8% (commercial ELISA kit). The estimated prevalence of schistosomiasis was 12% (95% CI: 9-15%) according to the LCA. Among all tests assessed, the commercial ELISA kit had the highest estimated sensitivity (100%), while the Kato-Katz had the highest estimated specificity (99%). Based on the accuracy measures observed, we proposed three 2-step diagnostic approaches for the active search of infected people in endemic settings. The approaches proposed consist of combinations of commercial ELISA kit and NAATs tests performed on stool. All the approaches had higher sensitivity and specificity than the mean values observed for the 11 tests (70.4 and 89.5%, respectively).

Conclusion

We showed that it is possible to achieve high specificity and sensitivity rates with lower costs by combining serological and NAATs tests, which would assist in the decision-making process for appropriate allocation of public funding aiming to achieve the WHO target of eliminating schistosomiasis as a public health problem by 2030.

Development of real-time and lateral flow recombinase polymerase amplification assays for rapid detection of Schistosoma mansoni

Background

Accurate diagnosis followed by timely treatment is an effective strategy for the prevention of complications together with reducing schistosomiasis transmission. Recombinase Polymerase Amplification (RPA) is a simple, rapid, sensitive, and specific isothermal method with low resource needs. This research aimed at the development and optimisation of a real-time (RT) and a lateral flow (LF) RPA assay for the detection of Schistosoma mansoni.

Methodology

Recombinase Polymerase Amplification reactions were performed at full- (as recommended) and half-volumes (to reduce costs), with RT or LF detection systems targeting the S. mansoni mitochondrial minisatellite region. The specificity was assessed using gDNA from other Schistosoma species, helminths co-endemic with S. mansoni, human stool, and urine, and Biomphalaria snail hosts. The analytical sensitivity was evaluated using serial dilutions of gDNA, synthetic copies of the target, and single eggs. The ability of both assays to detect the S. mansoni DNA in human urine and stool samples was also tested. The long-term stability of the RT-RPA reagents was evaluated by storing the reaction components in different temperature conditions for up to 3  weeks.

Results

The RT- and the LF-RPA (SmMIT- and SmMIT-LF-RPA, respectively) presented similar results when used full- and half-volumes, thus the latter was followed in all experiments. The SmMIT-RPA was 100% specific to S. mansoni, able to detect a single egg, with a limit of detection (LOD) of down to 1  fg of gDNA and one synthetic copy of the target. The assay was able to detect S. mansoni DNA from stool containing 1 egg/g and in spiked urine at a concentration of 10  fg/μl. SmMIT-RPA reagents were stable for up to 3  weeks when kept at 19°C, and 2  weeks when stored at 27°C. The SmMIT-LF-RPA cross-reacted with Clinostomidae, presented the LOD of 10  fg and one synthetic copy of the target, being able to detect a single egg and 1 egg/g in a stool sample. The LOD in spiked urine samples was 10  pg/μl.

Conclusion

The half-volume SmMIT-RPA is a promising method to be used in the field. It is specific, sensitive, robust, and tolerant to inhibitors, with a long-term stability of the reaction components and the real-time visualisation of results.

The role of environmental enteric dysfunction in the pathogenesis of Schistosoma mansoni-associated morbidity in school-aged children

Background

Studies have implicated schistosomiasis as a cause of intestinal barrier disruption, a salient feature of environmental enteric dysfunction (EED), as eggs translocate from the sterile bloodstream through the gut wall. We examined the longitudinal impact of praziquantel (PZQ) treatment on a) EED biomarkers and b) Insulin growth factor I (IGF-1), a key driver of childhood linear growth, since EED has been implicated in linear growth stunting.

Methodology

290 children infected with S. mansoni in Brazil were treated with PZQ at baseline. EED biomarkers lipopolysaccharide (LPS) and intestinal fatty acid binding-protein (I-FABP) were measured, as well as IGF-1 at baseline, 6 and 12-months. Multivariate regression analysis was applied to assess associations between S. mansoni intensity and plasma biomarkers (LPS, I-FABP, and IGF-1), controlling for potential confounding variables.

Principal findings

At baseline, S. mansoni infection intensities were 27.2% light, 46.9% moderate, and 25.9% heavy. LPS concentrations were significantly reduced at the 12-month visit compared to baseline (p = 0.0002). No longitudinal changes were observed for I-FABP or IGF-1 in the 6- or 12-month periods following baseline treatment. After 6-months, I-FABP concentration was significantly higher in high vs low intensity (p = 0.0017). IGF-1 concentrations were significantly lower among children with high and moderate vs low intensity infections at each study visit.

Conclusions/significance

We report that S. mansoni infection impacts LPS, I-FABP and IGF-1. These findings suggest a mechanistic role for EED in schistosomiasis-related morbidities, particularly linear growth.

Schistosoma mansoni is a tropical parasitic infection that causes intestinal schistosomiasis. In infected humans, the parasite worms shed eggs that migrate across the gut barrier, which damages intestinal structure and function. In children, intestinal schistosomiasis leads to anemia, undernutrition, and linear growth stunting. The mechanistic pathways between schistosomiasis and stunting are not fully understood, but this research explores the role of environmental enteric dysfunction (EED) in schistosomiasis-related morbidity. EED is an intestinal condition that affects children living in areas of poor water, sanitation, and hygiene and also leads to impaired growth and stunting. In a longitudinal cohort of Brazilian children infected with S. mansoni, we measured blood biomarkers of EED and linear growth at three time points over 12 months. All of the children were treated for schistosomiasis at baseline, and after 12 months, we observed a significant decrease in a marker of EED, suggesting improvement in gut integrity. We also found that children who had higher parasite egg burden at the baseline visit had lower levels of insulin-like growth factor-1, a hormone that drives growth in children. Our findings suggest that EED may play a role in schistosomiasis-related stunting and furthers our understanding for S. mansoni pathogenesis in children.

Kidney injury biomarkers and parasitic loads of Schistosoma mansoni in a highly endemic area in northeastern Brazil

Schistosomiasis affects approximately 240 million people worldwide. In Brazil, it is estimated that 1.5 million people are infected with Schistosoma mansoni and up to 15% of diagnosed individuals develop kidney damage. Renal involvement in schistosomiasis mansoni is characterized by glomerular lesions, with a high incidence, especially in chronically infected patients living in areas of high endemicity. Renal damage occurs slowly and is often asymptomatic, with a long-term manifestation of chronic kidney disease, with progressive loss of kidney functions, and early detection of subclinical kidney disease is of great importance. The aim of this study was to investigate kidney damage in patients infected with S. mansoni through urinary biomarkers of kidney injury and their association with the different parasite loads found. The patients were divided into two groups based on the diagnosis of infection by S. mansoni by the Kato-Katz and IgG-ELISA-SEA method: group of individuals infected by S. mansoni, Kato-Katz positive (PG); and group of individuals not infected by S. mansoni, Kato-Katz-negative (NG). Urinary creatinine and albuminuria were determined by immunoturbidimetry and proteinuria by the colorimetric method. The urinary biomarkers of podocyte injury (VEGF and Nephrin) and glomerular inflammation (MCP-1) were quantified by immunoassay and expressed by the urinary creatinine ratio. Urinary VEGF showed significantly higher levels in PG compared to NG (p = 0.004), increasing at all intensities of infection including low parasite load (p = 0.020). Our results show increased signs of podocyte damage in patients with schistosomiasis mansoni regardless of the parasite load, evidenced by increased urinary VEGF levels. However, further studies are needed since data related to schistosomiasis glomerulopathy and its association with new urinary biomarkers of kidney injury are scarce in the literature.

Persistence of Schistosomiasis-Related Morbidity in Northeast Brazil: An Integrated Spatio-Temporal Analysis

Objective: To analyze the temporal trend and spatial patterns of schistosomiasis-related morbidity in Northeast Brazil, 2001–2017. Methods: Ecological study, of time series and spatial analysis, based on case notifications and hospital admission data, as provided by the Ministry of Health. Results: Of a total of 15,574,392 parasitological stool examinations, 941,961 (6.0%) were positive, mainly on the coastline of Pernambuco, Alagoas and Sergipe states. There was a reduction from 7.4% (2002) to 3.9% (2017) of positive samples and in the temporal trend of the detection rate (APC—11.6*; Confidence Interval 95%—13.9 to −9.1). There was a total of 5879 hospital admissions, with 40.4% in Pernambuco state. The hospitalization rate reduced from 0.82 (2001) to 0.02 (2017) per 100,000 inhabitants. Conclusion: Despite the reduction in case detection and hospitalizations, the persistence of focal areas of the disease in coastal areas is recognized. This reduction may indicate a possible positive impact of control on epidemiological patterns, but also operational issues related to access to healthcare and the development of surveillance and control actions in the Unified Health System.

A loop-mediated isothermal amplification assay for Schistosoma mansoni detection in Biomphalaria spp. from schistosomiasis-endemic areas in Minas Gerais, Brazil

BACKGROUND

Schistosomiasis a neglected tropical disease  endemic in Brazil. It is caused by the trematode Schistosoma mansoni, which is transmitted by snails of the genus Biomphalaria. Among measures used to control and eliminate schistosomiasis, accurate mapping and monitoring of snail breeding sites are recommended. Despite the limitations of parasitological methods, they are still used to identify infected snails. Loop-mediated isothermal amplification (LAMP) is a sensitive, rapid, and cost-effective diagnostic method for the identification of infected snails. In the work reported here, we aimed to validate the use of LAMP for the detection of S. mansoni in snails of the genus Biomphalaria.

METHODS

Snails were collected in five municipalities of the Mucuri Valley and Jequitinhonha Valley regions in the state of Minas Gerais, Brazil. Snails were pooled according to collection site and then squeezed for the detection of S. mansoni and other trematode larvae. Pooled snails were subjected to pepsin digestion and DNA extraction. Molecular assays were performed for species-specific identification and characterization of the samples. A previously described LAMP assay was adapted, evaluated, and validated using laboratory and field samples.

RESULTS

Using the parasitological method described here, S. mansoni cercariae were detected in snails from two collection sites, and cercariae of the family Spirorchiidae were found in snails from one site. The snails were identified by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP). Biomphalaria glabrata, the main snail host of S. mansoni in Brazil, was detected in 72.2% of the collection sites. Biomphalaria kuhniana, which is resistant to S. mansoni infection, was found in the remaining sites. Multiplex, low stringency (LS), and conventional PCR allowed the detection of positive snails in four additional sites. Trematodes belonging to the families Strigeidae and Echinostomatidae were detected by multiplex PCR in two sites. The LAMP assay was effective in detecting the presence of S. mansoni infection in laboratory (7 days post-infection) and field samples with no cross-reactivity for other trematodes. When compared to LS and conventional PCR, LAMP showed 100% specificity, 85.7% sensitivity, and a κ index of 0.88.

CONCLUSIONS

Our findings suggest that LAMP is a good alternative method for the detection and monitoring of transmission foci of S. mansoni, as it was three times as effective as the parasitological examination used here for the detection of infection, and is more directly applicable in the field than other molecular techniques.

Economic evaluations addressing diagnosis and treatment strategies for neglected tropical diseases: an overview

Neglected tropical diseases (NTDs) are those affecting vulnerable people and causing additional social and economic burden. The aim of this study was to carry out a general overview of the health economic assessments involving the diagnosis and treatment of six NTDs: cutaneous leishmaniasis (CL), Chagas disease, cysticercosis, filariasis, schistosomiasis and visceral leishmaniasis (VL). The literature search was based on two of the main medical literature databases (Medline and SciELO) and identified 46 studies. Twenty-six studies (57%) addressed therapeutic strategies, while other 20 (43%) assessed diagnostic or both diagnostic and therapeutic approaches. The studies were published between 1994 and 2021, and 57% of them (26/46) were carried out in four countries. Cost-effectiveness analyses were conducted in 59% (27/46) of the studies. Economic studies of NTDs have timidly increased in recent years. Despite the improvement of analytical methods, completeness and accuracy of information, there are few new technologies applied to NTDs and public health systems. In addition, economic studies for NTDs are concentrated in a few countries. Thus, this review points out the need for investment in research, development and training of human resources dedicated to the economic analysis in health, especially on NTDs, as a strategy to reduce inequalities by optimizing the use of health resources.

Geographic Information System-based association between the sewage network, geographical location of intermediate hosts, and autochthonous cases for the estimation of risk areas of schistosomiasis infection in Ourinhos, São Paulo, Brazil

INTRODUCTION:

Ourinhos is a municipality located between the Pardo and Paranapanema rivers, and it has been characterized by the endemic transmission of schistosomiasis since 1952. We used geospatial analysis to identify areas prone to human schistosomiasis infections in Ourinhos. We studied the association between the sewage network, co-occurrence of Biomphalaria snails (identified as intermediate hosts [IHs] of Schistosoma mansoni), and autochthonous cases.

METHODS:

Gi spatial statistics, Ripley’s K12-function, and kernel density estimation were used to evaluate the association between schistosomiasis data reported during 2007-2016 and the occurrence of IHs during 2015-2017. These data were superimposed on the municipality sewage network data.

RESULTS:

We used 20 points with reported IH; they were colonized predominantly by Biomphalaria glabrata, followed by B. tenagophila and B. straminea. Based on Gi statistics, a significant cluster of autochthonous cases was superimposed on the Christoni and Água da Veada water bodies, with distances of approximately 300 m and 2200 m from the points where B. glabrata and B. straminea were present, respectively.

CONCLUSIONS:

The residence geographical location of autochthonous cases allied with the spatial analysis of IHs and the coverage of the sewage network provide important information for the detection of human-infection areas. Our results demonstrated that the tools used for direct surveillance, control, and elimination of schistosomiasis are appropriate.

A Real-Time PCR Assay for the Diagnosis of Intestinal Schistosomiasis and Cure Assessment After the Treatment of Individuals With Low Parasite Burden

The laboratorial diagnosis of the intestinal schistosomiasis is always performed using Kato-Katz technique. However, this technique presents low sensitivity for diagnosis of individuals with low parasite burden, which constitutes the majority in low endemicity Brazilian locations for the disease. The objective of this study was developed and to validate a real-time PCR assay (qPCR) targeting 121 bp sequence to detect Schistosoma spp. DNA for the diagnosis of intestinal schistosomiasis and a sequence of the human β-actin gene as internal control. Firstly, the qPCR was standardized and next it was evaluated for diagnosis and cure assessment of intestinal schistosomiasis in the resident individuals in Tabuas and Estreito de Miralta, two locations in Brazil endemic for intestinal schistosomiasis. The qPCR assay results were compared with those of the Kato-Katz (KK) test, examining 2 or 24 slides, Saline Gradient (SG) and “reference test” (24 KK slides + SG). The cure assessment was measured by these diagnostic techniques at 30, 90, and 180 days post-treatment. In Tabuas, the positivity rates obtained by the qPCR was 30.4% (45/148) and by “reference test” was of 31.0% (46/148), with no statistical difference (p = 0.91). The presumed cure rates at 30, 90, and 180 days post-treatment were 100, 94.4, and 78.4% by the analysis of 24 KK slides, 100, 94.4, and 78.4% by the SG, and 100, 83.3, and 62.1% by the qPCR assay. In Estreito de Miralta, the positivity obtained by qPCR was 18.3% (26/142) and with “reference test” was 24.6% (35/142), with no statistical difference (p = 0.20). The presumed cure rates were 93.3, 96.9, and 96.5% by the KK, 93.3, 96.9, and 100% by the SG, and 93.3, 93.9, and 96.5% by the qPCR at 30, 90, and 180 days post-treatment, respectively. This study showed that the diagnostic techniques presented different performance in the populations from the two districts (Tabuas and Estreito de Miralta) and reinforces the need of combining techniques to improve diagnosis accuracy, increasing the detection of individuals with low parasite burden. This combination of techniques consists an important strategy for controlling the disease transmission.

The potential risk of Schistosoma mansoni transmission by the invasive freshwater snail Biomphalaria straminea in South China

Schistosomes infect more than 200 million people worldwide, and globally, over 700 million people are at risk of infection. The snail Biomphalaria straminea, as one of the intermediate hosts of Schistosoma mansoni, consecutively invaded Hong Kong in 1973, raising great concern in China. In this study, a malacological survey was conducted over a period of four years, and investigations were performed on the mechanism of susceptibility of B. straminea to S. mansoni. B. straminea was investigated in China from 2014 to 2018. Out of 185 investigated sites, 61 were positive for stages of black B. straminea (BBS), which shows pigmented spots. Twenty of the 61 sites were positive for red B. straminea (RBS), which is partially albino and red colored. Phylogenetic analyses based on cox1 and 18S rRNA sequences demonstrated that both phenotypes were clustered with Brazilian strains. No S. mansoni infections were detected in field-collected snail. However, in laboratory experiments, 4.17% of RBS were susceptible to a Puerto Rican strain of S. mansoni, while BBS was not susceptible. The highest susceptibility rate (70.83%) was observed in the F2 generation of RBS in lab. The density of RBS has increased from south to north and from west to east in Guangdong since 2014. Five tyrosinase tyrosine metabolism genes were upregulated in BBS. Transcriptome comparisons of RBS and BBS showed that ficolin, C1q, MASP-like, and membrane attack complex (MAC)/perforin models of the complement system were significantly upregulated in BBS. Our study demonstrated that B. straminea is widely distributed in Hong Kong and Guangdong Province, which is expanding northwards very rapidly as a consequence of its adaptation to local environments. Our results suggest that B. straminea from South China is susceptible to S. mansoni, implying the high potential for S. mansoni transmission and increased S. mansoni infection risk in China.

Biomphalaria straminea is an important intermediate host for the blood fluke Schistosoma mansoni. B. straminea has spread in Hong Kong and in mainland China since 1973. However, whether resident snails can transmit intestinal schistosomiasis caused by S. mansoni remains unclear. Our results revealed that different types of B. straminea are widespread in cities such as Hong Kong, Shenzhen, Dongguan, Huizhou and Puning and that the distribution of the species has shifted northwards. The most important finding was that one of the phenotypes (red phenotype of B. straminea, RBS), which is highly susceptible to S. mansoni, has spread into the city of Shenzhen since 2016. The density of RBS in Guangdong Province has increased rapidly since 2014, especially since 2016. Transcriptome analysis showed that the high expression levels of ficolin, C1q, MASP-like, and membrane attack complex (MAC)/perforin models of the complement system might be associated with the mechanism of susceptibility. Our study suggested that B. straminea is susceptible to S. mansoni, implying a high potential risk of S. mansoni transmission in South China. More attention should be paid to the potential transmission of S. mansoni, and control measures should be established to prevent the spread of this snail in South China.

Cost and logistics implications of a nationwide survey of schistosomiasis and other intestinal helminthiases in Sudan: Key activities and cost components

It is vital to share details of concrete experiences of conducting a nationwide disease survey. By doing so, the global health community could adapt previous experiences to expand geographic mapping programs, eventually contributing to the development of disease control and elimination strategies. A nationwide survey of schistosomiasis and intestinal helminthiases was conducted from December 2016 to March 2017 in Sudan. We aimed to describe details of the key activities and cost components required for the nationwide survey. We investigated which activities were necessary to prepare and conduct a nationwide survey of schistosomiasis and intestinal helminthiases, and the types and amounts of transportation, personnel, survey equipment, and consumables that were required. In addition, we estimated financial and economic costs from the perspectives of the donor and the Ministry of Health. Cash expenditures incurred to implement the survey were defined as financial costs. For economic costs, we considered the true value for society as a whole, and this category therefore accounted for the costs of all goods and services used for the project, including those that were not sold in the market and therefore had no market price (e.g., time spent by head teachers and teachers). We organized costs into capital and recurrent items. We ran one-way sensitivity and probabilistic analyses using Monte-Carlo methods with 10,000 draws to examine the robustness of the primary analysis results. A total of USD 1,465,902 and USD 1,516,238 was incurred for the financial and economic costs, respectively. The key cost drivers of the nationwide survey were personnel and transportation, for both financial and economic costs. Personnel and transportation accounted for around 64% and 18% of financial costs, respectively. If a government finds a way to mobilize existing government officials with no additional payments using the health system already in place, the cost of a nationwide survey could be remarkably reduced.

Profiling Transcriptional Regulation and Functional Roles of Schistosoma mansoni c-Jun N-Terminal Kinase

Mitogen-activated protein kinases (MAPKs) play a regulatory role and influence various biological activities, such as cell proliferation, differentiation, and survival. Our group has demonstrated through functional studies that Schistosoma mansoni c-Jun N-terminal kinase (SmJNK) MAPK is involved in the parasite's development, reproduction, and survival. SmJNK can, therefore, be considered a potential target for the development of new drugs. Considering the importance of SmJNK in S. mansoni maturation, we aimed at understanding of SmJNK regulated signaling pathways in the parasite, correlating expression data with S. mansoni development. To better understand the role of SmJNK in S. mansoni intravertebrate host life stages, RNA interference knockdown was performed in adult worms and in schistosomula larval stage. SmJNK knocked-down in adult worms showed a decrease in oviposition and no significant alteration in their movement. RNASeq libraries of SmJNK knockdown schistosomula were sequenced. A total of 495 differentially expressed genes were observed in the SmJNK knockdown parasites, of which 373 were down-regulated and 122 up-regulated. Among the down-regulated genes, we found transcripts related to protein folding, purine nucleotide metabolism, the structural composition of ribosomes and cytoskeleton. Genes coding for proteins that bind to nucleic acids and proteins involved in the phagosome and spliceosome pathways were enriched. Additionally, we found that SmJNK and Smp38 MAPK signaling pathways converge regulating the expression of a large set of genes. C. elegans orthologous genes were enriched for genes related to sterility and oocyte maturation, corroborating the observed phenotype alteration. This work allowed an in-depth analysis of the SmJNK signaling pathway, elucidating gene targets of regulation and functional roles of this critical kinase for parasite maturation.