Multiplex PCR for bacterial, viral and protozoal pathogens in persistent diarrhoea or persistent abdominal pain in Côte d'Ivoire, Mali and Nepal.

In contrast to acute diarrhoea, the aetiology of persistent digestive disorders (≥ 14 days) is poorly understood in low-resource settings and conventional diagnostic approaches lack accuracy. In this multi-country study, we compared multiplex real-time PCR for enteric bacterial, parasitic and viral pathogens in stool samples from symptomatic patients and matched asymptomatic controls in Côte d'Ivoire, Mali and Nepal. Among 1826 stool samples, the prevalence of most pathogens was highest in Mali, being up to threefold higher than in Côte d'Ivoire and up to tenfold higher than in Nepal. In all settings, the most prevalent bacteria were EAEC (13.0-39.9%) and Campylobacter spp. (3.9-35.3%). Giardia intestinalis was the predominant intestinal protozoon (2.9-20.5%), and adenovirus 40/41 was the most frequently observed viral pathogen (6.3-25.1%). Significantly different prevalences between symptomatic and asymptomatic individuals were observed for Campylobacter, EIEC and ETEC in the two African sites, and for norovirus in Nepal. Multiple species pathogen infection was common in Côte d'Ivoire and Mali, but rarely found in Nepal. We observed that molecular testing detected multiple enteric pathogens and showed low discriminatory accuracy to distinguish between symptomatic and asymptomatic individuals. Yet, multiplex PCR allowed for direct comparison between different countries and revealed considerable setting-specificity.

Visceral leishmaniasis in the hills of western Nepal: A transmission assessment.

In Nepal, visceral leishmaniasis (VL) has been targeted for elimination as a public health problem by 2026. Recently, increasing numbers of VL cases have been reported from districts of doubtful endemicity including hills and mountains, threatening the ongoing VL elimination program in Nepal. We conducted a multi-disciplinary, descriptive cross-sectional survey to assess the local transmission of Leishmania donovani in seven such districts situated at altitudes of up to 1,764 meters in western Nepal from March to December 2019. House-to-house surveys were performed for socio-demographic data and data on past and current VL cases. Venous blood was collected from all consenting individuals aged ≥2 years and tested with the rK39 RDT. Blood samples were also tested with direct agglutination test, and a titer of ≥1:1600 was taken as a marker of infection. A Leishmania donovani species-specific PCR (SSU-rDNA) was performed for parasite species confirmation. We also captured sand flies using CDC light traps and mouth aspirators. The house-to-house surveys documented 28 past and six new VL cases of which 82% (28/34) were without travel exposure. Overall, 4.1% (54/1320) of healthy participants tested positive for L. donovani on at least one serological or molecular test. Among asymptomatic individuals, 17% (9/54) were household contacts of past VL cases, compared to 0.5% (6/1266) among non-infected individuals. Phlebotomus argentipes, the vector of L. donovani, was found in all districts except in Bajura. L. donovani was confirmed in two asymptomatic individuals and one pool of sand flies of Phlebotomus (Adlerius) sp. We found epidemiological and entomological evidence for local transmission of L. donovani in areas previously considered as non-endemic for VL. The national VL elimination program should revise the endemicity status of these districts and extend surveillance and control activities to curb further transmission of the disease.

The ongoing risk of Leishmania donovani transmission in eastern Nepal: an entomological investigation during the elimination era.

BACKGROUND: Visceral leishmaniasis (VL), a life-threatening neglected tropical disease, is targeted for elimination from Nepal by the year 2026. The national VL elimination program is still confronted with many challenges including the increasingly widespread distribution of the disease over the country, local resurgence and the questionable efficacy of the key vector control activities. In this study, we assessed the status and risk of Leishmania donovani transmission based on entomological indicators including seasonality, natural Leishmania infection rate and feeding behavior of vector sand flies, Phlebotomus argentipes, in three districts that had received disease control interventions in the past several years in the context of the disease elimination effort. METHODS: We selected two epidemiologically contrasting settings in each survey district, one village with and one without reported VL cases in recent years. Adult sand flies were collected using CDC light traps and mouth aspirators in each village for 12 consecutive months from July 2017 to June 2018. Leishmania infection was assessed in gravid sand flies targeting the small-subunit ribosomal RNA gene of the parasite (SSU-rRNA) and further sequenced for species identification. A segment (~ 350 bp) of the vertebrate cytochrome b (cytb) gene was amplified from blood-fed P. argentipes from dwellings shared by both humans and cattle and sequenced to identify the preferred host. RESULTS: Vector abundance varied among districts and village types and peaks were observed in June, July and September to November. The estimated Leishmania infection rate in vector sand flies was 2.2% (1.1%-3.7% at 95% credible interval) and 0.6% (0.2%-1.3% at 95% credible interval) in VL and non-VL villages respectively. The common source of blood meal was humans in both VL (52.7%) and non-VL (74.2%) villages followed by cattle. CONCLUSIONS: Our findings highlight the risk of ongoing L. donovani transmission not only in villages with VL cases but also in villages not reporting the presence of the disease over the past several years within the districts having disease elimination efforts, emphasize the remaining threats of VL re-emergence and inform the national program for critical evaluation of disease elimination strategies in Nepal.

Fabrication and Characterization of Zn Particle Incorporated Fibrous Scaffolds for Potential Application in Tissue Healing and Regeneration.

Zinc (Zn) metal and its alloys have received a lot of interest in biomedical applications due to their biodegradability, biocompatibility, antimicrobial activity, and ability to stimulate tissue regeneration. Bulk Zn has been successfully utilized in a variety of implant applications, most notably as bioabsorbable cardiac stents and orthopedic fixation devices, where it provides adequate mechanical properties while also releasing helpful Zn ions (Zn2+) during degradation. Such beneficial ions are dose-dependent and, when released in excess, can induce cellular toxicity. In this study, we hypothesize that embedding Zn metal particles into a polymer nanofibrous scaffold will enable control of the degradation and time release of the Zn2+. We designed and fabricated two polymer scaffolds, polycaprolactone (PCL) and polycaprolactone-chitosan (PCL-CH). Each scaffold had an increasing amount of Zn. Several physicochemical properties such as fiber morphology, crystallinity, mechanical strength, hydrophilicity, degradation and release of Zn2+, thermal properties, chemical compositions, and so forth were characterized and compared with the PCL fibrous scaffold. The biological properties of the scaffolds were evaluated in vitro utilizing direct and indirect cytotoxicity assays and cell viability. All the data show that the addition of Zn changed various physical properties of the PCL and PCL-CH scaffolds except their chemical structure. Further investigation reveals that the PCL-CH scaffolds degrade the Zn particles relatively faster than the PCL because the presence of the hydrophilic CH influences the faster release of Zn2+ in cell culture conditions as compared to the PCL fibrous scaffold. The combined advantages of CH and Zn in the PCL scaffold enriched 3T3 fibroblast cells' survival and proliferation except the ones with the higher concentration of Zn particles. These new composite scaffolds are promising and can be further considered for tissue healing and regeneration applications.

Chitin Nanofibrils Enabled Core-Shell Microcapsules of Alginate Hydrogel.

An engineered 3D architectural network of the biopolymeric hydrogel can mimic the native cell environment that promotes cell infiltration and growth. Among several bio-fabricated hydrogel structures, core-shell microcapsules inherit the potential of cell encapsulation to ensure the growth and transport of cells and cell metabolites. Herein, a co-axial electrostatic encapsulation strategy is used to create and encapsulate the cells into chitin nanofibrils integrated alginate hydrogel microcapsules. Three parameters that are critical in the electrostatic encapsulation process, hydrogel composition, flow rate, and voltage were optimized. The physicochemical characterization including structure, size, and stability of the core-shell microcapsules was analyzed by scanning electron microscope (SEM), FTIR, and mechanical tests. The cellular responses of the core-shell microcapsules were evaluated through in vitro cell studies by encapsulating NIH/3T3 fibroblast cells. Notably, the bioactive microcapsule showed that the cell viability was found excellent for more than 2 weeks. Thus, the results of this core-shell microcapsule showed a promising approach to creating 3D hydrogel networks suitable for different biomedical applications such as in vitro tissue models for toxicity studies, wound healing, and tissue repair.

Pulmonary Paragonimiasis: A Case Series.

Paragonimiasis contributes to significant foodborne zoonosis worldwide. The major mode of transmission in humans is by consumption of uncooked or undercooked crabs and crayfish harbouring Paragonimus metacercariae. It begins with symptoms like fever and lower respiratory involvement from a few months to a year, mimicking those of tuberculosis and leading to diagnostic delay. Here, we report two cases of paragonimiasis during a period of nine months. Both cases presented with symptoms of productive cough with rusty sputum, chest pain, along with eosinophilia, and pleural effusion and had a history of consumption of smoked crab from the local river. The diagnosis was established by microscopic demonstration of Paragonimus ova in the sputum. They were treated with praziquantel and recovered. Indeed, it is challenging to diagnose paragonimiasis due to the lack of its specific symptoms but should be considered in the differential diagnosis of eosinophilia and pleural effusion in such lung diseases. Keywords: case reports; eosinophilia; paragonimiasis; pleural effusion.

Incorporating nanoconfined chitin-fibrils in poly (ε-caprolactone) membrane scaffolds improves mechanical and chemical properties for biomedical application.

Engineered composite scaffolds composed of natural and synthetic polymers exhibit cooperation at the molecular level that closely mimics tissue extracellular matrix's (ECM) physical and chemical characteristics. However, due to the lack of smooth intermix capability of natural and synthetic materials in the solution phase, bio-inspired composite material development has been quite challenged. In this research, we introduced new bio-inspired material blending techniques to fabricate nanofibrous composite scaffolds of chitin nanofibrils (CNF), a natural hydrophilic biomaterial and poly (ɛ-caprolactone) (PCL), a synthetic hydrophobic-biopolymer. CNF was first prepared by acid hydrolysis technique and dispersed in trifluoroethanol (TFE); and second, PCL was dissolved in TFE and mixed with the chitin solution in different ratios. Electrospinning and spin-coating technology were used to form nanofibrous mesh and films, respectively. Physicochemical properties, such as mechanical strength, and cellular compatibility, and structural parameters, such as morphology, and crystallinity, were determined. Toward the potential use of this composite materials as a support membrane in blood-brain barrier application (BBB), human umbilical vein endothelial cells (HUVECs) were cultured, and transendothelial electrical resistance (TEER) was measured. Experimental results of the composite materials with PCL/CNF ratios from 100/00 to 25/75 showed good uniformity in fiber morphology and suitable mechanical properties. They retained the excellent ECM-like properties that mimic synthetic-bio-interface that has potential application in biomedical fields, particularly tissue engineering and BBB applications.

Multidrug-Resistant Acinetobacter: Detection of ESBL, MBL, bla NDM-1 Genotype, and Biofilm Formation at a Tertiary Care Hospital in Eastern Nepal.

Background: The Acinetobacter species is an important hospital-acquired pathogen. The rapid development of resistance to multiple drugs and the ability to form biofilm make these bacteria more adaptable to survive in healthcare facilities, thus posing a challenge to their effective management. Objective: This study aimed to characterize clinical isolates of Acinetobacter spp and to study their antimicrobial susceptibility patterns and ability to form biofilm. Resistant Acinetobacter was further analyzed for the detection of extended-spectrum ß-lactamases (ESBLs), metallo ß-lactamases (MBLs), carbapenemase production, and presence of blaNDM-1 gene. Materials and Methods: A total of 324 Acinetobacter species were isolated from various clinical specimens which were submitted to the Department of Microbiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal, and were studied for antibiotic susceptibility testing, detection of ESBL and MBL production, and formerly biofilm formation was performed by standard microbiological methods. PCR was carried out to determine the presence of the blaNDM-1 gene. Results: The predominant Acinetobacter species isolated was A calcoaceticus-baumannii Complex (Acb complex) 167 (51.5%). Among those, all A. species 128 (40%) were multidrug resistant (MDR). In which 13 (4.0%) were ESBL producers, 70 (61.9%) were MBL, and 12 (10.6%) were carbapenemases producers. The blaNDM1 gene was present in 33 isolates. Thirty-seven percent (121/324) of isolates formed biofilm. The majority of A. species were resistant to cefotaxime 73.8% (239) and cefepime 74.4% (241). A significant proportion of biofilm producers were MDR (p < 0.001). Conclusion: Drug-resistant Acinetobacter formed a substantial proportion of this hospital's samples with a large presence of the bla NDM-1 gene. A matter of great concern is the association of multidrug-resistant phenotype with biofilm formation. This situation warranted stringent surveillance and adherence to infection prevention and control practices.

Current Research on Zinc Oxide Nanoparticles: Synthesis, Characterization, and Biomedical Applications.

Zinc oxide nanoparticles (ZnO-NPs) have piqued the curiosity of researchers all over the world due to their extensive biological activity. They are less toxic and biodegradable with the capacity to greatly boost pharmacophore bioactivity. ZnO-NPs are the most extensively used metal oxide nanoparticles in electronic and optoelectronics because of their distinctive optical and chemical properties which can be readily modified by altering the morphology and the wide bandgap. The biosynthesis of nanoparticles using extracts of therapeutic plants, fungi, bacteria, algae, etc., improves their stability and biocompatibility in many biological settings, and its biofabrication alters its physiochemical behavior, contributing to biological potency. As such, ZnO-NPs can be used as an effective nanocarrier for conventional drugs due to their cost-effectiveness and benefits of being biodegradable and biocompatible. This article covers a comprehensive review of different synthesis approaches of ZnO-NPs including physical, chemical, biochemical, and green synthesis techniques, and also emphasizes their biopotency through antibacterial, antifungal, anticancer, anti-inflammatory, antidiabetic, antioxidant, antiviral, wound healing, and cardioprotective activity. Green synthesis from plants, bacteria, and fungus is given special attention, with a particular emphasis on extraction techniques, precursors used for the synthesis and reaction conditions, characterization techniques, and surface morphology of the particles.

Etiological spectrum of persistent fever in the tropics and predictors of ubiquitous infections: a prospective four-country study with pooled analysis.

BACKGROUND: Persistent fever, defined as fever lasting for 7 days or more at first medical evaluation, has been hardly investigated as a separate clinical entity in the tropics. This study aimed at exploring the frequencies and diagnostic predictors of the ubiquitous priority (i.e., severe and treatable) infections causing persistent fever in the tropics. METHODS: In six different health settings across four countries in Africa and Asia (Sudan, Democratic Republic of Congo [DRC], Nepal, and Cambodia), consecutive patients aged 5 years or older with persistent fever were prospectively recruited from January 2013 to October 2014. Participants underwent a reference diagnostic workup targeting a pre-established list of 12 epidemiologically relevant priority infections (i.e., malaria, tuberculosis, HIV, enteric fever, leptospirosis, rickettsiosis, brucellosis, melioidosis, relapsing fever, visceral leishmaniasis, human African trypanosomiasis, amebic liver abscess). The likelihood ratios (LRs) of clinical and basic laboratory features were determined by pooling all cases of each identified ubiquitous infection (i.e., found in all countries). In addition, we assessed the diagnostic accuracy of five antibody-based rapid diagnostic tests (RDTs): Typhidot Rapid IgM, Test-itTM Typhoid IgM Lateral Flow Assay, and SD Bioline Salmonella typhi IgG/IgM for Salmonella Typhi infection, and Test-itTM Leptospira IgM Lateral Flow Assay and SD Bioline Leptospira IgG/IgM for leptospirosis. RESULTS: A total of 1922 patients (median age: 35 years; female: 51%) were enrolled (Sudan, n = 667; DRC, n = 300; Nepal, n = 577; Cambodia, n = 378). Ubiquitous priority infections were diagnosed in 452 (23.5%) participants and included malaria 8.0% (n = 154), tuberculosis 6.7% (n = 129), leptospirosis 4.0% (n = 77), rickettsiosis 2.3% (n = 44), enteric fever 1.8% (n = 34), and new HIV diagnosis 0.7% (n = 14). The other priority infections were limited to one or two countries. The only features with a positive LR ≥ 3 were diarrhea for enteric fever and elevated alanine aminotransferase level for enteric fever and rickettsiosis. Sensitivities ranged from 29 to 67% for the three RDTs targeting S. Typhi and were 9% and 16% for the two RDTs targeting leptospirosis. Specificities ranged from 86 to 99% for S. Typhi detecting RDTs and were 96% and 97% for leptospirosis RDTs. CONCLUSIONS: Leptospirosis, rickettsiosis, and enteric fever accounted each for a substantial proportion of the persistent fever caseload across all tropical areas, in addition to malaria, tuberculosis, and HIV. Very few discriminative features were however identified, and RDTs for leptospirosis and Salmonella Typhi infection performed poorly. Improved field diagnostics are urgently needed for these challenging infections. TRIAL REGISTRATION: NCT01766830 at ClinicalTrials.gov.

Study of diagnostic utility of Xpert MTB/Rif test on pleural fluid in the evaluation of patients presenting with Pleural Tuberculosis in Nepal.

Introduction: Existing tests for the diagnosis of pleural tuberculosis (TB) have major limitations in terms of accuracy, time to diagnosis and drug resistance testing. A test which can diagnose pleural TB and detect resistance, like Xpert MTB/Rif, would be optimal for rapid diagnosis and treatment. Methods: A prospective observational study was done in a tertiary care hospital in Eastern Nepal. Fifty-one patients with clinic-radiologic suspicion of pleural TB were included. The results of pleural fluid Xpert MTB/Rif were compared with two Composite Reference Standards. Composite Reference Standard-1 consisted of positive pleural fluid smear, positive culture, positive histology of pleural biopsy, and positive sputum results. Composite Reference Standard-2 included those with Composite Reference Standard-1 and those with high ADA values (>40 U/l) with response to anti-tubercular treatment at 8 weeks of follow-up. Results: Thirty-six patients were diagnosed as Pleural TB. Nine fulfilled Composite Reference Standard-1. Pleural fluid Xpert MTB/Rif was positive in five cases with Composite Reference Standard-1 and nine cases with Composite Reference Standard-2. The sensitivity, specificity, positive predictive value and negative predictive value with reference to Composite Reference Standard-1 were 55.56%, 88.10%, 50%, and 90.24%, respectively. Using Composite Reference Standard-2 as reference, sensitivity, specificity, positive predictive value and negative predictive value were 25%, 93.33%, 90%, and 34.15%, respectively. Two cases were diagnosed Xpert Rif resistant on pleural fluid. Conclusion: Due to low sensitivity, the Xpert MTB/Rif test cannot be recommended as initial test of diagnosis in a high prevalence setting. At the same time its clinical utility lies in testing of patients suspected to have drug-resistant pleural tuberculosis.

A Multi-Country, Single-Blinded, Phase 2 Study to Evaluate a Point-of-Need System for Rapid Detection of Leishmaniasis and Its Implementation in Endemic Settings.

With the advancement of isothermal nucleic acid amplification techniques, detection of the pathogenic DNA in clinical samples at point-of-need is no longer a dream. The newly developed recombinase polymerase amplification (RPA) assay incorporated in a suitcase laboratory has shown promising diagnostic efficacy over real-time PCR in detection of leishmania DNA from clinical samples. For broader application of this point-of-need system, we undertook a current multi-country diagnostic evaluation study towards establishing this technique in different endemic settings which would be beneficial for the ongoing elimination programs for leishmaniasis. For this study purpose, clinical samples from confirmed visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL) patients were subjected to both real-time PCR and RPA assay in Bangladesh, India, and Nepal. Further skin samples from confirmed cutaneous leishmaniasis (CL) patients were also included from Sri Lanka. A total of 450 clinical samples from VL patients, 429 from PKDL patients, 47 from CL patients, and 322 from endemic healthy/healthy controls were under investigation to determine the diagnostic efficacy of RPA assay in comparison to real-time PCR. A comparative sensitivity of both methods was found where real-time PCR and RPA assay showed 96.86% (95% CI: 94.45-98.42) and 88.85% (95% CI: 85.08-91.96) sensitivity respectively in the diagnosis of VL cases. This new isothermal method also exhibited promising diagnostic sensitivity (93.50%) for PKDL cases, when a skin sample was used. Due to variation in the sequence of target amplicons, RPA assay showed comparatively lower sensitivity (55.32%) than that of real-time PCR in Sri Lanka for the diagnosis of CL cases. Except for India, the assay presented absolute specificity in the rest of the sites. Excellent concordance between the two molecular methods towards detection of leishmania DNA in clinical samples substantiates the application of RPA assay incorporated in a suitcase laboratory for point-of-need diagnosis of VL and PKDL in low resource endemic settings. However, further improvisation of the method is necessary for diagnosis of CL.

Anticancer Potential of Coumarin and its Derivatives.

Coumarins are found in higher plants like Rutaceae and Umbelliferae and essential oils of cinnamon bark, cassia leaf, and lavender oil. Coumarin compounds show different biological properties, viz antimicrobial, antibacterial, antifungal, antioxidant, antitumor, anti-HIV, antihypertension, anticoagulant, anticancer, antiviral, anti-inflammatory, analgesics, antidiabetic, anti-depressive, and other bioactive properties. Coumarin and its derivatives possess anticancer activity against different types of cancers such as prostate, renal, breast, laryngeal, lung, colon, CNS, leukemia, malignant melanoma. In this review, current developments of coumarin-based anticancer agents viz simple coumarin, furanocoumarin, pyranocoumarin, pyrone-substituted coumarin, and their important derivatives have been discussed. The coumarin-triazole, coumarin-chalcone, coumarin-thiosemicarbazone derivatives, and coumarin-metal complexes have been found more potent than coumarin. Hence, further study and structural improvement on coumarin and its derivatives may lead to the design and development of more potent anticancer agents.

Electrodynamic assisted self-assembled fibrous hydrogel microcapsules: a novel 3D in vitro platform for assessment of nanoparticle toxicity.

Nanoparticle (NP) toxicity assessment is a critical step in assessing the health impacts of NP exposure to both consumers and occupational workers. In vitro assessment models comprising cells cultured in a two-dimensional tissue culture plate (2D-TCP) are an efficient and cost-effective choice for estimating the safety risks of NPs. However, in vitro culture of cells in 2D-TCPs distorts cell-integrin and cell-cell interactions and is not able to replicate an in vivo phenotype. Three-dimensional (3D) in vitro platforms provide a unique alternative to bridge the gap between traditional 2D in vitro and in vivo models. In this study, novel microcapsules of alginate hydrogel incorporated with natural polymeric nanofibers (chitin nanofibrils) and synthetic polymeric nanofibers poly(lactide-co-glycolide) are designed as a 3D in vitro platform. This study demonstrates for the first time that electrodynamic assisted self-assembled fibrous 3D hydrogel (3D-SAF hydrogel) microcapsules with a size in the range of 300-500 µm in diameter with a Young's modulus of 12.7-42 kPa can be obtained by varying the amount of nanofibers in the hydrogel precursor solutions. The 3D-SAF microcapsules were found to mimic the in vivo cellular microenvironment for cells to grow, as evaluated using A549 cells. Higher cellular spreading and prolonged proliferation of A549 cells were observed in 3D-SAF microcapsules compared to control microcapsules without the nanofibers. The 3D-SAF microcapsule integrated well plate was used to assess the toxicity of model NPs, e.g., Al2O3 and ZnO. The toxicity levels of the model NPs were found to be dependent on the chemistry of the NPs and their physical agglomeration in the test media. Our results demonstrate that 3D-SAF microcapsules with an in vivo mimicking microenvironment can be developed as a physiologically relevant platform for high-throughput toxicity screening of NPs or pharmaceutical drugs.

Challenges in Laboratory Diagnosis of Malaria in a Low-Resource Country at Tertiary Care in Eastern Nepal: A Comparative Study of Conventional vs. Molecular Methodologies.

For ongoing malaria elimination programmes, available methods such as microscopy and rapid diagnostic tests (RDTs) cannot detect all malaria cases in acute febrile illness. These methods are entirely dependent on the course of infection, parasite load, and skilled technical resources. Our study objectives were to estimate the performance of light microscopy and a RDT as well as real-time PCR for the detection of the Plasmodium parasite. Altogether, 52 blood samples collected from patients with acute febrile illness were tested by microscopy, RDT, and real-time PCR. The results were compared in terms of sensitivity and specificity. Microscopy detected the malaria parasite in 5.8% of the blood samples whereas 13.5% were detected by the RDT and 27% by real-time PCR. Considering real-time PCR as the gold standard method, microscopy had a sensitivity of 21.4% and a specificity of 100%, and the RDT had a sensitivity of 28.6% and a specificity of 92.1%. Microscopy together with the RDT successfully detected malaria positive cases in blood samples of Ct value below 20, but both were unable to detect malaria cases between 26-40 Ct value ranges amplified by real-time PCR. Despite various diagnostic tools being available, microscopy still remains the method of choice for diagnosis, while the RDT is user-friendly when applied at the point of care. However, our preliminary results emphasize the need to implement the test with higher sensitivity and specificity in the context of a malaria elimination programme. Such programmes can be a crucial opportunity to understand the species prevalent in a low-endemic region. However, these results should be further verified with a large cohort study to document the submicroscopic infection.

Nanonet-nano fiber electrospun mesh of PCL-chitosan for controlled and extended release of diclofenac sodium.

Electrospun nanofiber (EN) technology has been used in the past to generate electrostatically charged multilayer-nanofibers. This platform offers versatile applications including in tissue engineering, drug delivery, wound dressings, and high-efficiency particulate air filters. In this study, we synthesized for the first time nanonet-nanofiber electrospun meshes (NNEMs) of polycaprolactone (PCL)-chitosan (CH) using EN technology. The fabricated NNEMs were utilized for high payload delivery and controlled release of a water-soluble drug. Diclofenac Sodium (DS), a hydrophilic anti-inflammatory drug, was selected as a model drug because of its high aqueous solubility and poor compatibility with insoluble polymers. Various compositions of DS drug-loaded NNEMs (DS-NNEMs) were synthesized. The physicochemical properties such as structure, morphology, and aqueous stability and the chemical properties of DS-NNEMs were evaluated. High drug entrapment efficiency and concentration-dependent drug release patterns were investigated for up to 14 days. Furthermore, the biocompatibility of the DS-NNEMs was tested with NIH 3T3 cells. The physicochemical characterization results showed that the DS drug is a key contributing factor in the generation of nanonet-nanofiber networks during electrospinning. DS-NNEMs also enhanced 3T3 cell adhesion, viability, and proliferation in the nanonet-nano fiber network through the controlled release of DS. The presented EN technology-based biodegradable NNEM material is not only limited for the controlled release of hydrophilic anti-inflammatory drugs, but also can be a suitable platform for loading and release of antiviral drugs.

Antibiotic Resistance and mecA Gene Characterization of Coagulase-negative Staphylococci Isolated from Clinical Samples in Nepal.

BACKGROUND: Coagulase-negative Staphylococci (CoNS) are a significant cause of hospital-acquired and foreign-body-related infections. We conducted this research to assess methicillin susceptibility of CoNS by disc diffusion, agar dilution, and polymerase chain reaction (PCR) methods and to assess the antimicrobial susceptibility pattern. METHODS: We received 123 CoNS isolates from different specimens including blood, endotracheal tube, and central venous catheter. We performed sample processing, identification, and characterization following standard guidelines. Antimicrobial susceptibility was tested based on clinical and laboratory standards institute guidelines. We detected methicillin-resistant coagulase-negative staphylococci (MRCoNS) through mecA gene, disc diffusion method, and agar dilution method and compared the accuracy with PCR as reference. RESULTS: We detected eight species of CoNS with Staphylococcus epidermidis as the most common. Most of the samples were received from the intensive care unit and blood was the dominant specimen followed by endotracheal-tube aspirate. Seventy-one percentage of isolates were methicillin-resistant by PCR method; disc diffusion and agar dilution method detected methicillin resistance with an accuracy of 96.7% and 98.3%, respectively. Antimicrobial susceptibility revealed an association between the different origins of samples, and also among the types of sample. Similarly, a comparison of the degree of resistance of antimicrobial agents between mecA gene positive and negative isolates showed significant differences. Vancomycin, linezolid, and teicoplanin are still effective for treating MRCoNS. CONCLUSION: CoNS are a crucial cause of human infections especially in an intensive care unit setup where the use of devices is common. Disc diffusion and agar dilution are reliable for the detection of MRCoNS. The degree of antimicrobial resistance is much higher in organisms obtained from intensive care unit and foreign-body-related infections.

Impact of the visceral leishmaniasis elimination initiative on Leishmania donovani transmission in Nepal: a 10-year repeat survey.

BACKGROUND: Nepal launched a visceral leishmaniasis (also known as kala-azar) elimination initiative in 2005. We primarily aimed to assess whether transmission of Leishmania donovani had decreased since the launch of the initiative. We also assessed the validity of the direct agglutination test (DAT) as a marker of infection, in view of future surveillance systems. METHODS: We did a repeat survey in a population aged 2 years and older for whom baseline serological data were available from 2006. Data were from three districts in the eastern region of Nepal. The primary outcome of interest was prevalent infection with L donovani as measured with DAT (cutoff value ≥1:3200). We compared age group-specific and cluster-specific seroprevalences in 2016 with those in 2006, using χ2 tests, with a specific focus on the comparison of seroprevalences in children born between 1996 and 2005, and those born between 2006 and 2015. To estimate the overall adjusted risk ratio for being seropositive in 2016 compared with 2006, we fitted a Poisson model controlling for age, sex, and cluster. FINDINGS: Between Oct 17, 2016, and Dec 26, 2016, we assessed 6609 individuals. DAT prevalence in children younger than 10 years was 4·1% (95% CI 3·2-5·4) in 2006 versus 0·5% (0·1-1·7) in 2016 (p<0·0001). Seroprevalence was lower in 2016 than in 2006 in all age groups and in all repeated clusters. The overall adjusted risk ratio of being seropositive was 0·44 (95% CI 0·37-0·52) for 2016 compared with 2006, and 0·04 (0·01-0·16) in children younger than 10 years. INTERPRETATION: Our findings show that transmission of L donovani in Nepal has decreased significantly between 2006 and 2016, coinciding with the elimination programme. DAT seems useful for monitoring of L donovani transmission. FUNDING: The Directorate-General for Development Cooperation of Belgium.