Rapid Test Research Articles

Detection of respiratory syncytial virus in cases of acute lower respiratory tract infection in pediatric age group by antigen detection and PCR analysis in a tertiary care hospital of eastern Odisha

: Respiratory Syncytial Virus (RSV) is one of the most common causes of acute lower respiratory infection (ALRI) in the paediatric age group. Various demographic and risk factors are associated with the severity of the disease.: This study was conducted to detect RSV from ALRI cases using two different methods and to correlate the findings with various risk factors.: The study was carried out over a period of 2 years on 242 ALRI cases in the Paediatrics Department of SCB Medical College and Hospital, Cuttack. Nasopharyngeal aspirates were collected using standard procedures and subjected to a rapid immunochromatographic test (ICT) for antigen detection, and molecular detection was performed using PCR.: Clinical and demographic data were collected and analyzed. Among the 242 clinically diagnosed ALRI cases, 14.05% were positive for RSV by one or both methods (ICT and RT-PCR). Considering real-time RT-PCR as the gold standard, the sensitivity, specificity, PPV, and NPV of the ICT were found to be 82.35%, 100%, 100%, and 97.19%, respectively. There was a significant association between risk factors such as prematurity, vitamin A supplement deficiency, and smokers in the household with RSV infections (p-values of 0.001, 0.003, and 0.002, respectively).: The study demonstrates two different methods for identifying RSV; thus, a simple, rapid method can be used as an alternative in resource-limited settings, enabling clinicians to avoid unnecessary antibiotic prescriptions in such cases. It also highlights risk factors that are adversely associated with disease morbidity, whose efficient control can significantly reduce the disease burden.

Implementation and validation of a new qPCR assay to detect imported human Plasmodium species.

Diagnosis of imported malaria is based on microscopic examination of blood smears (BS), detection of circulating plasmodial antigen by immunochromatography (ICT), or detection of Plasmodium spp. DNA by loop mediated isothermal amplification. We have developed duplex (Plasmodium spp. and Plasmodium falciparum) real-time PCR (qPCR) and species-specific qPCR assays for the identification and quantification of human Plasmodium species. Whole nucleic acids from 523 samples prospectively collected from 410 patients suspected of malaria between June 2016 and March 2021 were tested by qPCRs and compared to standard diagnostic procedures. All qPCRs were designed on 18S ribosomal ribonucleic acid. The limit of detection of duplex qPCR was 8 copies/reaction, and analytical specificity of species-specific qPCRs was 100%. Seventy-nine patients diagnosed for single species malaria involving P. falciparum, P. vivax, P. ovale, and P. malariae were positive with duplex and species-specific qPCRs. P. knowlesi qPCR detected DNA from a P. knowlesi culture. Of eight cases of mixed Plasmodium species infection, five were identified with our qPCR assays with better sensitivity as compared to BS and ICT. Eight out of 323 patients with negative BS were hospitalized for symptoms suggestive malaria after malaria-endemic area travel or known with history of malaria had a low positive duplex qPCR. Between day of diagnosis and post-treatment follow-up at D2-D4 of malaria, a 3.1-log P. falciparum load decrease was observed by qPCR. These new Plasmodium qPCRs allowing detection of human plasmodial species have excellent species specificity and allow rapid detection of P. falciparum cases, malaria with low parasitaemia, and mixed Plasmodium species infection.IMPORTANCEMalaria is a disease transmitted by a Plasmodium parasite genus. Most cases are caused by Plasmodium falciparum. Despite a significant drop of incidence and mortality since 2000, 249million cases and 608,000 deaths have been estimated in 2022, mainly in Africa. Due to the increasing number of travels to endemic areas, incidence of imported malaria is rising in Europe. Various techniques are used in European laboratories, such as microscopic examination of thin and thick smears and rapid diagnostic tests. However, these techniques require skilled operators to differentiate plasmodial species and have limited sensitivity. Actually, molecular diagnosis is carried out using point-of-care test for rapid results with excellent sensitivity but is unabled to determine involved species and assess parasitaemia. In this study, we developed a combined molecular tool based on both detection of all human plasmodial species (Plasmodium spp.) and P. falciparum. We have also developed specific qPCRs for each human plasmodial species.

Rapid determination of chemical losses in a microplate bioassay using fluorescence spectroscopy.

The increase in production and innovation of chemicals that humans interface with has enhanced the need for rapid toxicity testing of new and existing chemicals. This need, along with efforts to reduce animal testing, has led to the development of high-throughput bioassays typically conducted in microplates. These bioassays offer time and resource advantages over traditional animal models; however, significant chemical losses can occur in microplates. Current methods for measuring chemical losses in microplates require extensive sample preparation and highly sensitive instruments. We propose the use of fluorescence spectroscopy to measure chemical losses in high-throughput bioassays as a low resource alternative to the existing methods. A fluorescent plate reader was used to develop methods for quantifying the aqueous concentrations of two chemicals, 2-hydroxynaphthalene and acridine, in microwells of a 96-well microplate. A high-throughput, 5 day embryonic zebrafish bioassay was used as the model bioassay for method development. Chemical losses were attributed to a combination of photodegradation, sorption, and uptake by the zebrafish embryos, kinetics of which were derived from a pseudo-first order model. Chemical uptake amount was calculated to be approximately 50% and 21% of the total chemical amount added for 2-hydroxynaphthalene and acridine, respectively. Unexpected cranial deformities were observed in the embryonic zebrafish, suggesting further investigation of potential additive toxicity of the ultraviolet radiation exposure from fluorescence measurements and chemical exposure is needed. Nonetheless, this novel method provides a rapid, low resource approach to measuring chemical losses in microplates that can be extended to a variety of autofluorescent chemicals and microplate-based bioassays.

Post-mortem diagnosis of malaria in decomposed and embalmed body.

The diagnosis of malaria during the autopsy of a decomposed corpse may prove challenging. Macroscopic changes are non-specific and may include, among others, cerebral oedema, pulmonary oedema, hepatosplenomegaly and, on occasion, the presence of petechiae. The most effective diagnostic tools for malaria are the examination of blood smears and the use of rapid immunochromatographic tests. As a result of the progressive putrefaction of the corpse and blood hemolysis, classical tests are no longer viable. Consequently, the sole remaining option is the utilisation of real-time reaction (RT-PCR) to ascertain the presence of plasmodium DNA in specific organs. This study concerns the diagnosis of a fatal form of cerebral malaria in a 23-year-old Caucasian male who had travelled to Africa. The autopsy was conducted at a local hospital, after which the body was embalmed and stored in cold storage for a period of 8.5 months. Subsequently, the corpse was transported to Poland, where a further forensic autopsy was conducted. A significant challenge was to confirm the presence of malaria in a corpse that had been embalmed several months prior to the investigation. Samples were obtained from internal organs for genetic analysis to determine the presence of parasite DNA. An RT-PCR test was conducted on genetic material obtained from the brain, heart, lungs, kidney, liver, and spleen. The presence of Plasmodium falciparum genetic material was identified in samples obtained from the brain, lungs, kidney, liver, and spleen. These findings substantiated the post-mortem diagnosis of a severe form of cerebral malaria, which was the underlying cause of death.

Aptamer’s Structure Optimization for Better Diagnosis and Treatment of Glial Tumors

Background: Oncological diseases are a major focus in medicine, with millions diagnosed each year, leading researchers to seek new diagnostic and treatment methods. One promising avenue is the development of targeted therapies and rapid diagnostic tests using recognition molecules. The pharmaceutical industry is increasingly exploring nucleic acid-based therapeutics. However, producing long oligonucleotides, especially aptamers, poses significant production challenges. Objectives: This study aims to demonstrate the efficacy of using molecular modeling, supported by experimental procedures, for altering aptamer nucleotide sequences while maintaining their binding capabilities. The focus is on reducing production costs and enhancing binding dynamics by removing nonfunctional regions and minimizing nonspecific binding. Methods: A molecular modeling approach was employed to elucidate the structure of a DNA aptamer, Gli-55, facilitating the truncation of nonessential regions in the Gli-55 aptamer, which selectively binds to glioblastoma (GBM). This process aimed to produce a truncated aptamer, Gli-35, capable of forming similar structural elements to the original sequence with reduced nonspecific binding. The efficiency of the truncation was proved by flow cytometry, fluorescence polarization (FP), and confocal microscopy. Results: The molecular design indicated that the new truncated Gli-35 aptamer retained the structural integrity of Gli-55. In vitro studies showed that Gli-35 had a binding affinity comparable to the initial long aptamer while the selectivity increased. Gli-35 internalized inside the cell faster than Gli-55 and crossed the blood–brain barrier (BBB), as demonstrated in an in vitro model. Conclusions: The success of this truncation approach suggests its potential applicability in scenarios where molecular target information is limited. The study highlights a strategic and resource-efficient methodology for aptamer development. By employing molecular modeling and truncation, researchers can reduce production costs and avoid trial and error in sequence selection. This approach is promising for enhancing the efficiency of therapeutic agent development, particularly in cases lacking detailed molecular target insights.

Development of molecular sterility assay for rapid quality release of cord blood erythrocytes units for transfusion.

Umbilical cord blood (CB) units stored in banks are an important source of hematopoietic stem cells for transplantation and other cell therapies. New applications, such as their use in transfusions, require rapid quality release as cord blood red blood cells (CB-RBC) have a shorter shelf life. This project aims to investigate the most prevalent microbial contaminants in CB preparations and validate a rapid sterility testing strategy for CB-RBC based on an automated system (BACT/ALERT®) in tandem with a molecular assay (real-time PCR) capable of detecting at least 100 CFU/mL of Cutibacterium acnes in CB-RBC to accelerate the detection of the most common slow-growing bacteria. Microbial contamination incidence was assessed by reviewing 4696 CB sterility tests, revealing a positivity rate of 3.4%, with C. acnes being the most common slow-growing pathogen. The BACT/ALERT® system, which was validated according to European Pharmacopeia guidelines, was an appropriate method for sterility testing of CB-RBC, although it required up to 14 days of culture to detect C. acnes when iFAPlus and iFNPlus bottles were used to neutralize antimicrobials. Interestingly, the BACT/ALERT® method detected C. acnes at 30 CFU/mL within 14 days, while real-time PCR identified concentrations ≥65 CFU/mL by Day 4. In conclusion, we developed a rapid sterility testing strategy that combines automated culture systems and real-time PCR for early microbial contamination, enhancing CB-RBC shelf life for transfusion and emphasizing the importance of combining detection methods.

Canine Vector-Borne Diseases (CVBDs) in Liguria, North-West Italy: A Retrospective Study over an 11-Year Period (2013–2023)

Canine vector-borne diseases (CVBDs) pose a global threat to both canine and public health. This study evaluates the prevalence of Anaplasma spp., Ehrlichia spp., Borrelia burgdorferi sensu lato (s.l.), Rickettsia conorii, and Dirofilaria immitis in domestic dogs in Liguria, north-west Italy, a region where data were lacking. From 2013 to 2023, 8584 blood samples from shelter (74%) and owned dogs (26%) were submitted to the Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d’Aosta (IZSPLV) for serological testing (indirect immunofluorescence and/or rapid immunochromatographic tests). Overall, 18.8% (95% CI: 18.0–19.7) of the dogs tested positive for at least one pathogen, with positivity against R. conorii antigen being the most frequently recorded (24.4%, 95% CI: 23.3–25.5). Lower prevalence levels were observed for Anaplasma spp. (1.82%, 95% CI: 1.47–2.23), Ehrlichia spp., (1.25%, 95% CI: 0.97–1.60), B. burgdorferi s.l. (0.22%, 95% CI: 0.11–0.39), and D. immitis (0.84%, 95% CI: 0.65–1.06). Positive cases for all pathogens increased over time, with prevalence differing significantly between owned and shelter dogs. Topographical factors, land use, and monthly relative humidity appeared to influence the positivity in the dogs. These results update the epidemiology of the investigated CVBDs in Liguria, indicating a widespread exposure to Rickettsia spp. among local dogs.

Rapid and accurate testing for urinary tract infection: new clothes for the emperor.

SUMMARYUrinary tract infection (UTI) is among the most common infections in clinical practice. In some cases, if left untreated, it can lead to pyelonephritis and urosepsis. In other cases, UTI resolves without treatment. Clinical diagnosis is typically based on patient symptoms and/or urinalysis, including urine dipsticks. The standard urine culture method is sometimes employed to identify the suspected urinary pathogen (uropathogen) and/or guide antimicrobial choice, but results are rarely available before 24 h. The standard urine culture method also misses fastidious, anaerobic, and slow-growing uropathogens and rarely reports polymicrobial infections. The unexplained combination of negative urine cultures with persistent urinary tract symptoms is distressing to both patients and clinicians. Given the broad appreciation of the advantages provided by rapid testing (e.g., for COVID-19 or influenza A), a rapid, accurate diagnostic test is needed to deliver timely treatment to patients seeking care for UTI that optimizes antibiotic stewardship. Herein, we discuss progress being made toward an accessible, timely (i.e., within hours), accurate assay with results that are clinically useful for the treating clinician within the timeframe of the infection (i.e., the growth rate of the pathogen(s)). New and emerging uropathogens often overlooked by current diagnostic techniques are also reviewed.

Rapid detection of carbapenemase production in Aeromonas using phenotypic tests based on colorimetric microtube assay.

Antibiotic resistance, particularly carbapenem resistance, poses a significant global health threat due to the limited availability of effective antibiotics. Carbapenem-resistant Aeromonas are increasingly recognized for their role in various infections, necessitating rapid and accurate detection methods. This study aimed to evaluate several phenotypic tests, including the Carba NP test (CNPt), Carba NP-direct test (CNPd), and Blue-Carba test (BCT), for their effectiveness in rapidly detecting carbapenemase production in Aeromonas. These tests target both the chromosomally encoded CphA metallo-β-lactamase (MBL) and acquired carbapenemases. Additionally, a modified phenotypic test called the Colony-Carba NP test (c-CNPt) was introduced to enhance sensitivity and specificity. A retrospective analysis was conducted on 131 clinically conserved Aeromonas strains harboring identified carbapenem resistance genes, using CNPt, CNPd, BCT, and the newly developed c-CNPt and EDTA-Colony-Carba NP test (ec-CNPt). The stability of c-CNPt reagents stored at -80°C was also assessed. Additionally, a prospective study conducted from July 2021 to November 2023 evaluated 152 Aeromonas isolates to determine the clinical applicability of these tests. Our results demonstrated that CNPd and BCT achieved 100% sensitivity and specificity, surpassing the traditional CNPt, which showed only 63.6% sensitivity for Aeromonas strains. The c-CNPt also showed 100% sensitivity and specificity, with the ec-CNPt effectively differentiating between MBL and serine carbapenemase types. Stability tests confirmed that c-CNPt reagents could be stored at -80℃ for up to 1 year without performance degradation. These findings highlight the practicality and reliability of these phenotypic tests for routine laboratory use, providing a rapid and cost-effective method for detecting carbapenemase production.The rapid detection of carbapenemase production in Aeromonas is of paramount importance due to the significant clinical and public health implications associated with antibiotic resistance. The development and validation of rapid phenotypic tests such as the Colony-Carba NP test (c-CNPt) and the EDTA-Colony-Carba NP test (ec-CNPt) are crucial advancements in the field. These tests offer a highly sensitive and specific method for detecting carbapenemase production in Aeromonas, including the differentiation between metallo-β-lactamase and serine carbapenemases. The c-CNPt and ec-CNPt are cost-effective, easy to perform, and provide rapid results, making them suitable for routine clinical use. Additionally, the stability of the reagents ensures their practicality for long-term application in various healthcare settings. Implementing these phenotypic tests in clinical laboratories can significantly enhance the early detection and appropriate treatment of carbapenem-resistant Aeromonas infections.

Prenatal cfDNA Sequencing and Incidental Detection of Maternal Cancer

BackgroundCell-free DNA (cfDNA) sequence analysis to screen for fetal aneuploidy can incidentally detect maternal cancer. Additional data are needed to identify DNA-sequencing patterns and other biomarkers that can identify pregnant persons who are most likely to have cancer and to determine the best approach for follow-up.MethodsIn this ongoing study we performed cancer screening in pregnant or postpartum persons who did not perceive signs or symptoms of cancer but received unusual clinical cfDNA-sequencing results or results that were nonreportable (i.e., the fetal aneuploidy status could not be assessed) from one of 12 different commercial laboratories in North America. We used a uniform cancer-screening protocol including rapid whole-body magnetic resonance imaging (MRI), laboratory tests, and standardized cfDNA sequencing for research purposes with the use of a genomewide platform. The primary outcome was the presence of cancer in participants after the initial cancer-screening evaluation. Secondary analyses included test performance.ResultsCancer was present in 52 of the 107 participants in the initial cohort (48.6%). The sensitivity and specificity of whole-body MRI in detecting occult cancer were 98.0% and 88.5%, respectively. Physical examination and laboratory tests were of limited use in identifying participants with cancer. Research sequencing showed that 49 participants had a combination of copy-number gains and losses across multiple (≥3) chromosomes; cancer was present in 47 of the participants (95.9%) with this sequencing pattern. Sequencing patterns of cfDNA in which there were only chromosomal gains (multiple trisomies) or only chromosomal losses (one or more monosomies) were found in participants with nonmalignant conditions, such as fibroids.ConclusionsIn this study, 48.6% of participants who received unusual or nonreportable clinical cfDNA-sequencing results had an occult cancer. Further study of DNA-sequencing patterns that are suggestive of occult cancer during prenatal screening is warranted. (Funded by the NIH Intramural Research Programs; ClinicalTrials.gov number, NCT04049604.)

Prevalence of hepatitis coinfection and substance use among antiretroviral therapy clinic clients with hazardous alcohol use in Vietnam.

The confluence of injection drug use (IDU), alcohol consumption, and viral hepatitis increases morbidity among persons living with HIV (PWH). We present a secondary analysis of a randomized controlled trial of alcohol reduction interventions in Thai Nguyen, Vietnam conducted between 2016-2018. We assessed hepatitis B (HBV) and hepatitis C (HCV) coinfection among PWH reporting hazardous alcohol consumption and examined differences in IDU and alcohol use by coinfection status. Participants were ≥18 years old, living with HIV, and reported hazardous alcohol consumption per the WHO Alcohol Use Disorders Identification Test Consumption (AUDIT-C; score ≥4 for men, score ≥3 for women). At enrollment, participants were tested for hepatitis coinfection with HBV surface antigen tests and rapid serological HCV tests. Demographic information, IDU, and recent alcohol consumption were assessed via behavioral survey and 30-day timeline follow back. Fishers Exact and Kruskal-Wallis tests were used for statistical testing. Hepatitis coinfection was common among the 440 enrolled PWH: HCV: n = 355 (81%); HBV: n = 5 (1%); HBV and HCV: n = 37 (8%). Only 10% (n = 43) of participants had no hepatitis coinfection. Among those who tested positive for HBV, 36% had previously been diagnosed with HBV; among those who tested seropositive for HCV, 18% had previously received an HCV diagnosis. History of IDU was higher among those with hepatitis coinfection (HBV or HCV coinfection: 88%; HBV and HCV coinfections: 97%) than those without hepatitis coinfection (7%; p<0.01). Median days of alcohol consumption in the last 30 days was higher among those with coinfection (HBV or HCV coinfection: 20 (Interquartile Range (IQR): 10-30); HBV and HCV coinfections: 22 (IQR: 13-28) than those without hepatitis coinfection (10; IQR: 6-21; p<0.01). The syndemic conditions of HIV, hepatitis, IDU, and alcohol use are deeply entangled and challenging to parse out. Integrated health services are warranted to reduce the risk of liver-related morbidity.

Monitoramento pós-mercado dos testes rápidos para detecção de antígenos da COVID-19 no enfrentamento à pandemia

Introduction: Since the identification of atypical pneumonia of unknown etiology in Wuhan, China, in December 2019, called COVID-19, the disease caused by SARS-CoV-2 requires scientists and governments to take urgent and decisive measures for monitoring and control. Objective: To present the results of post-market monitoring of COVID-19 rapid antigen detection tests (AgTR) regarding clinical or diagnostic sensitivity and specificity. Method: Analysis of AgTR performance results were made available on the electronic panel of Microsoft® Power BI platform on the Brazilian National Health Surveillance Agency (Anvisa) portal from 04/06/2020 to 12/28/2021. Results: 504 results relating to performance analysis were identified: 366 (72.6%) rapid tests (RT), 56 (11.0%) chemiluminescence tests, 31 (6.15%) molecular tests, 22 (4.4%) immunoenzymatic assays, and 29 (5.7%) auxiliary products for the diagnosis of COVID-19. Of the 366 RT results, 304 (83.1%) were RT for antibody detection (AcTR) and 62 (16.9%) were AgTR. Of the 62 AgTR monitored, 49 (79.1%) presented compliant results and 13 (20.9%) did not. The 62 AgTR results corresponded to 50 lots from 42 manufacturers. Conclusions: Monitoring post-market products in compliance with RDC No. 379/2020 enabled the analysis and monitoring of COVID-19 tests. The analyses carried out (guidance and fiscal) in accordance with current legislation (Law No. 6360/1976, Law No. 6437/1977) guaranteed the transparency of the process and reinforced the precepts of health surveillance regarding resolving or preventing health risks. Non-compliant products were not sold, thus guaranteeing the safety and effectiveness of the tests available in the country.

A Robust Malaria Cell Detection Framework Using Adaptive and Atrous Convolution-Based Recurrent Mobilenetv2 with Trans-MobileUNet + + -Based Abnormality Segmentation.

The highly contagious malaria disease is spread by the female Anopheles mosquito. This disease results in a patient's death or incapacity to move their muscles, if it is not appropriately identified in the early stages. A Rapid Diagnostic Test (RDT) is a frequently used approach to find malaria cells in red blood cells. However, it might not be able to identify infections with small amounts of samples. In the microscopic detection model, blood stains are placed under a microscope for diagnosing malaria. But accurate diagnosis is hard in this method, particularly in developing nations where the disease is most common. The microscopic detection processes are expensive and time-consuming due to the usage of microscopes. The quality of the blood smears and the availability of a qualified specialist, who is skilled in recognizing the disease, impact the accuracy of malaria detection results. The traditional deep learning-based malaria identification models need more processing power. Therefore, a deep learning-based adaptive method is designed to detect malaria cells through the medical image. Hence, the images are gathered from the standard sites and then fed to the segmentation process. Here, the abnormality segmentation is carried out with the help of a developed Trans-MobileUNet + + (T-MUnet + +) network. Trans-MobileUNet + + captures global context, so it is well-suited for segmentation tasks. The segmented image is applied to the adaptive detection phase where the Adaptive and Atrous Convolution-based Recurrent MobilenetV2 (AA-CRMV2) model is designed for the effective recognition of malaria cells. The efficiency of the designed approach is elevated by optimizing the parameters from the AA-CRMV2 network with the help of the Updated Random Parameter-based Fennec Fox Optimization (URP-FFO) algorithm. Several experimental analyses are evaluated in the implemented model over classical techniques to display their effectualness rate.

Malaria parasite burden and heterogeneity of risk factors among Central African Republic refugees: a cross-sectional study in the Gado-Badzere refugee camp in Eastern Cameroon

BackgroundRefugees are vulnerable populations especially in malaria endemic areas where the disease claims many lives and constitutes an emerging challenge for humanitarian response. This study assessed how the influx and settlement of Central African Republic (CAR) refugees influences malaria burden in the Gado-Badzere refugee camp, Eastern Cameroon.MethodsA cross-sectional malariometric survey was conducted between November 2022 and October 2023 in 324 households comprising 1,304 individuals aged 1 month and above. Malaria parasite burden was determined using rapid diagnostic tests (RDTs) and Giemsa-stained microscopy. Demographic characteristics, malaria risk factors, treatment-seeking behaviors and costs to cure malaria were assessed using semi-structured questionnaires.ResultsOf the 1,304 participants, 525 (40.3%) were malaria parasite positive with moderate geometric mean parasite density (GMPD) of 1100 parasites/μl of blood. Plasmodium falciparum was the main species (99.8%), with mixed P. vivax infections (0.2%). Insecticide treated net (ITN) ownership was 53.7%, but its utilization was significantly low (22.4%) (P &amp;lt; 0.001). Reason for no ITN ownership was net damaged (74.7%). Net insufficiency (77.8%) accounted for non-frequent ITN use. Mean expenditure to treat malaria in the hospital was higher (USD 13.64 ± 8.67) than auto-medication (USD 1.13 ± 1.18). Significantly, malaria parasite prevalence and risk were higher for 0-5 years age (43.7%, OR = 1; P = 0.02), residents of sector 8 (49.2%, OR = 2.53; P &amp;lt; 0.001) of the camp, non-frequent ITN users (41.7%, OR = 2.08; P &amp;lt; 0.001), people living around stagnant water (44.4%, OR = 1.55; P &amp;lt; 0.001) and during the rainy season (43.5%, OR = 1.31; P = 0.02). The GMPD/µl was significantly higher in the 0-5 years age group (1456, P &amp;lt; 0.0001), inhabitants of sector 9 (1626, P = 0.04) and participants living around stagnant water (2097, P = 0.01).ConclusionThe malaria burden in CAR refugees may represent the reservoir for malaria transmission, especially with the circulation of P. vivax. The improper use of ITNs could be ameliorated through sensitization. Seasonal chemoprevention mainly during the rainy season and Indoor Residual Spraying (IRS) might be implemented for effective malaria control in refugee settings.

Usefulness of Point-of-Care Testing for Respiratory Viruses in a Pediatric Emergency Department Setting

Background: Respiratory tract infections (RTIs) are a leading cause of pediatric emergency department (PED) visits, especially in children under five. These infections are primarily viral, complicating diagnosis and management. This study assesses the impact of point-of-care (POC) rapid diagnostic tests for respiratory viruses on clinical and economic outcomes in a PED setting. Materials and Methods: A retrospective analysis of 1396 POC tests for RSV, adenovirus, and influenza A/B was conducted in the PED of the Giannina Gaslini Institute, Genoa, Italy, from December 2022 to April 2024. Demographics, blood tests, admissions, and readmission rates were evaluated. Statistical analyses were performed using appropriate tests for categorical and continuous variables. Results: Of the tests, 31.5% were positive for at least one virus. Positive patients were younger and had higher hospitalization rates (50.7% vs. 39.9%) but fewer blood tests (38.2% vs. 51.7%). Economic analysis indicated lower costs for virus-positive patients. RSV-positive patients showed a significant association with higher hospitalization rates (67.8%) and readmission within 72 h. Conclusions: POC testing significantly improves patient management in PEDs by enabling rapid diagnoses, reducing unnecessary tests and hospitalizations, and guiding appropriate treatment. This approach supports better resource allocation, crucial during peak seasons, and has implications for reducing antibiotic use and resistance. Further research is warranted to explore long-term impacts on patient outcomes and healthcare efficiency.

Evaluation of the immune status of dogs vaccinated against rabies by an enzyme-linked immunosorbent assay using crude preparations of insect cells infected with a recombinant baculovirus encoding the rabies virus glycoprotein gene.

Evaluation of the effectiveness of vaccination of animals against rabies is not routinely implemented. In cases where it is carried out, the rapid fluorescent focus inhibition test (RFFIT) or the fluorescent antibody virus neutralization (FAVN) test are the recommended tests. However, both of these tests require handling of live rabies virus (RABV), and are cumbersome to perform. In view of this, the enzyme-linked immunosorbent assay (ELISA) has been proposed as a surrogate test; however, availability of appropriate antigen is a major impediment for the development of ELISAs to detect anti-rabies antibodies. The most widely used antigen is the RABV glycoprotein (G) purified from cell culture-propagated virus, which requires a biosafety level 3 containment. The alternative is to use recombinantly expressed G, which needs to be to be properly glycosylated and folded to serve as the best antigen. The most suitable system for its production is the baculovirus expression system (BVES). However, purification of RABV G is challenging. We therefore tested partially purified preparations in the form of extracts of insect cells infected with baculovirus expressing RABV G, against sera from vaccinated dogs in an indirect ELISA. The results showed good concordance against RFFIT, with sensitivity and specificity of 90.48% and 80.00%, respectively. The system may be used for quick screening to determine the presence and an approximate level of antibodies, and can be modified to enable monitoring of mass dog vaccination programs, as well as to facilitate certification of dogs intended for international travel and transportation.

RT-RPA as a dual tool for detection and phylogenetic analysis of epidemic arthritogenic alphaviruses

Chikungunya (CHIKV), o’nyong-nyong (ONNV), and Mayaro (MAYV) viruses are transmitted by mosquitoes and known to cause a debilitating arthritogenic syndrome. These alphaviruses have emerged and re-emerged, leading to outbreaks in tropical and subtropical regions of Asia, South America, and Africa. Despite their prevalence, there persists a critical gap in the availability of sensitive and virus-specific point-of-care (POC) diagnostics. Traditional immunoglobulin-based tests such as enzyme-linked immunosorbent assay (ELISA) often yield cross-reactive results due to the close genetic relationship between these viruses. Molecular diagnostics such as quantitative polymerase chain reaction (qPCR) offer high sensitivity but are limited by the need for specialized laboratory equipment. Recombinase polymerase amplification (RPA), an isothermal amplification method, is a promising alternative to qPCR, providing rapid results with minimal equipment requirements. Here, we report the development and validation of three virus-specific RT-RPA-based rapid tests for CHIKV, ONNV, and MAYV. These tests demonstrated both speed and sensitivity, capable of detecting 10–100 viral copies within 20 min of amplification, without exhibiting cross-reactivity. Furthermore, we evaluated the clinical potential of these tests using serum and tissue samples from CHIKV, ONNV, and MAYV-infected mice, as well as CHIKV-infected human patients. We demonstrate that the RPA amplicons derived from the patient samples can be sequenced, enabling cost-effective molecular epidemiological studies. Our findings highlight the significance of these rapid and specific diagnostics in improving the early detection and management of these arboviral infections, particularly in resource-limited settings.

Genetic surveillance shows spread of ACT resistance during period of malaria decline in Vietnam (2018-2020)

IntroductionVietnam’s goal to eliminate malaria by 2030 is challenged by the further spread of drug-resistant Plasmodium falciparum malaria to key antimalarials, particularly dihydroartemisinin-piperaquine (DHA-PPQ).MethodsThe custom targeted NGS amplicon sequencing assay, AmpliSeq Pf Vietnam v2, targeting drug resistance, population genetic- and other markers, was applied to detect genetic diversity and resistance profiles in samples from 8 provinces in Vietnam (n = 354), in a period of steep decline of incidence (2018–2020). Variants in 14 putative resistance genes, including P. falciparum Kelch 13 (PfK13) and P. falciparum chloroquine resistance transporter (Pfcrt), were analyzed and within-country parasite diversity was evaluated. Other targets included KEL1-lineage markers and diagnostic markers of Pfhrp2/3.ResultsA concerning level of DHA-PPQ resistance was detected. The C580Y mutation in PfK13 was found in nearly 80% of recent samples, a significant rise from previous data. Vietnam has experienced a significant challenge with the spread of DHA-PPQ resistant malaria parasites, particularly in the provinces of Binh Phuoc and Gia Lai. Resistance spread to high levels in Binh Thuan prior to the country-wide treatment policy change from DHA-PPQ to pyronadine-artesunate (PA). A complex picture of PPQ-resistance dynamics was observed, with an increase of PPQ-resistance associated Pfcrt mutations, indicating an evolutionary response to antimalarial pressure. Additionally, the compensatory mutation C258W in Pfcrt, which increases chloroquine (CQ) resistance while reversing PPQ resistance, is emerging in Gia Lai following the adoption of PA as the first-line treatment. This study found high levels of multidrug resistance, with over 70% of parasites in 6 out of 8 provinces showing significant sulfadoxine-pyrimethamine (SP) resistance and widespread chloroquine-resistant Pfcrt haplotypes. We also report an absence of P. falciparum histidine rich protein 2 and 3 (Pfhrp2/3) gene deletions, ensuring the continued reliability of HRP2/3-based rapid diagnostic tests. P. falciparum populations in Vietnam are becoming more isolated, with clonal populations showing high geographical clustering by province. The central highlands, particularly Gia Lai province, have the highest residual malaria burden but exhibit low diversity and clonal populations, likely due to the pressures from the antimalarial drugs and targeted national malaria control program (NMCP) efforts.DiscussionIn conclusion, examining a broad panel of full-length resistance genes and SNPs provided high-resolution insights into genetic diversity and resistance evolution in Vietnam, offering valuable information to inform local treatment and intervention strategies.

Rapid Antibacterial Assessments for Plastic and Textile Materials Against Escherichia coli

Background: Standard test methods for evaluating the antibacterial performance of plastic (non-porous) and textile (porous) materials are accurate and reliable, but completing a standard assessment generally requires at least several days to a week. Well-trained and experienced technicians are also required to conduct the standard tests consistently and analyse the samples and test results systemically. These costs are often not favourable for the performance assurance of antimicrobial products in industrial production, nor for meeting the fast-return demands in research and development of antimicrobial materials nowadays. Methods: In this study, “Rapid Tests” are developed to evaluate the antibacterial activities of plastic and textile materials. Results: The assessment results from Rapid Tests for plastics and textiles are highly correlated to those from the ISO 22196 and the AATCC Test Method 100, respectively, whereas the evaluation operation can be completed within one day. Based on bioluminescence technology, colony-forming units of E. coli from the inoculated specimens are determined via luminometry. Antibacterial efficacy of the treated plastic and textile samples can be examined effectively. Conclusions: By analysing antimicrobial artificial leather samples composed of hydrophilic polyurethane polymer using Rapid Tests for plastics and textiles, the applicability and scope of these tests were remarkedly recognised and verified.

“You know, it feels like you can trust them”: mixed methods implementation research to inform the scale up of a health disparities-responsive COVID-19 school testing program

BackgroundHealth disparities lead to negative COVID-19 outcomes for Hispanic/Latino communities. Rapid antigen testing was an important mitigation tool for protecting schools and their communities as in-person learning resumed. Within the context of a 3-middle-school non-inferiority trial we assessed acceptability and appropriateness of at-home and school-based COVID-19 antigen testing and implementation barriers and facilitators to facilitate district-wide scale up.MethodsGuided by the Consolidated Framework for Implementation Research (CFIR) and acceptability and appropriateness implementation outcomes, we collected post-implementation qualitative (n = 30) and quantitative (n = 454) data in English and Spanish from trial participants, in-depth feedback sessions among program implementers (n = 19) and coded 137 project meeting minutes. Verbatim transcripts were thematically analyzed. We used multivariate linear models to evaluate program acceptability and appropriateness by COVID-19 testing modality and mixed qualitative and quantitative findings for interpretation.ResultsQuestionnaire respondents closely matched school demographics (> 80% Hispanic/Latino and 8% Filipino/Asian Pacific Islander). While both testing modalities were rated as highly acceptable and appropriate, at-home testing was consistently favorable. Qualitative findings provided actionable areas for at-home testing program refinement, guiding district-wide scale up including: maintaining a learning climate to accommodate modifications as guidelines changed, needs of the school community, and implementation challenges; ensuring an engaged school leadership and sufficient human resources; improving educational communication about COVID-19 and technology ease of use; and increased time for pre-implementation planning and engagement.ConclusionsResults underscore the value of the CFIR to inform program implementation, particularly programs to reduce disparities during a public health emergency. Results support optimal testing implementation strategies centering the needs and perspectives of Hispanic/Latinos.