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Objetivos. Determinar el rendimiento diagnóstico de la prueba rápida SD dengue DUO (Inyecta) para la detección de NS1, IgM e IgG en comparación con la prueba de ELISA. Materiales y métodos. Es una evaluación de prueba diagnóstica que incluyó 286 muestras de suero de pacientes con sintomatología atribuible a dengue de zonas endémicas del Perú. Las muestras se analizaron por ELISA y la prueba rápida SD dengue DUO (Inyecta) para IgM, NS1 e IgG en el Instituto de Investigación Nutricional en Lima. Resultados. La sensibilidad de la prueba rápida fue de 68% para NS1 e IgM, y 86% para IgG, mejorando este parámetro a 75% y 81% para NS1 e IgM, respectivamente, en los tres primeros días. La especificidad para los tres analitos fue mayor a 87%. La concordancia de los resultados obtenidos medidos por el coeficiente Kappa para los tres analitos fue buena y no se encontró reacción cruzada con otros arbovirus. Conclusiones. La prueba rápida SD Dengue DUO permite detectar con una adecuada sensibilidad y especificidad NS1, IgM e IgG. La sensibilidad para IgM y NS1 aumenta cuando se detecta en los tres primeros días de síntomas, por lo que se recomienda su implementación en los centros de primer nivel de atención para un diagnóstico temprano y oportuno.
Objectives . To assess the diagnostic performance of the SD dengue DUO rapid test (Inyecta) for the detection of NS1, IgM and IgG in comparison to the ELISA test. Materials and methods . This is a diagnostic test evaluation that included 286 serum samples from patients with symptomatology attributable to dengue from endemic areas of Peru. The samples were analyzed by ELISA and the SD dengue DUO rapid test (Inyecta) for IgM, NS1 and IgG at the Instituto de Investigación Nutricional in Lima. Results . The sensitivity of the rapid test was 68.0% for NS1 and IgM, and 86.0% for IgG, improving to 75.0% and 81.0% for NS1 and IgM, respectively, during the first three days. The specificity for all three analytes was greater than 87.0%. The concordance of the results, measured by the Kappa coefficient for the three analytes, was good and no cross-reaction with other arboviruses was found. Conclusions . The SD dengue DUO rapid test allows detection of NS1, IgM and IgG with adequate sensitivity and specificity. Sensitivity for IgM and NS1 increases when detected during the first three days of symptoms. Therefore, we recommend its implementation in primary care centers for early and timely diagnosis.
Subject(s)
Humans , Male , Female , Immunoglobulin M , Dengue , Dengue Virus , Antigens , Signs and Symptoms , Immunoglobulin G , Sensitivity and SpecificityABSTRACT
El dengue es una enfermedad infecciosa ocasionada por alguno de los cuatro serotipos del virus análogo, que se transmite a los humanos a través de la picadura de mosquitos infectados del género Aedes Objetivo: Identificar la prevalencia del virus de dengue y los factores de riesgo en los pacientes que asistieron a las unidades de salud del cantón Esmeraldas en el 2019. Materiales y Métodos: La investigación se enmarca dentro del diseño de investigación no experimental, de tipo retrospectivo, descriptivo, basado en la información de pacientes con diagnóstico de dengue positivo atendidos en las unidades de Salud del cantón Esmeraldas en el 2019.Resultados: En este estudio se encontró a 247 pacientes registrados con diagnóstico presuntivo de dengue, los cuales tomamos como población, se excluyeron a 4 muestras de pacientes, no procesadas, y a 121 muestras de pacientes con resultado negativo, quedándonos 121 muestras de pacientes con diagnóstico de dengue confirmadas, tomando a esta cantidad de pacientes como muestra para nuestro estudio, lo que representa el 49% como prevalencia de virus del dengue en pacientes que asistieron a las unidades de salud del cantón Esmeraldas durante el 2019.Conclusión: La prevalencia de dengue en pacientes que asistieron a las unidades de salud del cantón Esmeraldas es del 49%, la edad que más predomino fue la comprendida entre los 5 y 9 años, un número significativo de pacientes, provienen de la parroquia Simón Plata Torres, sectores con falta de infraestructura de servicios básicos, jardines y patios con malezas y vegetación, arbustos y árboles que rodean a las viviendas, aumentando las posibilidades de cría de mosquitos vectores de esta afección(AU)
Dengue is an infectious disease caused by one of the four serotypes of the analogous virus, which is transmitted to humans through the bite of infected mosquitoes of the genus Aedes Objective: To identify the prevalence of dengue virus and risk factors in the patients who attended the health units of the Esmeraldas canton in 2019. Materials and Methods: The research is part of the non-experimental, retrospective, descriptive research design, based on the information of patients with a positive dengue diagnosis. treated in the health units of the Esmeraldas canton in 2019. Results: In this study, 247 registered patients with a presumptive diagnosis of dengue were found, which we took as a population, 4 samples of patients, not processed, and 121 samples were excluded. of patients with a negative result, leaving us with 121 samples of patients with a confirmed diagnosis of dengue, taking to this number of patients as a sample for our study, which represents 49% as the prevalence of dengue virus in patients who attended the health units of the Esmeraldas canton during 2019. Conclusion: The prevalence of dengue in patients who attended the health units of the Esmeraldas canton is 49%, the most predominant age was between 5 and 9 years, a significant number of patients come from the Simón Plata Torres parish, sectors with a lack of basic services infrastructure, gardens and patios with weeds and vegetation, bushes and trees that surround the houses, increasing the chances of breeding mosquito vectors of this condition(AU)
Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Patients , Prevalence , Risk Factors , Dengue Virus , Health Centers , Communicable Diseases , Aedes , Mosquito VectorsABSTRACT
Purpose: To report a retrospective series of three cases of infectious panophthalmitis post?dengue fever with ex vivo confirmation of dengue virus ribonucleic acid (RNA) in the tissues of the eye. Methods: Four eyes of three patients, who were diagnosed with panophthalmitis following dengue fever and who underwent evisceration, were included. All demographic and clinical data were recorded. The eviscerated samples were subjected to direct microscopy, culture for bacteria, fungi, and parasites, and molecular virology (dengue virus [DENV] NS1?specific reverse transcription loop?mediated isothermal amplification (RT?LAMP) assay). Results: The time from the development of dengue fever to the occurrence of ocular symptoms was 4.33 ± 1.15 (median 5) days. DENV NS1 RNA, suggestive of the presence of the dengue virus, was confirmed in all evisceration specimens (uveal tissue, cornea). All the patients recovered completely from dengue fever and on follow?up had healthy eviscerated sockets. Conclusion: Demonstration of the DENV RNA in the eviscerated specimens of panophthalmitis following dengue fever implicates the DENV in the pathophysiology of the ocular infection.
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Dengue, a vector-borne disease remains as one of the most serious public health problems globally. Incidence of this disease is on an increasing trend and currently over a billion people in tropical and subtropical regions are at risk. In the absence of an operational vaccine, prevention of dengue virus (DENV) is primarily focused upon controlling mosquito vectors. Mosquito vector surveillance programmes require simple and rapid tools to detect mosquitoes infected with DENV. Here, we tested the commercially available DENV Detect™ NS1 ELISA kit (InBios International, Inc.) for detection of recombinant DENV-NS1 protein in Aedes mosquito samples. The kit was evaluated to find out the minimum detection limit of recombinant DENV-2 NS1 protein following the manufacturer’s instructions. Initially, the NS1 protein detection threshold of the kit was determined and later the assay was standardized for detection of NS1 protein in Aedes aegypti mosquito pools containing 5, 10 and 25 mosquitoes. The ELISA kit displayed high sensitivity towards detection of recombinant dengue virus-2 NS1 protein in mosquito pools (up to 25 mosquitoes per pool) at 25 pico gram concentration. Since the commercial NS1 ELISA is highly sensitive and follows a very simple procedure, it could be employed for DENV surveillance in Aedes aegypti mosquitoes, after carrying out laboratory and field bioassays with DENV infected specimens.
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: Dengue is still a public health problem in tropical countries. This disease, which had almost disappeared in some areas of the world, has become re-emergent in certain parts of the world including Africa.The aim of this study is to determine the seroprevalence and evolution of Dengue virus (DENV) infection from 2020 to 2021 at the Hospital Saint Camille de Ouagadougou (HOSCO), Burkina Faso. Methodology: This was a descriptive analytical study of patients seen in general practice with febrile syndrome referred for serological diagnosis of Dengue at the HOSCO laboratory over a period of 2 years (January 1, 2020 December 31, 2021). The "Dengue Duo (AgNS1/IgM/IgG)" kit from SD Bioline was used for the rapid diagnosis through the detection of NS1 antigen and IgM/IgG antibodies in plasma. Data were analysed with SPSS version 20.0 software. Association between demographic data and prevalence of DENV infection was determined by Chisquare test and odds ratio (with 95% confidence interval). P value less than 0.05 was considered statistical significance. Results: A total of 2957 patients aged 0-94 years were referred for serological diagnosis of DENV infection at the HOSCO laboratory over the period 2020-2021, comprising 56.3% females and 43.7% males. The overall prevalence of acute DENV infection (NS1Ag positive) was 5.4% (159/2957), with 2.4% (41/1700) in 2020 and 9.4% (118/1257) in 2021 (OR=4.192, 95% CI=2.915-6.028, p<0.0001). The prevalence of acute DENV infection of 7.0% (91/1292) in the males was significantly higher than 4.1% (68/1665) in the females (OR=1.779, 95% CI=1.288-2.458, p=0.0005), and also significantly higher in age groups 20-29 years (7.6%), 10-19 years (6.9%) and 40-49 years (5.8%) than other age groups (X 2=14.928, p=0.0107). The overall prevalence of DENV IgM and IgG antibodies was 3.2% and 37.3% respectively. The prevalence of DENV IgG antibodies was significantly higher in males (44.0%) than females (32.1%) (OR=1.667, 95%CI=1.434-1.938, p<0.0001) and in age groups 30-39 (43.4%), 40-49 (44.0%) and >50 years (49.3%) than other age groups (X2=121.0, p<0.0001), indicating that past exposure to DENV infection is higher among males and older age groups. The peak of DENV infection was between October and November with 84.3% (134/159) of NS1Ag positivity occurring during this period. Conclusion: The present study reports a high prevalence of acute Dengue virus infection in patients from October to November. To eradicate Dengue which has become a tropical silent epidemic, interventions such as vector control, availability of and accessibility to diagnostic tests, and good therapeutic management are of great importance
Subject(s)
Humans , Epidemiology , Dengue Virus , Burkina Faso , Seizures, Febrile , DengueABSTRACT
Dengue is a viral disease which is serious health concern from last few decades and the infection transmitted through mosquito bite into human. This study was conducted to carry out prevalence of dengue fever in District Swabi. A total of 196 blood sample were collected from patients with age ranges (0-80 years) having dengue fever on the basis of physical symptoms from Bacha Khan Medical Complex Swabi during August to October 2017. Serological test were performed for detection of IgM, IgG and NS1 (Non structural protein antigen of virus) against dengue. Out of total 196 confirmed dengue cases the most prone gender was male 123(62%) while 73(38%) were female. Among the age groups; 21-30 years group 62 (31.6%) was found the most predominated age group. The higly affected areas in district Swabi were Topi (40.8%) followed by Main Swabi (27%), Maneri (8.2%), Marghuz (6%), Shawa Ada (5.1%), Shah Mansoor (5.1%), Gohati (4.1%), and Chota Lahore (3.6%). Therefore, the health department should take actions by educating the public about basic cleanliness of the environment. The community should be encouraged to participate in the control of such vector based diseases/infections.
A dengue é uma doença viral que é um sério problema de saúde das últimas décadas e a infecção transmitida através da picada de mosquito em humanos. Este estudo foi realizado para realizar a prevalência da dengue no distrito de Swabi. Foram coletadas 196 amostras de sangue de pacientes com faixa etária (0 a 80 anos) com dengue com base nos sintomas físicos do Complexo Médico Bacha Khan de Swabi, no período de agosto a outubro de 2017. Foram realizados testes sorológicos para detecção de IgM, IgG e NS1 (antígeno proteico não estrutural do vírus) contra a dengue. Do total de 196 casos confirmados de dengue, o sexo mais propenso foi o masculino 123 (62%), enquanto 73 (38%) eram do sexo feminino. Entre as faixas etárias; A faixa etária de 21 a 30 anos 62 (31,6%) foi a faixa etária mais predominante. As áreas altamente afetadas no distrito de Swabi foram Topi (40,8%), seguidas por Main Swabi (27%), Maneri (8,2%), Marghuz (6%), Shawa Ada (5,1%), Shah Mansoor (5,1%), Gohati (4,1%) e Chota Lahore (3,6%). Portanto, o departamento de saúde deve tomar ações educando o público sobre a limpeza básica do meio ambiente. A comunidade deve ser incentivada a participar do controle de tais doenças / infecções baseadas em vetores.
Subject(s)
Humans , Male , Female , Infant, Newborn , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Dengue/epidemiology , Dengue Virus , Pakistan/epidemiology , Epidemiologic Studies , Disease OutbreaksABSTRACT
One of the major causes of morbidity and mortality in tropical and subtropical regions is Dengue viral infection. This virus belongs to family flaviviridae comprising of four antigenically distinct serotypes DENV 1 - 4. A small number of studies conducted in North Eastern (NE) Region of India reported Dengue cases in Assam, Meghalaya, Nagaland, Manipur and Arunachal Pradesh. However, no studies have been conducted in the state of Tripura, with regard to pattern of Dengue viral infection and its circulating serotypes. Therefore, this study was undertaken to identify the serotypes circulating in Tripura. MethodsPatients with acute febrile illness were tested for detecting Dengue viral infection by MAC ELISA and / or NS1 detection test at Viral Research and Diagnostic Laboratory (VRDL), of a tertiary care centre in Tripura for a period of 3 years. All NS1 positive samples were further tested for presence of viral RNA by Reverse Transcriptase –PCR (RT - PCR) and serotyping was done using serotype specific primers. ResultsA total of 2515 acute febrile cases seen over a period of 3 years from 2014 to 2017 was tested for Dengue virus infection by serology. Out of 2515 of cases, 405 cases tested for NS1 antigen, where 10.61 % (43 / 405) was NS1 positive. The remaining 2110 cases were tested for IgM antibody MAC ELISA and 15.68 % (331 / 2110) was MAC ELISA positive. Out of all NS1 antigen positive cases 34.88 % of PCR positive and serotype characterisation showed DENV - 1 was predominant serotype followed by DENV - 2 and DENV - 4 respectively. ConclusionsThere is a rising trend of Dengue virus infection in Tripura with circulation of multiple serotypes. Moreover, cocirculation of multiple serotypes is a risk to the emergence of recombinant strains and also heterotypic infection in the near future might lead to development of DHF and DSS. Hence, molecular characterization of circulating serotypes may be helpful in addressing the probabilities of Dengue outbreak and possibilities of complications.
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In many parts of India, Dengue has become a major public health problem and Kalaburagi District in North Karnataka region was previously not known to be an endemic area for dengue. Three clinical syndromes, classic dengue fever, dengue haemorrhagic fever and dengue shock syndrome are seen with dengue virus infection. This present study was undertaken to find out whether platelet count really influences the outcome of dengue patients in a tertiary health care centre in Kalaburagi, Karnataka.METHODSAbout hundred patients admitted in our hospital with positive Dengue NS1 and Dengue IgM were selected. The follow up of patients is done from the onset of fever to up to twelve days or until their recovery according to discharge criteria of WHO whichever of them is earlier.RESULTSIn this study, 100 cases were studied, out of which Dengue fever was seen in 73 cases, Dengue Hemorrhagic Fever in 17 cases and Dengue Shock Syndrome in 10 cases was seen based on WHO criteria. In this study, 99 percent patients had fever. In this study 73 percent of patients were Dengue NS1 Positive and 27 percent of patients were Dengue IgM Positive. In present study, continuously increasing pattern of platelet count was seen in 55 percent cases; initial fall then rise of platelet count was seen in 38 percent cases and persistently low pattern of platelet count was seen in 7 percent cases. This study showed that 30 percent of patients had bleeding manifestations and bleeding manifestations were maximum in patients having low platelet counts. In the present study, 92% cases improved and 8% cases expired.CONCLUSIONSAmong the three clinical syndromes, Dengue fever was more common than dengue haemorrhagic fever and dengue shock syndrome. It was found that platelet count influenced the outcome of dengue patients. Management of dengue case is mainly supportive
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Background: Dengue fever is one of the most common arboviral mediated outbreaks reported with increased prevalence over the last few years with considerable morbidity and mortality. This study was designed to study the clinical and biochemical parameters in dengue fever patients.Methods: Prospective observational study was undertaken among adult patients in a tertiary care hospital. fifty patients were studied and analysed. All patients who were NS1 (Non-Structural Protein 1) antigen or IgM dengue positive were included in the study. Clinical features, haematological and biochemical parameters were noted.Results: Of the 50 patients studied, majority were males (68%). Fever was the major symptom (100%) followed by Body ache (84%), Headache (64%), Retro-orbital pain (52%), Myalgia (48%), conjunctival injection (40%), Itching (40%), abdominal pain (36%), Bradycardia (34%), Rash (30%), pleural effusion and ascites both seen in (28%). Significant derangements in platelet (76%), leucocyte counts (84%) and serum transaminases (58%) were noted.Conclusions: Fever associated with headache, retroorbital pain, erythematous morbilliform rash, conjunctival injection and itching over palms and soles along with thrombocytopenia, leukopenia, elevated liver transaminases should prompt a clinician on the possibility of dengue infection. Platelet transfusions have little role in management of dengue patients unless patients having active bleeding secondary to thrombocytopenia due to dengue fever.
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Background: Serological diagnosis of dengue fever is based on the detection of NS1 antigen and further confirmed by the assay of dengue IgM and IgG. Rapid Diagnostic Tests (RDTs) are no longer recommended for use by the Government of India. However, there is a requirement of rapid results without compromising on the test quality. Accordingly, we undertook an evaluation of a novel cartridge-based system employing a unique table-top diagnostic device for dengue NS1 antigen by BluSense Diagnostics incorporating a patented Immuno-Magnetic Assay (IMA).Methods: A total of 309 samples were tested on unlinked anonymous basis. Each sample was tested using NS1 Ag ELISA (Microlisa, J. Mitra), ViroTrack and NS1 RDT (SD Alere) and results were recorded. Discordant samples were further tested by dengue NS1 AG ELISA (Panbio) and dengue IgG/IgM Maclisa (J. Mitra).Results: When compared with approved ELISA kits used globally the Virotrack test returned a sensitivity of 94.74%; specificity of 97.44%; PPV of 97.30%; NPV of 95% and accuracy of 96.10%. Hourly throughput is 5-6 samples.Conclusions: The Virotrack system is highly suitable as a POCT module in HCFs with low to moderate workload that employs novel technology, is rapid, user friendly and comparable to the ELISA in sensitivity and specificity. The equipment is user friendly and can work both on plasma/serum and whole blood. Model with multiple modules (3-4) will improve the throughput and turnaround time. Evaluation of this novel technology has been done in India for the first time.
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Background & objectives: Dengue diagnosis is routinely carried out by detection of dengue virus (DENV) antigen NS1 and/or anti-DENV IgM antibodies using enzyme-linked immunosorbent assays (ELISAs) and rapid diagnostic tests (RDTs). This study was aimed at evaluation of quality of diagnostic assays currently in use in India for the identification of DENV infection. Methods: During 2016 dengue season (July-November) in Pune, India, comparative assessment of a few immunoassays was undertaken using (i) WHO-approved Panbio-Dengue-Early-(NS1)-ELISA and Panbio-Dengue-IgM-Capture-ELISA as reference tests, and (ii) Bayesian latent class analysis (BLCA) which assumes that no test is perfect. The assays included J.Mitra-Dengue-NS1-Ag-MICROLISA (JME-NS1), J.Mitra-Dengue-IgM-MICROLISA (JME-IgM), and two RDTs, namely, J.Mitra-Dengue-Day-1-Test (JM-RDT) and SD-BIOLINE-Dengue-Duo (SDB-RDT). Serum samples from patients seeking dengue diagnosis (n=809) were tested using the diagnostic kits. The presence of NS1 and/or IgM was taken as evidence for dengue-positive diagnosis. Results: Panbio-NS1/IgM-ELISAs identified 38.6 per cent patients as dengue positive. With Panbio-ELISA as reference, all the tests were less sensitive for IgM detection, while for NS1, JM-RDT was less sensitive. For combined diagnosis (both markers), sensitivity of all the tests was low (55.7-76.6%). According to BLCA, Panbio-ELISA was 84 per cent sensitive for NS1, 86 per cent specific for IgM and 87 per cent specific for combined diagnosis. Accordingly, performance of the other tests was substantially improved with BLCA; however, sensitivity of both the RDTs for IgM detection remained unacceptable. The NS1 ELISAs and RDTs detected all four DENV serotypes, JME being most efficient. All IgM tests exhibited higher sensitivity in secondary infections. Interpretation & conclusions: These results confirmed superiority of ELISAs, and testing for both NS1 and IgM markers for dengue diagnosis, and emphasized on improvement in sensitivity of RDTs.
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Dengue fever has emerged as a big threat to human health since the last decade owing to high morbidity with considerable mortalities. The proposed study aims at the in silico investigation of the inhibitory action against DENV4-NS1 of phytochemicals from two local medicinal plants of Pakistan. Non-Structural Protein 1 of Dengue Virus 4 (DENV4-NS1) is known to be involved in the replication and maturation of viron in the host cells. A total of 129 phytochemicals (50 from Tanacetum parthenium and 79 from Silybum marianum) were selected for this study. The tertiary structure of DENV4-NS1 was predicted based on homology modelling using Modeller 9.18 and the structural stability was evaluated using molecular dynamics simulations. Absorption, distribution, metabolism, excretion and toxicity (ADMET) along with the drug-likeness was also predicted for these phytochemicals using SwissADME and PreADMET servers. The results of ADMET and drug-likeness predictions exhibited that 54 phytochemicals i.e. 25 from Tanacetum parthenium and 29 from Silybum marianum showed effective druglikeness. These phytochemicals were docked against DENV4-NS1 using AutoDock Vina and 18 most suitable phytochemicals with binding affinities ≤ -6.0 kcal/mol were selected as potential inhibitors for DENV4-NS1. Proposed study also exploits the novel inhibitory action of Jaceidin, Centaureidin, Artecanin, Secotanaparthenolide, Artematin, Schizolaenone B, Isopomiferin, 6, 8-Diprenyleriodictyol, and Anthraxin against dengue virus. It is concluded that the screened 18 phytochemicals have strong inhibition potential against Dengue Virus 4.
Subject(s)
Computer Simulation , Proteins/classification , Dengue , Dengue Virus , Phytochemicals/analysis , Plants, Medicinal/metabolism , Pharmacokinetics , Tanacetum parthenium/adverse effects , Molecular Dynamics SimulationABSTRACT
Dengue virus (DENV) is the most widely transmitted arbovirus in the world. Due to the lack of diagnostic technology to quickly identify the virus serotypes in patients, severe dengue hemorrhagic fever cases caused by repeated infections remain high. To realize the rapid differential diagnosis of different serotypes of DENV infection by immunological methods, in this study, four DENV serotype NS1 proteins were expressed and purified in mammalian cells. Monoclonal antibodies (MAbs) against NS1 protein were obtained by hybridoma technology after immunizing BALB/c mice. Enzyme-linked immunosorbent assay, indirect immunofluorescence assay, dot blotting, and Western blotting were used to confirm the reactivity of MAbs to viral native NS1 and recombinant NS1 protein. These MAbs include not only the universal antibodies that recognize all DENV 1-4 serotype NS1, but also serotype-specific antibodies against DENV-1, DENV-2 and DENV-4. Double antibody sandwich ELISA was established based on these antibodies, which can be used to achieve rapid differential diagnosis of serotypes of DENV infection. Preparation of DENV serotype-specific MAbs and establishment of an ELISA technology for identifying DENV serotypes has laid the foundation for the rapid diagnosis of DENV clinical infection.
Subject(s)
Animals , Humans , Mice , Antibodies, Monoclonal , Antibodies, Viral/metabolism , Dengue/diagnosis , Dengue Virus/immunology , Enzyme-Linked Immunosorbent Assay , Mice, Inbred BALB C , Sensitivity and Specificity , Serogroup , Viral Nonstructural Proteins/immunologyABSTRACT
@#In the search for universal vaccine candidates for the prevention of avian influenza, the non-structural (NS)-1 protein of avian influenza virus (AIV) H5N1 has shown promising potential for its ability to effectively stimulate the host immunity. This study was aimed to produce a bacterial expression plasmid using pRSET B vector to harbour the NS1 gene of AIV H5N1 (A/Chicken/Malaysia/5858/2004 (H5N1)) for protein expression in Escherichia coli (E. coli). The NS1 gene (687 bp) was initially amplified by polymerase chain reaction (PCR) and then cloned into a pGEM-T Easy TA vector. The NS1 gene was released from pGEM-T-NS1 using EcoRI and XhoI restriction enzymes (RE). The pRSET B vector was also linearized using the same RE. The digested NS1 gene and linearized pRSET B were ligated using T4 DNA ligase to form the expression plasmid, pRSET B-NS1. The NS1 gene sequence in pRSET B-NS1 was confirmed by DNA sequencing. To prepare recombinant bacterial cells for protein expression in the future, pRSET B-NS1 was transformed into E. coli strain BL21 (DE3) by heat-shock. Colonies bearing the recombinant plasmid were screened using PCR. The DNA sequencing analysis revealed that the NS1 gene sequence was 97% homologous to that of AIV H5N1 A/Chicken/Malaysia/5858/2004 (H5N1). These results indicated that the NS1 gene of influenza A/Chicken/Malaysia/5858/2004 (H5N1) was successfully amplified and cloned into a pRSET B vector. Bacterial colonies carrying pRSET B-NS1 can be used for the synthesis of NS1-based influenza vaccine in the future and thereby aid in the prevention of avian influenza.
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To determine the proportion of dengue non-structural protein 1 (NS1) positives among laboratory confirmed dengue IgM negative patients. Methods: Data for 1 732 samples received from January to October 2017 at the Virus Research and Diagnostic Laboratory (VRDL) for dengue diagnosis were downloaded from the National Institute of Epidemiology server. Samples that were previously reported as IgM negative for dengue diagnosis were identified and their NS1 status was determined using ELISA. Thus, 'missed out' NS1 positives were correlated with the duration of illness. Furthermore, an epidemic curve for the study period was constructed. The increase in positivity rate within and between the months was compared by McNemar's and Pearson's chi-square test, respectively. Results: The reported IgM-negatives were 813, of which, 22.5% (183) were retrospectively positive for NS1 antigen. The addition of NS1 positives revealed by this study has raised the reported positivity across the months that ranged from 8.1% to 29.6%. By analyzing the dengue positives per month and the epidemic curve, the period between January and September, 2017 was identified as non-epidemic while the epidemic started from the month of October, 2017. Conclusions: Acute dengue infection is widely confirmed by detecting NS1 antigen in serum. Missing out of NS1 positives happen due to shortened window period and such cases act as reservoir for further viral transmission. Hence, this study highly emphasizes performing all three tests for dengue diagnosis that warrants the accurate dengue proportion in India.
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To determine the proportion of dengue non-structural protein 1 (NS1) positives among laboratory confirmed dengue IgM negative patients. Methods: Data for 1 732 samples received from January to October 2017 at the Virus Research and Diagnostic Laboratory (VRDL) for dengue diagnosis were downloaded from the National Institute of Epidemiology server. Samples that were previously reported as IgM negative for dengue diagnosis were identified and their NS1 status was determined using ELISA. Thus, 'missed out' NS1 positives were correlated with the duration of illness. Furthermore, an epidemic curve for the study period was constructed. The increase in positivity rate within and between the months was compared by McNemar's and Pearson's chi-square test, respectively. Results: The reported IgM-negatives were 813, of which, 22.5% (183) were retrospectively positive for NS1 antigen. The addition of NS1 positives revealed by this study has raised the reported positivity across the months that ranged from 8.1% to 29.6%. By analyzing the dengue positives per month and the epidemic curve, the period between January and September, 2017 was identified as non-epidemic while the epidemic started from the month of October, 2017. Conclusions: Acute dengue infection is widely confirmed by detecting NS1 antigen in serum. Missing out of NS1 positives happen due to shortened window period and such cases act as reservoir for further viral transmission. Hence, this study highly emphasizes performing all three tests for dengue diagnosis that warrants the accurate dengue proportion in India.
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Objetivo: Se considera que el diagnóstico del dengue es fundamentalmente clínico; sin embargo, las pruebas rápidas basadas en la detección de IgM o NS1/IgM están siendo utilizadas en los servicios de salud. Este estudio determinó la contribución de las pruebas rápidas al diagnóstico de dengue en un área endémica antes de la introducción del virus zika. Metodología: Diseño de corte transversal de pruebas diagnósticas realizado a partir del análisis secundario de un estudio previo en 14 instituciones de salud del Valle del Cauca. Se obtuvo información de 632 participantes con resultados de prueba rápida, diagnóstico clínico y pruebas de referencia ELISA NS1, ELISA IgM y RT-PCR. Se compararon la sensibilidad, especificidad, valores predictivos y razones de verosimilitud del uso solo, en serie, y paralelo de los componentes NS1, IgM, NS1/IgM de la prueba rápida y el diagnóstico clínico con las pruebas Q de Cochran y McNemar para datos pareados. Resultados: La sensibilidad del diagnóstico clínico (61,4% IC95% 56%-66,7%) fue superior a la de las pruebas rápidas (37% IC95% 29,6%-44,7%) (P Conclusión: El diagnóstico clínico tiene una mayor sensibilidad que las pruebas rápidas, pero por si solo no es suficiente para confirmar o descartar dengue. Un resultado positivo en pruebas rápidas en pacientes con diagnóstico clínico de dengue es útil para confirmarlo, pero un resultado negativo no lo descarta.
Objective: Dengue diagnosis is considered to be mainly clinical; however, rapid tests that detect IgM or NS1/IgM are being used in health services. This study assessed the contribution of rapid tests to dengue diagnosis in an endemic area before the emergence of zika virus in Colombia. Methods: Cross-sectional study of diagnostic tests based on a secondary analysis of a previous study in 14 health care institutions in Valle del Cauca department. Results of dengue rapid test, clinical diagnosis, and reference tests ELISA NS1, ELISA IgM, and RT-PCR were obtained for 632 participants. The sensitivity, specificity, predictive values and likelihood ratios of the use alone, serial and parallel combinations of NS1, IgM, NS1/IgM of the rapid test and clinical diagnosis were compared using Cochran´s Q and MacNemar tests for paired data. Results: The sensitivity of clinical diagnosis (61.4% 95%IC 56-66.7) was higher than the sensitivity of rapid tests (37% 95% IC 29.6-44.7) (P<0.001). The serial used of NS1/IgM rapid test when clinical diagnosis was negative increased the sensitivity to 79.5% and, the serial use when clinical diagnosis was positive increased the specificity (from 66.3% to 98.7%). However, the latter decreased the sensitivity to 32.2%. While all negative likelihood ratios (LR-) were close to 1, the serial use of rapid tests when clinical diagnosis was positive had LR+ higher than 10. Conclusion: The clinical diagnosis is more sensitive than rapid tests, but by itself does not confirm or rule out dengue. A positive result in rapid tests is useful to confirm dengue but a negative result does not rule it out.
Subject(s)
Humans , Male , Female , Dengue , Dengue/diagnosis , Zika Virus , Sensitivity and Specificity , Viral Nonstructural Proteins/analysis , Colombia , Clinical Laboratory Techniques , Point-of-Care TestingABSTRACT
Background: Dengue is a vector borne disease by four different serotypes of dengue virus transmitted by bite of female Aedes mosquito. It is an acute febrile illness characterised by myalgia, joint pain, gastrointestinal manifestations. Complications like dengue hemorrhagic fever (DHF) and Dengue shock syndrome (DSS) , Extended Dengue Syndrome(EDS) may be fatal for patients. Authors analyse different clinical spectrum of of manifestations, complications and correlation bleeding to platelet level.Methods: This study conducted from July 2017 to December 2018 comprising of 100 dengue patients of age more than 15 years in IMS & SUM Hospital.Result: Out of 100 dengue patients’ males 73% and females 27%. From the patients 57% were NS1 Antigen positive, 29% IgM positive, 9% NS1 and IgM positive, 4% IgM and IgG positive and 2 % with all NS1, IgM, IgG positive. In our series in clinical manifestations, all cases (100%) presented with fever, myalgia (78%), headache (53%), rashes (14%), nausea, pain abdomen (21%) loose motion (17%), and Retro-orbital pain (6%). Bleeding manifestations in any form was seen in 39% cases like Purpura or Petechie (23%), malena (18%), hematemesis ( 2% ), epixtasis (6%), Gum bleeding (2%), Hematuria (1%), and Ophthalmic bleeding like sub conjunctival hemorrhage, intra-vitreal hemorrhage in 8% cases. Complications detected e.g. hepatopathy in 53%, nephropathy. 4%, ascites 8%, pneumonia 7%, DSS (4%), Multi Organ Dysfunction (MODS) (4%), DHF (8%) and EDS in 2% cases. It was observed that 95.8% of patients with platelet counts between 20,000-50,000/cu.mm and 61% of patients less than 25000 had bleeding manifestations.Conclusion: Wide clinical spectrum of manifestations and complications makes it common differential diagnosis of acute febrile illnesses and bleeding manifestation does not always corelate with lower platelet count.
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ackground: Dengue fever is caused by mosquito borne arbovirus of family Flaviviridae, Aedes agypti as the principle vector. In the recent past Delhi has witnessed several outbreaks affecting thousands of individuals and many of them get re-infected during subsequent years forming a bulk of secondary dengue cases putting them at risk of developing severe dengue.Methods: A total of 150 serum samples from suspected dengue cases were tested for dengue fever by NS-1 antigen and IgM antibody enzyme-linked immunosorbent assay (ELISA) followed by categorization into primary and secondary dengue using IgG avidity ELISA.Results: Out of total 150 clinically suspected dengue cases, 56 were positive either by Dengue NS-1 antigen or dengue IgM antibody or both. On the basis of dengue IgG avidity ELISA among 56 diagnosed dengue cases, 30 (53.57%) were found to be of secondary dengue.Conclusions: There is increasing trend of dengue cases in Delhi since past one decade. Being hyper-endemic area for dengue, more than 25% population have been reported to have past infection of dengue. Due to increased prevalence and simultaneous circulation of more than one serotypes, number of secondary dengue cases is also increasing. Since majority of severe dengue cases are associated with secondary dengue, early diagnosis and treatment can significantly reduce the fatal outcome. Thus, avidity testing for IgG antibody becomes an important tool.
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Introduction: In the recent few decades, there had beena dramatic rise in the global incidence of dengue. As thedisease is associated with high mortality and morbidity, arapid and accurate diagnosis is essential for early appropriatemanagement and for prevention of complications. Now days,a variety of rapid diagnostic tests (RDTs) kits and EnzymeLinked Immuno Sorbent Assay (ELISA) based test kits areavailable. In this present study we have attempted to doa diagnostic test evaluation of rapid ICT with ELISA fordetection of NS1 antigen and IgM antibody for acute denguediagnosis.Material and Methods: A Cross-Sectional study was carriedout in the Department of Microbiology, Govt. MedicalCollege, Raigarh from November 2017 to October 2018. 1200suspected serum samples were tested for dengue identificationby Immuno-chromatography (ICT) based RDT kit (J. Mitraand Co. Pvt.Ltd, India) which detects NS1 antigen, IgM andIgG antibodies. From the Dengue rapid reactive samples testdone by ICTs were subjected to ELISA tests for ConfirmationNS1 antigen and IgM antibodies.Results: The Rapid Dengue Test showed a sensitivity andspecificity of 98% and 74% for NS1 antigen detection and76% and 90% for IgM Antibody detection.Conclusion: Good sensitivity and specificity of rapiddiagnostic tests for early detection of dengue was observed.These kits are suitable for early detection of dengue cases,as with high sensitivity and specificity it can help in earlyscreening of patients and can further limit the spread ofdisease where ELISA facilities are not available