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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.
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Humans , Male , Female , Immunoglobulin M , Dengue , Dengue Virus , Antigens , Signs and Symptoms , Immunoglobulin G , Sensitivity and SpecificityABSTRACT
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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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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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: 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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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
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@# Abstract：Objective To establish a sensitive，rapid and convenient method for the detection of dengue antigen and assist clinical diagnosis of dengue. Methods In this paper，we developed a rapid detection method for dengue antigen based on microfluidic immune magnetic beads. Solidwork software was used to design microfluidic chip，which was prepared by mechanical processing and chemical sealing. Immunomagnetic beads of dengue antibody were prepared by chemical coupling reaction. Using HRP ⁃TMB ⁃H2O2 as color system，dengue NS1 antigen was detected on microfluidic chip carrier by double antibody sandwich method. Finally，57 clinical samples were tested by the novel method and traditional ELISA kit，and the accuracy of the method was analyzed，and the advantages and disadvantages of the two methods were compared. Results 20 minutes was needed to detect dengue NS1 antigen by using the novel ELISA method，and the reaction system only needed 10 μg beads and 10 μL samples. In the verification experiment，the method could distinguish the negative from the positive obviously. The positive sample had color rendering，while the negative and blank samples had no color rendering. In terms of detection performance，the coincidence rate between the new ELISA method and the traditional ELISA method reached 100%. Conclusion The novel ELISA detection platform had the advantages of simple，rapid，reagent and sample saving，high sensitivity，good stability and high accuracy，and could be used for the detection of dengue antigen.
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Background: Dengue fever is currently the most important arthropod borne viral disease. Since occurrence of dengue infections has been an epidemic in many parts of India and complications like DHF and DSS are increasing, while at the same time the diagnosis is challenging, particularly the laboratory diagnosis is confusing, this study was conducted to evaluate the different laboratory test methods and to compare their respective efficacy, timing, advantages and disadvantages.Methods: This study was done in the Department of Microbiology in collaboration with the Department of Medicine and Pediatrics in two tertiary care medical colleges and hospitals in eastern India. Blood samples from 319 patients with clinical features suggestive of Dengue fever were included in this study. Laboratory investigations were done which included immunological assays that were performed using commercially available kits - SD dengue duo NS1Ag + Ab combo rapid test, NS1 Ag capture ELISA, IgM capture ELISA, IgG capture ELISA test for dengue and other routine tests -full blood cell count, coagulation tests, routine biochemical and lipid profile were also done. Ethical considerations were taken care of and statistical evaluations were done.Results: An increased detection of IgM antibody (46.15%) was seen in the early febrile period (1-5 days) as compared to the mid-febrile period (6-10 days), and late febrile period (6-10 days) when it is 6.89%. IgG antibody is much less in early febrile period (4.16%). Compared to mid-febrile period (24.13%), and late febrile period (62.5%). IgM antibodies were detected in 44.5% of the samples, IgG antibodies were detected in 43.5% of the samples, Rapid test was positive in 36.9% and NS1AG ELISA was detected in 43.5% of the samples in the study.Conclusions: It can be inferred from our study that for detection of dengue in the early febrile period (1-5 days), estimation of dengue-specific serum IgM is the most sensitive antibody detection method.
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Introduction: Dengue is a major public health problem in tropical and sub-tropical regions of the world and it is known for serious life threatening complications. Detection of IgM antibodies forms the mainstay for diagnosis of dengue infection. However, IgM antibodies develop after 4-5 days of infection and there is an urgent need for an alternative diagnostic tools that can detect dengue infection earlier. Aim and Objectives: To evaluate the efficacy of NS1 antigen ELISA for early diagnosis of dengue virus infection in a tertiary care hospital Methods-A total of 2106 serum samples from patients with suspected dengue infection were tested for dengue NS1 antigen and IgM anti-body detection by ELISA. Results: 765 (36.32%) were positive for dengue NS1 antigen and 857 (40.69%) were positive for dengue IgM antibody. NS1 antigen was detectable in patient sera from day 1 onwards however; dengue IgM anti-body was detected from day 3 onwards. Out of 765 NS1 antigen positive samples, 562 (73.46%) were positive in acute phase of illness and 203 (26.54%) were positive in convalescent phase of illness. Out of 857 MAC ELISA positive samples, 312 (36.41%) were from acute phase of illness and 545 (63.59%) were from early convalescent phase of illness. Combination of two tests resulted in increase in the positivity rate to 52.66% as against to independent posi-tivity rate of 36.32% of NS1 ELISA and 40.69% of MAC ELISA. Conclusion: Combined use of NS1 antigen assay with MAC ELISA test could significantly improve diagnostic sensitivity of dengue infection
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Background: Dengue being the most prevalent mosquito borne arboviral infection in India, has become endemic in India with every year outbreaks. Despite substantial efforts to control the mosquito populations, dengue fever has spread, emerged and established itself rapidly. Objectives: This study is to correlate the platelet count and IgM /IgG and NS1 in the acute stage of dengue infection Materials & Methods: The present study was conducted for a period of 22 months in Heritage Institute of Medical Sciences from January 2016 to November 2017. Blood samples were collected from 1347 suspected Dengue patients. In all the serologically positive cases, serological confirmation and evaluation of platelet counts of dengue infection was done. Results: A total of 1347 suspected cases were admitted during the study period and among them, 155 (11.51%) were found to be seropositive for dengue. Among the dengue cases, Males (61.05%) were affected more than females (38.7%). Out of 155 positive cases, 108 [69.7%] cases were positive for NS1antigen either alone or in combination with antibodies.77 [49.7%] cases were exclusively positive for NS1 antigen only. Out of 108 cases that were positive for NS1, thrombocytopenia was observed in 70 cases (64.8%) whereas when the antibodies alone were considered, thrombocytopenia was observed in 18 out of 47 cases (38.3%. In a total of 155 cases, thrombocytopenia was seen in 88 cases (56.8%). Conclusion: The study draws attention toward diagnosis of dengue serologically by testing NS1 antigen and IgM / IgG antibodies. NS1inclusion in the diagnosis of dengue increases the chance of early diagnosis in order to avoid complications significantly
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Background: Dengue fever (DF) and dengue hemorrhagic fever (DHF) are important arthropod borne viral diseases. Dengue in India has dramatically expanded over the last few decades, with rapidly changing epidemiology. Dengue is emerging as major public health concern in northeast India and spreading with increased morbidity. Objective:This study was carried out to determine the seroprevalence of Dengue infection among patients attending in Fakhruddin Ali Ahmed Medical College and Hospital, Barpeta, Assam during the period 2013-2016. Methods: A retrospective study was done from the year 2013 to 2016. A total of 340 serum samples received in the department of microbiology FAAMCH, were tested for the confirmation of suspected cases of dengue. Dengue NS1 antigen and Dengue IgM antibody ELISA tests were performed for the confirmation of dengue cases. We estimated the incidence by applying age, sex and season adjusted dengue positivity. Results: Out of 340 samples tested, 68 were positive either by NS1 antigen or for IgM antibody ELISA tests. These comprised all age groups of both sexes with higher incidence of cases in young males aged 26– 60 years. Conclusion: From this study, it is apparent that dengue surveillance and control should be enhanced by wider use of laboratory testing to confirm dengue as a cause of fever of unknown origin, especially during the local dengue transmission season.
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@#The object of this study was to identify patients with diagnosed dengue infection, who were positive for both dengue-specific NS1 antigen and IgM antibody.
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Introduction: Dengue fever is one of the most prevalent and fastest spreading mosquito borne arboviral infection, occurring in tropical and subtropical regions. They are single stranded RNA viruses and transmitted by Aedes mosquitoes. There are four serotypes of dengue virus DENV 1, DENV2, DENV3, DENV 4. Following an infection lifelong immunity develops against the respective serotype. The clinical spectrum of dengue infection varies from undifferentiated fever, Classical Dengue fever, Dengue hemorrhagic fever, Dengue shock syndrome, Expanded dengue syndrome. Continuous surveillance of dengue fever is important for the proper and timely institution of vector control measures. Aim: The aim of present study was to evaluate the thrombocytopenia with prevalence of dengue infection along with seasonal variation. Materials and methods: The present study was a retrospective study conducted in the Department of Hematology, at Chalmeda Anand Rao Hospital, Karimnagar during the period from 2015 June to 2016 May. Blood samples were collected from 4047 patients presented with acute febrile illness clinically consistent with Dengue infection. Serological confirmation of dengue infection was done using “Rapid Visual test kit” for detection of NS1 antigen and differential detection of IgM and IgG. Platelet count was done on “Automatic cell counter XN1000” which was correlated with manual platelet count in all the serologically positive cases. Results: Out of 4047 suspected cases, 1505 cases were confirmed as serologically positive for dengue infection. Out of 1505cases, 742 samples were positive for only NS1, 70 were positive for only IgM, 361 were positive for only IgG, remaining 332 were positive for more than one serological markers (NS1, IgM, IgG). A majority, 655 (43.52%) of the dengue cases were noted in the age group of 15-30 years, followed by less than 15 years of age. Among the dengue cases, 61.8% were males and 38.2% Vidyadhara Rani P, Naveen Kumar S. Evaluation of thrombocytopenia in dengue infection along with seasonal variation. IAIM, 2018; 5(2): 57-63. Page 58 were females. A significantly higher number of serologically positive cases 1342 (89.2%) were noted in the post monsoon period. Conclusion: Incidence of dengue infection was higher in monsoon and post monsoon period. Thrombocytopenia provide high suspicion of dengue infection, which could be life threatening. Platelet count is an important predictive and recovery parameter of dengue infection.
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Studies have reported significant gender‑related differences in serological tests for detection of NS1 antigen and IgM antibody used for diagnosing dengue fever. However, no such study has been undertaken in India though dengue fever is endemic in this country. Therefore, this study was planned to study the association of serological findings with gender in 700 patients suspected to be suffering from dengue fever in the Indian setting. Haematological parameters of seropositive patients were also studied. Seropositivity and haemorrhagic findings were significantly associated with the female gender. Positive NS1 antigen and IgM antibody results were significantly associated with females and males, respectively.
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Objective: To high light some epidemiological, clinical and diagnostic features of dengue fever during an outbreak and the role of different diagnostic techniques to achieve the highest level of accuracy in results. Methods: Blood samples (n = 323) were collected along with epidemiological and clinical data from suspected dengue patients who visited different hospitals in Swat and Mansehra district of Pakistan between May-November 2013 during a dengue outbreak. Samples were tested for the detection of viral nucleic acid by real-time PCR, non structural protein-1 (NS1) antigen and IgM antibodies by ELISA. Results: Out of 323 cases with clinical dengue infection, 304 were positive by one or more diagnostic parameter; 201 samples were positive by real-time PCR, 209 were positive by NS1 ELISA and 190 were positive by IgM antibodies. Sensitivities of real-time PCR and NS1 ELISA were comparable for early diagnosis of dengue virus infection, IgM antibody detection assay was found useful for the diagnosis in the samples collected later than day 5 of onset. Conclusions: The use of real-time PCR or detection of non structural protein NS1 by ELISA followed by IgM antibodies detection can be recommended for early diagnosis of dengue virus infection with a high level of accuracy.
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Objective To evaluate NS1 antigen detection ELISA for the early laboratory diagnosis of dengue virus infection. Methods The present study was conducted to evaluate the overall positivity of NS1 antigen detection ELISA and its comparison with viral RNA detection via real time PCR and IgM antibodies detection by ELISA. Results A total of 1270 serum samples were tested 86% (1097/1270) were detected positive by one or more than one diagnostic test. Out of 1 270, 64% (807/1270) were positive by NS1 ELISA and 52% (662/1270), 51% (646/1270) were positive by real-time RT-PCR and IgM ELISA respectively. Conclusions NS1 antigen detection ELISA is highly suitable diagnostic tools and it also has great value for use in outbreak and epidemic situation.
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OBJECTIVE@#To high light some epidemiological, clinical and diagnostic features of dengue fever during an outbreak and the role of different diagnostic techniques to achieve the highest level of accuracy in results.@*METHODS@#Blood samples (n = 323) were collected along with epidemiological and clinical data from suspected dengue patients who visited different hospitals in Swat and Mansehra district of Pakistan between May-November 2013 during a dengue outbreak. Samples were tested for the detection of viral nucleic acid by real-time PCR, non structural protein-1 (NS1) antigen and IgM antibodies by ELISA.@*RESULTS@#Out of 323 cases with clinical dengue infection, 304 were positive by one or more diagnostic parameter; 201 samples were positive by real-time PCR, 209 were positive by NS1 ELISA and 190 were positive by IgM antibodies. Sensitivities of real-time PCR and NS1 ELISA were comparable for early diagnosis of dengue virus infection, IgM antibody detection assay was found useful for the diagnosis in the samples collected later than day 5 of onset.@*CONCLUSIONS@#The use of real-time PCR or detection of non structural protein NS1 by ELISA followed by IgM antibodies detection can be recommended for early diagnosis of dengue virus infection with a high level of accuracy.
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OBJECTIVE@#To evaluate NS1 antigen detection ELISA for the early laboratory diagnosis of dengue virus infection.@*METHODS@#The present study was conducted to evaluate the overall positivity of NS1 antigen detection ELISA and its comparison with viral RNA detection via real time PCR and IgM antibodies detection by ELISA.@*RESULTS@#A total of 1270 serum samples were tested 86% (1097/1270) were detected positive by one or more than one diagnostic test. Out of 1 270, 64% (807/1270) were positive by NS1 ELISA and 52% (662/1270), 51% (646/1270) were positive by real-time RT-PCR and IgM ELISA respectively.@*CONCLUSIONS@#NS1 antigen detection ELISA is highly suitable diagnostic tools and it also has great value for use in outbreak and epidemic situation.
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Serum samples from 150 NS1-negative (Platelia ELISA) patients presumptively diagnosed with dengue were analyzed by the TaqMan probed real-time reverse transcription PCR (TaqMan qRT-PCR) method. The qRT-PCR positive samples were tested for serotype by semi-nested RT-PCR and a qualitative immunochromatographic assay for IgG and IgM. Molecular detection methods showed 33 (22%) positive samples out of 150 NS1-antigen negative samples. Of these, 72% were collected up to day 2 after the onset of symptoms, when diagnostic sensitivity of NS1-antigen test assays is significantly enhanced. Most of the cases were not characterized as secondary infection. Twenty-eight samples were successfully serotyped, 75% of which for DENV-4, 14% for DENV-2, 7% for DENV-3 and 4% for DENV-1. These findings reaffirm the hyperendemic situation of the state of Roraima and suggest a lower sensitivity of the NS1 test, mainly when DENV-4 is the predominant serotype. Health care providers should therefore be aware of samples tested negative by NS1 antigen assays, especially when clinical symptoms and other laboratory data results show evidence of dengue infection.
Amostras séricas de 150 pacientes, com diagnóstico presuntivo de dengue e resultado negativo para dengue por ELISA-NS1-Antígeno do kit Platelia™ (NS1-Ag), foram analisadas pela técnica de TaqMan Transcrição Reversa seguida da Reação em Cadeia da Polimerase em Tempo Real (qRT-PCR). As amostras positivas por qRT-PCR, foram submetidas a identificação dos sorotipos por RT-Hemi nested-PCR e a ensaio imunocromatográfico para detecção qualitativa dos anticorpos IgG e IgM. A técnica molecular apresentou como resultado 33 (22%) amostras positivas entre as 150 negativas pela detecção do NS1-Ag, destas o 72% foram coletadas até o segundo dia de início dos sintomas da doença, período de maior sensibilidade para pesquisas de NS1-Ag. A maioria dos casos não evidenciou infecção secundária. Dessas amostras, 28 foram satisfatoriamente sorotipadas sendo 75% de DENV-4, 14% de DENV-2, 7% de DENV-3 e 4% de DENV-1. Os resultados reafirmam a situação hiperendêmica do Estado de Roraima e sugerem baixa sensibilidade do NS1 test, especialmente quando o sorotipo predominante é DENV-4. Sugerimos assim, que a comunidade médica deve ser alertada no sentido de ser cautelosa com resultados de NS1-Ag negativo, principalmente quando sintomas clínicos e outros resultados laboratoriais sejam indicativos de provável infecção por dengue.
Subject(s)
Humans , Antibodies, Viral/blood , Dengue/diagnosis , Reverse Transcriptase Polymerase Chain Reaction , Viral Nonstructural Proteins/immunology , Brazil , Enzyme-Linked Immunosorbent Assay , False Negative Reactions , Reagent Kits, Diagnostic , Sensitivity and SpecificityABSTRACT
The clinical spectrum of dengue fever ranges from asymptomatic infection to dengue shock syndrome. Dengue is classically considered a non-neurotropic virus. Neurological complications are not commonly seen in dengue. The neurological manifestations seen in dengue are encephalitis, meningitis, encephalopathy, stroke and Guillain-Barré syndrome. Dengue encephalitis is a rare disease. We report an interesting case of dengue encephalitis from Southern India. A 49-year-old gentleman presented with fever, altered sensorium and seizures. Dengue NS-1 antigen test was reactive. Dengue IgM was also positive. CSF PCR was negative for herpes simplex 1 & 2. Dengue encephalitis should be considered in the differential diagnosis of fever with altered sensorium, especially in countries like India where dengue is rampant.