Placental Sampling for Understanding Viral Infections - A Simplified Protocol for the COVID-19 Pandemic / Coleta placentária para entender infecções virais - Um protocolo simplificado para a pandemia de COVID-19

Abstract Objective The coronavirus disease 2019 (COVID-19) is a pandemic viral disease, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The impact of the disease among the obstetric population remains unclear, and the study of the placenta can provide valuable information. Adequate sampling of the placental tissue can help characterize the pathways of viral infections. Methods A protocol of placental sampling is proposed, aiming at guaranteeing representativity of the placenta and describing the adequate conservation of samples and their integrity for future analysis. The protocol is presented in its complete and simplified versions, allowing its implementation in different complexity settings. Results Sampling with the minimum possible interval from childbirth is the key for adequate sampling and storage. This protocol has already been implemented during the Zika virus outbreak. Conclusion A protocol for adequate sampling and storage of placental tissue is fundamental for adequate evaluation of viral infections on the placenta. During the COVID-19 pandemic, implementation of this protocol may help to elucidate critical aspects of the SARS-CoV-2 infection.

Resumo Objetivo A doença do novo coronavírus (COVID-19) é uma doença viral pandêmica causada pelo coronavírus da síndrome respiratória aguda 2 (SARS-CoV-2). O impacto da doença entre a população obstétrica ainda é incerto, e o estudo da placenta pode fornecer informações valiosas. Assim, a coleta adequada do tecido placentário pode ajudar a caracterizar algumas propriedades das infecções virais. Métodos Um protocolo de coleta placentária é proposto, objetivando a garantia de representatividade da placenta, descrevendo a maneira de conservação adequada das amostras, e visando garantir sua integridade para análises futuras. O protocolo é apresentado em suas versões completa e simplificada, permitindo sua implementação em diferentes configurações de infraestrutura. Resultados A amostragem com o intervalo mínimo possível do parto é essencial para coleta e armazenamento adequados. Esse protocolo já foi implementado durante a epidemia de vírus Zika. Conclusão Um protocolo para coleta e armazenamento adequados de tecido placentário é fundamental para a avaliação adequada de infecções virais na placenta. Durante a pandemia de COVID-19, a implementação deste protocolo pode ajudar a elucidar aspectos críticos da infecção por SARS-CoV-2.

SARS-CoV-2 Modelo de Inoculación en la Cavidad Oral. Revisión de la Literatura / SARS-CoV-2 Model of Inoculation in the Oral Cavity. Literature Review

RESUMEN: El virus SARS-CoV-2 ingresa al organismo de un individuo susceptible a través de la cavidad oral, nasal o de la mucosa conjuntival; busca ensamblarse por medio de su glicoproteína de superficie o espiga con los receptores de la enzima convertidora de angiotensina 2 que en boca los encontramos con mayor expresión en las células escamosas que recubren el epitelio lingual y las glándulas salivales, una vez que ingresa por medio de la activación de proteasas ingresa a la célula huésped para denudar su RNA viral, a diferencia de otros virus no necesita ir hasta el núcleo de tal forma que en el citoplasma inicia su replicación y utiliza los ribosomas del huésped para formar una gran cantidad de proteínas virales tanto estructurales como accesorias que le permita formar nuevos viriones potencialmente infecciosos; los estomatólogos deben tomar en cuenta esta vía de infección y extremar las medidas para disminuir su carga viral local en la cavidad oral y las barreras físicas de protección para el operador, el paciente y la ergonomía del consultorio.

ABSTRACT: SARS-CoV-2 virus enters the body of a susceptible individual through oral, nasal or conjunctival mucosa, seeking to bind to the spike glycoprotein surface through angiotensin-converting enzyme 2 receptors. These are found in the mouth with a higher expression in oral squamous cells that cover the lingual epithelium and salivary glands. Once proteolytic activation begins, it enters the host cell to denudate its viral RNA. In contrast with other viruses, it does not require nucleus access, and therefore replicates in the cytoplasm using the host's ribosomes to produce great amounts of both structural and accessory viral proteins. Since this generates new and potentially infectious virions, dentists must consider this route of infection and take extreme measures to decrease their viral load in the oral cavity. Physical protection barriers for the operator, the patient and the health and safety of the work place are critical in these cases.

Características clínico epidemiológicas de pacientes pediátricos con enfermedad boca, mano, pie / Clinical epidemiological characteristics of pediatric patients with mouth, hand and foot disease

Introducción: la enfermedad boca, mano, pie es una enfermedad febril eruptiva provocada por la infección por los virus Coxsackie, consistente en fiebre, exantema pápulo-vesicular en las manos, los pies y un enantema ulceroso en la boca. Objetivos: indagar la etiología viral y describir las características clínico epidemiológicas de la entidad. Métodos: estudio descriptivo prospectivo en 54 pacientes menores de 18 años, diagnosticados con la enfermedad boca, mano, pie, atendidos en el Hospital Pediátrico Docente del Cerro, de septiembre a noviembre de 2017. Se incluyeron aquellos con lesiones vesiculares o pápulas vesiculares, distribuidas en la piel y úlceras en la mucosa oral; y se excluyeron los pacientes con otras entidades exantemáticas o vesiculares. Las variables investigadas resultaron: la edad, el sexo, los signos, los síntomas clínicos de infección, el leucograma y el estudio virológico. La selección de la muestra fue de manera no probabilística consecutiva. Los datos se procesaron por el paquete estadístico XLSTAT con análisis univariado. Resultados: el grupo entre 1-3 años obtuvo 53,7 por ciento, y el sexo masculino el 68,5 por ciento. Las lesiones cutáneas fueron más frecuentes en la cara, las extremidades, los glúteos y el tronco (68,6 por ciento), seguido de la zonas de la cara, las extremidades y el tronco (29,6 por ciento). El enantema fue apreciado en el 48,1 por ciento, la fiebre en el 61,1 por ciento, la fiebre más secreción nasal en el 44,4 por ciento y el prurito en el 70,3 por ciento. El conteo leucocitario alcanzó 11,1 x 109 células. Los polimorfonucleares obtuvieron promedio de 37,9 y los linfocitos 70,3. En 49 de los 54 pacientes se aisló el virus Coxsackie A6. Conclusiones: se describe la enfermedad boca, mano, pie en forma atípica, cuyo cuadro clínico coincide con lo aparecido en la literatura(AU)

Introduction: mouth, hand and foot disease is an eruptive febrile illness caused by the infection of Coxsackie viruses, and it consists in fever, papulo-vesicular exanthema in the hands, feet and an ulcer enanthema in the mouth. Objectives: to investigate the viral etiology and describe the clinical epidemiological characteristics of the entity. Methods: prospective descriptive study in 54 patients under 18 years old diagnosed with mouth, hand and foot disease, and whom were attended at the Pediatric Teaching Hospital of Cerro from September to November 2017. Those with vesicular lesions or vesicular papules distributed in the skin, and ulcers in the oral mucosa were included in the research; and patients with other exanthematic or vesicular entities were excluded. The variables investigated were: age, sex, signs, clinical symptoms of infection, leukogram and virological study. The selection of the sample was consecutive non-probabilistic. The data was processed by the XLSTAT statistical package with univariate analysis. Results: the group from 1 to 3 years old represented the 53.7 percent, and the male sex the 68.5 percent y. Skin lesions were more frequent on the face, extremities, buttocks and trunk (68.6 percent), followed by facial, limbs and trunk areas (29.6 percent). Enanthem was visible in 48.1 percent, and fever appeared in 61.1 percent, fever plus nasal discharge in 44.4 percent and itching in 70.3 percent y The leukocyte count reached 11.1 x 109 cells. Polymorphonuclear cells obtained an average of 37.9 and lymphocytes of 70.3. In 49 of the 54 patients the Coxsackie A6 virus was isolated. Conclusions: mouth, hand, and foot disease is described in an atypical form, whose clinical manifestations coincide with what appeared in the literature(AU)

Nuevos progresos en el enfrentamiento a la hepatitis C / New progresses in hepatitis C management

RESUMEN El virus de la hepatitis C es la principal infección trasmitida por los derivados de la sangre en los Estados Unidos, con 3.2 millones de individuos infectados. El alfa interferón inyectable ha sido históricamente la piedra angular en la terapia del virus de hepatitis C. Se revisaron las publicaciones los trabajos publicados en Medline, Scielo, PubMed, e Hinari, hasta comienzos del año 2016. Las principales palabras clave utilizadas fueron virus de la hepatitis C, hepatitis C crónica, Interferón, antivirales. Recientes adelantos han llevado a la disponibilidad de nuevos medicamentos antivirales, que con el desarrollo de nuevas terapias orales libres de interferón han convertido la terapia del virus de la hepatitis C más eficaz además de simplificar los regímenes del tratamiento. Aunque estos regímenes de tratamiento aún permanecen complicados, las nuevas recomendaciones y guías evolucionan rápidamente. El rápido desarrollo de nuevas terapias para la hepatitis C, han logrado métodos más eficaces con menos reacciones adversas que optimizan el tratamiento de estos enfermos (AU).

ABSTRACT The hepatitis C virus is the main infection transmitted by blood products in the United States, with 3.2 million of infected individuals. The injected alpha interferon has historically been the key stone in the therapy of the hepatitis C virus. The works published in Medline, Scielo, PubMed and Hinary until the beginning of 2016 were reviewed. The main used key words were HVC, cronic hepatitis C, interferon, antivirals. Recent advances have led to the availability on new antiviral drugs, developing new interferon-free oral therapies that make the therapy of hepatitis C virus more efficacious and make easier the treatment regimens. Although these treatment regimens are still complicated, the new recommendations and guidelines evolve quickly. The fast development of new therapies against hepatitis C has led to more efficacious methods with less adverse reactions, optimizing the treatment of these patients (AU).

Comparison of Quantitation of Cytomegalovirus DNA by Real-Time PCR in Whole Blood with the Cytomegalovirus Antigenemia Assay

BACKGROUND: Quantitation of cytomegalovirus (CMV) DNA using real-time PCR has been utilized for monitoring CMV infection. However, the CMV antigenemia assay is still the 'gold standard' assay. There are only a few studies in Korea that compared the efficacy of use of real-time PCR for quantitation of CMV DNA in whole blood with the antigenemia assay, and most of these studies have been limited to transplant recipients. METHOD: 479 whole blood samples from 79 patients, falling under different disease groups, were tested by real-time CMV DNA PCR using the Q-CMV real-time complete kit (Nanogen Advanced Diagnostic S.r.L., Italy) and CMV antigenemia assay (CINA Kit, ArgeneBiosoft, France), and the results were compared. Repeatedly tested patients were selected and their charts were reviewed for ganciclovir therapy. RESULTS: The concordance rate of the two assays was 86.4% (Cohen's kappa coefficient value=0.659). Quantitative correlation between the two assays was a moderate (r=0.5504, P<0.0001). Among 20 patients tested repeatedly with the two assays, 13 patients were transplant recipients and treated with ganciclovir. Before treatment, CMV was detected earlier by real-time CMV DNA PCR than the antigenemia assay, with a median difference of 8 days. After treatment, the antigenemia assay achieved negative results earlier than real-time CMV DNA PCR with a median difference of 10.5 days. CONCLUSIONS: Q-CMV real-time complete kit is a useful tool for early detection of CMV infection in whole blood samples in transplant recipients.

An improved purification procedure for Leishmania RNA virus (LRV)

Leishmania RNA Virus (LRV, Totiviridae) infect Leishmania cells and subvert mice immune response, probably promoting parasite persistence, suggesting significant roles for LRV in host-parasite interaction. Here we describe a new LRV1-4 purification protocol, enabling capsid visualization by negatively stained electron microscopy representing a significant contribution to future LRV investigations.

Frequência de anticorpos contra o vírus da língua azul em ovinos do estado do Ceará, Brasil / Antibodies against the bluetongue virus in sheep flocks of Ceará state, Brazil

O objetivo deste trabalho foi avaliar a ocorrência de ovinos soropositivos para o vírus da línguaazul (VLA) no Estado do Ceará, Brasil, e analisar as proteínas imunogênicas das cepas virais circulantes nesses rebanhos. O teste de imunodifusão em gel de agarose (IDGA) foi utilizado para pesquisar 271 amostras de soro oriundas de 16 rebanhos. Os resultados demonstraram que 27,3% (74/271) das amostras analisadas apresentaram anticorpos contra o agente e 68,8% (11/16) das propriedades tiveram animais positivos. O immunoblotting (IB) foi utilizado para analisar as proteínas imunogênicas do VLA a partir dos soros de animais positivos no IDGA. Os soros demonstraram forte reação contra a proteína viral VP2. Para o VLA, das sete proteínas estruturais, a VP2 é a principal a estimular a resposta imune protetora. Concluiu-se que a soropositividade para a língua azul (LA) nos rebanhos ovinos estudados no Ceará é alta, apesar dos animais não apresentarem sinais clínicos, indicativo de que o vírus ocorra de forma endêmica. Além disso, a resistência à doença apresentada pelos animais pode estar relacionada com a forte reação imunológica desses à proteína VP2. Sendo assim, outros estudos são necessários para melhor esclarecer a situação epidemiológica da LA no país, através da identificação dos vetores e sorotipos virais circulantes nas diferentes regiões.

Antibodies against the bluetongue virus in sheep flocks of Ceará state, Brazil. The objective of this work was to verify the occurrence of sheep serologically positive for bluetongue virus (BTV) in the state of Ceará, Brazil, and analyze immunogenic proteins of circulating viral strains in these flocks. The agar gel immunodifusion test (AGID) was used to examine 271 serum samples from 16 herds. The results demonstrated that 27.3% (74/271) ofthe analyzed samples presented antibodies for the agent, and that 68.8% (11/16) of the propertiespresented positive animals. Immunoblotting (IB) was used to analyze the immunogenicproteins of BTV derived from AGID positive sera. Sera showed strong reaction against viral protein VP2. Of the seven BTV structural proteins, VP2 is the major protein to elicit protective immuneresponses. It was concluded that bluetongue (BT) seropositivity in sheep flocks studied in Ceará is high, despite that the animal's do not show clinical signs, indicating that it occurs in an endemic form. The animals’ resistance to the disease may be related to the strong immune response to the protein VP2. Therefore, further studies are needed to better clarify the epidemiological situation of BT in Brazilian sheep flocks, through the identification of viral vectors and serotypes circulating in different regions.

Evaluation of Virologic Methods for Early Detection of HIV-1 in a Resource-limited Setting: Performance and Cost Analysis

Introduction : Rapid testing and detection of acute HIV infection are two important arms in the prevention of HIV infection. Virologic testing for HIV remains the mainstay for early diagnosis of the infection. Nucleic acid-based testing for HIV however; requires expensive laboratory infrastructure and well-trained personnel; thereby making it not easily accessible in Low- Middle- Income Countries (LMIC). HIV DNA polymerase chain reaction is currently used by few laboratories in many LMIC to detect HIV in children born of HIV-positive mothers before 18 months. Challenges relating to timely result notification can be reduced if the Early Infant Diagnosis (EID) Programme is decentralized and with easy access to laboratory facilities using other tests with high performance characteristics. Methods: We evaluated the performance of five assays to identify HIV antibodies; p24 antigen; proviral DNA or viral RNA in 109 infants born to HIV-positive mothers in Yaounde; Cameroon. Results: The test performance (using plasma) of the HIV p24 antigen ELISA by Perkin Elmer; Roche Amplicor HIV-1 DNA PCR and the Abbott Realtime HIV-1 assay was 100 identifying 12 positive cases. A positive and significant correlation between the HIV-1 RNA viral load and HIV p24 antigen level was found (p0.05). Conclusion: Therefore; HIV p24 antigen detection by ELISA can be used for early diagnosis of HIV and thus recommended for a decentralized EID Programme in LMIC

Respuesta a la terapia antirretroviral altamente activa en pacientes de 50 años de edad o más viviendo con infección VIH/SIDA / Highly actve antirretroviral therapy responce in patients over 50 years old living with HIV/AIDS infection

Para el 2015 >50% de la población con infección por el virus de inmunodeficiencia humana será >50 años, proponiéndose diversos retos en su atención. En el presente estudio se planteó como objetivo evaluar la respuesta a la terapia antirretroviral altamente activa, características epidemiológicas y clínicas en pacientes con infección del virus de inmunodeficiencia humana/síndrome de inmunodeficiencia adquiridad >50 años. Se realizó estudio descriptivo, retrospectivo, observacional, no experimental, con diseño de casos y controles (pacientes >50 años, casos; y <50 años, controles), comparando sus evaluaciones basales, a los 6 y a los 12 meses, entre enero 2005 y junio 2009. Se incluyeron 311 pacientes, 99 casos (>50 años) y 121 controles (<50 años), representado el género femenino un tercio de la población. Más del 65% consultaron en etapas avanzadas de la enfermedad, 47% correspondieron con síndrome de inmunodeficiencia adquirida estadio C3. La medida del lapso entre diagnóstico e inicio de la terapia antirretroviral altamente activa fue >1 año, en los grupos. Los regímenes de terapia antirretroviral altamente activa más usados fueron AZT/3TC/EFV y AZT/3TC+LOP/RIT. No se encontraron diferencias significativas en la respuesta inmunológica ni virológica a la terapia antirretroviral altamente activa a los 6 y 12 meses entre los grupos; valores promedio de carga viral a los 6 meses: 58221,08 copias de ARN/mm³ (2,21 log) y 6081,92 copias de ARN/mm³ (2,28 log) para adultos mayores y jóvenes, respectivamente. En adultos mayores , el incremeto de valores promedio de linfocitos TCD4+pos-terapia antirretroviral altamente activa fue significativa (P<0,05) comparando niveles basales y a los 12 meses; en los jóvenes dicha significancia se alcanzó a los 6 meses. Más del 85% de los pacientes tuvieron carga viral indetectable por 12 meses. En los pacientes >50 años se observó buena respuesta inmunológica y virológica similar a los jóvenes, a los 6 y 12 meses de la terapia....

For the year 2015 >50% of the population living with the human immunodeficiency virus infection will be >50 years old, facing it diverse challenges in their attention. In the current study the objetive to assess the response to the highly active antiretroviral therapy (HAART), epidemiological and clinical characteristics in patients with human immnodeficiency virus infection/acquired immunodeficiency syndrome >50 years old, was proposed. A descriptive, retrospective, observational, non-experimental, cases and control desing study (patients >50 years old, cases; and <50 years old, controls), comparing their basal, at 6 months and t 12 months evalutions, between january 2005 and june 2009, was done. A total 311 patients, 99 cases (>50 years old) and 212 controls (<50 years old) were included. Females represented a third of the population. More than 65% of the patients consulted in advanced stages of diseases, 47% corresponded with acquired immnodeficiency syndrome stage C3. Mean time between diagnosis and beginning of highly active antiretroviral therapy was >1 year, in both groups. Most used highly active antiretroviral therapy schemes were AZT/3TC/EFV and AZT/3TC+LOP/RIT. No significant differences between immunological and virological responce to highly active antiretroviral therapy at 6 and 12 months between both groups were found; mean values of viral load at 6 months: 5,821.08 RNA copies/mm³ (2.21 log) and 6,081.92 RNA copies/mm³ (2.28 log) for mayor adults and young patients, respectively. In mayor adults, increase in mean values of TCD4 + lymphocyte counts post-highly active antiretroviral therapy were significant (P<0.05) when compared basal with 12 months moments. In young patients that significant change was reached at 6 months. More than 85% of the patients had undetectable viral at 12 months. In patients >50 years old a good immunological and virological responce was observed, being similar to that seen in young patients, at 6 and 12 months.....

Use of John Cunningham virus polymerase chain reaction in the diagnosis of progressive multifocal leucoencephalopathy - A rare presenting manifestation in an HIV-positive patient.

John Cunningham virus infection is an important cause of progressive multifocal leucoencephalopathy (PML) in the context of advanced human immunodeficiency virus infection. Limited data are available regarding the true incidence of PML as a presenting manifestation of HIV. We report one such case and also highlight the effective use of polymerase chain reaction in confirming its diagnosis.

Prevalence of influenza virus among the paediatric population in Mumbai during 2007-2009.

Purpose: Influenza has a major impact on public heath, annually affecting 15-20% of the global population. Information on the activity of influenza virus in Mumbai is limited. The present study was carried out to determine the prevalence of influenza viruses causing acute respiratory infections in children by molecular methods. Objective: To study the prevalence of influenza viruses among the paediatric population in Mumbai by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR). Materials and Methods: From July 2007 to July 2009, 100 respiratory samples (nasal and throat swabs) were collected from paediatric patients with acute respiratory symptoms. attending out patients department, and admitted to the paediatric wards of B. J. Wadia Hospital for Children, Mumbai. The samples were collected and processed as per World Health Organization (WHO) guidelines. Viral RNA was extracted and one-step rRT-PCR was performed to detect influenza type A (H1 and H3) and influenza type B virus. Results: Out of 100 samples processed by rRT-PCR, a total of 11 samples (11%) were positive for influenza virus. The typing for influenza A subtypes showed 1% (1) positivity for H1 and 5% (5) positivity for H3 subtypes and 5% (5) samples tested positive for influenza type B virus. Conclusion: It was observed that both influenza type A and B viruses were prevalent in Mumbai during the study period. Such surveillance data are important in the early detection of any antigenic variants that may be helpful in global influenza vaccine preparation and for any pandemic preparedness activity.

Comparison of primers for the detection of genogroup II noroviruses in India.

Purpose: Noroviruses (NoV) are increasingly recognized as an important cause for acute gastroenteritis, worldwide. Reverse transcription polymerase chain reaction (RT-PCR) and sequencing are the methods of choice for the detection of NoVs, but there is currently no consensus about the primers to be used in these assays. Materials and Methods: In this study, five published primer sets were evaluated for the detection of genogroup II (GII) NoVs in India. The primers target different regions of the NoV genome. Three primer sets detect an NoV in a single round RT-PCR platform, while the remaining two primer sets are based on a nested RT-PCR platform. Result: A panel of 100 samples from previous studies on norovirus diarrhoea in children were tested by all five primer sets. Of them, 74 samples were identified as positive for NoV, by at least one primer set. Subsets of positive amplicons were sequenced to check for specificity. Conclusion: The most sensitive primer set was Girish 2002, which detected GII NoV by nested RT-PCR, and was modified from the previously published primers. This study demonstrates that higher detection can be obtained by either using multiple primer sets or using a sensitive nested RT-PCR assay. It also demonstrates the differences in primer sensitivity for detection of Genogroup II (GII) NoVs in India.

Transfusion-transmitted hepatitis E: Is screening warranted.

Hepatitis E virus (HEV) is an emerging infectious threat to blood safety. In recent years, there have been a number of publications delineating this threat by providing evidence of the transmissibility of this virus through transfusions. The extent of transmission and its clinical relevance are issues under debate at present. HEV usually causes a self-limiting illness which subsides in a few weeks barring a few cases where fulminant hepatic failure occurs. The virus poses a risk of higher morbidity and mortality in pregnant females, patients with pre-existing liver disease and solid organ transplant recipients. As these categories of patient often require repeated transfusions or massive transfusions, they are exposed to a greater risk of transmission of HEV. At present, there is little evidence to advocate universal screening for this virus but considering that there is no definitive treatment for HEV induced hepatitis, selective screening should be advocated in blood products for high risk recipients in endemic areas.

Comparison of a conventional polymerase chain reaction with real-time polymerase chain reaction for the detection of neurotropic viruses in cerebrospinal fluid samples.

Purpose : To compare a conventional polymerase chain reaction (PCR) and real-time PCR for the detection of neurotropic DNA viruses. Materials and Methods : A total of 147 cerebrospinal fluid (CSF) samples was collected from patients attending a tertiary care hospital in South India for a period from 2005 to 2008. All these samples were tested using a conventional multiplex/uniplex PCR and a real-time multiplex/uniplex PCR. This technique was used to detect a large number of herpes viruses responsible for central nervous system infections, including HSV-1, HSV-2, VZV, CMV and EBV and the polyoma virus JCV. Results : Overall, in the entire set of samples, the real-time PCR yielded 88 (59.9%) positives and conventional PCR had six (4.1%) positives. Conclusion : Our results suggest that the real-time PCR assay was more sensitive compared with the conventional PCR. The advantage of real-time PCR is that it can be performed much faster than conventional PCR. Real-time PCR is less time-consuming, less labour-intensive and also reduces the chance of contamination as there is no post-amplification procedure. In the entire study population, the major viruses detected using real-time PCR were EBV (34%), HSV-2 (10.8%) and VZV (6.8%).

Evaluation of a commercial Dengue NS1 enzyme-linked immunosorbent assay for early diagnosis of dengue infection.

Purpose: Dengue is one of the most serious mosquito-borne viral infections affecting tropical and subtropical countries in the world. Since there is no immunoprophylactic or specific antiviral therapy available, timely and rapid diagnosis plays a vital role in patient management and implementation of control measures. This paper evaluates a commercially available NS1 antigen capture ELISA vis-a-vis SD bioline Dengue NS1 antigen test for early detection of dengue virus. Materials and Methods: To evaluate a commercial NS1 antigen detection kit vis-a-vis SD bioline Dengue NS1 antigen test, a total of 91 clinical samples were tested. Virological investigations with regard to dengue virus, viz. NS1 antigen capture ELISA (Panbio, Australia), SD bioline Dengue NS1 antigen test, RT-PCR and virus isolation were performed. Results: Out of 91 samples, 24 (26%) were positive by NS1 antigen capture ELISA, 15 (16%) by SD bioline Dengue NS1 antigen test and 11(12%) positive by RT-PCR analysis. The RT-PCR-positive samples were further subjected to virus isolation and resulted in three isolates. The results of the Panbio NS1 antigen capture ELISA, SD bioline Dengue NS1 antigen test, RT-PCR and virus isolation were correlated among themselves. Conclusions: The present study comprehensively established the utility of NS1 antigen ELISA in early diagnosis of dengue infection.

Pandemic Influenza A (H1N1) 2009 in India: Duration of virus shedding in patients under antiviral treatment.

Background: National Centre for Disease Control (NCDC), Delhi, is a national nodal centre for surveillance of pandemic Influenza A (H1N1) in India. The present study was undertaken to see the period of infectivity in positive cases undergoing antiviral therapy. Objective: To assess the duration of virus shedding by real-time polymerase chain reaction (real-time PCR) in some of the positive patients taking Oseltamivir treatment. Materials and Methods: Clinical samples (throat swabs, nasal swabs and nasopharyngeal swabs) collected by the clinicians from patients quarantined in government hospitals in different parts of India are being sent to the designated reference laboratory at Delhi for screening presence of pandemic Influenza virus. The samples are tested by Real-Time PCR using CDC recommended reagents and protocol for confirmation of the H1N1 novel influenza virus. In 150 of the positive cases, we requested the clinicians to send samples for 5 consecutive days after administration of antiviral therapy, to see the trend of therapy response on viral shedding. Samples for more than 5 days were received from patients till they showed no amplification for any of the three target genes (Influenza A, Swine Influenza A or Swine H1). Results and Conclusion: In 99.33% (149/150) cases, the influenza infection resolved within 10 days. Sixty-four percent (96/150) of the positive patients turned negative within 5 days of the start of antiviral treatment. Only one patient belonging to high risk group showed prolonged virus shedding (19 days).