The rare enterovirus c99 and echovirus 29 strains in Brazil: potential risks associated to silent circulation

Human enteroviruses (EVs) are associated with a wide spectrum of human diseases. Here we report the complete genome sequences of one EV-C99 strain and one E29 strain obtained from children suffering from acute gastroenteritis, without symptoms of enteroviral syndromes. This is the first report of EV-C99 in South America, and the second E29 genome described worldwide. Continuous surveillance on EVs is vital to provide further understanding of the circulation of new or rare EV serotypes in the country. The present study also highlights the capacity of EVs to remain in silent circulation in populations.

La vacuna polio oral en lactantes no interfiere con la detección de enterovirus en sangre / Oral polio vaccine in infants does not interfere in detection of enterovirus in blood

Introduction: There is not known if a viraemia post-oral polio vaccine (OPV) is detectable by modern molecular techniques. Such viraemia could affect the performance of the real time-polymerase chain reaction (PCR) for non polio enterovirus (EV) detection, technique of growing clinical use for the study of febrile infants. Objective: To determine viraemia post-first dose of OPV in healthy infants, by molecular techniques. Patients and Methods: 50 infants less than three months without previous VPO were randomized in 5 groups: a control group with pre-vaccination blood sample (BS), group 1 BS at day 2, group 2 BS at day 4, group 3, BS at day 6 and group 4, BS at day 8 post-vaccination. Conventional and specific PCR for poliovirus and real time PCR for non polio EV were performed in BS and in OPV samples. Results: No genetic material of poliovirus was detected in any infant, while in 9 of them (18%) non polio EV was identified. Real time PCR for EV did not amplify poliovirus from OPV samples. Discussion: Results suggest that no post VPO viraemia detectable by molecular methods exists. Considering that real time PCR for EV does not allow to identify polio virus, no false positives of the test are expected as a result of a recent VPO vaccination. We documented presence of non polio EV in blood of healthy asymptomatic infants.

Introducción: No existen estudios que indiquen si la vacuna polio oral (VPO) produce viremia detectable mediante métodos moleculares. Una eventual viremia podría afectar el rendimiento de la RPC tiempo real para detectar enterovirus (EV) no polio, examen de creciente uso clínico en lactantes pequeños con fiebre sin foco. Objetivo: Determinar viremia post VPO en lactantes sanos, por métodos moleculares. Métodos: 50 menores de 3 meses, al momento de recibir su primera VPO se distribuyeron en forma aleatoria en 5 grupos: control, muestra de sangre pre-vacunación; grupo 1, muestra al 2° día; grupo 2, al 4° día; grupo 3, al 6° día y grupo 4, al 8° día post-vacunación. Se realizó RPC convencional específica para virus polio y RPC tiempo real para EV no polio en las muestras de sangre y en muestras de VPO. Resultados: No se identificó presencia de material genético de virus polio en lactante alguno, mientras que en 9 (18%) se identificó presencia de EV no polio. La RPC tiempo real para EV no polio no amplificó material genético a partir de las muestras de VPO. Discusión: Los resultados sugieren que no existe viremia post-VPO detectable por métodos moleculares. Considerando que la RPC tiempo real de EV no polio de uso clínico no permite identificar la presencia de virus polio, estos hallazgos indican que no existirán falsos positivos de este examen como resultado de una vacunación VPO reciente. Adicionalmente se documentó presencia de EV no polio en sangre de lactantes asintomáticos.

Acute Viral Myopericarditis Presenting as a Transient Effusive-Constrictive Pericarditis Caused by Coinfection with Coxsackieviruses A4 and B3

Acute myopericarditis is usually caused by viral infections, and the most common cause of viral myopericarditis is coxsackieviruses. Diagnosis of myopericarditis is made based on clinical manifestations of myocardial (such as myocardial dysfunction and elevated serum cardiac enzyme levels) and pericardial (such as inflammatory pericardial effusion) involvement. Although endomyocardial biopsy is the gold standard for the confirmation of viral infection, serologic tests can be helpful. Conservative management is the mainstay of treatment in acute myopericarditis. We report here a case of a 24-year-old man with acute myopericarditis who presented with transient effusive-constrictive pericarditis. Echocardiography showed transient pericardial effusion with constrictive physiology and global regional wall motion abnormalities of the left ventricle. The patient also had an elevated serum troponin I level. A computed tomogram of the chest showed pericardial and pleural effusion, which resolved after 2 weeks of supportive treatment. Serologic testing revealed coxsackievirus A4 and B3 coinfection. The patient received conservative medical treatment, including nonsteroidal anti-inflammatory drugs, and he recovered completely with no complications.

Development of a new method for diagnosis of Group B Coxsackie genome by reverse transcription loop-mediated isothermal amplification.

Background: Coxsackie B viruses (genus, Enterovirus; family, Picornaviridae) can cause aseptic meningitis, encephalitis, pleurodynia, and fatal myocarditis, and are implicated in the pathogenesis of dilated cardiomyopathy. The differentiation of the group B Coxsackieviruses into their subtypes has potential clinical and epidemiological implications. Objective: In this study, we developed a one-step, single-tube genogroup-specific reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the detection of group B Coxsackie genomes targeting 5′ UTR region. Materials and Methods: The amplification can be obtained in less than 1 hour by incubating all the reagents in a single tube with reverse transcriptase and Bst DNA polymerase at 63°C. Detection of gene amplification could be accomplished by agarose gel electrophoresis and the monitoring of gene amplification can also be visualised with the naked eye by using SYBR green I fluorescent dye. Results: A total of 40 samples comprising 31 positive samples and 9 negative samples were used in this study for comparative evaluation. The results were compared with those from Real-Time Polymerase Chain Reaction (RT-PCR). None of the RT-PCR-positive samples were missed by RT-LAMP, thereby indicating a higher sensitivity of the RT-LAMP assay. Conclusion: Thus, due to easy operation without a requirement of sophisticated equipment and skilled personnel, the RT-LAMP assay reported here is extremely rapid, cost-effective, highly sensitive, and specific and has potential usefulness for rapid detection of non-polio enterovirus (NPEV) not only by well-equipped laboratories but also by peripheral diagnostic laboratories with limited financial resources in developing countries.

Echovirus 30 associated with cases of aseptic meningitis in state of Pará, Northern Brazil

Investigation of the aetiology of viral meningitis in Brazil is most often restricted to cases that occur in the Southern and Southeastern Regions; therefore, the purpose of this study is to describe the viral meningitis cases that occurred in state of Pará, Northern Brazil, from January 2005-December 2006. The detection of enterovirus (EV) in cerebrospinal fluid was performed using cell culture techniques, RT-PCR, nested PCR and nucleotide sequencing. The ages of the 91 patients ranged from < one year old to > 60 years old (median age 15.90 years). Fever (87.1 percent), headache (77.0 percent), vomiting (61.5 percent) and stiffness (61.5 percent) were the most frequent symptoms. Of 91 samples analyzed, 18 (19.8 percent) were positive for EV. Twelve were detected only by RT- PCR followed by nested PCR, whereas six were found by both cell culture and RT-PCR. From the last group, five were sequenced and classified as echovirus 30 (Echo 30). Phylogenetic analyses revealed that Echo 30 detected in Northern Brazil clustered within a unique group with a bootstrap value of 100 percent and could constitute a new subgroup (4c) according to the phylogenetic tree described by Oberste et al. (1999). This study described the first molecular characterization of Echo 30 in Brazil and this will certainly contribute to future molecular analyses involving strains detected in other regions of Brazil.

Echovirus 6 associated to aseptic meningitis outbreak, in São Joaquim da Barra, São Paulo, Brazil

An aseptic meningitis outbreak occurred during a period from February to May 2004 in São Joaquim da Barra, a town in the northern region of São Paulo State. A total of 40 cases were reported to the Epidemiological Surveillance Center of São Paulo State. Cerebrospinal fluid samples obtained from 23 patients were sent to the Adolfo Lutz Institute for isolation of the virus. These samples were inoculated into RD, HEp2 and Vero cell lineages and those presenting a cytopathogenic effect were selected for analysis by indirect immunofluorescence assay (IFA), neutralization testing (Nt) and reverse transcriptase-polymerase chain reaction (RT-PCR). Cytopathogenic effects were observed in 52.2 percent (12/23) of these samples. All isolated viruses were identified as human enterovirus by IFA and RT-PCR and echovirus 6 was typed by IFA and Nt. Our results confirmed the participation and importance of echovirus as the etiological agent responsible for this outbreak and the serotype diversity of human enteroviruses circulating in São Paulo State.

Entre fevereiro e maio de 2004, em São Joaquim da Barra, Estado de São Paulo, foi notificado ao Centro de Vigilância Epidemiológica (CVE) um surto de meningite asséptica (MA) envolvendo 40 indivíduos. Foram enviadas ao Instituto Adolfo Lutz amostras de líquido cefalorraquidiano (LCR) de 23 pacientes com MA para tentativa de isolamento viral. Estas amostras foram inoculadas em 3 linhagens celulares: RD, HEp2 e Vero. Culturas celulares que apresentaram efeito citopático (ECP) foram submetidas a ensaio de Imunofluorescência Indireta (IFI), reação de Neutralização (Nt) e RT-PCR (Transcrição Reversa Reação em Cadeia da Polimerase). Em 52,2 por cento (12/23) das amostras foi observado ECP. Todos os vírus isolados foram identificados como gênero HEV por IFI e RT-PCR e o sorotipo echovirus 6 (E-6) por IFI e Nt. Nossos resultados confirmam a participação e importância dos echovirus como agente etiológico responsável pelo surto ocorrido e a diversidade de sorotipos circulantes no Estado de São Paulo.

RT-PCR for confirmation of echovirus 30 isolated in Belém, Brazil

Echovirus (Echo) 30 or human enterovirus B is the most frequent enterovirus associated with meningitis cases. Epidemics and outbreaks of this disease caused by Echo 30 have occurred in several countries. In Brazil, Echo 30 has been isolated from sporadic cases and outbreaks that occurred mainly in the south and southeast regions. We used RT-PCR to examine Echo 30 isolates from meningitis cases detected from March 2002 to December 2003 in Belém, state of Pará, in northern Brazil. The patients were attended in a Basic Health Unit (State Health Secretary of Pará), where cerebrospinal fluid (CSF) was collected and stored in liquid nitrogen. Weekly visits were made by technicians from Evandro Chagas Institute to the health unit and samples were stored at -70°C in the laboratory until use. HEp-2 and RD cell lines were used for viral isolation and neutralization with specific antisera for viral identification. RNA extraction was made using Trizol reagent. The RT-PCR was made in one step, and the total mixture (50 æL) was composed of: RNA, reaction buffer, dNTP, primers, Rnase inhibitor, reverse transcriptase, Taq polymerase and water. The products were visualized in agarose gel stained with ethidium bromide, visualized under UV light. Among the 279 CSF samples examined, 30 (10.7 percent) were EV positive, 29 being Echo 30 and one was Cox B. Nineteen Echo 30 were examined with RT-PCR; 18 tested positive (762 and 494 base pairs). The use of this technique permitted viral identification in less time than usual, which benefits the patient and is of importance for public-health interventions.

Epidemiología de los enterovirus asociados a enfermedades neurológicas / Epidemiology of enterovirus associated with neurologic diseases

El presente estudio describe los resultados de la investigación de los enterovirus humanos (HEV) mediante cultivo celular y reacción en cadena de la polimerasa y su tipificación molecular en 2167 casos de parálisis fláccida aguda, meningitis aséptica y encefalitis aguda, obtenidos entre 1991 y 1998 en la Argentina. La frecuencia de detección de HEV en parálisis fláccida aguda fue 19.5% (130/666) y de poliovirus Sabin 5.4% (36/666). La tasa de detección de HEV en los casos de meningitis fue 28.8% (231/801) y en encefalitis 3.0% (21/700). El grupo etario más afectado por las meningitis fue entre 1 y 9 años (75.3%) y en los casos de parálisis fláccida aguda, de 1 a 4 años (58%). En muestras de brotes de meningitis se identificó echovirus (E) 4, E9, E30 y E17, y en casos esporádicos virus coxsackie A (CAV) 2, B (CBV) 2 y CBV5, E7, E11, E19, E24 y E29, y enterovirus (EV) 71. Finalmente, en casos de encefalitis se detectó E4, E7 y E24. En casos de parálisis fláccida aguda se identificaron 28 serotipos distintos de enterovirus no polio. En la Argentina y en otros países latinoamericanos existe escasa información acerca de la circulación de los HEV y su relación con diversas enfermedades neurológicas. Este estudio proporciona información que puede servir como base para posteriores investigaciones.

This report describes the results of human enterovirus (HEV) detection and characterization using cell culture, polymerase chain reaction and molecular typing in 2167 samples obtained from acute flaccid paralysis, aseptic meningitis and acute encephalitis patients, from 1991 to 1998 in Argentina. HEV were isolated in 130 out of 666 cases (19.5%) and 36 out of 666 (5.4%). HEV RNA was detected in 28.8% (231/801) and 3.0% (21/700) of the patients with meningitis and encephalitis, respectively. Children with ages ranging from 1 to 9 years accounted for 75.3% of the meningitis cases and from 1 to 4 years for 58% of acute flaccid paralysis patients. Echovirus 4 (E4), E9, E30 and E17 were identified from meningitis outbreaks. Coxsackievirus A2 (CAV2), CBV2, CBV5, E7, E11, E19, E24, E29 and enterovirus 71 were recovered only from sporadic cases. Three different serotypes were identified in encephalitis patients: E4, E7 and E24. A total of 28 different serotypes of non-polio enteroviruses were detected from acute flaccid paralysis cases. The information here presented contributes to improving our knowledge about enteroviruses epidemiology in Argentina and their relationship with different neurological diseases. This study provides valuable data that could be useful to further research.

Investigation of circulating anti-coxsackie B, anti- polio and anti-adeno IgG in newly diagnosed T1DM children

Viruses may be involved in the pathogenesis of Type 1 Diabetes Mellitus [T1DM], either through direct beta-cell infection or as triggers of autoimmunity. To investigate the presence of specific anti- viral IgG antibodies for Coxsackie virus type B [CVB5], Poliovirus, and Adenovirus which proposed to be involved in the etiology of T1DM. A total of 60 Iraqi T1DM children were included in the present study. They were new onset of the disease [diagnosis was from one week up to five months]. For the purpose of comparisons, 50 apparently healthy control subjects were selected. Serum IgG against Coxsackie virus type B[5], Adenovirus type 3, 4, and 7, and Poliovaccin Trivalent were detected quantitatively with an indirect ELISA. High proportion of anti-CVB5 IgG [20%][p<0.05] and anti- Polio IgG [31.67%] were found in T1DM children compared to controls [8%, 26% respectively], while anti- Adeno IgG were detected in diabetic patients only [6.67%][p<1.0001]

Echovirus 4 associated to hand, foot and mouth disease / Echovirus 4 associado à doença de mão, pé e boca

Hand, foot and mouth disease (HFMD) is a contagious enteroviral infection occurring primarily in children and characterized by vesicular palmoplantar eruptions and erosive stomatitis. Echovirus 4 (EV-4) has been commonly associated with aseptic meningitis. The association of HFMD with EV-4 has not been reported previously. Two samples of a 14-month child who presented mild fever, sores in the mouth, rash with blisters on the palm of hands and soles of feet were sent to Enteric Viruses Laboratory of Adolfo Lutz Institute. Clinical samples were inoculated in three different cell lines, and those which presented cytopathic effect (CPE), were submitted to Indirect Immunofluorescence Assay (IFA) and "one step" RT-PCR. Agarose gel electrophoresis from RT-PCR product, showed a product with 437 bp, which is characteristic of Enterovirus group. Echovirus 4 was identified by IFA. Although HFMD is a viral infection associated mainly with Enterovirus 71 (HEV-71) and Coxsackievirus A16 (CV-A16), our results demonstrate a diversity of serotype related to HFMD and stress the importance of epidemiological surveillance to this disease and its complications.

A Doença de Mão, Pé e Boca (DMPB) é uma infecção enteroviral contagiosa que ocorre principalmente em crianças sendo caracterizada por erupções palmoplantares vesiculares e estomatite. Echovirus 4 (EV-4) é comumente associado a meningite asséptica. A associação de DMPB por EV-4 não foi descrita anteriormente. Duas amostras provenientes de uma criança de 14 meses apresentando febre, secreções na garganta e exantemas nas palmas das mãos e dos pés, foram enviadas para o Laboratório de Vírus Entéricos do Instituto Adolfo Lutz. As amostras foram inoculadas em três diferentes linhagens celulares; aquelas que apresentaram efeito citopático (ECP), foram submetidas a ensaio de imunofluorescência indireta (IFI) e "one step" RT-PCR. A eletroforese em gel de agarose realizada com o produto de PCR apresentou um produto de 437pb, característico de grupo Enterovirus. O sorotipo EV-4 foi identificado por IFI. Apesar da DMPB ser uma infecção viral associada principalmente com Enterovirus 71 (HEV-71) e Coxsackievirus A16 (CV-A16), nossos resultados enfatizam a necessidade de estudos epidemiológicos e laboratoriais direcionados ao EV-4 como agente causador de DMPB.

Myocardial injury occurs earlier than myocardial inflammation in acute experimental viral myocarditis

Endomyocardial biopsy often fails to show myocardial inflammation for patients with clinically suspected myocarditis. The serum isoforms of troponin T (cTnT) level is a very sensitive marker of myocardial injury and it is elevated even in the absence of myocardial inflammation. We investigated the correlations for myocardial injury, virus titers and inflammation in acute viral infection. Using the murine coxsackievirus group B3 (CVB3) myocarditis model, the histopathologic findings and virus titers in mouse hearts were compared with the serum cTnT levels measured by ELISA at various time points. Viable virus titers in the hearts peaked at 3 days after infection (8.22+/-0.13 log10 PFU/100 mg of heart); they decreased at day 7 and no viable virus was detected from day 14. Myocardial inflammation was minimal at day 3, peaked at day 7 and markedly decreased at day 14. The individual serum TnT levels were significantly increased at day 3 (7.37+/-1.46 ng/ml), persisted to day 7 (0.73+/-0.08 ng/ml), and normalized at day 14. Serum cTnT levels were correlatable with virus titers in the heart (r=0.744, P <0.01), but the serum cTnT levels were not correlated with the degrees of inflammation. Using the less myocarditic strain of CVB3, similar relationships were observed between the changes for the serum cTnT levels and the heart virus titers. During the course of viral infection, myocardial injury precedes the pathologic evidence of inflammation, and the elevated cTnT levels provide evidence of myocardial injury even in the absence of any histologic findings of myocarditis.

Non-polio enteroviruses in acute flaccid paralysis.

OBJECTIVE: Human enteroviruses are the major cause of aseptic meningitis and also cause a wide range of other acute illnesses, including neonatal sepsis like disease, meningitis, acute flaccid paralysis and acute hemorrhagic conjunctivitis. Infection in neonates is particularly life threatening. METHODS: Stool samples of 523 children (age < 4 years) showing symptoms of acute flaccid paralysis (AFP) were studied. National Polio Surveillance Project workers from different parts of Uttar Pradesh and Bihar collected the samples during June to October 1998. Non-polio enteroviruses (NPEV) were isolated in 191 cases only, by cell culture based neutralization assay. These NPEV isolates were further studied to find the frequent enterovirus serotype detected in stool of children having AFP. RESULTS: Data generated will help future studies on NPEV serotypes circulating in this area. CONCLUSION: In addition it may reduce unnecessary hospitalization, allow immune globulin batches of high titres to frequently circulating serotypes, to be reserved for intravenous therapy of neonates and guide the formulation of antigens for rapid and less expensive diagnosis.

Meningoencefalitis virales por Enterovirus en Cuba en el período 1990-1995 / Viral meningoencephalities due to enteroviruses in Cuba during 1990-1995

Se describen los resultados del estudio de enterovirus como agentes causanes de meningoencefalitis viral (MEV) en Cuba, desde 1990 hasta 1995. En este período fueron estudiados 586 muestras de heces, 108 líquidos cefalorraquídeos y 1095 sueros pareados para un total de 1789 muestras, procedentes de 1458 pacientes diagnosticados clínicamente con esta patología. Las muestras para el aislamiento viral se inocularon en dos sistemas celulares diferentes, encontrándose 225 muestras positivas a enterovirus que representan el 32,42 o/o del total; el mayor número de aislamientos (217) fue a partir de heces, en células diploides de fibroblastos de pulmón humano (PHuE-1). Las determinaciones de anticuerpos se realizaron por prueba de neutralizacion en micrométodo, enfrentándolos con 10 antígenos de enterovirus (Echovirus 4, 6, 9, 11 y Coxsackievirus B1-6) y, en períodos epidémicos, además con el virus aislado. En los años estudiados se produjeron tres brotes epidémicos por Coxsackievirus A9 (1990-91), Echovirus 30 (1994) y Coxsackievirus B5 (1995). Es de señalar que desde 1970 los Coxsackievirus A9 y Echovirus 30 se vincularon en nuestro país, por primera vez, con epidemias de MEV. En los sueros pareados se obtuvo 66,84 o/o de positivos, siendo la mayor positividad a los Echovirus 6 y 11. Al considerar en conjunto la positividad por aislamiento y serología, más del 80 o/o de los casos estudiados pudieran tener ua explicación por algún enterovirus, lo uqe demuestra la importancia de estos agentes como causantes de MEV en Cuba

Brote de meningoencefalitis por Coxsackievirus B5 en Cuba, 1995 / Outbreak of meningoencephalitis due to Coxsackievirus in Cuba, 1995

Se detectó un incremento en los casos reportados de meningoencefalitis viral (MEV) en los meses de octubre y noviembre de 1995 con respecto a igual período de 1994. Se recibieron en el Laboratorio de Enterovirus del Instituto de Medicina Tropical "Pedro Kouri" 43 muestras de heces fecales procedentes de niños con este diagnóstico, y se obtuvieron 23 aislamientos (53,4 por ciento) identificados como Coxsackievirus B5. Además, en 43 sueros pareados investigados por la prueba de neutralización frente a varios Enterovirus, se obtuvieron 21 positivos (48,8 por ciento) al agente aislado. Esto nos permitió afirmar, apoyados en el cuadro clínico y en la epidemiología, que estábamos en presencia de un brote de MEV producido por coxsackievirus B5

Human enterovirus infection in stray dogs: some aspects of interest to public health

Foram estudados 212 caes errantes, capturados em areas perifericas no municipio de Sao Paulo, com o objetivo de investigar o possivel papel desses animais como reservatorios de enterovirus humanos. Os animais capturados foram divididos em 19 grupos compostos por 10 a 20 animais cada um. Foram efetuadas tentativas de isolamento em amostras de fezes em 126/212 caes, obtendo-se resultados positivos em 12 deles, assim distribuidos: poliovirus tipo 1 (dois caes), poliovirus tipo 3 (um cao), echovirus tipo 7 (oito caes) e echovirus tipo 15 (um cao). Dos 12 animais infectados, quatro apresentaram anticorpos neutralizantes homotipicos com titulos>-16. Todos os 212 caes foram submetidos a pesquisa de anticorpos neutralizantes contra enterovirus humanos...

Aislamiento de virus coxsakie B-5 en un caso fatal de meningoencefalitis / Isolation of coxsakie B-5 virus in a meningoencephalitis fatal case

A 9 month old boy was admitted to the hospital with the diagnosis of meningoencephalitis 15 days after having a clinically diagnosed chickenpox. Lumbar puncture showed clear CSF with 0.23 g/l of proteins, 57 mg/dl of glucpse, 30 red cells/mm3 and 5 leukocytes/mm3. Blood count showed a packed red cell volume of 22 percent, a hemoglobin of 7 g/dl, 14800 leukocytes with 1 percent eosinophils, 5 percent band and 39 percent segmented neutrophils, 50 percent lymphocytes and 5 percent monocytes and a decreased platelet count. On the fourth hospitalization day, the patient had vomiting, irritability and stiff neck. A new lumbar puncture showed a clear CSF that differed from the former only on the glucose level that increased to 102 mg/dl. The patient died and the necropsy showed a congestive and enlarged brain and congestive meninges infiltrated with lymphocytes. There was lymphoid follicle hyperplasia in the small bowel and enlarged mesenteric lymph nodes. Samples of brain, brain stem, spinal cord and tools were sent for virological study. A coxsakie B-5 virus was isolated from the spinal cord sample

Neuropatia epidemica cubana. Parte IV. Relacion antigenica de los aislamientos virales con estructuras del sistema nervioso central. ?Posible mecanismo etiopatogenico? / Cuban epidemic neuropathy. Part IV. Antigenic relation of viral isolations to central nervous system structures. A possible etiopathogenic mechanism?

Se presentan resultados que permiten plantear la existencia de relaciones antigenicas entre los virus aislados del liquido cefalorraquideo de pacientes con neuropatia epidemica y estructuras del sistema nervioso central humana. Estas evidencias se han obtenido por 2 vias distintas e independientes: 1)por metodo de doble difusion en agarosa, inmunoblot e inmunohistoquimicos, comprobandose que los anticuerpos inducidos por los virus aislados reaccionan con antigenos del sistema nervioso central y perferico, 2)el suero obtenido por inmunizacion de un conejo con extracto de cerebro humano neutraliza los mismos virus que los neutralizados por los sueros hiperinmunes obtenidos con los aislamientos. Se discute la posible participacion de los virus como mediadores de un proceso autoinmune en la etiopatogenia de la enfermedad

Relative efficacy of egg albumin as blocking agent in dot immunobinding assay for detection of group B coxsackieviruses.

Non specific binding (NSB) is an important factor affecting sensitivity and specificity in dot immunobinding assay (DIA). Several blocking agents e.g. egg albumin, casein, gelatin, milk powder and goat serum were evaluated for their relative efficacy vis-a-vis bovine serum albumin (BSA) for DIA system purported for detection of group B coxsackieviruses (CVB). The results suggest that egg albumin (5%) which is economical and readily available may act as an effective blocking agent in DIA system.