224 research outputs found
Infecção por virus sincicial respiratĂłrio: o papel dos anticorpos sĂ©ricos especĂficos
INTRODUCTION: Respiratory syncytial virus (RSV) is a major etiological agent of lower respiratory tract infection in infants. Genotypes of this virus and the role of the infants' serum antibodies have yet to be fully clarified. This knowledge is important for the development of effective therapeutic and prophylactic measures. OBJECTIVES: To evaluate the types and genotypes of RSV causing respiratory tract infection in infants, to analyze the association of subtype-specific serum antibodies with the occurrence of infection and to evaluate the presence of subtype-specific antibodies in the infants' mothers and their association with the profile of the childrens' serum antibodies. METHODS: This was a prospective study on infants hospitalized with respiratory infection. Nasopharyngeal secretions were collected for viral investigation using indirect immunofluorescence and viral culture and blood was collected to test for antibodies using the Luminex Multiplex system. RESULTS: 192 infants were evaluated, with 60.9% having RSV (73.5%- A and 20.5% B). Six genotypes of the virus were identified: A5, A2, B3, B5, A7 and B4. The seroprevalence of the subtype-specific serum antibodies was high. The presence and levels of subtype-specific antibodies were similar, irrespective of the presence of infection or the viral type or genotype. The mothers' antibody profiles were similar to their infants'. CONCLUSIONS: Although the prevalence of subtype-specific antibodies was elevated, these antibodies did not provide protection independently of virus type/genotype. The similarity in the profiles of subtype-specific antibodies presented by the mothers and their children was consistent with transplacental passage.INTRODUĂĂO: O vĂrus sincicial respiratĂłrio Ă© um dos principais agentes etiolĂłgicos das infecçÔes do aparelho respiratĂłrio inferior em lactentes. Os genĂłtipos deste vĂrus e o papel dos anticorpos sĂ©ricos ainda nĂŁo estĂŁo esclarecidos. Este conhecimento Ă© importante para o desenvolvimento de medidas terapĂȘuticas e profilĂĄticas. OBJETIVOS: Avaliar: os tipos e genĂłtipos do vĂrus sincicial que causam infecção respiratĂłria em lactentes e a associação dos anticorpos sĂ©ricos subtipo-especĂficos com a ocorrĂȘncia de infecção; a presença de anticorpos subtipo-especĂficos nas mĂŁes e sua associação com o perfil de anticorpos da criança. MĂTODOS: Estudo prospectivo incluindo lactentes hospitalizados com infecção respiratĂłria. Foi coletada secreção de nasofaringe para investigação viral usando imunofluorescĂȘncia indireta e cultivo viral. Foi coletado sangue para pesquisa de anticorpos usando o sistema Luminex Multiplex. RESULTADOS: Avaliados 192 lactentes: 60,9% com vĂrus sincicial (73,5% - A e 20,5% - B). Seis genĂłtipos de vĂrus sincicial respiratĂłrio foram identificados: A5,A2,B3,B5,A7 e B4. A soroprevalĂȘncia dos anticorpos subtipos-especĂficos foi alta. A presença e o nĂvel de anticorpos subtipos-especĂficos foram semelhantes, independentemente da presença de infecção, tipo e genĂłtipo do vĂrus. As mĂŁes e as crianças apresentaram perfis semelhantes de anticorpos. CONCLUSĂES: A prevalĂȘncia dos anticorpos subtipos-especĂficos foi elevada mas estes anticorpos nĂŁo conferiram proteção, independentemente do tipo/genĂłtipo do vĂrus. A semelhança dos perfis de anticorpos das mĂŁes e das crianças foi compatĂvel com transmissĂŁo transplacentĂĄria
VĂrus da cinomose canina: detecção do RNA viral pelo Nested RT-PCR em cĂŁes com diagnĂłstico clĂnico
Canine distemper virus (CDV) is a pathogen which affects dogs and causes severe disease leading to death. Dogs infected with CDV can be diagnosed by RNA detection by Nested PCR technique. The following study proposed to valuate CDV RNA in blood, urine and saliva samples. The Nested-PCR technique was able to detect CDV RNA in different types of biologic samples. The higher number of positive results was obtained in urine samples.O vĂrus da cinomose canina (CDV) Ă© um patĂłgeno que afeta cĂŁes, causando doença grave e que pode levar a morte. Os cĂŁes infectados pelo CDV podem ser diagnosticados pela detecção do RNA utilizando-se a tĂ©cnica de Nested-PCR. O presente estudo teve como objetivo avaliar o RNA do CDV no sangue, urina e saliva em cĂŁes com diagnĂłstico clĂnico de cinomose. A tĂ©cnica de Nested-PCR foi capaz de detectar o RNA em diferentes tipos de amostras biolĂłgicas. Obteve-se um maior nĂșmero de resultados positivos em amostras de urina
Genetic diversity of environmental Aspergillus flavus strains in the state of SĂŁo Paulo, Brazil by random amplified polymorphic DNA
Aspergillus flavus is a very important toxigenic fungus that produces aflatoxins, a group of extremely toxic substances to man and animals. Toxigenic fungi can grow in feed crops, such as maize, peanuts, and soybeans, being thus of high concern for public health. There are toxigenic and non-toxigenic A. flavus variants, but the necessary conditions for expressing the toxigenic potential are not fully understood. Therefore, we have studied total-DNA polymorphism from toxigenic and non toxigenic A. flavus strains isolated from maize crops and soil at two geographic locations, 300 km apart, in the Southeast region of Brazil. Total DNA from each A. flavus isolate was extracted and subjected to polymerase chain reaction amplification with five randomic primers through the RAPD (random amplified polymorphic DNA) technique. Phenetic and cladistic analyses of the data, based on bootstrap analyses, led us to conclude that RAPD was not suitable to discriminate toxigenic from non toxigenic strains. But the present results support the use of RAPD for strain characterization, especially for preliminary evaluation over extensive collections
The importance of viral load in the severity of acute bronchiolitis in hospitalized infants
OBJECTIVE: The relationship between viral load and the clinical evolution of bronchiolitis is controversial. Therefore, we aimed to analyze viral loads in infants hospitalized for bronchiolitis.
METHODS: We tested for the presence of human respiratory syncytial virus (HRSV) or human rhinovirus (HRV) using quantitative molecular tests of nasopharyngeal secretions and recorded severity outcomes.
RESULTS: We included 70 infants [49 (70%) HRSV, 9 (13%) HRV and 12 (17%) HRSV+HRV]. There were no differences among the groups according to the outcomes analyzed individually. Clinical scores showed greater severity in the isolated HRSV infection group. A higher isolated HRSV viral load was associated with more prolonged ventilatory support, oxygen therapy, and hospitalization days, even after adjustment for the age and period of nasopharyngeal secretion collection. In the co-infection groups, there was a longer duration of oxygen therapy when the HRSV viral load was predominant. Isolated HRV infection and co-infection with a predominance of HRV were not associated with severity.
CONCLUSION: Higher HRSV viral load in isolated infections and the predominance of HRSV in co-infections, independent of viral load, were associated with greater severity. These results contribute to the development of therapeutic and prophylactic approaches and a greater understanding of the pathophysiology of bronchiolitis
Chapparvoviruses occur in at least three vertebrate classes and have a broad biogeographic distribution
Chapparvoviruses are a highly divergent group of parvoviruses (family Parvoviridae) that have recently been identified via metagenomic sampling of animal faeces. Here we report the sequences of six novel chapparvoviruses identified through both metagenomic sampling of bat tissues and in silico screening of published vertebrate genome assemblies. The novel chapparvoviruses share several distinctive genomic features, and group together as a robustly supported monophyletic clade in phylogenetic trees. Our data indicate that chapparvoviruses have a broad host range in vertebrates, and a global distribution
Exantema após vacinação do sarampo: anålise laboratorial de casos notificados em São Paulo
OBJECTIVE: The clinical differential diagnosis of rash due to viral infections is often difficult, and misdiagnosis is not rare, especially after the introduction of measles and rubella vaccination. A study to determine the etiological diagnosis of exanthema was carried out in a group of children after measles vaccination. METHODS: Sera collected from children with rash who received measles vaccine were reported in 1999. They were analyzed for IgM antibodies against measles virus, rubella virus, human parvovirus B19 (HPV B19) using ELISA commercial techniques, and human herpes virus 6 (HHV 6) using immunofluorescence commercial technique. Viremia for each of those viruses was tested using a polimerase chain reaction (PCR). RESULTS: A total of 17 cases of children with exanthema after measles immunization were reported in 1999. The children, aged 9 to 12 months (median 10 months), had a blood sample taken for laboratory analysis. The time between vaccination and the first rash signs varied from 1 to 60 days. The serological results of those 17 children suspected of measles or rubella infection showed the following etiological diagnosis: 17.6% (3 in 17) HPV B19 infection; 76.5% (13 in 17) HHV 6 infection; 5.9% (1 in 17) rash due to measles vaccine. CONCLUSIONS: The study data indicate that infection due to HPV B19 or HHV 6 can be misdiagnosed as exanthema due to measles vaccination. Therefore, it is important to better characterize the etiology of rash in order to avoid attributing it incorrectly to measles vaccine.OBJETIVO: O diagnĂłstico diferencial de doenças exantemĂĄticas causadas por vĂrus Ă© geralmente difĂcil, e equĂvocos nĂŁo sĂŁo raros, especialmente depois da introdução da vacina contra o sarampo e a rubĂ©ola. Um estudo laboratorial foi conduzido com o objetivo de estabelecer o diagnĂłstico etiolĂłgico de casos de exantema em crianças que receberam a vacina contra o sarampo. MĂTODOS: Soros de casos de exantema em crianças que receberam vacina contra o sarampo, em 1999, foram analisados para anticorpos IgM contra os vĂrus do sarampo, da rubĂ©ola e do parvovĂrus humano B19 (HPV B19), por tĂ©cnicas comerciais de Elisa, e o herpes vĂrus humano tipo 6 (HHV 6), por tĂ©cnica comercial de imunofluorecĂȘncia. A viremia para cada um desses vĂrus foi testada pela reação em cadeia da polimerase (PCR). RESULTADOS: Foram notificados, em 1999, 17 casos de crianças com exantema pĂłs-vacinal. A idade das crianças era de nove a 12 meses (mediana, dez meses). Uma amostra de sangue colhida para investigação laboratorial foi obtida para cada criança. O tempo decorrido entre a aplicação da vacina e o aparecimento do exantema variou de um a 60 dias. Os resultados da sorologia das 17 crianças sugeriram o seguinte diagnĂłstico etiolĂłgico para o exantema: 17,6% (trĂȘs em 17) infecção pelo HPV B19; 76,5% (13 em 17) infecção pelo HHV 6; 5,9% (um em 17) exantema originado pela vacina do sarampo. CONCLUSĂO: Os resultados indicaram que a infecção pelo HPV B19 ou pelo HHV 6 pode ser diagnosticada como sarampo de origem vacinal. Portanto, Ă© fundamental incluir esses vĂrus no diagnĂłstico laboratorial para corretamente apontar a etiologia das doenças exantemĂĄticas, evitando, assim, atribuir Ă vacina do sarampo efeito colateral
Occurrence of human astrovirus in S. Paulo City, Brazil
Human astrovirus was detected during a 13-month longitudinal study of the incidence of diarrhoea viruses among hospitalized children (Foram detectados astrovĂrus humanos durante estudo longitudinal de 13 meses sobre a incidĂȘncia de vĂrus diarrĂ©icos em 146 crianças menores de 2 anos de idade, hospitalizadas em clĂnica pediĂĄtrica de um hospital universitĂĄrio, na cidade de SĂŁo Paulo, SP, Brasil. Das 67 crianças internadas com diarrĂ©ia aguda, 3% foram positivas para astrovĂrus, por ocasiĂŁo de sua admissĂŁo, pelo Ensaio ImunoenzimĂĄtico Monoclonal Amplificado (ASTROVIRUS BIOTIN-AVIDIN ELISA, CDC, USA). As 79 crianças sem diarrĂ©ia, admitidas durante o mesmo perĂodo por outra causa (controles), foram negativas para astrovĂrus, por ocasiĂŁo de seu internamento. Entretanto, 4,8% do total de crianças hospitalizadas sofreram infecçÔes por astrovĂrus durante sua permanĂȘncia no hospital. Este Ă© o primeiro estudo sobre a ocorrĂȘncia de astrovĂrus humanos no Brasil, que assim participam significativamente na etiologia da gastroenterite infantil em nosso meio
Kelp gulls, Larus dominicanus (Aves: Laridae), breeding in Keller Peninsula, King George Island, Antarctic Peninsula
- âŠ