Acute respiratory viral infections in children in Rio de Janeiro and Teresópolis, Brazil

The frequency of viral pathogens causing respiratory infections in children in the cities of Rio de Janeiro and Teresópolis was investigated. Nasal swabs from children with acute respiratory illnesses were collected between March 2006 and October 2007. Specimens were tested for viral detection by conventional (RT)-PCR and/or real time PCR. Of the 205 nasal swabs tested, 64 (31.2%) were positive for at least one of the viral pathogens. Single infections were detected in 56 samples, 50 of those were caused by RNA viruses: 33 samples tested positive for rhinovirus, five for influenza A, five for metapneumovirus, four for coronavirus and, three for respiratory syncytial virus. For the DNA viruses, five samples were positive for bocavirus and one for adenovirus. Co-infections with these viruses were detected in eight samples. Our data demonstrate a high frequency of viral respiratory infections, emphasizing the need for a more accurate diagnosis particularly for the emerging respiratory viruses. The fact that the emerging respiratory viruses were present in 9.2% of the tested samples suggests that these viruses could be important respiratory pathogens in the country

Genetic Diversity of Avian Infectious Bronchitis Virus Isolated from Domestic Chicken Flocks and Coronaviruses from Feral Pigeons in Brazil Between 2003 and 2009

To detect the presence of infectious bronchitis virus or avian coronavirus, a nested reverse transcriptase PCR (RT-PCR) method was developed with the aim of amplifying a fragment of 530 bases, comprising the gene coding SI protein. In the first step, all samples were submitted to RNA extraction, RT-PCR, and nested PCR. Next, only the positive nested-PCR samples were propagated in specific-pathogen-free (SPF) embryonated chicken eggs for virus isolation. Positive samples were then sequenced and analyzed using a molecular phylogeny approach. Tracheal swab samples were collected from 23 different domestic chickens distributed in three regions of Brazil, in the period between 2003 and 2009. Also analyzed were six swab samples (tracheal and cloacal) from asymptomatic pigeons (Columba livia), caught in an urbanized region in southeastern Brazil. The study revealed two major phylogenetic groups: one clustered with the Massachusetts vaccine serotype and another joined with the D207 strain. Interestingly, samples grouped with the Connecticut and Arkansas serotypes were also found. Pigeon isolates clustered with the Massachusetts serotype showed significant similarity (close to 100%) to those obtained from chickens. Only one pigeon isolate was seen to be grouped with the Connecticut serotype, and no correlation was observed between sample grouping and region origin. Understanding the diversity of genotypes and eco-epizootiology of the disease in different environments is expected to be helpful for vaccine production aimed at the main circulating variants. In this respect, one could also expect benefits in the management of other bird species that may act as avian coronavirus reservoirs.5441191119

Detection of and phylogenetic studies with avian metapneumovirus recovered from feral pigeons and wild birds in Brazil

The aim of the present study was to determine whether avian metapneumovirus (aMPV)-related viruses were present in wild and synanthropic birds in Brazil. Therefore, we analysed samples from wild birds, feral pigeons and domestic chickens in order to perform a phylogenetic comparison. To detect the presence of aMPV, a nested reverse transcriptase-polymerase chain reaction was performed with the aim of amplifying a fragment of 270 bases for subtype A and 330 bases for subtype B, comprising the gene coding the G glycoprotein. Positive samples for aMPV subtypes A and B were found in seven (13.2%) different asymptomatic wild birds and pigeons (50%) that had been received at the Bosque dos Jequitibas Zoo Triage Center, Brazil. Also analysed were positive samples from 15 (12.9%) domestic chickens with swollen head syndrome from several regions of Brazil. The positive samples from wild birds, pigeons and domestic chickens clustered in two major phylogenetic groups: some with aMPV subtype A and others with subtype B. The similarity of the G fragment nucleotide sequence of aMPV isolated from chickens and synanthropic and wild avian species ranged from 100 to 97.5% (from 100 to 92.5% for the amino acids). Some positive aMPV samples, which were obtained from wild birds classified in the Orders Psittaciformes, Anseriformes and Craciformes, clustered with subtype A, and others from the Anas and Dendrocygma genera (Anseriformes Order) with subtype B. The understanding of the epizootiology of aMPV is very important, especially if this involves the participation of non-domestic bird species, which would add complexity to their control on farms and to implementation of vaccination programmes for aMPV.40544545

Genotypes and Clinical Data of Respiratory Syncytial Virus and Metapneumovirus in Brazilian Infants: A New Perspective

The aim of this study was to determine if there was a correlation between respiratory syncytial virus (RSV) and metapneumovirus (MPV) genotypes and clinical data of Brazilian infants hospitalized for acute lower respiratory infection. The viruses in the patients' nasopharyngeal secretions were studied using the polymerase chain reaction and phylogenetic analysis. The study assessed 144 infants; 31.9% were RSV positive and 5.6% were MPV positive. Statistical analysis was performed using the chi-squared test, Fisher's test, Odds ratio, univariate logistic regression, non-conditional multivariate logistic regression and the forward - stepwise method. Multivariate analysis confirmed a significant relationship between a positive PCR test for RSV and hospitalization during the month of May and with pulse oximetry less than 90%. The phylogenetic analysis indicated the genotypes GA2, GA5, SAA1 (Group A), SAB1, SAB3 and BA (Group B) for RSV and Group B, subgroup B1, for MPV.131353

Variant isolates of human metapneumovirus subgroup B genotype 1 in Campinas, Brazil

Background: Human metapneumovirus (HMPV) is a paramyxovirus associated with respiratory illness. The genotypes of HMPV isolates in Brazil have not been well characterized. Objectives: To investigate the presence of HMPV in clinical samples collected from pediatric patients of two university hospitals in the region of Campinas (Sao Paulo, Brazil) and to genotype them by partial sequencing of the HMPV F gene. Study design: Nasopharyngeal aspirates were collected from children hospitalized between April and September, 2004 because of acute respiratory infections (ARI). Results: We identified HMPV in 8 of 142 (5.6%) clinical samples. We determined through phylogenetic analysis that HMPV isolates in Campinas during the study were clustered within subgroup B genotype 1. Two of the isolates analyzed showed significant differences from previously isolated B I viruses, when compared to HMPV isolated in South Africa and,Canada, and clustered in a separate branch within this genotype. Conclusions: In 2004 in our geographic region all HMPV isolates from pediatric patients were in the B I HMPV genetic group, with two variant isolates. (c) 2007 Elsevier B.V. All rights reserved.421788

Newcastle Disease Virus Vaccine Strains: Immunogenicity is not Influenced by ICPI

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Intracerebral pathogenicity index (ICPI) and mean death time (MDT) were determined using commercial live vaccines against Newcastle disease available in Brazil. The ICPI profiles obtained for 131 vaccine strains were nonvirulent and varied from 0 to 0.19, and their MDT was 104-116 hours. The LaSota strains had an ICPI varying between 0.02 and 0.37 and MDT from 92 to 116 hours. ICPI and MDT for the Clone 30 were 0.11 and 104 hours, respectively. For Ulster vaccines, ICPI and MDT were 0 and >150 hours; for VG-GA was 0.03 and 140 hours; and for C2, 0.04 and >144 hours. Eye drop vaccination and IM challenge, at the 1(st) week and the 4(th) week, respectively, resulted in highest protection for B1 (95-100%) and LaSota (90-100%) strains. The variability in vaccine ICPI did not interfere with immune response and all vaccines provided similar protection. All vaccines were considered non virulent and were classified as lentogenic according to the immuncibiological product standards.112129133Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq