First report of porcine respirovirus 1 in Brazil.

Porcine respirovirus 1 (PRV1), currently referred to as Respirovirus suis, was first described in deceased pigs at a Hong Kong slaughterhouse. Since then, PRV1 strains have been detected in pig herds in American, European, and Asian countries. Considering that Brazil is the fourth-largest global producer and exporter of pork, we aimed to detect the PRV1 RNA in biological samples collected from intensive pig farming in the midwestern region of Brazil. Oropharyngeal and rectal swabs were collected from pigs of different ages at an intensive commercial pig operation. These samples were tested using reverse transcription semi-nested polymerase chain reaction. In this study, the frequency of identification of PRV1 RNA in feces was found to be 2% (1/50), whereas the detection rate of PRV1 in the respiratory mucosa was approximately 1% (1/90). Therefore, a low rate of PRV1 detection was observed only in weaned pigs aged 33-50 days. Sequence analyses revealed that the two Brazilian PRV1 strains were closely related to previously reported strains mainly from Asian countries such as Vietnam, China, and South Korea. These strains clustered with PRV1 sequences classified into the European lineage 1. This is the first report of PRV1 in a commercial pig herd in Brazil. To accurately determine the frequency of detection of PRV1 among pigs in intensive commercial pig farms in Brazil, additional prospective and retrospective studies should be conducted. These studies should aim to detect PRV1 in pig herds with diverse respiratory disease statuses.

First report of porcine respirovirus 1 in South America.

Porcine respirovirus 1 (PRV1) is an emerging virus in pigs that has been previously described in the USA and China. There are no reports of its presence in the rest of the world. The objective of this study was to determine the occurrence of PRV1 in Chile and to determine its phylogeny. Thus, we collected samples (oral fluids, nasal swabs, and lungs) from a swine influenza A virus (IAV) surveillance program, most of which belonged to pigs with respiratory disease. The samples were analyzed by RT-PCR, and the viral sequencing was obtained using RNA whole-genome sequencing approach. Maximum likelihood phylogeny was constructed with the available references. Thirty-one of 164 samples (18.9 %) were RT-PCR positive for PRV1: 62.5 % oral fluids, 19.0 % nasal swabs, and 8.6 % lungs. All 6 farms in this study had at least one positive sample, with 6-40 % of positive results per farm, which suggests that PRV1 is disseminated in Chilean swine farms. Twenty-one of 31 (677%) PRV1-positive samples were also positive for IAV, so the role of PRV1 as secondary pathogen in respiratory disease needs to be further evaluated. Near to complete genome of two PRV1s were obtained from two farms. The phylogenies, in general, showed low bootstrap support, except the concatenated genome and the L gene trees which showed clustering of the Chilean PRV1 with Asian sequences, suggesting a close genetic relationship. This is the first report of PRV1 in the Southern Hemisphere. Further studies are necessary to determine the genetic diversity of this virus in Chile.

Human parainfluenza virus surveillance in pediatric patients with lower respiratory tract infections: a special view of parainfluenza type 4 / Vigilância dos vírus parainfluenza humanos em pacientes pediátricos com infecções do trato respiratório inferior: uma visão especial do parainfluenza tipo 4

Abstract Objective: Characterize the role of human parainfluenza virus and its clinical features in Brazilian children under 2 years of age presenting with acute lower respiratory tract infections. Methods: Real-time assays were used to identify strains of human parainfluenza virus and other common respiratory viruses in nasopharyngeal aspirates. One thousand and two children presenting with acute lower respiratory tract illnesses were enrolled from February 2008 to August 2010. Results: One hundred and four (10.4%) patients were human parainfluenza virus positive, of whom 60 (57.7%) were positive for human parainfluenza virus-3, 30 (28.8%) for human parainfluenza virus-4, 12 (11.5%) for human parainfluenza virus-1, and two (1.9%) for human parainfluenza virus-2. Seven (6.7%) patients had more than one strain of human parainfluenza virus detected. The most frequent symptoms were tachypnea and cough, similar to other viral respiratory infections. Clinical manifestations did not differ significantly between human parainfluenza virus-1, -2, -3, and -4 infections. Human parainfluenza virus-1, -3, and -4 were present in the population studied throughout the three years of surveillance, with human parainfluenza virus-3 being the predominant type identified in the first two years. Conclusion: Human parainfluenza viruses contribute substantially to pediatric acute respiratory illness (ARI) in Brazil, with nearly 30% of this contribution attributable to human parainfluenza virus-4.

Resumo Objetivo: Caracterizar o papel do VPH-4 e suas características clínicas em crianças brasileiras com menos de dois anos de idade com infecções agudas do trato respiratório inferior. Métodos: Ensaios em tempo real foram utilizados para identificar tipos de VPH e outros vírus respiratórios comuns em aspirados nasofaríngeos. Mil e duas crianças com doença aguda do trato respiratório inferior foram inscritas para participar de fevereiro de 2008 a agosto de 2010. Resultados: 104 (10,4%) pacientes eram VPH positivos, dos quais 60 (57,7%) eram positivos para VPH-3, 30 (28,8%) para VPH-4, 12 (11,5%) para VPH-1 e dois (1,9%) para VPH-2. Sete (6,7%) pacientes apresentaram mais de um tipo de VPH detectado. Os sintomas mais frequentes foram tosse e taquipneia, semelhantes a outras infecções respiratórias virais. As manifestações clínicas não diferiram de forma significativa entre as infecções por VPH-1, -2, -3 e -4. Os VPH-1, -3 e -4 estavam presentes na população estudada ao longo dos três anos de vigilância, e o VPH-3 foi o tipo predominante identificado nos primeiros dois anos. Conclusão: Os VPHs contribuem substancialmente para a DRA pediátrica no Brasil com quase 30% dessa contribuição atribuível ao VPH-4.

Human parainfluenza virus surveillance in pediatric patients with lower respiratory tract infections: a special view of parainfluenza type 4.

OBJECTIVE: Characterize the role of human parainfluenza virus and its clinical features in Brazilian children under 2 years of age presenting with acute lower respiratory tract infections. METHODS: Real-time assays were used to identify strains of human parainfluenza virus and other common respiratory viruses in nasopharyngeal aspirates. One thousand and two children presenting with acute lower respiratory tract illnesses were enrolled from February 2008 to August 2010. RESULTS: One hundred and four (10.4%) patients were human parainfluenza virus positive, of whom 60 (57.7%) were positive for human parainfluenza virus-3, 30 (28.8%) for human parainfluenza virus-4, 12 (11.5%) for human parainfluenza virus-1, and two (1.9%) for human parainfluenza virus-2. Seven (6.7%) patients had more than one strain of human parainfluenza virus detected. The most frequent symptoms were tachypnea and cough, similar to other viral respiratory infections. Clinical manifestations did not differ significantly between human parainfluenza virus-1, -2, -3, and -4 infections. Human parainfluenza virus-1, -3, and -4 were present in the population studied throughout the three years of surveillance, with human parainfluenza virus-3 being the predominant type identified in the first two years. CONCLUSION: Human parainfluenza viruses contribute substantially to pediatric acute respiratory illness (ARI) in Brazil, with nearly 30% of this contribution attributable to human parainfluenza virus-4.