RESUMO
We conducted a prospective, observational study to characterize the clinical manifestations of respiratory infections caused by human metapneumovirus (hMPV) and other viruses in 194 premature infants and young children with chronic lung disease or congenital heart disease in Buenos Aires. Children had 567 episodes of respiratory illness and were monitored until they were 2 years old or until the completion of the study. hMPV elicited 12 infections (2%) year-round; 30% were of moderate or greater severity. Human parainfluenza virus type 3 caused 24 infections (4%), and 5 (25%) of 20 lung infections led to hospitalization. Respiratory syncytial virus (RSV) caused 33 episodes--17% of infections and 32% of hospitalizations during the respiratory season. None of the 10 children infected with influenza virus had severe disease. The present study of at-risk children suggests that hMPV and influenza virus are infrequent agents of severe disease and highlights the need for preventive interventions against RSV in developing countries.
Assuntos
Cardiopatias Congênitas/complicações , Doenças do Prematuro , Pneumopatias/complicações , Metapneumovirus/isolamento & purificação , Infecções por Paramyxoviridae/fisiopatologia , Infecções Respiratórias/fisiopatologia , Adulto , Argentina , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/fisiopatologia , Doenças do Prematuro/virologia , Masculino , Orthomyxoviridae/isolamento & purificação , Vírus da Parainfluenza 3 Humana/isolamento & purificação , Infecções por Paramyxoviridae/complicações , Pneumonia Viral/complicações , Pneumonia Viral/fisiopatologia , Pneumonia Viral/virologia , Estudos Prospectivos , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/complicações , Infecções Respiratórias/virologia , Índice de Gravidade de DoençaRESUMO
The attachment protein (glycoprotein) of respiratory syncytial virus (RSV) has long been associated with disease potentiation and respiratory symptoms. The glycoprotein has a conserved cysteine-rich region (GCRR) whose function is unknown and which is not necessary for efficient viral replication. In this report, we show that the GCRR is a powerful inhibitor of the innate immune response against RSV, and that early secretion of glycoprotein is critical to modulate inflammation after RSV infection. Importantly, the GCRR is also a potent inhibitor of cytokine production mediated by several TLR agonists, indicating that this peptide sequence displays broad antiinflammatory properties. These findings have important implications for RSV pathogenesis and describe an inhibitor of TLR-mediated inflammatory responses that could have clinical applications.