ABSTRACT
Epidemiological and molecular characteristics of human metapneumovirus (hMPV) were compared with human respiratory syncytial virus (hRSV) in infants and young children admitted for acute lower respiratory tract infections in a prospective study during four consecutive years in subtropical Brazil. GeneScan polymerase chain assays (GeneScan RT-PCR) were used to detect hMPV and hRSV in nasopharyngeal aspirates of 1,670 children during January 2003 to December 2006. hMPV and hRSV were detected, respectively, in 191 (11.4%) and in 702 (42%) of the children admitted with acute lower respiratory tract infections at the Sao Paulo University Hospital. Sequencing data of the hMPV F gene revealed that two groups of the virus, each divided into two subgroups, co-circulated during three consecutive years. It was also shown that a clear dominance of genotype B1 occurred during the years 2004 and 2005, followed by genotype A2 during 2006.
Subject(s)
Genetic Variation , Metapneumovirus/genetics , Molecular Epidemiology , Paramyxoviridae Infections/epidemiology , Respiratory Tract Infections , Brazil/epidemiology , Child, Preschool , Female , Humans , Incidence , Infant , Infant, Newborn , Male , Metapneumovirus/classification , Metapneumovirus/isolation & purification , Paramyxoviridae Infections/virology , Phylogeny , RNA, Viral/analysis , RNA, Viral/isolation & purification , Respiratory Syncytial Virus Infections/epidemiology , Respiratory Syncytial Virus Infections/virology , Respiratory Syncytial Virus, Human/classification , Respiratory Syncytial Virus, Human/genetics , Respiratory Syncytial Virus, Human/isolation & purification , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/virology , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNAABSTRACT
OBJECTIVE: Detection of the eight most common respiratory viruses: human respiratory syncytial virus (HRSV), influenza virus A and B (IA and IB), parainfluenza viruses 1, 2 and 3 (HPIV1, 2 and 3), adenovirus (Ad) and human metapneumovirus (HMPV), in order to establish the etiology of acute respiratory infections (ARIs) and the epidemiology of these viruses in young children seen at Hospital Universitário, Universidade de São Paulo, in São Paulo, Brazil, during 2003. METHODS: The epidemiological surveillance was conducted in all children younger than 5 years hospitalized at the Hospital for lower respiratory tract infections (LRTI) from January 1, 2003 to December 30, 2003. Nasal and throat samples were scanned for respiratory viruses by polymerase chain reaction and detected by the GeneScan assay. RESULTS: Of 336 samples collected from 336 patients, 187 (55.6%) were positive for at least one of the respiratory viruses studied. Of all the children, HRSV was identified in 24.1%, HMPV in 17.8%, HPIV3 in 8.3%, Ad in 6.8%, IA in 5%, HPIV1 in 0.6%, but no virus could be detected in 44.1%. Dual virus infections were detected in 7.1% of all samples (12.8% of positive samples). HPIV2 and IB were not detected in the present study. CONCLUSIONS: This study confirms that children younger than 5 years and particularly younger than 1 year have a high hospitalization rate due to HRSV, HMPV, HPIV, influenza and adenovirus. We were able to determine the etiology and epidemiology of most ARIs and trace the seasonal profile of the commonest respiratory viruses among young children.
Subject(s)
Respiratory Tract Infections/virology , Acute Disease , Brazil/epidemiology , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Population Surveillance , Prospective Studies , RNA, Viral/analysis , Respiratory Tract Infections/epidemiology , Reverse Transcriptase Polymerase Chain Reaction , SeasonsABSTRACT
OBJETIVO: Detecção de oito vírus respiratórios mais comuns: vírus respiratório sincicial humano (VRSH), vírus influenza tipo A e B (IA e IB), vírus da parainfluenza 1, 2 e 3 (VPIH1, 2 e 3), adenovírus (Ad) e metapneumovírus humano (MPVH), a fim de estabelecer a etiologia das infecções respiratórias agudas (IRA) e a epidemiologia desses vírus em crianças pequenas atendidas no Hospital Universitário da Universidade de São Paulo, em São Paulo, Brasil, durante o ano de 2003. MÉTODOS: A vigilância epidemiológica foi realizada em todas as crianças menores de 5 anos hospitalizadas por causa de doenças do trato respiratório inferior (DTRI) entre 1º de janeiro de 2003 e 20 de dezembro de 2003, no hospital universitário. Amostras coletadas de nasofaringe foram analisadas quanto à presença de vírus respiratórios através da reação em cadeia da polimerase e detectadas pelo programa GeneScan. RESULTADOS: Das 336 amostras coletadas, 187 (55,6 por cento) foram positivas para pelo menos um dos vírus respiratórios estudados. De todas as crianças, o VRSH foi identificado em 24,1 por cento, o MPVH em 17,8 por cento, o VPIH3 em 8,3 por cento, o Ad em 6,8 por cento, o IA em 5 por cento, o VPIH1 em 0,6 por cento, sendo que nenhum vírus foi detectado em 44,1 por cento. Infecções virais duplas foram detectadas em 7,1 por cento de todas as amostras (12,8 por cento das amostras positivas). O VPIH2 e o IB não foram detectados no presente estudo. CONCLUSÕES: Este estudo confirma que as crianças menores de 5 anos, e especialmente aquelas menores de 1 ano, apresentam uma alta taxa de hospitalização devido aos seguintes vírus: VRSH, MPVH, VPIH, influenza e adenovírus. Foi possível determinar a etiologia e epidemiologia da maioria das IRAs e traçar o perfil de sazonalidade dos vírus respiratórios mais comuns entre as crianças pequenas.
OBJECTIVE: Detection of the eight most common respiratory viruses: Human respiratory syncytial virus (HRSV), influenza virus A and B (IA and IB), parainfluenza viruses 1, 2 and 3 (HPIV1, 2 and 3), adenovirus (Ad) and human metapneumovirus (HMPV), in order to establish the etiology of acute respiratory infections (ARIs) and the epidemiology of these viruses in young children seen at Hospital Universitário, Universidade de São Paulo, in São Paulo, Brazil, during 2003. METHODS: The epidemiological surveillance was conducted in all children younger than 5 years hospitalized at the Hospital for lower respiratory tract infections (LRTI) from January 1, 2003 to December 30, 2003. Nasal and throat samples were scanned for respiratory viruses by polymerase chain reaction and detected by the GeneScan assay. RESULTS: Of 336 samples collected from 336 patients, 187 (55.6 percent) were positive for at least one of the respiratory viruses studied. Of all the children, HRSV was identified in 24.1 percent, HMPV in 17.8 percent, HPIV3 in 8.3 percent, Ad in 6.8 percent, IA in 5 percent, HPIV1 in 0.6 percent, but no virus could be detected in 44.1 percent. Dual virus infections were detected in 7.1 percent of all samples (12.8 percent of positive samples). HPIV2 and IB were not detected in the present study. CONCLUSIONS: This study confirms that children younger than 5 years and particularly younger than 1 year have a high hospitalization rate due to HRSV, HMPV, HPIV, influenza and adenovirus. We were able to determine the etiology and epidemiology of most ARIs and trace the seasonal profile of the commonest respiratory viruses among young children.