RESUMO
Respiratory syncytial virus (RSV) in Alaska Native children from the Yukon Kuskokwim (YK) Delta is associated with a hospitalization rate five times higher than that reported for the general US child population. The role of other viral respiratory pathogens has not been studied in this population. YK Delta children <3 years of age hospitalized with respiratory infections and same aged community control children were prospectively enrolled between October 2005 and September 2007. Polymerase chain reaction detection of viruses was performed on nasopharyngeal samples. Characteristics of hospitalized and asymptomatic control children were analyzed. From October 2005 to September 2007, 440 hospitalized and 425 control children were analyzed. Respiratory viruses were detected in 90% (395) of hospitalized children: 194 (44%) rhinovirus, 131 (30%) adenovirus, 102 (23%) RSV, 77 (18%) para influenza viruses (PIV), 66 (15%) human metapneumovirus (hMPV), 23 (5%) influenza, and 25 (6%) coronavirus. Fifty-two percent (221) of control children had a virus detected, most commonly rhinovirus (33%), and adenovirus (16%). RSV, PIV, hMPV, and influenza were significantly more common in hospitalized cases than control children, but rhinovirus, adenovirus, and coronavirus were not. RSV and hMPV were associated with higher severity of illness. In this study, RSV remains the most important virus associated with respiratory hospitalization, although hMPV and PIV were also common. RSV and hMPV were associated with more severe illness. Rhinovirus and adenovirus were detected in two-thirds of hospitalized children, but their frequent detection in control children made their role in respiratory hospitalization uncertain.
Assuntos
Infecções Respiratórias/epidemiologia , Adenoviridae/genética , Adenoviridae/isolamento & purificação , Alaska/epidemiologia , Pré-Escolar , DNA Viral/genética , Feminino , Hospitalização , Humanos , Lactente , Recém-Nascido , Vírus da Influenza A/genética , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/genética , Vírus da Influenza B/isolamento & purificação , Masculino , Metapneumovirus/genética , Metapneumovirus/isolamento & purificação , Nasofaringe/virologia , Paramyxoviridae/genética , Paramyxoviridae/isolamento & purificação , Reação em Cadeia da Polimerase , Estudos Prospectivos , RNA Viral/genética , Vírus Sincicial Respiratório Humano/genética , Vírus Sincicial Respiratório Humano/isolamento & purificação , Infecções Respiratórias/virologia , Rhinovirus/genética , Rhinovirus/isolamento & purificação , Estações do Ano , Índice de Gravidade de DoençaRESUMO
Haemophilus influenzae type b (Hib) invasive disease and oropharyngeal carriage continue in rural Alaska despite widespread vaccination. This study investigated whether invasive-disease reemergence during 1996-1997 could be attributed to strains distinguishable from strains carried by vaccinated children. Twenty-four invasive and 42 carriage Hib isolates, collected during 1992-1997, were characterized by pulsed-field gel electrophoresis (PFGE), multilocus enzyme electrophoresis, and biotyping. This Hib population was highly clonal, since only 2 strains, electrophoretic type (ET) 55/PFGE 1 and ET 56/PFGE 3, accounted for 62% of all isolates. The ET 55/PFGE 1 and ET 56/PFGE 3 strains were found in 74% of the carriers and caused 80% of the invasive Hib disease that occurred during April 1996-March 1997. Strains causing invasive disease could not be distinguished from strains carried by vaccinated children. Continued monitoring of Hib carriage may provide insights into the epidemiology of continued transmission in an era of widespread vaccination.