title: Longitudinal study on respiratory viral co-infections in the presence or absence of clinical manifestation in infants aged 0-2 years.
abstract: We conducted a long-term follow-up study between December 2005 and February 2007 on 4 immunocompetent infants, who repeatedly presented with respiratory symptoms, using PCR-based techniques targeting 14 viruses related to acute respiratory tract infection. Of 38 specimens, 30 were collected from symptomatic infants and 8 were collected when respiratory symptoms were absent. Overall, one or more respiratory viruses were detected in 94.7% (36/38) of the specimens. Of the 36 PCR-positive specimens, 77.8% (28/36) were positive for more than one virus. Most of these co-infections were double infections (55.6% or 20/36). Of note, co-infections with 4 and 3 viruses were observed in 3 (8.3% or 3/36) and 5 (13.9% or 5/36) specimens, respectively. Of the 8 specimens collected from the 4 infants when apparent respiratory symptoms were absent, 7 (87.5%) were positive for respiratory viruses. Respiratory viral co-infections were also frequent and found in 5 of the specimens (62.5%). However, apparent correlation between disease severity and co-infection was undetectable due to the limit of the number of cases studied. Taken together, this longitudinal study revealed that respiratory viral co-infections were not infrequent in infants aged 0-2 years, regardless of the presence of respiratory symptoms (62.5-77.8%).
authors.affiliation: Division of Virology, Department of Infectious Diseases, Osaka Prefectural Institute of Public Health.
authors.forename: Takako
authors.initials: T
authors.lastname: Kawabuchi-Kurata
authors.forename: Takako
authors.initials: T
authors.lastname: Misaki
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suehiro
authors.forename: Atsushi Jun
authors.initials: AJ
authors.lastname: Komano
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kase
authors.forename: Kazuo
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D060085:Coinfection / Q000453:epidemiology / Q000821:virology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000821:virology*; D014777:Virus Diseases / Q000453:epidemiology / Q000821:virology*; D014780:Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*