Contribution of influenza and respiratory syncytial virus to community cases of influenza-like illness: an observational study.
BACKGROUND
Respiratory syncytial virus (RSV) is an important cause of lower-respiratory-tract infection in children and elderly people, but its effect in other age-groups is uncertain. We did a community-based observational study of RSV infection in community-dwelling individuals of all ages who presented to general practices in the UK with influenza-like illnesses during three successive winters (1995-96, 1996-97, and 1997-98).


METHODS
Nasopharyngeal swabs routinely submitted for virological surveillance were examined by multiplex reverse transcription PCR for influenza A and B viruses and RSV A and B, and findings were related to the clinical incidence of influenza-like illness and acute bronchitis at that time. RSV strains identified were compared with those obtained from hospital admissions.


RESULTS
480 RSV and 709 influenza viruses were identified from a total of 2226 swabs submitted. Both types of virus were found in all age-groups for between 12 and 20 weeks in each winter. RSV A accounted for 60% of RSV detections. Similar strains of RSV were present in hospital and community patients within the same year, but there were different lineages each year.


CONCLUSIONS
In individuals diagnosed with influenza-like illness, there is a substantial potential for confusion between illnesses caused by influenza and those caused by RSV. The burden of illness attributable to each needs to be clarified to define optimum management routines.
Zambon
M C
MC
Virus Reference Division, PHLS Central Public Health Laboratory, 61 Colindale Avenue, NW9 5HT, London, UK. mzambon@phls.org.uk
Stockton
J D
JD
Clewley
J P
JP
Fleming
D M
DM
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000821:virology*; D004196:Disease Outbreaks; D006801:Humans; D015994:Incidence; D007223:Infant; D007251:Influenza, Human / Q000453:epidemiology / Q000821:virology*; D008875:Middle Aged; D008969:Molecular Sequence Data; D009975:Orthomyxoviridae / Q000302:isolation & purification*; D011159:Population Surveillance; D012367:RNA, Viral / Q000235:genetics; D012136:Respiratory Syncytial Viruses / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D006113:United Kingdom / Q000453:epidemiology
D012367:RNA, Viral