Comparison of influenza A and influenza B virus infection in hospitalized children.
BACKGROUND
Influenza A and B viruses were cocirculating in Australia in the winter of 1997.


OBJECTIVE
To compare the clinical and demographic features of children with influenza A or influenza B virus infection admitted to a paediatric tertiary referral centre.


METHODS
Retrospective chart review of 91 hospitalized children with culture-proven influenza A or B virus infection during 1997.


RESULTS
Thirty-six (56%) of 64 children with influenza A were under 12 months of age compared with seven (26%) of 27 children with influenza B virus infection (P = 0.02). Influenza B virus infection was more common in children with underlying medical problems (P = 0. 01). Neurological manifestations were present in eight (12.5%) of 64 children with influenza A and none with influenza B virus infection (P = 0.09). There were no significant differences in signs and symptoms of children with influenza A and B virus infection, in severity of illness or in duration of hospital stay.


CONCLUSIONS
A greater proportion of children admitted with influenza A virus infection were under 12 months of age. Influenza B virus infection is associated more commonly with underlying medical disorders. It is not possible to differentiate between influenza A or B virus infection from presenting clinical signs and symptoms.
Department of Immunology and Infectious Diseases, Royal Alexandra Hospital for Children, Westmead, New South Wales, Australia. andrewd@icpmr.wsahs.nsw.gov.au
A J
AJ
Daley
R
R
Nallusamy
D
D
Isaacs
D001315:Australia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D006192:Haemophilus Infections / Q000175:diagnosis / Q000453:epidemiology / Q000534:rehabilitation / Q000821:virology; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D019741:Haemophilus influenzae type b / Q000302:isolation & purification; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007902:Length of Stay; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index