Human metapneumovirus and respiratory syncytial virus infections in older children with cystic fibrosis.
BACKGROUND
Human metapneumovirus (hMPV) has been isolated from children with acute respiratory infection worldwide. Its epidemiology remains to be defined in children with cystic fibrosis (CF). We describe the epidemiology and clinical impact of hMPV in CF children and compared it to respiratory syncytial virus (RSV).


METHODS
CF children ages 7-18 years were studied prospectively during the 1998 -1999 RSV season. Nasopharyngeal specimens were collected during acute respiratory illnesses and tested for respiratory viruses. Blood specimens were drawn early, mid, and end of the RSV season, and tested for serological evidence of hMPV and RSV infections. Rates of lower respiratory tract illnesses (LRTI) and hospitalizations for pulmonary exacerbations were compared during the time intervals they developed serological evidence of infection to their non-infection intervals.


RESULTS
Six of 44 CF children had a virus positive respiratory illness in 56 LTRI events and 18 hospitalizations. Serological evidence of hMPV and RSV infections occurred in 16 and 20 CF children, respectively; 8 had infections with both viruses. A greater proportion of CF children had >or=1 LRTI during their infection intervals compared to their non-infection intervals (13/25 vs. 5/25; P=0.03). A trend for higher rates of LRTI was observed in the infection intervals compared to non-infection intervals (9.5 +/- 11.0 vs. 4.2 +/- 9.9 per 1,000 child-days; P=0.06), and it was significantly greater with a more conservative estimate (one event per child per interval; 7.4 +/- 7.7 vs. 2.6 +/- 5.4 per 1,000 child-days; P <or=0.01). No differences in hospitalizations rates were detected.


CONCLUSIONS
The infection rates and clinical impact observed for hMPV were comparable to that for RSV in CF children 7-18 years of age.
Garcia
Daniel F
DF
Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA.
Hiatt
Peter W
PW
Jewell
Alan
A
Schoonover
Shauna L
SL
Cron
Stanley G
SG
Riggs
Mark
M
Grace
Susan
S
Oermann
Christopher M
CM
Piedra
Pedro A
PA
D000293:Adolescent; D002648:Child; D003550:Cystic Fibrosis / Q000821:virology*; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D029121:Metapneumovirus / Q000302:isolation & purification; D009017:Morbidity; D009305:Nasopharynx / Q000821:virology; D018184:Paramyxoviridae Infections / Q000175:diagnosis / Q000453:epidemiology*; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis / Q000453:epidemiology*; D018113:Respiratory Syncytial Virus, Human / Q000302:isolation & purification; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000453:epidemiology*