Down syndrome: a novel risk factor for respiratory syncytial virus bronchiolitis--a prospective birth-cohort study.
OBJECTIVE
Respiratory syncytial virus is the single-most important cause of lower respiratory tract infections in children. Preterm birth and congenital heart disease are known risk factors for severe respiratory syncytial virus infections. Although Down syndrome is associated with a high risk of respiratory tract infections, little is known about the incidence of respiratory syncytial virus infections in this group. The aim of our study was to determine the incidence of respiratory syncytial virus lower respiratory tract infection-associated hospitalization among children with Down syndrome.


METHODS
We performed a retrospective observational study and a prospective nationwide birth-cohort study of children with Down syndrome. The retrospective cohort comprised 176 children with Down syndrome. A birth cohort of 219 children with Down syndrome was prospectively followed until 2 years of age. All 276 siblings of the birth cohort were used as controls.


RESULTS
Of the 395 patients with Down syndrome, 180 (45.6%) had a known risk factor for severe respiratory syncytial virus infections; 39 (9.9%) of these were hospitalized for respiratory syncytial virus lower respiratory tract infections. Two control children (0.7%) versus 9 term children with Down syndrome without congenital heart disease (7.6%) were hospitalized for respiratory syncytial virus lower respiratory tract infections. The median duration of hospitalization was 10 days; mechanical ventilation was required for 5 children (12.8%).


CONCLUSIONS
This is the first study, to our knowledge, to demonstrate that Down syndrome is a novel independent risk factor for severe respiratory syncytial virus lower respiratory tract infections. These findings should prompt studies to investigate possible mechanisms that underlie severe respiratory syncytial virus lower respiratory tract infections in children with Down syndrome. The effect of respiratory syncytial virus prophylaxis in this specific population needs to be established.
Bloemers
Beatrijs L P
BL
Division of Infectious Diseases, University Medical Centre Utrecht, Department of Pediatrics, 3508 AB, Utrecht, The Netherlands.
van Furth
A Marceline
AM
Weijerman
Michel E
ME
Gemke
Reinoud J B J
RJ
Broers
Chantal J M
CJ
van den Ende
Kimberly
K
Kimpen
Jan L L
JL
Strengers
Jan L M
JL
Bont
Louis J
LJ
D000293:Adolescent; D000328:Adult; D001990:Bronchiolitis, Viral / Q000453:epidemiology*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004314:Down Syndrome / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007223:Infant; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D010102:Oxygen Inhalation Therapy / Q000706:statistics & numerical data; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000706:statistics & numerical data; D012136:Respiratory Syncytial Viruses; D012189:Retrospective Studies; D012307:Risk Factors