Respiratory syncytial virus and seasonal influenza cause similar illnesses in children with sickle cell disease.
BACKGROUND
Respiratory syncytial virus (RSV) is a cause of acute chest syndrome (ACS) in sickle cell disease (SCD), but its clinical course and acute complications have not been well characterized. We compared RSV to seasonal influenza infections in children with SCD.


METHODS
We defined cases as laboratory-confirmed RSV or seasonal influenza infection in inpatients and outpatients <18 years of age with SCD from 1 September 1993 to 30 June 2011. We used Fisher's exact test to compare proportions, Student's t-test or Wilcoxon rank-sum test to compare continuous variables, and logistic regression to evaluate associations.


RESULTS
We identified 64 children with RSV and 91 with seasonal influenza. Clinical symptoms, including fever, cough, and rhinorrhea were similar for RSV and influenza, as were complications, including ACS and treatments for SCD. In a multivariable logistic regression model, older age (OR 1.2 per year, 95% CI [1.02-1.5], P = 0.04), increased white blood cell count at presentation (OR 1.1 per 1,000/μl increase, 95% CI [1.03-1.3], P = 0.008), and a history of asthma (OR 7, 95% [CI 1.3-37], P = 0.03) were independently associated with increased risk of ACS in children with RSV. The hospitalization rate for children with SCD and RSV (40 per 1,000 <5 years and 63 per 1,000 <2 years) greatly exceeds the general population (3 in 1,000 <5 years).


CONCLUSIONS
We conclude that RSV infection is often associated with ACS and similar in severity to influenza infection in febrile children with SCD.
Division of Pediatric Pulmonology, Department of Pediatrics, Johns Hopkins University, Baltimore, Maryland.
Sara Christina
SC
Sadreameli
Megan E
ME
Reller
David G
DG
Bundy
James F
JF
Casella
John J
JJ
Strouse
D056586:Acute Chest Syndrome / Q000175:diagnosis / Q000821:virology; D000755:Anemia, Sickle Cell / Q000175:diagnosis* / Q000821:virology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D005334:Fever / Q000175:diagnosis / Q000821:virology; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D009980:Influenza A virus / Q000472:pathogenicity*; D007251:Influenza, Human / Q000175:diagnosis*; D008297:Male; D011379:Prognosis; D018357:Respiratory Syncytial Virus Infections / Q000175:diagnosis*; D012136:Respiratory Syncytial Viruses / Q000472:pathogenicity*; D012621:Seasons
acute chest syndrome; influenza; respiratory syncytial virus; sickle cell disease