American Society of Hematology: Sickle Cell Disease, Increased Severity of Pandemic H1N1 Influenza in Children and Young Adults #ASH09

Patients with sickle cell disease are more susceptible to infection than the general population. In particular, influenza, a viral disease that affects the respiratory system, is more than 50 times more frequent in children with sickle cell disease than in the general population, according to research conducted by John J. Strouse, MD, PhD, the lead author on this study, and colleagues. As H1N1 influenza, which began circulating in the United States in April 2009, has been reported to cause more severe illness in children and young adults than seasonal flu, researchers from The Johns Hopkins University School of Medicine in Baltimore sought to compare the clinical characteristics and complications associated with these infections in sickle cell disease patients under the age of 21 through a prospective analysis of patient discharge and billing records from September 1993 through July 2009.

During the study period, 99 patients who were seen at The Johns Hopkins Hospital in Baltimore were identified as having both sickle cell disease and influenza (89 with seasonal influenza and 10 with H1N1 influenza). Clinical symptoms, such as fever, cough, and runny nose, were similar between the two groups, although those with H1N1 influenza were at an estimated three-fold increased risk for life-threatening complications, such as acute chest syndrome (a severe lung illness), and nine times more likely to require intensive care, such as ventilator support.

 “Our findings underscore that receiving a vaccination against H1N1 influenza, in addition to seasonal influenza, is extremely important for the health and safety of children and young adults with sickle cell disease,” said lead author John J. Strouse, MD, PhD, Assistant Professor of Pediatrics and Medicine at The Johns Hopkins University School of Medicine in Baltimore.