Clinical and demographic characteristics of seasonal influenza in pediatric patients with cancer.

BACKGROUND

Changes in oncology care and the diagnosis and management of influenza over the past several decades may have altered the epidemiology and outcomes of influenza in pediatric oncology patients.

METHODS

The clinical features and outcomes of 102 pediatric patients undergoing cancer therapy during 107 episodes of influenza between January 2002 and April 2009 were retrospectively ascertained.

RESULTS

Median age at the time of influenza was 7.2 years (interquartile range: 3.8-11.2 years); 46% of patients were male. Nineteen patients (18%) were recipients of hematopoietic stem cell transplants. Patients' median absolute neutrophil and lymphocyte counts were 1300/μL (interquartile range: 500-2967/μL) and 360/μL (interquartile range: 180-836/μL), respectively. Twelve patients (11%) had coinfections with influenza and one or more other respiratory pathogens. Influenza prompted patients' hospitalization during 64% of episodes, and 75% received antiviral therapy. Complications occurred in 30% of infections and serious complications occurred in 7%. Three patients died, but no deaths were directly attributable to influenza. Most patients had delays in cancer therapy; the median delay was 5 days. Neutropenia, concurrent infection, increasing age and having received hematopoietic stem cell transplant increased the risk of serious complications.

CONCLUSIONS

Advances in the management of pediatric cancer and influenza have not altered the epidemiology and outcome of influenza in oncology patients. Clinical features identify subgroups of patients with influenza who are at risk of poor outcomes and those with a good prognosis.