A Comparison of Characteristics and Outcomes in Severe Human Metapneumovirus and Respiratory Syncytial Virus Infections in Children Treated in an Intensive Care Unit

Background: Human metapneumovirus (HMPV) and respiratory syncytial virus (RSV) are among the leading causes of respiratory tract infections requiring admission to the pediatric intensive care unit (PICU). We evaluated the risk factors, clinical courses and outcomes of severe HMPV disease relative to severe RSV in children admitted to the PICU. Methods: Retrospective chart review of children 18 years old admitted to a tertiary PICU between October 2008 through July 2010 with acute respiratory tract infection and positive direct antigen stain or polymerase chain reaction for RSV or HMPV. Results: One hundred thirty-three patients met inclusion criteria: 107 (80.5%) with RSV and 26 (19.5%) with HMPV. HMPV-infected patients were older than RSV children (3.4 vs. 1.5 years, P = 0.002) and more likely to have congenital heart disease (34.6% vs. 10.3%, P = 0.002). Although HMPV children required longer duration of mechanical ventilation (11 vs. 7 days, P = 0.01), there were no other differences in hospital course. HMPV patients were more likely to be discharged receiving inhaled steroids (53.8% vs. 30.8%, P = 0.03), but there were no differences in other outcome assessments. Conclusions: Children admitted to the PICU with HMPV are significantly older and more likely to have congenital heart disease than those with RSV. The course of illness was similar between the 2 groups, but HMPV-infected children were more likely to be discharged with inhaled steroid therapy.