Human metapneumovirus: an emerging respiratory pathogen.

Human metapneumovirus (hMPV) is an important emerging respiratory pathogen, previously unreported in the Emergency Medicine literature. It is primarily associated with the clinical syndromes of bronchiolitis and pneumonia. hMPV may predispose to bacterial pneumonia; coinfection with respiratory syncytial virus may lead to increased severity of clinical disease, and complications include asthma and chronic obstructive pulmonary disease exacerbations. Given its high prevalence and potential clinical implications as these patients present to the Emergency Department with initial infection or subsequent complications, a better understanding of hMPV will aid in their care. We report the case of a 13-month old who developed lobar pneumonia 3 weeks after being diagnosed with hMPV. The epidemiology, clinical presentation, complications, and treatment of hMPV are then discussed.