A new study shows that maternal asthma may increase risk for human metapneumovirus (hMPV) lower respiratory tract illness (LRTI) in children.

hMPV is associated with 5% to 25% of all cases of LRTI in infants and young children and can elicit life-threatening disease. A potential association between hMPV and asthma suggests that hMPV may preferentially affect patients with asthma. Therefore, researchers conducted a prospective multicenter active surveillance study to characterize the burden of severe LRTI in children from a low-income region in Buenos Aires, Argentina, from 2011 to 2013. 

Of 3947 children, 383 (10%) were infected with hMPV. The hospitalization rate for hMPV LRTI was 3.8 per 1000 infants and 2.26 per 1000 children younger than 2 years, 39 (10.2%) patients infected with hMPV experienced life-threatening disease, and 2 patients died. In a subgroup of children with hMPV (either as a single pathogen or as part of a coinfection), the researchers explored whether these children experienced disease of different severity than children infected with other viruses. The researchers found that hMPV LRTI was milder than disease that stemmed from respiratory syncytial virus, human rhinovirus, and/or influenza A (odds ratio, 0.53; 95% CI, 0.36-0.79)