Maternal asthma may increase the risk for life-threatening disease in children who are hospitalized for severe human metapneumovirus (hMPV) lower respiratory tract illness (LRTI), according to study results published in The Journal of Infectious Diseases.
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)
However, children born to mothers with asthma are at increased risk for life-threatening disease, as 28% of hMPV-infected patients hospitalized with LRTI and born to mothers with asthma experienced life-threatening disease compared with only 8% of hMPV-infected patients hospitalized and born to mothers without asthma.
Some study limitations were noted, including the observational nature of the design as well as the fact that no analysis was performed for all other possible viruses (eg, coronavirus or parainfluenza virus type 3).
“While the virus appears to elicit milder disease among hospitalized children than other agents, among children admitted with hMPV LRTI, those born to asthmatic mothers are at increased risk for life-threatening disease,” the researchers wrote. “…If confirmed in other studies and populations, these observations would be of considerable public health importance, given that asthma is the most frequent chronic disease during pregnancy with rising prevalence…”
Libster R, Esteban I, Bianchi A, et al; for the INFANT Respiratory Network. Role for maternal asthma in severe human metapneumovirus lung disease susceptibility in children [published on January 22, 2020]. J Infect Dis. doi:10.1093/infdis/jiaa019