Daily viral prevalence was the greatest predictor of asthma hospitalizations in children, according to Rosalind M. Eggo and her associates.
Asthma hospitalizations in children occurred most frequently during the school year, and dropped off dramatically when school was out. Increases were not driven by triggers within the school environment, but by increased transmission and prevalence of viruses such as the common cold, the researchers noted. Common cold transmission rates were 45% lower during school holidays and breaks, and asthma hospitalizations decreased accordingly.
In adults, asthma hospitalizations were greatest during the winter and were most influenced by influenza prevalence. Low temperatures were an important risk factor for both groups; however, ozone and particulate matter were not.
“In general, future risk assessments and interventions for asthma, particularly in children, should explicitly consider both the school calendar and the seasonal dynamic of infectious triggers, either through spatiotemporal modeling or when possible, viral surveillance data,” the investigators concluded.
Find the study in PNAS (doi: 10.1073/pnas.1518677113).