Assessment of Wheezing Frequency and Viral Etiology on Childhood and Adolescent Asthma Risk

Abstract

Viral respiratory wheezing illnesses are common in early childhood, and many children who wheeze subsequently develop asthma. In the Childhood Origins of ASThma (COAST) cohort, we have previously reported that rhinovirus (RV) wheezing illnesses in infancy and early childhood are the most robust predictor of subsequent asthma development in high-risk children at age 6 years, regardless of aeroallergen sensitization or other risk factors.(1) However, a similar high-risk birth cohort has recently reported that the number of lower respiratory episodes in the first three years of life, as opposed to a specific viral or bacterial etiology, is associated with asthma risk, and suggested that the specific microbiologic trigger is not important for the risk of later asthma development.(2) This discrepancy in the literature is important to address as it may impact how risk of childhood asthma is ascertained; accurate identification of high-risk children may be key to asthma prevention. Therefore, we assessed the contribution of etiology and frequency of wheezing illnesses on asthma risk from ages 6 to 13 years in the COAST birth cohort study, which included children born to parents with either allergy or asthma. We hypothesized that the number of RV wheezing illnesses would be a more robust predictor of asthma development and persistence when compared to the number of non-RV wheezing illnesses.

Microbes, allergic sensitization, and the natural history of asthma

“…(33) However, in the COAST cohort, the number of early life wheezing illnesses, irrespective of etiology, is also found to be important for asthma risk; however, the number of rhinovirus wheezing illnesses is the most robust asthma predictor in children to age 13. (34) Wheezing with RSV in the first 3 years of life was associated with an increased risk of asthma at ages 6, 8, and 11 years, but this was no longer significant at 13 years (OR, 2.8, 2.6, 2.9, and 1.6). (12) Wheezing with RV during the first 3 years of life was associated with a greater increased risk of asthma at age 6, 8, and 11 years that, unlike RSV, persisted out to the 13th year of age (OR, 7.9, 7.5, 6, and 3.4) In a multivariate model adjusted for wheezing with other viruses, RSV wheezing in the first 3 years of life was not associated with an increased asthma risk at any age.…”

Beyond Respiratory Syncytial Virus and Rhinovirus in the Pathogenesis and Exacerbation of Asthma

“…4,5 RV and RSV are the most frequently detected pathogens (see Table 1), with RSV more prevalent in younger children in winter months and RV more prevalent in older children. 2 There is a large body of evidence implicating the association of RV [6][7][8] and RSV 9,10 with the subsequent development of recurrent wheezing and/or asthma. Viruses other than RV or RSV can be detected in 50% of wheezing illnesses, 1,11,12 but there are limited data regarding the association of these other viruses and asthma.…”

Lessons learned from birth cohort studies conducted in diverse environments

“…33 Furthermore, statistical models that included viral cause were most informative for predicting the risk for asthma at 6-, 8-, 11-, or 13-year assessments. 65 Rhinoviruses were detected in 49% of wheezing episodes in the first 3 years, and the number of rhinovirus-related wheezing episodes were most predictive for asthma risk. 65 …”

“…65 Rhinoviruses were detected in 49% of wheezing episodes in the first 3 years, and the number of rhinovirus-related wheezing episodes were most predictive for asthma risk. 65 …”