Association of Rhinovirus and Potentially Pathogenic Bacteria Detections in the First 3 Months of Life With Subsequent Wheezing in Childhood

Determining association between viral and bacterial infections in the first 3 months of life with wheezing by 2 years or asthma by 5 to 7 years.Infants in Australia born 36 to 42 weeks’ gestation without congenital or chronic conditions from 2 metropolitan hospitals (government funded and private).This was a birth cohort study of 158 infants between September 2010 to October 2012. The patients had weekly nasal swabs obtained by parents and symptom diaries until 2 years of life for wheezing and questionnaires annually from 3 to 7 years. Swabs were sent for polymerase chain reaction testing of multiple respiratory viruses and potentially pathogenic bacteria (S. pneumoniae, M. catarrhalis, and H. influenzae). Asthma was considered if the family self-reported diagnosis by a physician or if the patient had used an inhaled corticosteroid or beta-2 agonist.One hundred forty six infants completed the 3 to 24 month portion and 84 completed the subsequent 3 to 7 year follow up. The majority were 39 to 41 weeks’ gestation, first children, and had at least 1 parent with a history of asthma. Swabs that identified either virus and/or potentially pathogenic bacteria totaled 33.1%. Within the first 3 months of life, 48.6% of positive swabs had rhinovirus, 49.3% for S. pneumoniae, 28.1% for M. catarrhalis, and 10.9% for H. influenzae. Rhinovirus infections within the first 3 months of life were not statistically significant for wheezing episodes but nearing significance (inter-rater reliability 1.16, 95% confidence interval 0.99–1.35). Regarding asthma diagnosis at age 5 to 7 years, only H. influenzae infections had odds nearing significance (odds ratio 2.35, confidence interval 0.99–5.58).Although there was no significant association between early life infections and later development of wheeze and/or asthma in this cohort, rhinovirus infections had a risk nearing significance for wheezing and infections with H. influenzae for later asthma diagnosis; however, these results were less significant when considering confounding variables.Increased attention is being directed at causative exposures during infancy and childhood conferring increased risk of atopic disease. Although the goal of this birth cohort was to identify causative infectious agents, the power was small and was unable to reach significance to draw any specific conclusions. However, this, and other studies examining early childhood exposures, should encourage stratification of infants and children at risk for the progression of respiratory tract disease later in life, and, thus, more likely to benefit from earlier intervention of controller therapy. This study continues to grow the evidence that other viral infections beyond respiratory syncytial virus may affect the risk of asthma.