Distribution and seasonality of rhinovirus and other respiratory viruses in a cross-section of asthmatic children in Trinidad, West Indies.

ABSTRACT

BACKGROUND: Childhood asthma in the Caribbean is advancing in prevalence and morbidity. Though viral respiratory tract infections are reported triggers for exacerbations, information on these infections with asthma is sparse in Caribbean territories. We examined the distribution of respiratory viruses and their association with seasons in acute and stable asthmatic children in Trinidad. METHODS: In a cross-sectional study of 70 wheezing children attending the emergency department for nebulisation and 80 stable control subjects (2 to 16 yr of age) in the asthma clinic, nasal specimens were collected during the dry (n=38, January to May) and rainy (n=112, June to December) seasons. A multitarget, sensitive, specific high-throughput Respiratory MultiCode assay tested for respiratory-virus sequences for eight distinct groups human rhinovirus, respiratory syncytial virus, parainfluenza virus, influenza virus, metapneumovirus, adenovirus, coronavirus, and enterovirus. RESULTS: Wheezing children had a higher [chi square =5.561, p=0.018] prevalence of respiratory viruses compared with stabilized asthmatics (34.3 per cent (24) versus (vs.) 17.5 per cent (14)). Acute asthmatics were thrice as likely to be infected with a respiratory virus (OR = 2.5, 95 per cent CI = 1.2 - 5.3). The predominant pathogens detected in acute versus stable asthmatics were the rhinovirus (RV) (n=18, 25.7 per cent vs. n=7, 8.8 per cent; p=0.005), respiratory syncytial virus B (RSV B) (n=2, 2.9 per cent vs. n=4, 5.0 per cent), and enterovirus (n=1, 1.4 per cent vs. n=2, 2.5 per cent). Strong odds for rhinovirus infection were observed among nebulised children compared with stable asthmatics (p=0.005, OR = 3.6, 95 per cent CI = 1.4 - 9.3,). RV was prevalent throughout the year (Dry, n=6, 15.8 per cent; Rainy, n=19, 17.0 per cent) and without seasonal association [chi square =0.028, p=0.867]...