This study aimed to determine which meteorological conditions are associated with respiratory syncytial virus (RSV) isolates in a population of children hospitalized with acute lower respiratory infection (ALRI) in Bogota, Colombia. In an analytical cross-sectional study, links were examined between the number of monthly RSV infections and monthly average climatic variation (temperature, relative humidity, rainfall, wind speed, solar radiation) between 1 January 2010 and 30 April 2011 in a population of hospitalized children aged <3 years with ALRI caused by RSV. Out of a total of 1548 children included in the study (mean age 9·2 ± 8·5 months), 1194 (77·1%) presented RSV infection during the 3-month period from March to May. In the multivariate analysis, after controlling for wind speed, relative humidity, and solar radiation, monthly average temperature [incident rate ratio (IRR) 3·14, 95% confidence interval (CI) 1·56-6·30, P = 0·001] and rainfall (IRR 1·008, 95% CI 1·00-1·01, P = 0·048) were independently associated with the monthly number of RSV infections. In conclusion, in Bogota, a tropical Latin American city, average temperature and rainfall are the meteorological variables most strongly associated with RSV isolation in children hospitalized with ALRI in the city.

Although predictors of severe viral acute lower respiratory infections (ALRIs) in children have been reported, there have been few research studies performed in low- and middle-income countries (LMIC). The aim of the present study was to determine predictors of disease severity in a population of Colombian children <5 years of age with ALRI. In a prospective cohort study, we determined independent predictors of severe ALRI in a hospitalized population of children under 5 years old with ALRI during a 1-year period. We included both underlying disease conditions and the infecting respiratory viruses as predictor variables of severe disease. We defined severe disease as the necessity of pediatric intensive care unit admission. Of a total of 1,180 patients admitted with a diagnosis of ALRI, 416 (35.3%) were included because they were positive for any kind of respiratory virus. After controlling for potential confounders, it was found that a history of pulmonary hypertension (RR 3.62; CI 95% 2.38-5.52; P < 0.001) and a history of recurrent wheezing (RR 1.77; CI 95% 1.12-2.79; P = 0.015) were independent predictors of severe disease. The present study shows that respiratory viruses are significant causes of ALRI in infants and young children in Colombia, a typical tropical LMIC, especially during the rainy season. Additionally, the results of the present study show that clinical variables such as a history of pulmonary hypertension and a history of recurrent wheezing are more relevant for predicting ALRI severity than the infecting respiratory viruses.

Although there is increasing evidence showing that infants with viral bronchiolitis exhibit a high degree of heterogeneity, a core uncertainty shared by many clinicians is with regard to understanding which patients are most likely to benefit from bronchodilators such as albuterol. Based on our review, we concluded that older infants with rhinovirus (RV) bronchiolitis, especially those with a nasopharyngeal microbiome dominated by Haemophilus influenzae; those affected during nonpeak months or during non-respiratory syncytial virus (RSV) predominant months; those with wheezing at presentation; those with clinical characteristics such as atopic dermatitis or a family history of asthma in a first-degree relative; and those infants infected with RSV genotypes ON1 and BA, have the greatest likelihood of benefiting from albuterol. Presently, this patient profile could serve as the basis for rational albuterol administration in patients with viral bronchiolitis, at least on a therapeutic trial basis, and it could also be the starting point for future targeted randomized clinical trials (RCTs) on the use of albuterol among a subset of infants with bronchiolitis.