Multiple simultaneous viral infections in infants with acute respiratory tract infections in Spain

BACKGROUND: The clinical significance of the presence of more than one type of virus in the respiratory specimens of children with respiratory infections is not clear. OBJECTIVES: To describe the clinical characteristics of multiple viral infections versus single infection by respiratory syncytial virus (RSV) in hospitalized infants. STUDY DESIGN: This is a prospective study conducted in all infants under 2 years of age admitted for acute respiratory infection (September 2000–June 2003) in a secondary teaching hospital. Virological diagnosis was made by two different multiplex reverse transcription-nested polymerase chain reaction (RT-PCR) assays in nasopharyngeal aspirates. We describe the clinical characteristics of the patients with multiple viral infections and compare them to a group of 86 randomly selected patients infected only with RSV. RESULTS: 749 specimens taken were analyzed. Respiratory viruses were detected in 65.9% of the samples. 86 children had multiple viral infections (17.4% of all positive specimens). The most frequent clinical diagnosis in this group was recurrent wheezing in 44% and bronchiolitis in 52%. Fever was significantly more frequent (p < 0.001), hospital stays were longer (p = 0.05), and antibiotic treatment was used more (p = 0.03) in infants with multiple viral infections than in the RSV-infected group. CONCLUSIONS: Multiple viral infections are frequent in hospitalized children with respiratory tract disease (17.4%). Multiple viral infections are linked to higher fever, longer hospital stays and more frequent use of antibiotics than in the case of infants with single RSV infections.