Viral Coinfection in Childhood Respiratory Tract Infections()

INTRODUCTION: The introduction of molecular techniques has enabled better understanding of the etiology of respiratory tract infections in children. The objective of the study was to analyze viral coinfection and its relationship to clinical severity. METHODS: Hospitalized pediatric patients with a clinical diagnosis of respiratory infection were studied during the period between 2009 and 2010. Clinical and epidemiological data, duration of hospitalization, need for oxygen therapy, bacterial coinfection and need for mechanical ventilation were collected. Etiology was studied by multiplex PCR and low-density microarrays for 19 viruses. RESULTS: A total of 385 patients were positive, 44.94% under 12 months. The most frequently detected viruses were RSV-B: 139, rhinovirus: 114, RSV-A: 111, influenza A H1N1-2009: 93 and bocavirus: 77. Coinfection was detected in 61.81%, 36.36% with two viruses, 16.10% and 9.35% with three to four or more. Coinfection was higher in 2009 with 69.79 vs 53.88% in 2010. Rhinovirus/RSV-B on 10 times and RSV-A/RSV-B on five times were the most detected coinfections. Hospitalization decreased with greater number of viruses (P<.001). Oxygen therapy was required by 26.75% (one virus was detected in 55.34% of cases). A larger number of viruses resulted in less need for oxygen (P<.001). Ten cases required mechanical ventilation, four patients with bacterial coinfection and five with viral coinfection (P=.69). CONCLUSIONS: An inverse relationship was found between the number of viruses detected in nasopharyngeal aspirate, the need for oxygen therapy and hospitalization days. More epidemiological studies and improved quantitative detection techniques are needed to define the role of viral coinfections in respiratory disease and its correlation with the clinical severity.