Short-term relevance of lower respiratory viral coinfection in inpatients under 2 years of age.

Introduction: Advances in molecular diagnosis have made it possible to detect previously unknown viral agents as causative agents of lower respiratory tract infections (LRTI). The frequency and relevance of viral coinfections is still debatable.

Objective: Compare clinical presentation and severity between single virus infection and viral coinfection in children admitted for LRTI.

Methods: A 3-year period observational study (2012-2015) included children younger than two years admitted for LRTI. Viral identification was performed using PCR technique for 16 viruses. Clinical data and use of health resources was gathered during hospital stay using a standard collection form and we compared single virus infection and viral coinfections.

Results: The study included 524 samples (451 patients); 448 (85.5%) had at least one virus identified. Viral coinfections were found in 159 (35.5%). RSV and HRV were the most commonly identified virus; bronchiolitis and pneumonia the most frequent diagnosis. Patients with viral coinfections were older, attended day-care centers, had previous recurrent wheezing more frequently and were more symptomatic at admission. These patients did not have more complementary exams performed but were prescribed medications more often. Viral coinfection group did not show longer length of hospital stay and oxygen need, more need for ICU nor ventilatory support.

Discussion: Our study showed a significant proportion of viral coinfections in young infants admitted with LRTI and confirmed previous data showing that prescription was more frequent in inpatients with viral coinfections, without an association with worst clinical outcome.