Respiratory viruses in infants in a pediatric sentinel surveillance unit, Brazil

Abstract

Purpose: There are scarce data in determining the epidemiology and etiology of, and risk factors for severe acute lower respiratory infection (ALRI) in middle and low-income countries. Brazil developed a surveillance system for severe cases of ALRI after influenza pandemic in 2009. Therefore, we evaluated and analyzed data from a pediatric sentinel site for influenza and other respiratory viruses in Brazil. Methods & Materials: We performed a descriptive study in a pediatric intensive care unit, which is a sentinel unit for influenza and other respiratory viruses surveillance, located in Brasilia, Brazil. The study included all cases of ALRI in children ≤24 months old, with a positive result of a viral pathogen obtained from a nasopharyngeal sample, from January 2013 to June 2017. Samples were processed by polymerase chain reaction (PCR). Results: There were 314 cases of ALRI in the study period, 148 had samples collected and 69 (47%) were positive and, thus, included in the study. Fifty-eight (84%) were RSV, 8(11%) were influenza and 5 (5%) were other viruses. Forty-three children (62%) were male, the median age were 4 months (1–20) and 42 (61%) were < 6 months-old. Fifty-six children (81%) presented at least one comorbidity: including preterm birth or low birth weight. RSV cases predominated from March to July. The median time from the beginning of symptoms to hospital admission were 3 days (1–12) and to ICU admission were 5 (1–30). The median time to obtain the laboratory results was 7 days (2–23). Sixty-two children (90%) needed mechanical ventilation, 40 (58%) received oseltamivir and 63 (90%) received antibiotics. There were 3 deaths (4%). Conclusion: The burden of viral severe ALRI in young children is high in middle-income countries, posing a challenge to health services, especially during seasonal epidemics. RSV is the main pathogen of ALRI in children ≤24 months old; the high usage of oseltamivir and antibiotics is mostly useless for children in this age, new preventive methods as vaccine or antivirals are urgently needed. Surveillance systems for respiratory viruses should improve their timeliness to health services access, including ICU and their laboratory capacity.