Respiratory syncytial virus (RSV) in infants hospitalized for acute lower respiratory tract disease: incidence and associated risks

• Published in: The Brazilian journal of infectious diseases Vol. 10; no. 5; pp. 357 - 361
• Main Authors: Riccetto, Adriana Gut Lopes, Ribeiro, José Dirceu, Silva, Marcos Tadeu Nolasco da, Almeida, Renata Servan de, Arns, Clarice Weis, Baracat, Emílio Carlos Elias
• Format: Journal Article
• Language: English
• Published: Brazil Brazilian Society of Infectious Diseases 01.10.2006; Elsevier
• Subjects: Acute Disease; Acute respiratory infection; Brazil - epidemiology; Epidemiologic Methods; Female; Humans; Infant; Infant, Newborn; INFECTIOUS DISEASES; Male; respiratory syncytial virus; Respiratory Syncytial Virus Infections - epidemiology; Respiratory Tract Infections - epidemiology; Respiratory Tract Infections - virology; risk factors; Seasons; Socioeconomic Factors; Brazil; respiratory syncytial virus; risk factors; Acute respiratory infection
• ISSN: 1413-8670; 1678-4391; 1413-8670
• DOI: 10.1590/s1413-86702006000500011

Respiratory syncytial virus (RSV) is one of the main causes of acute lower respiratory tract infections worldwide. We examined the incidence and associated risks for RSV infection in infants hospitalized in two university hospitals in the state of São Paulo. We made a prospective cohort study involving 152 infants hospitalized for acute lower respiratory tract infections (ALRTI) in two university hospitals in Campinas, São Paulo, Brazil, between April and September 2004. Clinical and epidemiological data were obtained at admission. RSV was detected by direct immunofluorescence of nasopharyngeal secretions. Factors associated with RSV infection were assessed by calculating the relative risk (RR). The incidence of RSV infection was 17.5%. Risk factors associated with infection were: gestational age less than 35 weeks (RR: 4.17; 95% confidence interval (CI) 2.21-7.87); birth weight less than or equal to 2,500 grams (RR: 2.69; 95% CI 1.34-5.37); mother's educational level less than five years of schooling (RR: 2.28; 95% CI 1.13-4.59) and pulse oximetry at admission to hospital lower than 90% (RR: 2.19; 95% CI 1.10-4.37). Low birth weight and prematurity are factors associated with respiratory disease due to RSV in infants. Low educational level of the mother and poor socioeconomic conditions also constitute risk factors. Hypoxemia in RSV infections at admission indicates potential severity and a need for early oxygen therapy.