Respiratory syncytial virus infection in hospitalized children older than 2 years with community-acquired pneumonia.

BACKGROUND/AIM Respiratory syncytial virus (RSV) is one of the main causes of bronchiolitis and pneumonia in infants and young children. The aims of the present study were to evaluate the role of RSV in children >2 years old hospitalized with community-acquired pneumonia (CAP) and to type the circulating RSV strains. MATERIALS AND METHODS Serum and throat swab samples were taken upon admission from Greek children aged > 2 years, hospitalized with atypical CAP, and when possible, a second serum sample was also taken. RSV IgG and IgM antibodies were determined by Enzyme Linked Immunosorbent Assay (ELISA), while throat swab samples were tested by nested RT-PCR. Additional serological testing was performed to find out probable co-infections. RESULTS A total of 101 children with atypical CAP were included in the study, aged 2.5-14 years (median 8.25). RSV IgM antibodies were detected in 21 (20.7%) cases, either in the first or/and in the second serum sample, while RSV genome was detected in 11 out of 15 (73%) IgM-positive patients, which were further tested by PCR. PCR-positive results were obtained up to the 7(th) day of illness. Among the 11 cases, one was of type B, and all the rest were of type A. The median age of the RSV-positive children was 4 years (range 3-13 years). Although RSV was detected in all seasons, the majority of cases (31%) were detected in winter. Co-infection was detected in 3 cases (two with Mycoplasma pneumoniae and one with adenovirus). CONCLUSIONS Apart from the known role of RSV as the most important pathogen causing acute respiratory disease in infants and young children, it is also a significant viral pathogen in older children hospitalized because of CAP. Genetic typing provides further insight into the epidemiology of the disease.