Detection and typing by molecular techniques of respiratory viruses in children hospitalized for acute respiratory infection in Rome, Italy

Abstract

Detection of a broad number of respiratory viruses is not undertaken currently for the diagnosis of acute respiratory infection due to the large and always increasing list of pathogens involved. A 1-year study was undertaken on children hospitalized consecutively for acute respiratory infection in a Pediatric Department in Rome to characterize the viruses involved. Two hundred twenty-seven children were enrolled in the study with a diagnosis of asthma, bronchiolitis, bronchopneumonia, or laringo-tracheo bronchitis. A molecular approach was adopted using specific reverse transcription (RT)-PCR assays detecting 13 respiratory viruses including metapneumovirus (hMPV) and the novel coronaviruses NL63 and HKU1; most amplified fragments were sequenced to confirm positive results and differentiate the strain. Viral pathogens were detected in 97 samples (42.7%), with 4.8% of dual infections identified; respiratory syncytial virus (RSV) was detected in 17.2% of children, followed by rhinovirus (9.7%), parainfluenza virus type 3 (PIV3) (7.5%), and influenza type A (4.4%). Interestingly, more than half the patients (9/17) that have rhinovirus as the sole respiratory pathogen had pneumonia. HMPV infected children below 3 years in two peaks in March and June causing bronchiolitis and pneumonia. One case of NL63 infection is described, documenting NL63 circulation in central Italy. In conclusion, the use of a comprehensive number of PCR-based tests is recommended to define the burden of viral pathogens in patients with respiratory tract infection.

Parainfluenza virus infections in a tropical city: clinical and epidemiological aspects

“…The rate of detection of HPIV in clinical samples of children included in the present study is within the range of minimum (0.31%) and maximum (13%) rates reported in other studies [16][17][18][19][20][21][22][23]. The highest rates of identification of HPIV (13%) have been achieved using isolation in cell culture and RT-PCR [22,23].…”

“…The predominance of HPIV-3 among the three subtypes of HPIV analyzed in this study was also demonstrated in several studies [6][7][8][18][19][20]26,27]. In an Italian study of ARI in hospitalized children, using nasal wash as the clinical sample and molecular techniques for thirteen respiratory viruses, HPIV-3 was the only HPIV found, representing 7.5% of identified viruses [21]. It is interesting to compare the results of the present study with those obtained during a community based study conducted in the city of Fortaleza over 29 consecutive months, when 62 infections by HPIV were identified and HPIV-2, HPIV-1 and HPIV-3 represented 54.8%, 21% and 13%, respectively of HPIV identified [28].…”

Comparison of direct immunofluorescence, conventional cell culture and polymerase chain reaction techniques for detecting respiratory syncytial virus in nasopharyngeal aspirates from infants

“…However, the IF technique requires a sample rich in cells, expertise in handling an immunofluorescence microscope 10 and is less sensitive than RT-PCR 18,20,22 . Our in house RT PCR could detect as few as 100 RSV copies, and this analytic sensitivity is similar to RT assays used in other studies 16 . We excluded the possibility of non-specificity of the RT-PCR assay using sequencing to confirm samples that were positive for RSV.…”

RSV Associated Disease in Hospitalized Children in Southeast Brazil: Higher Frequency in Older Children Than in Infants

“…As expected, RSV was significantly associated with bronchiolitis 68.2% (p≤0.001), a finding that confirms most previously published studies (Peret et al 1998, Pierangeli et al 2007, Vicente et al 2003, Jartti et al 2004). …”