PREVALENCE OF RESPIRATORY VIRUSES IN CASES OF PEDIATRIC ACUTE RESPIRATORY TRACT ILLNESSES IN BULGARIA
I. TRIFONOVA1*, S. ANGELOVA1, I. GEORGIEVA1, S. VOLEVA1, I. TZOCHEVA2, S. LAZOVA2, S. PARINA2, P. PERENOVSKA2, N. KORSUN1
1 National Laboratory “Influenza and ARD”, Department of Virology, National Centre of Infectious and Parasitic Diseases (NCIPD), Sofia, Bulgaria.
2 Pediatric clinic, University Hospital Alexandrovska, Medical University, Sofia, Bulgaria
*Corresponding author:e-mail: trifonova.ivelina@abv.bg
Keywords: pediatric acute respiratory illnesses, respiratory viruses, pneumonia, bronchiolitis
Abstract: Acute respiratory illnesses (ARI) are the most prevalent infectious diseases in pediatrics. This study aimed to determinate the frequency and clinical significance of the most often respiratory viruses among children aged <5 years with ARI in Bulgaria during the 2016/17 winter season.
Nasopharyngeal specimens of 398 young children from different country regions were collected and tested using individual Real Time PCR assays for detection of influenza viruses A/B, respiratory-syncytial virus (RSV), metapneumovirus (MPV), parainfluenza viruses (PIV 1/2/3), rhinoviruses (RV), adenoviruses (AdV) and bocaviruses (BoV). Samples with negative results were tested for human coronaviruses, PIV4 and enteroviruses (EV) by Multiplex PCR method using a Seeplex RV15 ACE Detection kit.
A total of 365 respiratory viruses were identified using Real Time PCR and the numerical distribution of influenza A(H1N1)pdm09, A(H3N2) and B, AdV, RV, RSV, BoV, MPV, PIV 1, PIV 2, PIV 3 was obtained as: 4 (1,1%), 85 (23%), 4 (1,1%), 40 (11%), 34 (9%), 142 (39%), 12 (3,3%), 25 (7%), 0 (0%), 5 (1,4%), 15 (4,1%), respectively. Among the 91 samples tested by Multiplex PCR, coronaviruses NL63 and OC4, EV and PIV 4 were detected in 8%, 1% and 1% of specimens, respectively. Viral respiratory tract infections occurred mainly in December, January and February.
According to study results, RSV, influenza A(H3N2) and AdV were the most frequently detected viruses and affected at most 0-4 age group. The study highlights the necessity of routine surveillance of respiratory viruses in order to determine their spreading and participation in etiology of ARI