Molecular Characterization of Circulating Respiratory Syncytial Virus (RSV) Genotypes in Gilgit Baltistan Province of Pakistan during 2011-2012 Winter Season

Abstract

Respiratory syncytial virus (RSV) is the major cause of acute lower respiratory tract infections in young children, but very little is known about its epidemiology and circulating genotypes in Pakistan. This study analyzed the epidemiological and molecular characteristics of RSV genotypes detected in Pakistani children less than 2 years of age with acute respiratory tract infections (ARIs) in a tertiary care hospital in Gilgit Baltistan (GB) province during 2011-12 winter season. RSV was detected in 75 out of 105 children presenting with acute respiratory infection. Male infants between 2-6 months age made up the highest percentage of RSV positive cases. Epidemiological factors such as pre-maturity, mean weight, clinical features and diagnosis when compared between RSV positive and negative groups were found to be statistically insignificant. Phylogenetic analysis classified all 75 of the RSV strains into 71 strains of subgroups A and 4 strains of subgroup B, respectively. Strains belonging to subgroups A and B were further subdivided into NA1/GA2 and BA, respectively. The nucleotide and deduced amino acid sequence identities were relatively high among these strains (>90%). Both RSV-A and RSV-B isolates had two potential N-glycosylation sites in HVR2 of G protein and with heavy O-glycosylation of serine and threonine residues (G scores of 0.5-0.7). This report highlights the significance of RSV as a dominant viral etiologic agent of pediatric ARIs, and need for continued molecular epidemiological surveys for early detection of prevalent strains and newly emerging genotypes to understand epidemiology of RSV infections in various regions of Pakistan.

Co-Circulation of 72bp Duplication Group A and 60bp Duplication Group B Respiratory Syncytial Virus (RSV) Strains in Riyadh, Saudi Arabia during 2014

“…Earlier studies have reported maximum number of cases of RSV in children less than 2 years of age [45,57,58]. Maximum number of cases were recruited in 0–6 months in the present investigation that coincides with higher percentage of RSV infection in this age group as reported earlier [57].…”

“…Further, more number of male cases with RSV infection were observed as compared to the females that is due to the fact that more number of male patients were recruited in the study. Higher percentage of RSV infection in male children has been reported earlier also [5,57]. Fever and nasal discharge were the most common clinical symptoms observed among the patients.…”

“…Earlier studies have reported maximum number of cases of RSV in children less than 2 years of age [45,57,58]. Maximum number of cases were recruited in 0–6 months in the present investigation that coincides with higher percentage of RSV infection in this age group as reported earlier [57]. But statistical analysis of age wise distribution of RSV positive cases of less than 2 years of age did not reveal any striking differences (data not shown).…”

“…Thus, taken together the amino acid substitutions and change in pattern of glycosylation in the ON1 and BA genotypes may lead to evasion of host immune response. This may further lead to continuous circulation and global spread of these viruses to new territories [57]. …”

Respiratory Syncytial Virus: From Discovery to Treatment

“…The second HVR (HVR2) carries the C terminus of the protein and is commonly sequenced to exam the genetic variability of RSV strains within a given population (Da Silva et al 2008). National (Da Silva et al 2008) and international (Aamir et al 2013, Entemadi et al 2013) researches aimed to correlate epidemiological and clinical aspects of different groups (A or B) and several genotypes of RSV. They found variation by local research center and by current genotypes distribution.…”