Circulation of HRSV in Belgium: From Multiple Genotype Circulation to Prolonged Circulation of Predominant Genotypes

Abstract

Molecular surveillance of HRSV in Belgium for 15 consecutive seasons (1996–2011) revealed a shift from a regular 3-yearly cyclic pattern, into a yearly alternating periodicity where HRSV-B is replaced by HRSV-A. Phylogenetic analysis for HRSV-A demonstrated the stable circulation of GA2 and GA5, with GA2 being dominant over GA5 during 5 consecutive seasons (2006–2011). We also identified 2 new genotype specific amino acid mutations of the GA2 genotype (A122 and Q156) and 7 new GA5 genotype specific amino acid mutations (F102, I108, T111, I125, D161, S191 and L217). Several amino acid positions, all located in the second hypervariable region of HRSV-A were found to be under positive selection. Phylogenetic analysis of HRSV-B showed the circulation of GB12 and GB13, where GB13 represented 100% of the isolated strains in 4 out of 5 consecutive seasons (2007–2011). Amino acids under positive selection were all located in the aminoterminal hypervariable region of HRSV-B, except one amino acid located in the conserved region. The genotype distribution within the HRSV-B subgroup has evolved from a co-circulation of multiple genotypes to the circulation of a single predominant genotype. The Belgian GB13 strains circulating since 2006, all clustered under the BAIV branch and contained several branch specific amino acid substitutions. The demographic history of genotypes GA2, GA5 and GB13 demonstrated a decrease in the total GA2 and GA5 population size, coinciding with the global expansion of the GB13 population. The emergence of the GB13 genotype resulted in a newly established balance between the predominant genotypes.

Conservation of G-Protein Epitopes in Respiratory Syncytial Virus (Group A) Despite Broad Genetic Diversity: Is Antibody Selection Involved in Virus Evolution?

“…1B that genotype dominance has alternated in different time periods. While several genotypes cocirculated most of the time with alternating dominance, the GA2 genotype has become almost exclusive since 2005, as reported in several studies (30,33) and observed with recent viruses from Madrid and Panama (Fig. 2).…”

“…Recent publications have drawn attention to the shift from "multiple genotype circulation to prolonged circulation of predominant genotypes," as seen in Belgium between 1996 and 2011 (30). In addition, a novel GA2 variant with a 72-nt duplication, named ON1 and first detected in Ontario (Canada) in December 2010 (31), has spread rapidly worldwide (32)(33)(34), exacerbating the current dominance of the GA2 genotype.…”

Prevalence of human respiratory syncytial virus circulating in Iran

“…[29]. The interplay of pre-existing immunity in the community and the genetic and antigenic properties of the RSV virus to evade the immune response may explain changes in genotype dominance over time [30]. The predominance of RSV-A viruses has been attributed to increased variability among RSV-A strains [30].…”

“…The interplay of pre-existing immunity in the community and the genetic and antigenic properties of the RSV virus to evade the immune response may explain changes in genotype dominance over time [30]. The predominance of RSV-A viruses has been attributed to increased variability among RSV-A strains [30]. Based on the fact that the dominant strains shift yearly, evasion of immunity induced by previous strains may be a mechanism for re-infection [31].…”

“…Monitoring circulating RSV strains in different geographical regions is essential, particularly in the western, eastern, northwestern, and southeastern parts of Iran, where available data is lacking. The continuous circulation of genotype GA2 emphasizes the stability of this subtype; it has become an epidemic in Europe, Asia and Africa [30,32,33]. Genotypes GA2 and BA are also the most common RSV genotypes worldwide [30,32,34].…”