Molecular epidemiology of respiratory syncytial virus (RSV) of group A in Stockholm, Sweden, between 1965 and 2003.

The epidemiology of respiratory syncytial virus (RSV) group A was followed by nucleotide sequencing of the variable parts of the glycoprotein (G) gene. The amino acid sequences of an aminoterminal (A-terminal, amino acids 90-132) and carboxyterminal (C-terminal, amino acids 262-298) portion of the G protein in 47 virus strains, collected in Stockholm, between 1965 and 2004, were determined. In phylogenetic analysis jointly with previously described genotypes (GA1 to GA7 and SAA1), 33 virus strains (isolated between 1991 and 2004) belonged to genotype GA5, seven to GA2, three to genotype GA1 (isolated before 1991), one to genotype GA4 (isolated in 1982) and three to genotype GA7 (isolated in 1993 and 2001). Genotype GA5 was predominant in four epidemics, between 2000/2001 and 2003/2004. Little or no variation with time of the C-terminal amino acid sequence of the G protein was found when the virus strains were compared within their own genotype. Identical and nearly identical nucleotide sequences were found between strains isolated more than 10 (GA5) and 25 (GA2) years apart. The A-terminal part of they G protein of genotype GA2 was highly conserved. In contrast, the A-terminal part of the G protein of genotype GA5 exhibited a pronounced variation in its amino acid sequence over time.