Molecular depiction of rotavirus detected
Rotavirus was detected in 17.2% (577/3347) of the 3374 participants who submitted specimens (Figure 1). G1P[8] was the most prevalent genotype (25.8%, 149/574), followed by G12P[8] (21.5% 124/577), G9P[8] (20.6%, 119/577) and G2P[4] (14.2%, 82/577) genotypes. Prior to the introduction of RV1 in Alberta (i.e., 2014-15), G9P[8] predominated; however, following RV1 introduction, G1P[8], G2P[4] and G12P[8] were the primary genotypes during the 2015-16, 2016-17 and 2017-18 seasons, respectively (Table 1). Of note, the RV1 derived strain, was detected during the three seasons post RV1 implementation but not prior. Unusual strains of common human G2 or G9 types combined with potential zoonotic P[6] or P[9] types and two mixed infections were also identified.
Rotavirus was detected year-round with peaks observed between March and May (Figure 2). Prior to RV1 introduction in 2014-15, almost 60% of the total number of rotavirus AGE cases occurred during its seasonal peak. This was reduced to below 40% the first year, below 20% the second year and back to below 40% during the third year after vaccination initiation.