Genótipos de rotavírus do grupo a e antígenos de grupo sanguíneo em crianças com diarreia aguda infectadas por rotavírus e norovírus

Abstract

Rotavirus and norovirus are the leading cause of acute diarrhea in children worldwide. Host susceptibility according to human histo-blood group antigens (HBGAs) is widely known for norovirus infection, but is less described for rotavirus. Due to the variable HBGA polymorphism among populations, we aimed to evaluate the association between HBGA phenotypes (ABH, Lewis and secretor status) and susceptibility to rotavirus and norovirus symptomatic infection, and the polymorphisms of FUT2 and FUT3, of children from southeastern Brazil. Moreover, we evaluated the rotavirus P and G genotypes and norovirus genotypes infecting these children. Fecal samples from 307 children with acute diarrhea and buccal swabs from 272 of those were used to detect and determine rotavirus and norovirus genotypes and HBGAs phenotypes and genotypes, respectively. Altogether, 100 (36.8%) children were infected with rotavirus and norovirus. The rotavirus G12P[8] (48,6%) genotype was the most frequently among the samples followed by G3P[8] (11,4%) and G2P[4] (5,7%). The nucleotide sequencing of G3P[8] samples, the only genotype detected in the 2018 samples, demonstrated that they belonged to the emergent G3P[8] “equine-like” genotype, the strain that predominates currently in cases of diarrhea in Brazil and worldwide. Most of the noroviruses (93.8%) belonged to genogroup II (GII). GII.4 Sydney represented 76% (35/46) amongst five other genotypes. Rotavirus and noroviruses infected predominantly children with secretor status (97% and 98.5%, respectively). However, fewer rotavirus-infected children were Lewis-negative (8.6%) than the norovirus-infected ones (18.5%). FUT3 single nucleotide polymorphisms (SNP) occurred mostly at the T59G > G508A > T202C > C314T positions. The predominance of emerging genotypes in the study shows the importance of continuous surveillance of rotaviruses in order to monitor the emergence of unusual genotypes and the impact they can bring to the vaccination program. In addition, our results reinforce the current knowledge that secretors are more susceptible to infection by both rotavirus and norovirus than non-secretors. The high rate for Lewis negative (17.1%) and the combination of SNPs, beyond the secretor status, may reflect the highly mixed population in Brazil.