Detection and characterization of Rotavirus G and P types from children participating in a Rotavirus vaccine trial in Belém, Brazil

ABSTRACT

This study sought the characterization of rotaviruses in a trial with a tetravalent rhesus-human rotavirus vaccine in Belém, Brazil in children who received three doses of vaccine or placebo in the 1st, 3rd and 5th months of life. Rotavirus electropherotypes, subgroups, G serotypes, G, [P] and [P],G genotypes were determined in 93.3 percent, 95.9 percent, 93.3 percent, 73.3 percent, 95.5 percent and 92.2 percent of isolates, respectively. Serotypes G1, G2 and G4 were detected in 58.9 percent, 30 percent and 4.4 percent of the cases, respectively. Rotavirus genotype G5 was detected for the first time in Northern region in 4.4 percent of the infections. Rotavirus genotypes P[8], P[4], P[6] and P[8+6] were detected in 54.5 percent, 26.7 percent, 12.2 percent, and 2.2 percent of the cases, respectively. The predominant genotypes were P[8],G1 and P[4],G2 with 53 percent and 26.6 percent of the infections, respectively. Unusual strains accounted for 20.5 percent including P[4],G1, P[6],G1, P[6],G4, P[6],G5, P[8],G2, P[8],G5. Mixed infections involving P[8+6],G2 and P[8+6],G1 were also noted. The neonatal P[6] strains associated with diarrhea were detected among children aged 9-24 months. To our knowledge, this study represents the first in Brazil to analyse, on molecular basis, rotavirus genotypes from children participating in a rotavirus vaccine trial. These results are of potential importance regarding future rotavirus vaccination strategies in Brazil