Rotavirus A (RVA) is a prominent cause of acute gastroenteritis globally; yet, little research has examined RVA genetics in conjunction with population monitoring. For this study, researchers wanted to look at the clinical data, genetic diversity, and coinfection patterns of RVA infections in children aged 2 to 36 months who had community childhood diarrhea in the Brazilian semiarid area during the post-vaccination era. They enrolled and gathered socioeconomic/clinical information from 291 children using a standardized questionnaire and fecal samples. To diagnose RVA, viral RNA samples were isolated and evaluated using quantitative reverse transcription-polymerase chain reaction. Sequencing of VP7 and VP4 (VP8) areas, as well as phylogenetic analyses, were carried out.

RVA-negative diagnoses were linked to children aged 24 to 36 months who had completed their immunization program. G1P[8] was the most common genotype (57%), however rare genotypes such as G1P[4], G2P[8], and G3P[9] were also found. G1- and P[8]-positive samples were highly similar to the vaccination strain. RVA co-infections were common, with enteroaggregative Escherichia coli being the most common pathogen.

These findings show that genotype G1P[8] was the most common strain. These youngsters had VP7 and/or VP8 gene segments derived from the RV1 vaccine strain, implying shedding or herd immunization. Furthermore, these findings suggested that complete immunization was necessary for protection against RVA infections.