Researchers from the National Center for Microbiology (CNM) have developed a study in which they examine the genetic diversity of rotavirus and the factors that influence hospital admission of minors, finding that "not having the vaccination schedule completed increases the risk of gastroenteritis caused by rotavirus by up to four times."
The work, carried out at the Carlos III Health Institute (ISCIII) and published in the journal 'Scientific Reports', has been conducted together with a team from the National Center for Epidemiology (CNE). The research included more than 600 children with gastroenteritis caused by this pathogen, with the aim of understanding its circulation pattern, the predominant genetic variants, and the clinical impact of the infection.
"Combining clinical, epidemiological, and genomic information allows for better interpretation of the circulation of rotavirus and assessment of the real impact of the detected variants," stated the head of the Viral Gastroenteritis group at the CNM, a member of the Epidemiology and Public Health Area of the Networked Biomedical Research Center (CIBERESP) and the principal author of the work, María Dolores Fernández-García.
To reach these conclusions, the study also involved the participation of groups from the Infectious Diseases Area of CIBER (CIBERINFEC) and the university hospitals in Madrid of Móstoles, Puerta de Hierro de Majadahonda, and Severo Ochoa de Leganés, combining clinical surveillance with genomic analysis in minors residing in the Community of Madrid.
The results indicate that the factors most related to the need for pediatric hospitalization are "not being fully vaccinated and having pre-existing conditions," according to the authors, who also emphasize that "it has been confirmed that the viral genotype - the type of genetic variant of the virus - is not associated with greater clinical severity."
Predominance of genotype G3P[8] in the analyzed cases
The rotavirus is one of the main agents responsible for acute gastroenteritis in infants and young children and, although in many patients the infection resolves without complications, it can trigger severe episodes of diarrhea, vomiting, and dehydration, especially in younger children and those with pre-existing illnesses. In this context, the study has identified a clear predominance of the genotype "G3P[8]", especially of "equine-like" variants, which accounted for 62.4 percent of the characterized strains in circulation.
The genomic analyses carried out also show a wide diversity among the strains that are circulating. Although differences have been detected between some of them and those that are part of the available vaccines, the researchers point out that the data do not indicate the emergence of variants with significant changes in their clinical impact nor signs of vaccine escape, that is, the ability of the virus to modify its structure to the point of evading the antibodies generated after natural infection or immunization.
Finally, and in light of the data obtained, the specialists point out that "differences have been observed according to the type of vaccine received." Specifically, "the strains 'G2P[4]' and 'G3P[8] equine-like' are more frequent among cases vaccinated with 'Rotarix', while the classic 'G3P[8]' strains appear more among younger children vaccinated with 'RotaTeq'", they specified.