From the common cold virus to severe respiratory illness in children 

Breastfed babies under two years old are especially vulnerable to rhinoviruses and enteroviruses infections. These viruses are responsible for the common cold, presenting a mild clinical picture in most of the population. 

These viruses' infections are responsible for bronchiolitis and bronchospasms in breastfed babies and children, and that can cause hospital admissions, with a higher incidence in breastfed babies. In addition, one in ten entries requires care in the Pediatric Intensive Care Unit. And in recent years, the rate of income in these groups has increased. 

"Rhinoviruses and enteroviruses are the viruses that cause the common cold, which is banal in most of us. But we do not know why some children present such a serious manifestation, and others do not. This question was the one that in 2017 prompted us to start a study to look for possible answers." Comments Dr Cristian Launes, co-principal investigator and IRSJD member · Infectious Diseases and Microbiome group 

Dr Cristian Launes and Dr Carmen Múñoz-Almagro (IRSJD researchers), with Dr Daniel Penela-Sánchez and Dr Georgina Armero, started a project in 2017 intending to answer this question. This project analyses demographic, environmental, epidemiological and microbiological variables, the study of co-infections by other respiratory viruses, and the nasopharyngeal microbiota. This project received funding in the competitive Call of the Strategic Action in Health (AES), convened annually by the Carlos III Health Institute. 

THE IMPACT OF VIRAL CO-INFECTION IN breastfed babies

The IRSJD researchers, with Dr Maria Cabrerizo's group from the Enterovirus Unit of the National Microbiology Center, analyzed viral co-infection in hospitalized children. That is, simultaneously detecting more than one virus to understand if this could be the cause of the most severe symptoms. 

"The results were published in the scientific journal Viruses. Our results show that rhinovirus or enterovirus infection and their co-infection with the respiratory syncytial virus were present in children with severe symptoms. Therefore, the presence of co-infections with highly contagious viruses was not necessary for a child to have severe disease. And even, in some cases, co-infection with more than two viruses could be a protective factor, even though they are highly pathogenic when they infect in isolation." The research team comments. 

In the study, the researchers perform rhinovirus genetic typing to distinguish them from enteroviruses better. Because both are very similar viruses and are challenging to differentiate in the usual laboratory tests or the development of the clinical picture. 

"This project allows us to know and better understand the different variables that condition a rhinovirus infection to present with a milder or more severe condition. These results will allow us to establish the prognosis of patients better and identify possible therapeutic targets to develop more effective treatments. In addition, we are also studying what role the nasopharyngeal microbiota can play in the severity of these infections." Concludes the research team.

Paper

Penela-Sánchez D, González-de-Audicana J, Armero G, Henares D, Esteva C, de-Sevilla MF, Ricart S, Jordan I, Brotons P, Cabrerizo M, Muñoz-Almagro C, Launes C. Lower Respiratory Tract Infection and Genus Enterovirus in Children Requiring Intensive Care: Clinical Manifestations and Impact of Viral Co-Infections. Viruses. 2021 Oct 14;13(10):2059. doi: 10.3390/v13102059. PMID: 34696489; PMCID: PMC8541154.