A new lineage of echovirus 11 has been discovered in Spain

A team from the National Center for Microbiology (CNM) of the Carlos III Institute of Health (ISCIII) identified appeal V Spain from new echovirus line 11type enterovirus which usually causes mild illness but can cause serious complications in newborns, but in this case it was not associated with an increase in cases of serious illness in newborns in the country, as has happened in other countries.

The study, carried out by the Enteroviruses and Viral Gastroenteritis Unit of the CNM-ISCIII as part of an outbreak that emerged in Europe last year and published in Eurosurveillance, analyzed how the virus circulated in Spain to determine its characteristics and possible links to serious neonatal infections.

In June 2023 France have notified Member States of the European Union and the European Economic Area (EU/EEA) of an increase in serious infections among newborns caused by a certain type of infection. enterovirus, echovirus 11 (E11). In total, they determined nine infected newborns with E11, who had sepsis and liver failure, of whom seven died. All E11 sequences associated with these severe neonatal infections belonged to a new lineage called lineage 1, which was first identified in April 2022.

In the same way, Italy notified two cases from premature twins with fulminant hepatitis caused by E11, the sequences of which were also grouped into lineage 1. During 2023, four more countries (Croatia, Spain, UK and Sweden) reported cases.

To verify the situation in Spain, the research team examined 1,288 enterovirus-positive samples obtained and genotyped at the National Center of Microbiology ISCIII as part of the Microbiological Surveillance Program between 2019 and 2023. 98 they turned out to be positive for type echovirus 11 and 33.7 percent affected newborns.

As in the French study, phylogenetic analysis showed that lineage 1 E11 strains emerged first time V Spain V 2022and prevailed in 2022 and 2023. Also consistent with the French study, the new lineage 1 included sequences from both severe and non-severe neonatal infections as well as non-neonatal infections.

However, unlike France, the severe cases observed in 2022 and 2023 in Spain were not exclusively associated with the new lineage 1. That is, although the new lineage 1 has been circulating in Spain since 2022, was not associated with an increase in severe disease

V newborns. Another difference was that the detection rate of E11 was the same before and after the discovery of new lineage 1 in Spain in 2022.

The study’s authors, including Maria Dolores Fernandez Garcia and Maria Cabrerizo as the first and last signatories, explained that in enteroviruses, recombination events almost always occur outside the capsid-coding region used for genotyping, and that it is therefore critical to obtain a complete genome to analyze the frequency of events and associated events. . Therefore, 10 E11-positive samples were sequenced using untargeted metagenomics, yielding the complete genome of these viruses.

Through analysis of these complete genomes, three new recombinant genomic forms were discovered in echovirus 11, none of which were part of the new lineage 1. Two of these three new E11 recombinant viruses were associated with severe disease requiring intensive care unit admission (one. was associated with sepsis with liver failure, and the other with severe meningoencephalitis).

Finally, examining the virome of these E11-positive samples using metagenomics allowed us to detect coinfecting viruses in four out of ten samples. This highlights the need to investigate possible (co)infections as they may contribute to serious or fatal outcomes in E11 infections.

Experts noted that the results obtained highlight need

from strengthen That genomic surveillance from E11 to monitor whether these or other new recombinant strains are causing serious E11 infections in Spain and other European countries, in addition to the new lineage 1 strains.

Likewise, the authors concluded that the data presented in this study highlight the value of conducting combined studies at the molecular, genomic, and clinical levels to fully describe the epidemiology and evolution of childhood enteroviral infections in the context of a public health concern.