Enteroviruses (EVs) are a large group of genotypes that cause a variety of pathologies, some of them very serious. This study analyzed the last 10 years (2014–2023) of EVs diagnosis and classification. In 166,674 samples collected, EVs were found in 9,535 (5.7%) by rt-RT-PCR, and 332 (3.5%) were classified by Sanger methods. Symptoms were analyzed in 7623 cases. EVs were found in 5718/63,829 (8.9%) before, 1384/42,373 (3.3%) during and 2433/60,472 (4%) after the Covid pandemic (p < 0.0001), and in 7249/69,700 (10.4%) children under 6 years and in 2286/96,974 (2.35%) in oldest (p < 0.0001). The positive rate of EVs was high but decreased during the Covid period. In the youngest children EVs-A (associated with exantematohous disorders as well as respiratory manifestations and febrile syndromes) was most common, while EVs-B (frequent in neurological symptoms) was most common in children aged 6–15 years and EVs-D (associated to respiratory manifestations) in adults.

The ability of a virus to adapt is key to its survival, and this is achieved through mutation, which allows the virus to change and adapt to new environments. To capture the full extent of SARS-CoV-2 diversity in Asturias, samples obtained from nasopharyngeal swabs were characterised using whole-genome sequencing. Between 2020 and July 2024, a total of 4001 sequences were analysed and 5302 mutations were identified. An increase in the positivity rate was observed between 2022 and 2024 in children under 1 year of age. During this period, 55 new circulating variants belonging to 41 pangolin lineages were detected: 24 originated throughout the world and 31 in Asturias (10 detected only in the region, 8 in the rest of Spain, and 13 around the world). A total of 31 new non-synonymous mutations were fixed in the viral population 250 ± 46 (93–620) days after their appearance. During seasonal SARS-CoV-2 circulation, surveillance systems developed during the pandemic continue to detect new indigenous and imported variants without indicating an increase in severity.

The Potassium Ribosate, which has been shown to have an enhancer effect in limiting replication and viability in cancer cells, also appears to show promise in alterating viral replication. To determine its activity against SARS-CoV-2, an inhibition assay was performed using 26 strains obtained from clinical samples from patients isolated on the Vero E6 cell line. For this, the strains were serially diluted and treated with 125mM Potassium Ribosate. The Potassium Ribosate was administered at a single concentration (125mM stock) in two ways: 24 hours before infection and in the culture medium after removal of the infectious inoculum. The culture medium was changed 3 days after inoculation. Seven days after inoculation, a visual reading of the cytopathic effect (ECP) and RT-qRCP were performed to calculate the viral load. Reduction of 3log (9Ct) between with or without Ribosate was considerate a very good response. Of the 26 evaluable strains, a reduction in viral replication was observed in 13 (50%) and 16 (61.5%) of the pre-treatment and treatment study (p=0.29). This response was good or very good in 10 (38.4%) and 11 (42.3%) (p=0.4), respectively. Potassium Ribosate administration reduced the viral load of SARS-CoV-2 cultures in Vero E6 cells in more than half of the cases, both at infection and pre-infection administration.

Background: The mutation of a new virus is key to its ability to adapt, as it allows the virus to change and survive in new environments. We try to capture the full extent of SARS-CoV-2 diversity in Asturias. Methods: Samples from nasopharyngeal swabs belonging to SARS-CoV-2 infected patients were characterized by the whole genome sequencing. Results: A total of 4,001 sequences were analysed between 2020 and July 2024. During this time, 5302 mutations were found (157 occurred in more than 5% of the viral population). Between 2022 and 2024, 88 new non-synonymous mutations occurred in over 5% of the viral population, of which 31 are currently maintained and were fixed 250±46 (93-620) days after their appearance. Besides, 55 new circulating variants (NCVs) belonging to 41 pangolin lineages were detected. Of these NCVs, 24 were originated throughout the world, and the other 31 in Asturias (10 were only detected in the region, 8 also in Spain, and 13 around the world).Conclusions: New variants circulating around the world continually appear in our region, leading to a constant rotation of lineages. Although most of the changes have little or no impact on the virus's properties, the continued emergence of new variants warrant continued genomic surveillance.