Atypical Mutational Spectrum of SARS-CoV-2 Replicating in the Presence of Ribavirin.

We report that ribavirin exerts an inhibitory and mutagenic activity on SARS-CoV-2-infecting Vero cells, with a therapeutic index higher than 10. Deep sequencing analysis of the mutant spectrum of SARS-CoV-2 replicating in the absence or presence of ribavirin indicated an increase in the number of mutations, but not in deletions, and modification of diversity indices, expected from a mutagenic activity. Notably, the major mutation types enhanced by replication in the presence of ribavirin were A→G and U→C transitions, a pattern which is opposite to the dominance of G→A and C→U transitions previously described for most RNA viruses. Implications of the inhibitory activity of ribavirin, and the atypical mutational bias produced on SARS-CoV-2, for the search for synergistic anti-COVID-19 lethal mutagen combinations are discussed.

Quasispecies Fitness Partition to Characterize the Molecular Status of a Viral Population. Negative Effect of Early Ribavirin Discontinuation in a Chronically Infected HEV Patient.

The changes occurring in viral quasispecies populations during infection have been monitored using diversity indices, nucleotide diversity, and several other indices to summarize the quasispecies structure in a single value. In this study, we present a method to partition quasispecies haplotypes into four fractions according to their fitness: the master haplotype, rare haplotypes at two levels (those present at <0.1%, and those at 0.1−1%), and a fourth fraction that we term emerging haplotypes, present at frequencies >1%, but less than that of the master haplotype. We propose that by determining the changes occurring in the volume of the four quasispecies fitness fractions together with those of the Hill number profile we will be able to visualize and analyze the molecular changes in the composition of a quasispecies with time. To develop this concept, we used three data sets: a technical clone of the complete SARS-CoV-2 spike gene, a subset of data previously used in a study of rare haplotypes, and data from a clinical follow-up study of a patient chronically infected with HEV and treated with ribavirin. The viral response to ribavirin mutagenic treatment was selection of a rich set of synonymous haplotypes. The mutation spectrum was very complex at the nucleotide level, but at the protein (phenotypic/functional) level the pattern differed, showing a highly prevalent master phenotype. We discuss the putative implications of this observation in relation to mutagenic antiviral treatment.

SARS-CoV-2 Mutant Spectra at Different Depth Levels Reveal an Overwhelming Abundance of Low Frequency Mutations.

Populations of RNA viruses are composed of complex and dynamic mixtures of variant genomes that are termed mutant spectra or mutant clouds. This applies also to SARS-CoV-2, and mutations that are detected at low frequency in an infected individual can be dominant (represented in the consensus sequence) in subsequent variants of interest or variants of concern. Here we briefly review the main conclusions of our work on mutant spectrum characterization of hepatitis C virus (HCV) and SARS-CoV-2 at the nucleotide and amino acid levels and address the following two new questions derived from previous results: (i) how is the SARS-CoV-2 mutant and deletion spectrum composition in diagnostic samples, when examined at progressively lower cut-off mutant frequency values in ultra-deep sequencing; (ii) how the frequency distribution of minority amino acid substitutions in SARS-CoV-2 compares with that of HCV sampled also from infected patients. The main conclusions are the following: (i) the number of different mutations found at low frequency in SARS-CoV-2 mutant spectra increases dramatically (50- to 100-fold) as the cut-off frequency for mutation detection is lowered from 0.5% to 0.1%, and (ii) that, contrary to HCV, SARS-CoV-2 mutant spectra exhibit a deficit of intermediate frequency amino acid substitutions. The possible origin and implications of mutant spectrum differences among RNA viruses are discussed.

Vaccine breakthrough infections with SARS-CoV-2 Alpha mirror mutations in Delta Plus, Iota, and Omicron.

Replication of SARS-CoV-2 in the human population is defined by distributions of mutants that are present at different frequencies within the infected host and can be detected by ultra-deep sequencing techniques. In this study, we examined the SARS-CoV-2 mutant spectra of amplicons from the spike-coding (S-coding) region of 5 nasopharyngeal isolates derived from patients with vaccine breakthrough. Interestingly, all patients became infected with the Alpha variant, but amino acid substitutions that correspond to the Delta Plus, Iota, and Omicron variants were present in the mutant spectra of the resident virus. Deep sequencing analysis of SARS-CoV-2 from patients with vaccine breakthrough revealed a rich reservoir of mutant types and may also identify tolerated substitutions that can be represented in epidemiologically dominant variants.

SARS-CoV-2 Point Mutation and Deletion Spectra and Their Association with Different Disease Outcomes.

Mutant spectra of RNA viruses are important to understand viral pathogenesis and response to selective pressures. There is a need to characterize the complexity of mutant spectra in coronaviruses sampled from infected patients. In particular, the possible relationship between SARS-CoV-2 mutant spectrum complexity and disease associations has not been established. In the present study, we report an ultradeep sequencing (UDS) analysis of the mutant spectrum of amplicons from the nsp12 (polymerase)- and spike (S)-coding regions of 30 nasopharyngeal isolates (diagnostic samples) of SARS-CoV-2 of the first COVID-19 pandemic wave (Madrid, Spain, April 2020) classified according to the severity of ensuing COVID-19. Low-frequency mutations and deletions, counted relative to the consensus sequence of the corresponding isolate, were overwhelmingly abundant. We show that the average number of different point mutations, mutations per haplotype, and several diversity indices was significantly higher in SARS-CoV-2 isolated from patients who developed mild disease than in those associated with moderate or severe disease (exitus). No such bias was observed with RNA deletions. Location of amino acid substitutions in the three-dimensional structures of nsp12 (polymerase) and S suggest significant structural or functional effects. Thus, patients who develop mild symptoms may be a richer source of genetic variants of SARS-CoV-2 than patients with moderate or severe COVID-19. IMPORTANCE The study shows that mutant spectra of SARS-CoV-2 from diagnostic samples differ in point mutation abundance and complexity and that significantly larger values were observed in virus from patients who developed mild COVID-19 symptoms. Mutant spectrum complexity is not a uniform trait among isolates. The nature and location of low-frequency amino acid substitutions present in mutant spectra anticipate great potential for phenotypic diversification of SARS-CoV-2.

Breastfeeding experiences during the COVID-19 pandemic in Spain:a qualitative study.

BACKGROUND: The pandemic caused by COVID-19 has affected reproductive and perinatal health both through the infection itself and, indirectly, as a consequence of changes in medical care, social policy or social and economic circumstances. The objective of this study is to explore the impact of the pandemic and of the measures adopted on breastfeeding initiation and maintenance. METHODS: A qualitative descriptive study was conducted by means in-depth semi-structured interviews, until reaching data saturation. The study was conducted between the months of January to May 2021. Participants were recruited by midwives from the Primary Care Centres of the Andalusian provinces provinces of Seville, Cádiz, Huelva, Granada, and Jaén. The interviews were conducted via phone call and were subsequently transcribed and analysed by means of reflexive inductive thematic analysis, using Braun and Clarke's thematic analysis. RESULTS: A total of 30 interviews were conducted. Five main themes and ten subthemes were developed, namely: Information received (access to the information, figure who provided the information), unequal support from the professionals during the pandemic (support to postpartum hospitalization, support received from Primary Health Care during the postpartum period), social and family support about breastfeeding (support groups, family support), impact of confinement and of social restriction measures (positive influence on breastfeeding, influence on bonding with the newborn), emotional effect of the pandemic (insecurity and fear related to contagion by coronavirus, feelings of loneliness). CONCLUSION: The use of online breastfeeding support groups through applications such as WhatsApp®, Facebook® or Instagram® has provided important breastfeeding information and support sources. The main figure identified that has provided formal breastfeeding support during this period was that of the midwife. In addition, the social restrictions inherent to the pandemic have exerted a positive effect for women in bonding and breastfeeding, as a consequence of the increase in the time spent at their homes and in the family nucleus co-living.

Clinical features and respiratory pathophysiology of COVID-19 patients ventilated in the prone position: a cohort study.

INTRODUCTION: There are few studies that have investigated the response to the prone position in mechanically ventilated COVID-19 patients with acute respiratory distress syndrome (ARDS). We describe the characteristics and outcomes of those patients in a tertiary hospital in Spain. MATERIAL AND METHODS: This is an observational study in consecutive, mechanically ventilated COVID-19 patients. The primary endpoint was to describe the respiratory pathophysio-logy and clinical outcomes of COVID-19 patients treated by mechanical ventilation in the prone position. RESULTS: Of 84 patients mechanically ventilated in the prone position, 19 (22%) were successfully extubated and 43 (51%) were discharged from the ICU. The duration of mechanical ventilation and ICU length of stay were 11 days (IQR 8-16) and 15 days (IQR 9-25), respectively. On admission to ICU, 61% patients had a moderate ARDS according to the Berlin criteria. 76% had 4 lung quadrants affected. After intubation, the median PaO2/FiO2 was 105 (IQR 76-138), ventilatory ratio was 1.48 (IQR 1.16-1.88), and compliance was 33 mL cm H 2 O-1 (IQR 25-41). The median number of cycles in the prone position was 2 (1-3), with a median of total hours in the prone position of 76 (IQR 64-111).72 h after the first prone position cycle the median PaO2/FiO2 increase was up to 193 (IQR 152-251), but the compliance was similar to the basal level (34 mL cm H 2 O-1 [IQR 26-43]). However, the percentage of patients with normal compliance (> 50 mL cm H 2 O-1) increased with the prone position from 15% (n = 13) to 32% (n = 27) after 72 h. CONCLUSIONS: In our study, the COVID-19 patients with respiratory failure presented respiratory mechanics, gas exchange parameters, and a response to prone ventilation similar to those observed in other causes of ARDS.

Population Disequilibrium as Promoter of Adaptive Explorations in Hepatitis C Virus.

Replication of RNA viruses is characterized by exploration of sequence space which facilitates their adaptation to changing environments. It is generally accepted that such exploration takes place mainly in response to positive selection, and that further diversification is boosted by modifications of virus population size, particularly bottleneck events. Our recent results with hepatitis C virus (HCV) have shown that the expansion in sequence space of a viral clone continues despite prolonged replication in a stable cell culture environment. Diagnosis of the expansion was based on the quantification of diversity indices, the occurrence of intra-population mutational waves (variations in mutant frequencies), and greater individual residue variations in mutant spectra than those anticipated from sequence alignments in data banks. In the present report, we review our previous results, and show additionally that mutational waves in amplicons from the NS5A-NS5B-coding region are equally prominent during HCV passage in the absence or presence of the mutagenic nucleotide analogues favipiravir or ribavirin. In addition, by extending our previous analysis to amplicons of the NS3- and NS5A-coding region, we provide further evidence of the incongruence between amino acid conservation scores in mutant spectra from infected patients and in the Los Alamos National Laboratory HCV data banks. We hypothesize that these observations have as a common origin a permanent state of HCV population disequilibrium even upon extensive viral replication in the absence of external selective constraints or changes in population size. Such a persistent disequilibrium-revealed by the changing composition of the mutant spectrum-may facilitate finding alternative mutational pathways for HCV antiviral resistance. The possible significance of our model for other genetically variable viruses is discussed.

Assessment of the Anxiety Level of Andalusian Podiatrists during the COVID-19 Pandemic: The Increase Phase.

Coronavirus disease (COVID-19) is caused by SARS-CoV-2 and represents the causative agent of a potentially fatal disease that is of great global public health concern. COVID-19 is a respiratory disease produced by the coronavirus family. The World Health Organization declared the disease a pandemic on 11 March 2020. Podiatrists are in a peculiar situation regarding the COVID-19 pandemic: that of a health professional aspect and the singularity that most of them practise as self-employed workers. The aim of the study is to evaluate in a group of podiatrists, working at a national level, their knowledge, perception and degree of anxiety related to the COVID-19 pandemic via the use of a questionnaire specifically developed to this end in the initial phase of the pandemic. We employed a transversal descriptive study with 302 participants, with a purposive sampling technique. The degree of perception and knowledge of the podiatrists about COVID-19 was analysed as well as the cognitive impact of the situation of confinement. The results showed that the podiatrists perceive this situation as serious at the economic and health level, that they have a thorough knowledge of the disease and that they are in a moderate to severe percentile of anxiety. Additionally, 76.2% cancelled their usual work. The COVID-19 pandemic is negatively perceived by this group of podiatrists at the personal, professional, health and economic level, with even a state of anxiety being produced.