Genetic and structural analyses reveal the low potential of the SARS-CoV-2 EG.5 variant.

The severe acute respiratory syndrome coronavirus 2 EG.5 lineage is the latest variant under monitoring, and it is generating significant concern due to its recent upward trend in prevalence. Our aim was to gain insights into this emerging lineage and offer insights into its actual level of threat. Both genetic and structural data indicate that this novel variant presently lacks substantial evidence of having a high capacity for widespread transmission. Their viral population sizes expanded following a very mild curve and peaked several months after the earliest detected sample. Currently, neither the viral population size of EG.5 nor that of its first descendant is increasing. The genetic variability appear to be flattened, as evidenced by its relatively modest evolutionary rate (9.05 × 10-4 subs/site/year). As has been observed with numerous prior variants, attributes that might theoretically provide advantages seem to stem from genetic drift, enabling the virus to continually adjust to its host, albeit without a clear association with enhanced dangerousness. These findings further underscore the necessity for ongoing genome-based monitoring, ensuring preparedness and a well-documented understanding of the unfolding situation.

Epidemic history and evolution of an emerging threat of international concern, the severe acute respiratory syndrome coronavirus 2.

This comprehensive review focuses on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its impact as the cause of the COVID-19 pandemic. Its objective is to provide a cohesive overview of the epidemic history and evolutionary aspects of the virus, with a particular emphasis on its emergence, global spread, and implications for public health. The review delves into the timelines and key milestones of SARS-CoV-2's epidemiological progression, shedding light on the challenges encountered during early containment efforts and subsequent waves of transmission. Understanding the evolutionary dynamics of the virus is crucial in monitoring its potential for adaptation and future outbreaks. Genetic characterization of SARS-CoV-2 is discussed, with a focus on the emergence of new variants and their implications for transmissibility, severity, and immune evasion. The review highlights the important role of genomic surveillance in tracking viral mutations linked to establishing public health interventions. By analyzing the origins, global spread, and genetic evolution of SARS-CoV-2, valuable insights can be gained for the development of effective control measures, improvement of pandemic preparedness, and addressing future emerging infectious diseases of international concern.

Integrative Genome-Based Survey of the SARS-CoV-2 Omicron XBB.1.16 Variant.

The XBB.1.16 SARS-CoV-2 variant, also known as Arcturus, is a recent descendant lineage of the recombinant XBB (nicknamed Gryphon). Compared to its direct progenitor, XBB.1, XBB.1.16 carries additional spike mutations in key antigenic sites, potentially conferring an ability to evade the immune response compared to other circulating lineages. In this context, we conducted a comprehensive genome-based survey to gain a detailed understanding of the evolution and potential dangers of the XBB.1.16 variant, which became dominant in late June. Genetic data indicates that the XBB.1.16 variant exhibits an evolutionary background with limited diversification, unlike dangerous lineages known for rapid changes. The evolutionary rate of XBB.1.16, which amounts to 3.95 × 10-4 subs/site/year, is slightly slower than that of its direct progenitors, XBB and XBB.1.5, which have been circulating for several months. A Bayesian Skyline Plot reconstruction suggests that the peak of genetic variability was reached in early May 2023, and currently, it is in a plateau phase with a viral population size similar to the levels observed in early March. Structural analyses indicate that, overall, the XBB.1.16 variant does not possess structural characteristics markedly different from those of the parent lineages, and the theoretical affinity for ACE2 does not seem to change among the compared variants. In conclusion, the genetic and structural analyses of SARS-CoV-2 XBB.1.16 do not provide evidence of its exceptional danger or high expansion capability. Detected differences with previous lineages are probably due to genetic drift, which allows the virus constant adaptability to the host, but they are not necessarily connected to a greater danger. Nevertheless, continuous genome-based monitoring is essential for a better understanding of its descendants and other lineages.

Initial introduction and spread of the SARS-CoV-2 AY.4.2.1 Delta variant in Bulgaria, a genomic insight.

The evolution of the emerging SARS-CoV-2 variants carrying mutations in the spike protein raises concerns about the possibility of accelerated transmission in the ever-evolving COVID-19 pandemic worldwide. AY.4.2, a sublineage of the Delta variant, was considered a variant under investigation (VUI) and also gained the nickname "Delta Plus," due to its extra mutations, Y145H and A222V. In this study, using genomic epidemiology, we provide the first insights into the introduction of AY.4.2 in Bulgaria and the AY.4.2.1 sublineage that found larger dissemination only in Bulgaria and the United Kingdom.

SARS-CoV-2 AY.4.2 variant circulating in Italy: Genomic preliminary insight.

The appearance of emerging variants of SARS-CoV-2 carrying mutations into the spike protein has recently raised concern with respect to tracking their transmission and mitigating the impact in the evolving pandemic across countries. AY.4.2, a recently detected Delta variant sublineage, is considered a new variant under investigation (VUI) as it carries specific genetic signatures present in the spike protein, called Y145H and A222V. Here, using genomic epidemiology, we provide the first preliminary insight regarding the circulation of this emerging VUI in Italy.

SARS-CoV-2 Lineages and Sub-Lineages Circulating Worldwide: A Dynamic Overview.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in Wuhan, China, in early December 2019 has rapidly widespread worldwide, becoming one of the major global public health issues of the last centuries. Key Messages: Over the course of the pandemic, due to the advanced whole-genome sequencing technologies, an unprecedented amount of genomes have been generated, providing invaluable insights into the ongoing evolution and epidemiology of the virus during the pandemic. Therefore, this large amount of data played an important role in the SARS-CoV-2 mitigation and control strategies. Key Messages: The active monitoring and characterization of the SARS-CoV-2 lineages circulating worldwide is useful for a more specific diagnosis, better care, and timely treatment. In this review, a concise characterization of all the lineages and sub-lineages circulating and co-circulating across the world has been presented in order to determine the magnitude of the SARS-CoV-2 threat and to better understand the virus genetic diversity and its dispersion dynamics.

Trends of anterior cruciate ligament reconstruction in children and young adolescents in Italy show a constant increase in the last 15 years.

PURPOSE: The aim of this 15-year nationwide study was to investigate the trend in ACL reconstructive surgeries in patients younger than 15 years old in Italy, as well as their social and economic impact. MATERIALS AND METHODS: The National Hospital Discharge records (SDO) collected by the Italian Ministry of Health in the 15-year period between 2001 and 2015 were analyzed. This contains anonymous data including patients' age, gender, ICD-9-CM codes for diagnosis and intervention, census region, region of hospitalization, length of the hospitalization, and public or private reimbursement. RESULTS: 1,350 ACL reconstructions were performed in Italy in the population younger than 15 years old, with an incidence rate ranging from 0.16 to 2.04 procedures per 100,000 age-matched individuals. Similarly, the percentage of surgeries in 0-14 year old patients increased with respect to the total number of ACL reconstruction from 0.13% in 2001 to 0.95% in 2015. The age range 10-14 years is the most involved, accounting for 97.3% of surgeries recorded in the study period. The male:female ratio was 1.05 and most of these procedures were performed in the North of Italy (78.3%). CONCLUSION: ACL reconstructions in patients aged 10-14 years are increasing constantly since 2001, and thus, specific actions aimed to define the best management strategy as well as national educational programs to prepare the future surgeons to this new reality are mandatory in the interest of the public health. LEVEL OF EVIDENCE: Level III.

Correction to: HBV molecular epidemiology and clinical condition of immigrants living in Italy.

The original version of this article unfortunately contained a mistake. The name of the author Mara Caroprese was rendered wrongly. The correct name is shown above.

Molecular epidemiology of HIV-1 infection in immigrant population in northern Italy.

Human immunodeficiency virus-1 (HIV-1) is characterised by a vast genetic diversity classified into distinct phylogenetic strains and recombinant forms. We describe the HIV-1 molecular epidemiology and evolution of 129 consecutive HIV-1 positive migrants living in Milan (northern Italy). Polymerase gene sequences of 116 HIV-1 subtype-B positive patients were aligned with HIV-1 reference sequences (https://www.ncbi.nlm.nih.gov/) by using MAFFT alignment and edited by using Bioedit software. A maximum likelihood (ML) phylogenetic tree was performed by MEGA7 and was visualised by using FigTree v1.4.3. Of 129 migrants, 35 were born in Europe (28 in Eastern Europe), 70 in the Americas (67 in South America), 15 in Africa and nine in Asia; 76.4% were men who have sex with men (MSM). The serotype HIV-1-B prevailed (89.9%), followed by -C, -F1, -D and -A. Compared with 116 HIV-B patients, the 13 with HIV-non-B showed lower Nadir of CD4+ cell/mmc (P = 0.043), more frequently had sub Saharan origin (38.5 vs. 1.72%, P = 0.0001) and less frequently were MSM (40 vs. 74.5%, P = 0.02). The ML phylogenetic tree of the 116 HIV-1 subtype-B positive patients showed 13 statistically supported nodes (bootstrap > 70%). Most of the sequences included in these nodes have been isolated from male patients from the Americas and the most common risk factor was MSM. The low number of HIV-1 non-B subtype patients did not allow to perform this analysis. These results suggest a shift of HIV-1 prevention projects' focus and a continuous monitoring of HIV-1 molecular epidemiology among entry populations. Prevention efforts based on HIV molecular epidemiology may improve public health surveillance setting.

Epidemiology of Achilles tendon surgery in Italy: a nationwide registry study, from 2001 through 2015.

BACKGROUND: This study aims (1) to estimate the yearly number of Achilles tendon (AT) surgeries in Italy from 2001 to 2015 based on official hospitalization records; (2) to investigate the eventual presence of geographical variation in equity in access to AT surgery between three macroregions of Italy (North, Center and South); (3) to perform statistical projections of the number of AT procedure volumes and rates based on these data. METHODS: We analysed the National Hospital Discharge records (SDO) maintained at the Italian Ministry of Health for a 15-year period, from 2001 through 2015. These data are anonymous and include the patient's age (evaluated in the class of age), sex, census region, the region of hospitalization, length of the hospitalization, public or private reimbursement and diagnosis. RESULTS: During the 15-year study period, 118,652 AT repair were performed in Italy, whose peak of incidence was in 2010. More than half of AT repairs was performed in the North of Italy (52.1%), while 27.2% was performed in the South of Italy and 20.6% Center of Italy. The projection model predicted a slight growth of 2.65% in 2025 in comparison with 2015. CONCLUSION: The current study provides detailed information about the national population-weighted incidence of AT surgery, distribution and projection. The peak of average age was 35-45 year. The majority of AT procedures was performed in the North of Italy. The projection model predicts a slight growth of AT surgery by 2025. Furthermore, this 15-year nationwide registry study shows that the age of incidence of AT injuries shifted from 30 to 40 to 35-45 years compared to the available literature. The higher prevalence of AT surgery was found in men during the working age. Moreover, a low rate of procedures in pediatric and elder age classes was observed.

Correction to: Epidemiology of Achilles tendon surgery in Italy: a nationwide registry study, from 2001 through 2015.

An amendment to this paper has been published and can be accessed via the original article.

The phylogenetic approach for viral infectious disease evolution and epidemiology: An updating review.

In the last decade, the phylogenetic approach is recurrent in molecular evolutionary analysis. On 12 May, 2019, about 2 296 213 papers are found, but typing "phylogeny" or "epidemiology AND phylogeny" only 199 804 and 20 133 are retrieved, respectively. Molecular epidemiology in infectious diseases is widely used to define the source of infection as so as the ancestral relationships of individuals sampled from a population. Coalescent theory and phylogeographic analysis have had scientific application in several, recent pandemic events, and nosocomial outbreaks. Hepatitis viruses and immunodeficiency virus (human immunodeficiency virus) have been largely studied. Phylogenetic analysis has been recently applied on Polyomaviruses so as in the more recent outbreaks due to different arboviruses type as Zika and chikungunya viruses discovering the source of infection and the geographic spread. Data on sequences isolated by the microorganism are essential to apply the phylogenetic tools and research in the field of infectious disease phylodinamics is growing up. There is the need to apply molecular phylogenetic and evolutionary methods in areas out of infectious diseases, as translational genomics and personalized medicine. Lastly, the application of these tools in vaccine strategy so as in antibiotic and antiviral researchers are encouraged.

Human hepatitis E virus circulation in Bulgaria: Deep Bayesian phylogenetic analysis for viral spread control in the country.

Hepatitis E virus (HEV) infection in Bulgaria is endemic, as demonstrated by the seroprevalence of antibody against the virus in the general population and by the high prevalence of clinical cases registered. In this study, a deep Bayesian phylogenetic analysis has been performed to provide information on the genetic diversity and the spread of HEV genotypes in Bulgaria. Three different data sets of HEV virus was built for genotyping by the maximum likelihood method, for evolutionary rate estimated by Bayesian Markov Chain Monte Carlo approach, for demographic history investigation and for selective pressure analysis. The evolutionary rate for genotype 3e, was 351 × 10-3 substitution/site/year (95% highest posterior density [95% HPD]: 145 × 10 -3 -575 × 10 -3 ). The root of the time to the most recent common ancestor of the Bayesian maximum clade credibility tree of HEV 3e genotype corresponded to 1965 (HPD 95% 1949-1994). The Bulgarian sequences mainly clustered in the main clade (clade A). The monophyletic clade included all Bulgarian genotype 3e sequences. The demographic history showed a slight growth from 1995 to 2000, followed by a sort of bottleneck in 2010s, a peak in 2011 and a new growth to 2015. Selection pressure analysis did not show sites under positive pressure but 64 statistically significant sites under negative selection. Molecular epidemiological surveillance by Bayesian phylogeny of HEV virus can contribute to trace the way of human infection after contact with swine source directly or heating meat improving public health control.

The transmission dynamic of Madariaga Virus by bayesian phylogenetic analysis: Molecular surveillance of an emergent pathogen.

Madariaga Virus (MADV) is an emergent Alphavirus of the eastern equine encephalitis virus (EEEV) strain complex causing epizootic epidemics. In this study the genetic diversity and the transmission dynamics of Madariaga virus has been investigated by Bayesian phylogenetics and phylodynamic analysis. A database of 32 sequences of MADV group structural polyprotein were downloaded from GenBank, aligned manually edited by Bioedit Software. ModelTest v. 3.7 was used to select the simplest evolutionary model that adequately fitted the sequence data. Neighbor-joining tree was generated using MEGA7. The phylogenetic signal of the dataset was tested by the likelihood mapping analysis. The Bayesian phylogenetic tree was built using BEAST. Selective pressure analysis revealed one positive selection site. The phylogenetic trees showed two main clusters. In particular, Lineage II showed an epizootic infection in monkeys and Lineage III, including 2 main clusters (IIIa and IIIB), revealing an epizootic infection in humans in Haiti and an epizootic infection in humans in Venezuela during the 2016, respectively. The Bayesian maximum clade credibility tree and the time of the most common recent ancestor estimates, showed that the root of the tree dated back to the year 346 with the probable origin in Brazil. Gene flow analysis revealed viral exchanges between different neighbor countries of South America. In conclusion, Bayesian phylogenetic and phylodynamic represent useful tools to follow the transmission dynamic of emergent pathogens to prevent new epidemics spreading worldwide.

Efficacy of radiofrequency ablation in autonomous functioning thyroid nodules. A systematic review and meta-analysis.

Whether thermal ablation is effective to treat toxic thyroid nodules (TTN) is still unknown. Aim of this review was to achieve more robust evidence on the efficacy of radiofrequency ablation (RFA) in treating TTN in terms of TSH normalization, thyroid scintiscan, and volume reduction rate (VRR). A comprehensive literature search of PubMed/Medline and Scopus was performed in November 2018 to retrieve published studies. Original papers reporting TTN treated by RFA and later followed-up were eligible. Excluded were: articles not within this field, articles with unclear data, overlapping series, case/series reports. Discordances were solved in a final collegial meeting. Information was collected concerning population features, treatment procedure, follow-up, cases with TSH normalization, cases with scintiscan normalization, VRR of nodules. Pooled prevalence of patients with TSH or scintiscan normalization, and pooled VRR over time were calculated. For statistical analysis, the random-effects model was used. Eight articles published between 2008 and 2018 were included. The overall number of AFTN treated by RFA was 205. Five studies used a single session of treatment. The time of follow-up ranged from six to 24 months. The pooled rate of patients with TSH normalization was 57%. The pooled rate of patients with scintigraphically proven optimal response was 60%. The pooled VRR at 1 year was 79%. Baseline nodules volume was associated with the rate of TSH normalization. In conclusion, a moderate efficacy of RFA in treating TTN was found, and this can represent a solid starting point in this field.

Correction to: Efficacy of radiofrequency ablation in autonomous functioning thyroid nodules. A systematic review and meta-analysis.

The authors of this paper declare that their correct family and first names and their correct affiliations are shown in this correction paper.

Genetic diversity in the env V1-V2 region of proviral quasispecies from long-term controller MHC-typed cynomolgus macaques infected with SHIVSF162P4cy.

Intra-host evolution of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) has been shown by viral RNA analysis in subjects who naturally suppress plasma viremia to low levels, known as controllers. However, little is known about the variability of proviral DNA and the inter-relationships among contained systemic viremia, rate of reservoir reseeding and specific major histocompatibility complex (MHC) genotypes, in controllers. Here, we analysed the proviral DNA quasispecies of the env V1-V2 region, in PBMCs and in anatomical compartments of 13 long-term controller monkeys after 3.2 years of infection with simian/human immunodeficiency virus (SHIV)SF162P4cy. A considerable variation in the genetic diversity of proviral quasispecies was present among animals. Seven monkeys exhibited env V1-V2 proviral populations composed of both clusters of identical ancestral sequences and new variants, whereas the other six monkeys displayed relatively high env V1-V2 genetic diversity with a large proportion of diverse novel sequences. Our results demonstrate that in SHIVSF162P4cy-infected monkeys there exists a disparate pattern of intra-host viral diversity and that reseeding of the proviral reservoir occurs in some animals. Moreover, even though no particular association has been observed between MHC haplotypes and the long-term control of infection, a remarkably similar pattern of intra-host viral diversity and divergence was found within animals carrying the M3 haplotype. This suggests that in animals bearing the same MHC haplotype and infected with the same virus, viral diversity follows a similar pattern with similar outcomes and control of infection.

What is changed in HBV molecular epidemiology in Italy?

Hepatitis B virus (HBV) infection represents the most common cause of chronic liver diseases worldwide. Consequently, to the introduction of the universal HBV vaccination program, the prevalence of hepatitis B surface antigen was markedly reduced and less than 1% of the population of Western Europe and North America is chronically infected. To date, despite great advances in therapeutics, HBV chronic infection is considered an incurable disease. Ten hepatitis B virus genotypes (A-J) and several subgenotypes have been identified so far, based on intergroup divergences of 8% and 4%, respectively, in the complete viral genome. HBV-D genotype has been found throughout the world, with highest prevalence in the Mediterranean area. In the present review, several articles concerning HBV epidemiology, and phylogeny in Italy have been analyzed, mainly focusing on the changes occurred in the last decade.

Genotype I hepatitis A virus introduction in Italy: Bayesian phylogenetic analysis to date different epidemics.

Despite a significant decrease in acute hepatitis A in the last 2 decades in Italy, outbreaks were observed occurring mostly in southern Italy. In this study, Bayesian phylogenetic analysis was used to analyze the origin of these epidemics. With this aim, 5 different data sets of hepatitis A virus sequences were built to perform genotyping by the neighbor-joining method to estimate the evolutionary rates by using a Bayesian Markov chain Monte Carlo approach and to investigate the demographic history by independent Markov chain Monte Carlo runs enforcing both a strict and relaxed clock. The estimated mean value of the evolutionary rate, representing Ia and Ib strains, was 1.21 × 10-3 and 2.0 × 10-3 substitutions/site/year, respectively. The Bayesian maximum clade credibility tree of hepatitis A virus (HAV) Ia and Ib strains showed that Italian sequences mostly formed separate clusters. The root of the time for the most recent common ancestor (tMRCA) for HAV Ia and Ib strains dated back to 1981 and to 1988, respectively, showing in both cases different epidemic entrances. Phylodynamic analysis showed that genotype Ia increased in 1997, when the Apulia epidemic started, then suffered a bottleneck, probably consequent to vaccination and to the herd immunity, followed by a new increase in virus population in the years 2013-2014 consequent to the epidemic caused by the ingestion of mixed frozen berries. A similar trend without an evident bottleneck was observed also in the case of genotype Ib. In conclusion, the Bayesian phylogenetic analysis represents a good tool to measure the effectiveness of the public health plans used for HAV control.

Multi-drug resistant Pseudomonas aeruginosa nosocomial strains: Molecular epidemiology and evolution.

Pseudomonas aeruginosa causes a wide variety of nosocomial infections. In the study, phylogenetic, selective pressure analysis and homology modelling were applied to oprD efflux pump gene with the aim to characterize multi-drug resistant strains circulating in the nosocomial setting, their transmission dynamics and ongoing evolution. One hundred ninety-three consecutive inpatients with Pseudomonas aeruginosa infection were enrolled at the University Campus Bio-Medico of Rome, between January 2015 and December 2016. oprD gene was sequenced in 20 nosocomial multi-drug resistant P. aeruginosa strains. Phylogeographic, selective pressure, residue conservation analysis and homology modelling were performed. Clinical epidemiological data were extracted from patient medical records. Multi-drug resistant strains accounted for the 36% of total strains and were responsible of 20 cases of nosocomial infections. P. aeruginosa infections occurred prevalently in the West area, especially at the location IIIW and in the Geriatric ward. The time of the most recent common ancestor indicated that strains could have been introduced in the hospital since the end of the year 2009 with the most probable location in general surgery ward. By selective pressure analysis, 29 positions under diversifying selection have been identified and mapped onto the OprD model. Most of the observed residue substitutions are predicted to be destabilizing and some of them occurred in the Loops 2 and 3 that are involved in solute selection and carbapenem susceptibility. The molecular and evolutionary analysis of Multi-drug resistant strains circulating in the nosocomial setting may provide useful insights into the epidemiology and the mechanisms leading to resistance, contributing to infection control improvement.