Overview of hepatitis B virus mutations and theirimplications in the management of infection

Hepatitis B virus(HBV)affects approximately two billion people worldwide and more than 240 million people in the world are currently chronic carrier that could develop serious complications in the future,like liver cirrhosis and hepatocellular carcinoma.Although an extended HBV immunization program is being carried out since the early‘80s,representing effective preventive measure,leading to a dramatic reduction of HBV hepatitis incidence,globally HBV infection still represents a major public health problem.The HBV virus is a DNA virus belongs to the Hepadnaviridae family.The HBV-DNA is a circular,partial double strand genome.All coding information is on the minus DNA strand and it is organized into four open reading frames.Despite hepatitis B virus is a DNA virus,it has a high mutation rate due to its replicative strategy,that leads to the production of many nonidentical variants at each cycle of replication.In fact,it contains a polymerase without the proofreading activity,and uses an RNA intermediate(pg RNA)during its replication,so error frequencies are comparable to those seen in retroviruses and other RNA viruses rather than in more stable DNA viruses.Due to the low fidelity of the polymerase,the high replication rate and the overlapping reading frames,mutations occur throughout the genome and they have been identified both in the structural and not structural gene.The arise of mutations being to develop of a whole of viral variants called"quasi-species"and the prevalent population,which favors virus replication,was selected by viral fitness,host’s immune pressure and external pressure,i.e.,vaccination or antiviral therapy.Naturally occurring mutations were found both in acute and chronic subjects.In the present review we examine and discuss the most recent available data about HBV genetic variability and its significance.

Hepatitis C virus in the new era:Perspectives in epidemiology,prevention,diagnostics and predictors of response to therapy

Despite the great successes achieved in the fields of virology and diagnostics,several difficulties affect improvements in hepatitis C virus(HCV)infection control and eradication in the new era.New HCV infections still occur,especially in some of the poorest regions of the world,where HCV is endemic and long-term sequelae have a growing economic and health burden.An HCV vaccine is still no available,despite years of researches and discoveries about the natural history of infection and host-virus interactions:several HCV vaccine candidates have been developed in the last years,targeting different HCV antigens or using alternative delivery systems,but viral variability and adaption ability constitute major challenges for vaccine development.Many new antiviral drugs for HCV therapy are in preclinical or early clinical development,but different limitations affect treatment validity.Treatment predictors are important tools,as they provide some guidance for the management of therapy in patients with chronic HCV infection:in particular,the role of host genomics in HCV infection outcomes in the new era of direct-acting antivirals may evolve for new therapeutic targets,representing a chance for modulated and personalized treatment management,when also very potent therapies will be available.In the present review we discuss the most recent data about HCV epidemiology,the new perspectives for the prevention of HCV infection and the most recent evidence regarding HCV diagnosis,therapy and predictors of response to it.

Indoor Air Quality in a Real Operating Theatre under Effective Use Conditions

The aim of this study is to investigate the impact of surgical staff on the indoor air quality in a uni-directional ventilation Operating Theatre (OT). Experimental measurements of particles and microclimate were acquired at rest and in operational conditions. The real OT (operational) use was simulated by a sham hip arthroplasty. CFD simulations were carried out outlining the studied environment used for experimental measurement campaign. A standard k-ε closure scheme based on RANS equations was implemented to solve the velocity and pressure field using an eddy viscosity approach. Temperature and relative humidity distributions were also computed keeping into account sensible and latent heat sources inside the OT. An Euler-based approach was applied to solve the concentration fields of gaseous contaminant and small particles (up to 5 μm in diameter) in the indoor air. An innovative strategy is proposed to estimate, by an iterative comparison between experimental data and numerical results, the emission rate of particles (differentiated by diameters) released by the occupants to be considered as source terms in the numerical model. Compliance with literature evidence concerning thermal and velocity fields and CO2 concentration was confirmed. From our analyses, some IAQ indexes were deduced, allowing monitoring of the local and overall OT air quality level supplied by the ventilating system during real operational conditions. The highest values of microbial air contamination were recorded during surgical activity;nevertheless, results showed the suitability of the ventilation system in providing the expected air quality.

Assessing Ebola-related web search behaviour: insights and implications from an analytical study of Google Trends-based query volumes

Background:The 2014 Ebola epidemic in West Africa has attracted public interest worldwide,leading to millions of Ebola-related Internet searches being performed during the period of the epidemic.This study aimed to evaluate and interpret Google search queries for terms related to the Ebola outbreak both at the global level and in all countries where primary cases of Ebola occurred.The study also endeavoured to look at the correlation between the number of overall and weekly web searches and the number of overall and weekly new cases of Ebola.Methods:Google Trends(GT)was used to explore Internet activity related to Ebola.The study period was from 29 December 2013 to 14 June 2015.Pearson’s correlation was performed to correlate Ebola-related relative search volumes(RSVs)with the number of weekly and overall Ebola cases.Multivariate regression was performed using Ebola-related RSV as a dependent variable,and the overall number of Ebola cases and the Human Development Index were used as predictor variables.Results:The greatest RSV was registered in the three West African countries mainly affected by the Ebola epidemic.The queries varied in the different countries.Both quantitative and qualitative differences between the affected African countries and other Western countries with primary cases were noted,in relation to the different flux volumes and different time courses.In the affected African countries,web query search volumes were mostly concentrated in the capital areas.However,in Western countries,web queries were uniformly distributed over the national territory.In terms of the three countries mainly affected by the Ebola epidemic,the correlation between the number of new weekly cases of Ebola and the weekly GT index varied from weak to moderate.The correlation between the number of Ebola cases registered in all countries during the study period and the GT index was very high.Conclusion:Google Trends showed a coarse-grained nature,strongly correlating with global epidemiological data,but was weaker at country level,as it was prone to distortions induced by unbalanced media coverage and the digital divide.Global and local health agencies could usefully exploit GT data to identify disease-related information needs and plan proper communication strategies,particularly in the case of health-threatening events.