Is avian influenza virus A(H5N1) a real threat to human health?

The A(H5N1) influenza remains a disease of birds with a significant species barrier: in the presence of some tens million cases of infection in poultry - with a wide geographical spread -, only a few hundreds cases have occurred in humans. To date, human cases have been reported in 15 countries - mainly in Asia - and all were related to the onset of outbreaks in poultry. A peak of H5N1 human cases was recorded in 2006, then decreasing in subsequent years. Despite this trend, the H5N1 virus still represents a possible threat to human health, considering that more than half of human cases of H5N1 have been fatal. Moreover, despite the drop in the number of cases, the risk of a novel pandemic cannot be excluded, since H5N1 continues to circulate in poultry in countries with elevated human population density and where monitoring systems are not fully appropriate. In addition, there is a major global concern about the potential occurrence of a reassortment between the 2009 pandemic H1N1 and the highly pathogenic H5N1 influenza viruses following a co-infection in a susceptible host. Therefore, the implementation of appropriate surveillance and containment measures is crucial in order to minimize such risk. In conclusion, H5N1 avian influenza is still a rare disease in humans but its clinical severe outcome requires a careful monitoring of the virus?s ability to evolve and to trigger a new pandemic

COVID-19 VACCINES: EVIDENCE, CHALLENGES AND THE FUTURE

Through an unprecedented research and development process, in early 2021, just one year after the COVID-19 pandemic started devastating the world, there are several vaccines commercially available or in advanced phase of testing, each with its own characteristics and challenges. For the first time in the history of vaccination, a global immunization programme has started at a time of intense pandemic activity characterized by high virus transmission, facilitating selection of variants potentially able to escape the vaccine-induced antibody response. The reality is that one cannot rely on a single vaccine when dealing with a pandemic emergency: the urgent need of billions of doses clashes with the production capacity of the pharmaceutical industry. There is therefore no ideal vaccine, but there are many good vaccines to be used immediately. Today,  the international debate about COVID-19 vaccines is the hottest topic in global health whether it relates to technical and scientific issues or to the ethical aspects of access to vaccinations for all. This article aims at reviewing the status of vaccines that are used, or about to be used, in immunization campaigns worldwide

Molecular epidemiology and genotyping of Chlamydia trachomatis infection in a cohort of young asymptomatic sexually active women (18-25 years) in Milan, Italy.

IntroductionChlamydia trachomatis (Ct) is the most common bacterial cause of sexually transmitted infections (STI) and is associated with severe long-term sequelae in female populations.In Italy Ct infections are not submitted to a screening programme, and its epidemiological profile is understudied. Even scarcer information is available about the genetic diversity on ompA gene, whose sequence defines 18 different genovars.This study aims at evaluating the prevalence of Ct infection in young sexually active asymptomatic women aged 18-25, and characterizing the molecular epidemiology of the different circulating genovars in this population. MethodsCervical samples collected from 909 sexually-active-young women (mean age 21.5 years) were analyzed through molecular assay for the detection of Ct infection. Phylogenetic analysis on the ompA gene was performed on Ct positive samples to identify the circulating genovars. ResultsThe overall prevalence of Ct-infection was 4.4% (95%CI: 3.2-5.9%): 5.3% among women aged 18-21 years and 3.5% among those aged 22-25 years. Phylogenetic analysis has identified 5 different genovars: D, E, F, G, and H. The most common genovar was the E (46%), followed by genovar F and G (18.9% each), D (13.5%), and H (2.7%). ConclusionsThis study underlines the high prevalence of asymptomatic Ct-infections among young women. Overall, about half of asymptomatic infections is sustained by genovar E. The introduction in Italy of a systematic screening program should be considered to allow a better understanding of Ct spreading and providing women with an opportunity for early treatment to protect their sexual and reproductive health

Laboratory-based surveillance of invasive listeriosis in Northern Italy over a fourteen-year period: epidemiological and clinical results

Introduction Invasive listeriosis is a rare foodborne disease with a large public health impact, because of the severity of its clinical manifestations and high fatality rate. In this study, we provide a snapshot of epidemiology of listeriosis in Lombardy Region, Northern Italy, reviewing enhanced surveillance data collected over fourteen years, after the implementation of a voluntary laboratory-based surveillance system for the referral of clinical isolates of Listeria monocytogenes to a regional reference laboratory, since 2005. Methods Invasive listeriosis cases data from 2005 to 2018 were extracted from the regional laboratory-based surveillance system database and compared with the regional mandatory notification disease system data. Results Over the fourteen period under study, 533 Listeria monocytogenes isolates were detected by the laboratory surveillance system, 55 of which from pregnancy-related cases. The median age of non-pregnancy-associated patients was 71 years, with 64.6% of cases observed in the elderly. Cases with underlying medical risk conditions accounted for 92.1%, and the fatality rate was 26.2%. By integrating data from the two sources, a total of 935 cases were recorded. The collection of data through the laboratory surveillance system allowed to increase the surveillance sensitivity by 18%. Conclusions Our results documented the growing epidemiological relevance of listeriosis through the analysis of two information sources. The data we obtained were consistent with the literature, except for pregnancy-related cases, which are often underdiagnosed. This study highlighted the importance of laboratory-based surveillance system, which led to a significant increase in the sensitivity of the mandatory notification system

Molecular characterization and phylogenetic analysis of human influenza A viruses in three consecutive seasons with different epidemiological profiles

Introduction. Influenza activity and influenza virus circulation were observed in Lombardy (northern Italy) during three con- secutive seasons and the molecular characteristics of circulating viruses analysed to control for introduction of new variants. Methods. The molecular characterization of 38 isolates, namely 20 A/H3N2 and 18 A/H1N1 influenza strains from the 2005/06, 2006/07 and 2007/08 seasons, was performed by sequence analy- sis of the globular head region of the HA protein (HA1 subunit), specific for influenza virus A/H3 and A/H1. Results and discussion. The last three influenza seasons in the study region were characterized by medium-low activity. A typical co-circulation of several variants was shown for A/H3 viruses for approximately two years and were subsequently almost entirely substituted by new emerging variants. Vice versa, A/H1 viruses had a more homogeneous circulation with a single lineage clearly dominating each season. The HA sequences of the A/H3 and the A/H1 viruses isolated in the last three seasons fell into 4 and 3 principal phylogenetic groups, respectively. No evidence of positive or negative selection in the sequence align- ments was observed. Conclusions. Molecular characterization of the influenza viruses in three consecutive seasons highlighted considerable heteroge- neity in their HA sequences. A careful surveillance of genetic changes in the HA1 domain during seasonal influenza epidemics may reveal immune escape and provide early information on newly emerging strains with epidemiologic inference

Viable Newcastle Disease Vaccine Strains in a Pharmaceutical Dump

To assess the viability of discarded and buried vaccine strains, we examined vaccines that had been buried for >20 years in an industrial waste dump in the city of Milan, Italy. Viability results showed potential biological risk associated with uncontrolled burial of pharmaceutical industry waste, including some live vaccines

Early co-circulation of different clades of influenza A/H1N1v pandemic virus in Northern Italy

Introduction. The spatial diffusion over time of pandemic influenza A/H1N1 virus (A/H1N1v) was surveyed in Northern Italy (nearly 10 million inhabitants) from April to December 2009, and the molecular characteristics of circulating viruses were analyzed to identify the appearance of drift variants. About 45% of analyzed samples were laboratory-confirmed cases of A/H1N1v. Sporadic cases occurred until the middle of June 2009, then, case numbers began to increase delineating distinct epidemiological phases of viral circulation. Methods. RNA was extracted using RNeasy Mini kit (QIAGEN GmbH, Germany). Virological diagnosis of A/H1N1v infection was carried out by real-time RT-PCR assay. Sequence analysis of hemagglutinin (HA) gene was performed through a RT-PCR assay specific for a 995 bp fragment (nt. 64-1,058) in the HA1 domain. The nucleotide sequences were obtained by automated DNA sequencing. The HA1 sequences were aligned with other sequences collected from GenBank database by ClustalX software. The multiple sequence alignment was used to perform a basic phylogenetic analysis and a phylogenetic tree from HA sequences was constructed. Results. The HA gene sequences of A/H1N1v analyzed segregated into three genetically distinct clades and were characterized by the appearance of amino acid variations that were progressively fixed in the field viral population under scrutiny. Conclusions. These data suggest an early co-circulation of genetically distinct A/H1N1v variants and emphasize the importance of a close molecular surveillance to detect rapidly the spread of new viral variants and to define their epidemiological impact

Observational constraints on a cosmological model with Lagrange multipliers

Cosmological models with Lagrange multipliers are appealing because they could explain the behaviour of the dark sector in a unified way. In this work we analyse extensions to the "Dust of Dark Energy model" proposed in arXiv:1003.5751 by including spatial curvature and more general potentials of the scalar field. We perform dynamical system analysis and we determine the evolution of the equation of state parameter as a function of the scale factor. We present observational constraints on this model by using Union2.1 dataset and H(z) data.Comment: 14 pages, 7 figures. Accepted for publication in PL