1,721,036 research outputs found
Gaudio E., Tarricone L., Terregino C., Piccirillo. A."Screening for Avian Influenza and Paramyxovirus Type 1 in wild birds admitted to a rehabilitation centre in Veneto Region (Northern Italy): preliminary results", Proceedings of the International Conference on Diseases of Zoo and Wild Animal 2015, page 119, Barcelona, Spain (13/05/2015-16/05/2015).
No full textA systematic review of human coronaviruses survival on environmental surfaces
No full textThe current pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has led people to implement preventive measures, including surface disinfection and use of alcohol-based hand gel, in order to avoid viral transmission via fomites. However, the role of surface transmission is still debated. The present systematic review aims to summarize all the evidence on surface survival of coronaviruses infecting humans. The analysis of 18 studies showed the longest coronavirus survival time is 28 days at room temperature (RT) on different surfaces: polymer banknotes, vinyl, steel, glass, and paper banknotes. Concerning SARS-CoV-2 human infection from contaminated surfaces, dangerous viral load on surfaces for up to 21 days was determined on polymer banknotes, steel, glass and paper banknotes. For viruses other than SARS-CoV-2, the longest period of survival was 14 days, recorded on glass. Environmental conditions can affect virus survival, and indeed, low temperatures and low humidity support prolonged survival of viruses on contaminated surfaces independently of surface type. Furthermore, it has been shown that exposure to sunlight significantly reduces the risk of surface transmission. Although studies are increasingly investigating the topic of coronavirus survival, it is difficult to compare them, given the methodology differences. For this reason, it is advisable to define a reference working protocol for virus survival trials, but, as an immediate measure, there is also a need for further investigations of coronavirus survival on surfaces
Prevalence of SARS-CoV-2 RNA on inanimate surfaces: a systematic review and meta-analysis
No full textCoronavirus disease (COVID-19) is a respiratory disease affecting many people and able to be transmitted through direct and perhaps indirect contact. Direct contact transmission, mediated by aerosols or droplets, is widely demonstrated, whereas indirect transmission is only supported by collateral evidence such as virus persistence on inanimate surfaces and data from other similar viruses. The present systematic review aims to estimate SARS-CoV-2 prevalence on inanimate surfaces, identifying risk levels according to surface characteristics. Data were obtained from studies in published papers collected from two databases (PubMed and Embase) with the last search on 1 September 2020. Included studies had to be papers in English, had to deal with coronavirus and had to consider inanimate surfaces in real settings. Studies were coded according to our assessment of the risk that the investigated surfaces could be contaminated by SARS-CoV-2. A meta-analysis and a metaregression were carried out to quantify virus RNA prevalence and to identify important factors driving differences among studies. Thirty-nine out of forty retrieved paper reported studies carried out in healthcare settings on the prevalence of virus RNA, five studies carry out also analyses through cell culture and six tested the viability of isolated viruses. Overall prevalences of SARS-CoV-2 RNA on high-, medium- and low-risk surfaces were 0.22 (CI95 [0.152-0.296]), 0.04 (CI95 [0.007-0.090]), and 0.00 (CI95 [0.00-0.019]), respectively. The duration surfaces were exposed to virus sources (patients) was the main factor explaining differences in prevalence
Replication of Influenza D Viruses of Bovine and Swine Origin in Ovine Respiratory Explants and Their Attachment to the Respiratory Tract of Bovine, Sheep, Goat, Horse, and Swine
Full text linkBovine is considered the main reservoir of influenza D virus (IDV), however, low levels of seropositivity in other farmed species suggest a wide range of potential hosts. Nevertheless, it is not clear whether this scenario is the result of rare spillover events upon contact with bovines, or a lack of adaptation of IDV to these hosts. Among these species, sheep represents a crucial component of the rural economy in many developing countries, but little is known about its role in the ecology of the disease. To evaluate the susceptibility of sheep to IDV viruses of different origin, we used ovine respiratory tissues as an ex vivo model and investigated the infective phenotype of two IDV strains isolated from either bovine (IDV-BOV) or swine (IDV-SW). For translatability purposes, we included a parainfluenza type 3 virus, as positive control, given its known respiratory tropism in sheep. We performed a timed evaluation of the viral infectivity, cell tropism and the associated histopathology, by means of tissue culture infectious dose assays on supernatants and histological/immunohistochemical analyses on explanted tissues, respectively. To further investigate differences in the phenotype of these two strains and to identify the potential targets of replication in the most commonly land-based farmed mammalian species, we carried out virus binding assays on histological sections of the respiratory tract of bovine, caprine, ovine, horse and swine. Our results demonstrated that IDV successfully replicates in nasal, tracheal and lung ovine tissues, suggesting a moderate susceptibility of this species to IDV infection. Interestingly, despite the high genetic identity of these strains, IDV- BOV consistently replicated to higher titers than IDV-SW in all respiratory tracts, suggesting IDV viruses might display considerable levels of variability in their phenotype when crossing the species barrier. Virus binding assays confirmed a superior affinity of the IDV viruses for the bovine upper respiratory tract, and a preference for the pharyngeal epithelium of small ruminants, indicating possible targets to improve the sensitivity of virological sampling for diagnostic and post-mortem purposes. Further pathogenesis and cross-species transmission studies will be necessary to elucidate the ecology of IDV and eventually allow the design of cost-effective surveillance strategies
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Occurrence of Chlamydiae in Corvids in Northeast Italy
Full text linkChlamydiaceae occurrence has been largely evaluated in wildlife, showing that wild birds
are efficient reservoirs for avian chlamydiosis. In this study, DNA extracted from cloacal swabs of
108 corvids from Northeast Italy was screened for Chlamydiaceae by 23S real-time (rt)PCR. The positive
samples were characterised by specific rtPCRs for Chlamydia psittaci, Chlamydia abortus, Chlamydia
gallinacea, Chlamydia avium, Chlamydia pecorum and Chlamydia suis. Cloacal shedding of Chlamydiaceae
was detected in 12 out of 108 (11.1%, 5.9%–18.6% 95% CI) corvids sampled. Molecular characterisation
at the species level was possible in 8/12 samples, showing C. psittaci positivity in only one sample
from a hooded crow and C. abortus positivity in seven samples, two from Eurasian magpies and five
from hooded crows. Genotyping of the C. psittaci-positive sample was undertaken via PCR/highresolution
melting, clustering it in group III_pigeon, corresponding to the B genotype based on former
ompA analysis. For C. abortus genotyping, multilocus sequence typing was successfully performed on
the two samples with high DNA load from Eurasian magpies, highlighting 100% identity with the
recently reported Polish avian C. abortus genotype 1V strain 15-58d44. To confirm the intermediate
characteristics between C. psittaci and C. abortus, both samples, as well as two samples from hooded
crows, showed the chlamydial plasmid inherent in most C. psittaci and avian C. abortus, but not in
ruminant C. abortus strains. The plasmid sequences were highly similar (99%) to those of the Polish
avian C. abortus genotype 1V strain 15-58d44. To our knowledge, this is the first report of avian
C. abortus strains in Italy, specifically genotype 1V, confirming that they are actively circulating in
corvids in the Italian region tested
Identification and genetic characterization of equine hepaciviruses in Italy
No full textViruses similar to human hepatitis C virus, hepaciviruses, have been identified in various animal species. Equine hepacivirus (EqHV) is the closest relative of human hepaciviruses. Although detected worldwide, information on EqHV epidemiology, genetic diversity and pathogenicity is still limited. In this study we investigated the prevalence and genetic diversity of EqHV in Italian equids. The RNA of EqHV was detected in 91/1932 sera (4.7%) whilst it was not detectable in 134 donkey sera screened by a TaqMan-based quantitative assay. Upon sequencing and phylogenetic analysis of genomic portions located in the NS5B, 5â 2UTR and NS3 genes, the Italian EqHV strains segregated into two distinct clades that are also co-circulating globally, without apparent geographic restrictions
Histopathological and immunohistochemical study of exocrine and endocrine pancreatic lesions in avian influenza A experimentally-infected turkeys showing evidence of pancreatic regeneration
No full textIn order to investigate the pancreatic lesions caused by the infection with either H7N1 or H7N3 low-pathogenicity avian influenza viruses, 28 experimentally infected turkeys were submitted for histopathology, immunohistochemistry, haematobiochemistry and real-time reverse transcriptase polymerase chain reaction after different days post-infection (DPI). The localization of viral antigen and the measurement of insulin and glucagon expression in the pancreas were assessed to verify the progression from pancreatitis to metabolic disorders, such as diabetes. At the early infection phase (4–7 DPI), a severe acute necrotizing pancreatitis was recognized. During the intermediate phase (8–17 DPI), a mixed acute/chronic change associated with regenerative ductular proliferation was observed. A loss of pancreatic islets was detected in most severe cases and viral antigen was found in the pancreas of 11/28 turkeys (4–10 DPI) with the most severe histological damage. In turkeys euthanized at 39 DPI (late phase), a chronic fibrosing pancreatitis was observed with the reestablishment of both the exocrine and the endocrine pancreas. Insulin and glucagon expression manifested a progressive decrease with subsequent ductular positivity. Haematobiochemistry revealed increased lipasemia in the first week post-infection and hyperglycaemia in the second, with a progressive normalization within 21 DPI. This study allowed the identification of progressive virus-associated exocrine and endocrine pancreatic damage, suggesting that influenza virus might be responsible for metabolic derangements. Moreover, it highlighted a remarkable post-damage hyperplastic and reparative process from a presumptive common exocrine/endocrine precursor. This potential regeneration deserves further investigation for its relevance in a therapeutic perspective to replace lost and non-functional cells in diabetes mellitus
Detection of avian influenza virus: a comparative study of the in silico and in vitro performances of current RT-qPCR assays
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