127 research outputs found
Human and animal integrated influenza surveillance: a novel sampling approach for an additional transmission way in the aquatic bird reservoir.
Background: infectious low pathogenic avian influenza viruses (LPAIVs) have been recently detected
on feathers of wild ducks. Laboratory trial results suggested that the preen oil gland secretion,
covering waterbirds\u2019 feathers, may attract and concentrate virus particles from AIV-contaminated
waters to birds\u2019 bodies. We evaluated whether ducks can become infected by the ingestion of preen
oil-associated viral particles, experimentally smeared on their plumage. In addition, we compared
virologic and serologic results obtained from mallards whose feathers were experimentally infected,
with those from wild mallards naturally carrying AIVs on feathers.
Methods: we experimentally coated 7 mallards (Anas plathyrynchos) using preen oil mixed with
a LPAIV (H10N7 subtype), and housed them for 45 days with a control, uncoated duck. Cloacal,
oropharyngeal and feather swabs were collected from all birds and examined for AIV molecular
detection and isolation. Blood samples were also taken to detect influenza specific antibodies. In
addition, sera from 10 wild mallards, carrying on feathers infectious LPAIV H10N7, were examined.
Results: virologic and serologic results indicated that through self- and allopreening all the birds
experimentally coated with the preen oil/AIV mix and the control duck ingested viruses covering
feathers and became infected. Virus isolation from feathers was up to 32 days post-coating treatment.
One out of 8 wild mallards showing antibodies against type A influenza virus was seropositive for H10
subtype too.
Conclusions: our experimental and field results show evidences suggesting that uninfected birds
carrying viruses on their feathers, including immune ones, might play an active role in spreading AIV
infection in nature. For this reason, routine AIV surveillance programs, aimed at detecting intestinal
and/or respiratory viruses, should include the collection of samples, such as feather swabs, enabling
the detection of viruses sticky to preened birds\u2019 bodies
A Digital Pattern Methodology supporting Railway Industries in Portfolio Management
The object of this paper is the development of a decision support system involved in
the bidding for invitations to tender in the railway field. The proposed methodology
is based on the characterization of the whole train and its components, through
several attributes according to a digital pattern approach. In particular some key
components were chosen such as the traction motor, the bogie and the auxiliary
equipment converter. The system measures the extent to which the products offered
by the company fit the one required by the customer, comparing the homologous
attributes. Such analysis is called ‘adopt/adapt/innovate’ (AAI). In this way it is
possible to identify products already designed that fully or partly fit what required,
obtaining huge benefits in terms of effectiveness and efficiency
Investigation of an imported case of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection in Florence, Italy, May to June 2013.
Co-circulation of the two influenza B lineages during 13 consecutive influenza surveillance seasons in Italy, 2004-2017
BACKGROUND: Since 1985, two antigenically distinct lineages of influenza B viruses (Victoria-like and Yamagata-like) have circulated globally. Trivalent seasonal influenza vaccines contain two circulating influenza A strains but a single B strain and thus provide limited immunity against circulating B strains of the lineage not included in the vaccine. In this study, we describe the characteristics of influenza B viruses that caused respiratory illness in the population in Italy over 13 consecutive seasons of virological surveillance, and the match between the predominant influenza B lineage and the vaccine B lineage, in each season. METHODS: From 2004 to 2017, 26,886 laboratory-confirmed influenza cases were registered in Italy, of which 18.7% were type B. Among them, the lineage of 2465 strains (49%) was retrieved or characterized in this study by a real-time RT-PCR assay and/or sequencing of the hemagglutinin (HA) gene. RESULTS: Co-circulation of both B lineages was observed each season, although in different proportions every year. Overall, viruses of B/Victoria and B/Yamagata lineages caused 53.3 and 46.7% of influenza B infections, respectively. A higher proportion of infections with both lineages was detected in children, and there was a declining frequency of B/Victoria detections with age. A mismatch between the vaccine and the predominant influenza B lineage occurred in eight out of thirteen influenza seasons under study. Considering the seasons when B accounted for >\u200920% of all laboratory-confirmed influenza cases, a mismatch was observed in four out of six seasons. Phylogenetic analysis of the HA1 domain confirmed the co-circulation of both lineages and revealed a mixed circulation of distinct evolutionary viral variants, with different levels of match to the vaccine strains. CONCLUSIONS: This study contributes to the understanding of the circulation of influenza B viruses in Italy. We found a continuous co-circulation of both B lineages in the period 2004-2017, and determined that children were particularly vulnerable to Victoria-lineage influenza B virus infections. An influenza B lineage mismatch with the trivalent vaccine occurred in about two-thirds of cases
Frequency of D222G and Q223R Hemagglutinin Mutants of Pandemic (H1N1) 2009 Influenza Virus in Japan between 2009 and 2010
BACKGROUND: In April 2009, a novel swine-derived influenza A virus (H1N1pdm) emerged and rapidly spread around the world, including Japan. It has been suggested that the virus can bind to both 2,3- and 2,6-linked sialic acid receptors in infected mammals, in contrast to contemporary seasonal H1N1 viruses, which have a predilection for 2,6-linked sialic acid. METHODS/RESULTS: To elucidate the existence and transmissibility of α2,3 sialic acid-specific viruses in H1N1pdm, amino acid substitutions within viral hemagglutinin molecules were investigated, especially D187E, D222G, and Q223R, which are related to a shift from human to avian receptor specificity. Samples from individuals infected during the first and second waves of the outbreak in Japan were examined using a high-throughput sequencing approach. In May 2009, three specimens from mild cases showed D222G and/or Q223R substitutions in a minor subpopulation of viruses infecting these individuals. However, the substitutions almost disappeared in the samples from five mild cases in December 2010. The D187E substitution was not widespread in specimens, even in May 2009. CONCLUSIONS: These results suggest that α2,3 sialic acid-specific viruses, including G222 and R223, existed in humans as a minor population in the early phase of the pandemic, and that D222 and Q223 became more dominant through human-to-human transmission during the first and second waves of the epidemic. These results are consistent with the low substitution rates identified in seasonal H1N1 viruses in 2008
Limiting worker exposure to highly pathogenic avian influenza a (H5N1): a repeat survey at a rendering plant processing infected poultry carcasses in the UK
<p>Abstract</p> <p>Background</p> <p>Current occupational and public health guidance does not distinguish between rendering plant workers and cullers/poultry workers in terms of infection risk in their respective roles during highly pathogenic avian influenza poultry outbreaks. We describe an operational approach to human health risk assessment decision making at a large rendering plant processing poultry carcasses stemming from two separate highly pathogenic avian influenza A (H5N1) outbreaks in England during 2007.</p> <p>Methods</p> <p>During the first incident a uniform approach assigned equal exposure risk to all rendering workers in or near the production line. A task based exposure assessment approach was adopted during the second incident based on a hierarchy of occupational activities and potential for infection exposure. Workers assessed as being at risk of infection were offered personal protective equipment; pre-exposure antiviral prophylaxis; seasonal influenza immunisation; hygiene advice; and health monitoring. A repeat survey design was employed to compare the two risk assessment approaches, with allocation of antiviral prophylaxis as the main outcome variable.</p> <p>Results</p> <p>Task based exposure assessment during the second incident reduced the number of workers assessed at risk of infection from 72 to 55 (24% reduction) when compared to the first incident. No cases of influenza like illness were reported in workers during both incidents.</p> <p>Conclusions</p> <p>Task based exposure assessment informs a proportionate public health response in rendering plant workers during highly pathogenic avian influenza H5N1 outbreaks, and reduces reliance on extensive antiviral prophylaxis.</p
Can Preening Contribute to Influenza A Virus Infection in Wild Waterbirds?
Wild aquatic birds in the Orders Anseriformes and Charadriiformes are the main reservoir hosts perpetuating the genetic pool of all influenza A viruses, including pandemic viruses. High viral loads in feces of infected birds permit a fecal-oral route of transmission. Numerous studies have reported the isolation of avian influenza viruses (AIVs) from surface water at aquatic bird habitats. These isolations indicate aquatic environments have an important role in the transmission of AIV among wild aquatic birds. However, the progressive dilution of infectious feces in water could decrease the likelihood of virus/host interactions. To evaluate whether alternate mechanisms facilitate AIV transmission in aquatic bird populations, we investigated whether the preen oil gland secretions by which all aquatic birds make their feathers waterproof could support a natural mechanism that concentrates AIVs from water onto birds' bodies, thus, representing a possible source of infection by preening activity. We consistently detected both viral RNA and infectious AIVs on swabs of preened feathers of 345 wild mallards by using reverse transcription–polymerase chain reaction (RT-PCR) and virus-isolation (VI) assays. Additionally, in two laboratory experiments using a quantitative real-time (qR) RT-PCR assay, we demonstrated that feather samples (n = 5) and cotton swabs (n = 24) experimentally impregnated with preen oil, when soaked in AIV-contaminated waters, attracted and concentrated AIVs on their surfaces. The data presented herein provide information that expands our understanding of AIV ecology in the wild bird reservoir system
Genetic Structure of Human A/H1N1 and A/H3N2 Influenza Virus on Corsica Island: Phylogenetic Analysis and Vaccine Strain Match, 2006–2010
Background: The aim of this study was to analyse the genetic patterns of Hemagglutinin (HA) genes of influenza A strains circulating on Corsica Island during the 2006-2009 epidemic seasons and the 2009-2010 pandemic season. [br/]
Methods: Nasopharyngeal samples from 371 patients with influenza-like illness (ILI) were collected by General Practitioners (GPs) of the Sentinelles Network through a randomised selection routine. [br/]
Results: Phylogenetic analysis of HA revealed that A/H3N2 strains circulating on Corsica were closely related to the WHO recommended vaccine strains in each analyzed season (2006-2007 to 2008-2009). Seasonal Corsican influenza A/H1N1 isolated during the 2007-2008 season had drifted towards the A/Brisbane/59/2007 lineage, the A/H1N1 vaccine strain for the 2008-2009 season. The A/H1N1 2009 (A/H1N1pdm) strains isolated on Corsica Island were characterized by the S220T mutation specific to clade 7 isolates. It should be noted that Corsican isolates formed a separate sub-clade of clade 7 as a consequence of the presence of the fixed substitution D222E. The percentages of the perfect match vaccine efficacy, estimated by using the p(epitope) model, against influenza viruses circulating on Corsica Island varied substantially across the four seasons analyzed, and tend to be highest for A/H1N1 compared with A/H3N2 vaccines, suggesting that cross-immunity seems to be stronger for the H1 HA gene. [br/]
Conclusion: The molecular analysis of the HA gene of influenza viruses that circulated on Corsica Island between 2006-2010 showed for each season the presence of a dominant lineage characterized by at least one fixed mutation. The A/H3N2 and A/H1N1pdm isolates were characterized by multiples fixation at antigenic sites. The fixation of specific mutations at each outbreak could be explained by the combination of a neutral phenomenon and a founder effect, favoring the presence of a dominant lineage in a closed environment such as Corsica Island
Viral Etiology of Influenza-Like Illnesses in Antananarivo, Madagascar, July 2008 to June 2009
In Madagascar, despite an influenza surveillance established since 1978, little is known about the etiology and prevalence of viruses other than influenza causing influenza-like illnesses (ILIs).From July 2008 to June 2009, we collected respiratory specimens from patients who presented ILIs symptoms in public and private clinics in Antananarivo (the capital city of Madagascar). ILIs were defined as body temperature ≥38°C and cough and at least two of the following symptoms: sore throat, rhinorrhea, headache and muscular pain, for a maximum duration of 3 days. We screened these specimens using five multiplex real time Reverse Transcription and/or Polymerase Chain Reaction assays for detection of 14 respiratory viruses. We detected respiratory viruses in 235/313 (75.1%) samples. Overall influenza virus A (27.3%) was the most common virus followed by rhinovirus (24.8%), RSV (21.2%), adenovirus (6.1%), coronavirus OC43 (6.1%), influenza virus B (3.9%), parainfluenza virus-3 (2.9%), and parainfluenza virus-1 (2.3%). Co-infections occurred in 29.4% (69/235) of infected patients and rhinovirus was the most detected virus (27.5%). Children under 5 years were more likely to have one or more detectable virus associated with their ILI. In this age group, compared to those ≥5 years, the risk of detecting more than one virus was higher (OR = 1.9), as was the risk of detecting of RSV (OR = 10.1) and adenovirus (OR = 4.7). While rhinovirus and adenovirus infections occurred year round, RSV, influenza virus A and coronavirus OC43 had defined period of circulation.In our study, we found that respiratory viruses play an important role in ILIs in the Malagasy community, particularly in children under 5 years old. These data provide a better understanding of the viral etiology of outpatients with ILI and describe for the first time importance of these viruses in different age group and their period of circulation
Effect of D222G Mutation in the Hemagglutinin Protein on Receptor Binding, Pathogenesis and Transmissibility of the 2009 Pandemic H1N1 Influenza Virus
Influenza viruses isolated during the 2009 H1N1 pandemic generally lack known molecular determinants of virulence associated with previous pandemic and highly pathogenic avian influenza viruses. The frequency of the amino acid substitution D222G in the hemagglutinin (HA) of 2009 H1N1 viruses isolated from severe but not mild human cases represents the first molecular marker associated with enhanced disease. To assess the relative contribution of this substitution in virus pathogenesis, transmission, and tropism, we introduced D222G by reverse genetics in the wild-type HA of the 2009 H1N1 virus, A/California/04/09 (CA/04). A dose-dependent glycan array analysis with the D222G virus showed a modest reduction in the binding avidity to human-like (α2-6 sialylated glycan) receptors and an increase in the binding to avian-like (α2-3 sialylated glycan) receptors in comparison with wild-type virus. In the ferret pathogenesis model, the D222G mutant virus was found to be similar to wild-type CA/04 virus with respect to lethargy, weight loss and replication efficiency in the upper and lower respiratory tract. Moreover, based on viral detection, the respiratory droplet transmission properties of these two viruses were found to be similar. The D222G virus failed to productively infect mice inoculated by the ocular route, but exhibited greater viral replication and weight loss than wild-type CA/04 virus in mice inoculated by the intranasal route. In a more relevant human cell model, D222G virus replicated with delayed kinetics compared with wild-type virus but to higher titer in human bronchial epithelial cells. These findings suggest that although the D222G mutation does not influence virus transmission, it may be considered a molecular marker for enhanced replication in certain cell types.Centers for Disease Control and Prevention (U.S.)United States. National Institutes of Health (merit award R37 GM057073-13)Singapore-MIT Alliance for Research and Technolog
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