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1.
mSphere ; 5(1)2020 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024713

RESUMO

While working overnight at a swine exhibition, we identified an influenza A virus (IAV) outbreak in swine, Nanopore sequenced 13 IAV genomes from samples we collected, and predicted in real time that these viruses posed a novel risk to humans due to genetic mismatches between the viruses and current prepandemic candidate vaccine viruses (CVVs). We developed and used a portable IAV sequencing and analysis platform called Mia (Mobile Influenza Analysis) to complete and characterize full-length consensus genomes approximately 18 h after unpacking the mobile lab. Exhibition swine are a known source for zoonotic transmission of IAV to humans and pose a potential pandemic risk. Genomic analyses of IAV in swine are critical to understanding this risk, the types of viruses circulating in swine, and whether current vaccines developed for use in humans would be predicted to provide immune protection. Nanopore sequencing technology has enabled genome sequencing in the field at the source of viral outbreaks or at the bedside or pen-side of infected humans and animals. The acquired data, however, have not yet demonstrated real-time, actionable public health responses. The Mia system rapidly identified three genetically distinct swine IAV lineages from three subtypes, A(H1N1), A(H3N2), and A(H1N2). Analysis of the hemagglutinin (HA) sequences of the A(H1N2) viruses identified >30 amino acid differences between the HA1 of these viruses and the most closely related CVV. As an exercise in pandemic preparedness, all sequences were emailed to CDC collaborators who initiated the development of a synthetically derived CVV.IMPORTANCE Swine are influenza virus reservoirs that have caused outbreaks and pandemics. Genomic characterization of these viruses enables pandemic risk assessment and vaccine comparisons, though this typically occurs after a novel swine virus jumps into humans. The greatest risk occurs where large groups of swine and humans comingle. At a large swine exhibition, we used Nanopore sequencing and on-site analytics to interpret 13 swine influenza virus genomes and identified an influenza virus cluster that was genetically highly varied to currently available vaccines. As part of the National Strategy for Pandemic Preparedness exercises, the sequences were emailed to colleagues at the CDC who initiated the development of a synthetically derived vaccine designed to match the viruses at the exhibition. Subsequently, this virus caused 14 infections in humans and was the dominant U.S. variant virus in 2018.

2.
MMWR Morb Mortal Wkly Rep ; 69(7): 177-182, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32078591

RESUMO

During the 2019-20 influenza season, influenza-like illness (ILI)* activity first exceeded the national baseline during the week ending November 9, 2019, signaling the earliest start to the influenza season since the 2009 influenza A(H1N1) pandemic. Activity remains elevated as of mid-February 2020. In the United States, annual vaccination against seasonal influenza is recommended for all persons aged ≥6 months (1). During each influenza season, CDC estimates seasonal influenza vaccine effectiveness in preventing laboratory-confirmed influenza associated with medically attended acute respiratory illness (ARI). This interim report used data from 4,112 children and adults enrolled in the U.S. Influenza Vaccine Effectiveness Network (U.S. Flu VE Network) during October 23, 2019-January 25, 2020. Overall, vaccine effectiveness (VE) against any influenza virus associated with medically attended ARI was 45% (95% confidence interval [CI] = 36%-53%). VE was estimated to be 50% (95% CI = 39%-59%) against influenza B/Victoria viruses and 37% (95% CI = 19%-52%) against influenza A(H1N1)pdm09, indicating that vaccine has significantly reduced medical visits associated with influenza so far this season. Notably, vaccination provided substantial protection (VE = 55%; 95% CI = 42%-65%) among children and adolescents aged 6 months-17 years. Interim VE estimates are consistent with those from previous seasons, ranging from 40%-60% when influenza vaccines were antigenically matched to circulating viruses. CDC recommends that health care providers continue to administer influenza vaccine to persons aged ≥6 months because influenza activity is ongoing, and the vaccine can still prevent illness, hospitalization, and death associated with currently circulating influenza viruses as well as other influenza viruses that might circulate later in the season.


Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Vigilância da População , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Vacinas contra Influenza/imunologia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Estações do Ano , Estados Unidos/epidemiologia , Adulto Jovem
3.
Influenza Other Respir Viruses ; 14(2): 215-225, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31659871

RESUMO

A major lesson learned from the public health response to the 2009 H1N1 pandemic was the need to shorten the vaccine delivery timeline to achieve the best pandemic mitigation results. A gap analysis of previous pre-pandemic vaccine development activities identified possible changes in the Select Agent exclusion process that would maintain safety and shorten the timeline to develop candidate vaccine viruses (CVVs) for use in pandemic vaccine manufacture. Here, we review the biosafety characteristics of CVVs developed in the past 15 years to support a shortened preparedness timeline for A(H5) and A(H7) subtype highly pathogenic avian influenza (HPAI) CVVs. Extensive biosafety experimental evidence supported recent changes in the implementation of Select Agent regulations that eliminated the mandatory chicken pathotype testing requirements and expedited distribution of CVVs to shorten pre-pandemic and pandemic vaccine manufacturing by up to 3 weeks.

4.
Int J Infect Dis ; 91: 169-173, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31765821

RESUMO

Following the detection of the first human case of avian influenza A subtype H9N2 in 1998, more than 40 cases were diagnosed worldwide. However, the spread of the virus has been more remarkable and significant in global poultry populations, causing notable economic losses despite its low pathogenicity. Many surveillance studies and activities conducted in several countries have shown the predominance of this virus subtype. We present the case of a 14-month-old female in Oman with an A(H9N2) virus infection. This is the first human case of A(H9N2) reported from Oman and the Gulf Cooperation Countries, and Oman is the second country outside of southern and eastern Asia to report a case (cases have also been detected in Egypt). The patient had bronchial asthma and presented with a high-grade temperature and symptoms of lower respiratory tract infection that necessitated admission to a high dependency unit in a tertiary care hospital. It is of urgency that a multisector One Health approach be established to combat the threat of avian influenza at the animal-human interface. In addition to enhancements of surveillance and control in poultry, there is a need to develop screening and preventive programs for high-risk occupations.

5.
J Infect Dis ; 221(3): 367-371, 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31541547

RESUMO

Susceptibility of influenza A viruses to baloxavir can be affected by changes at amino acid residue 38 in the polymerase acidic (PA) protein. Information on replicative fitness of PA-I38-substituted viruses remains sparse. We demonstrated that substitutions I38L/M/S/T not only had a differential effect on baloxavir susceptibility (9- to 116-fold) but also on in vitro replicative fitness. Although I38L conferred undiminished growth, other substitutions led to mild attenuation. In a ferret model, control viruses outcompeted those carrying I38M or I38T substitutions, although their advantage was limited. These findings offer insights into the attributes of baloxavir-resistant viruses needed for informed risk assessment.

6.
J Infect Dis ; 221(1): 8-15, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31665373

RESUMO

BACKGROUND: Increased illness due to antigenically drifted A(H3N2) clade 3C.3a influenza viruses prompted concerns about vaccine effectiveness (VE) and vaccine strain selection. We used US virologic surveillance and US Influenza Vaccine Effectiveness (Flu VE) Network data to evaluate consequences of this clade. METHODS: Distribution of influenza viruses was described using virologic surveillance data. The Flu VE Network enrolled ambulatory care patients aged ≥6 months with acute respiratory illness at 5 sites. Respiratory specimens were tested for influenza by means of reverse-transcriptase polymerase chain reaction and were sequenced. Using a test-negative design, we estimated VE, comparing the odds of influenza among vaccinated versus unvaccinated participants. RESULTS: During the 2018-2019 influenza season, A(H3N2) clade 3C.3a viruses caused an increasing proportion of influenza cases. Among 2763 Flu VE Network case patients, 1325 (48%) were infected with A(H1N1)pdm09 and 1350 (49%) with A(H3N2); clade 3C.3a accounted for 977 (93%) of 1054 sequenced A(H3N2) viruses. VE was 44% (95% confidence interval, 37%-51%) against A(H1N1)pdm09 and 9% (-4% to 20%) against A(H3N2); VE was 5% (-10% to 19%) against A(H3N2) clade 3C.3a viruses. CONCLUSIONS: The predominance of A(H3N2) clade 3C.3a viruses during the latter part of the 2018-2019 season was associated with decreased VE, supporting the A(H3N2) vaccine component update for 2019-2020 northern hemisphere influenza vaccines.

7.
MMWR Morb Mortal Wkly Rep ; 68(40): 880-884, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31600182

RESUMO

During May 19-September 28, 2019,* low levels of influenza activity were reported in the United States, with cocirculation of influenza A and influenza B viruses. In the Southern Hemisphere seasonal influenza viruses circulated widely, with influenza A(H3) predominating in many regions; however, influenza A(H1N1)pdm09 and influenza B viruses were predominant in some countries. In late September, the World Health Organization (WHO) recommended components for the 2020 Southern Hemisphere influenza vaccine and included an update to the A(H3N2) and B/Victoria-lineage components. Annual influenza vaccination is the best means for preventing influenza illness and its complications, and vaccination before influenza activity increases is optimal. Health care providers should recommend vaccination for all persons aged ≥6 months who do not have contraindications to vaccination (1).


Assuntos
Saúde Global/estatística & dados numéricos , Vacinas contra Influenza/química , Influenza Humana/epidemiologia , Vigilância da População , Farmacorresistência Viral , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/efeitos dos fármacos , Vírus da Influenza B/genética , Vírus da Influenza B/isolamento & purificação , Influenza Humana/virologia , Estações do Ano , Estados Unidos/epidemiologia
8.
Vaccine X ; 2: 100031, 2019 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-31384746

RESUMO

The recent reduction of live attenuated influenza vaccine (LAIV) effectiveness in multivalent formulations was particularly associated with the A(H1N1)pdm09 component. In the 2017 the WHO vaccine composition committee changed its recommendations for the A(H1N1)pdm09 component to include an A/Michigan/45/2015-like virus. We evaluated effectiveness and quality of newly developed and previous A(H1N1)pdm09 LAIV reassortants through assessment of their thermal and pH stability, receptor binding specificity and replication fitness in primary human airway epithelial cells of nasal origin (hAECN). Our analysis showed that LAIV expressed hemagglutinin (HA) and neuraminidase (NA) from an A/Michigan/45/2015-like strain A/New York/61/2015 (A/New York/61/2015-CDC-LV16A, NY-LV16A), exhibit higher thermal and pH stability compared to the previous vaccine candidates expressing HA and NA from A/California/07/2009 and A/Bolivia/559/2013 (A17/Cal09 and A17/Bol13). Reassortants A/South Africa/3626/2013-CDC-LV14A (SA-LV14A) and NY-LV16A showed preferential binding to α2,6 sialic acid (SA) receptors and replicated at higher titers and more extensively in hAECN compared to A17/Cal09 and A17/Bol13, which had an α2,3 SA receptor binding preference. Our data analysis supports selection of A/New York/61/2015-CDC-LV16A for LAIV formulation and the introduction of new assays for LAIV characterization.

10.
Emerg Infect Dis ; 25(10): 1969-1972, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31287050

RESUMO

Baloxavir showed broad-spectrum in vitro replication inhibition of 4 types of influenza viruses (90% effective concentration range 1.2-98.3 nmol/L); susceptibility pattern was influenza A ˃ B ˃ C ˃ D. This drug also inhibited influenza A viruses of avian and swine origin, including viruses that have pandemic potential and those resistant to neuraminidase inhibitors.

11.
MMWR Morb Mortal Wkly Rep ; 68(24): 544-551, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31220057

RESUMO

Influenza activity* in the United States during the 2018-19 season (September 30, 2018-May 18, 2019) was of moderate severity (1). Nationally, influenza-like illness (ILI)† activity began increasing in November, peaked during mid-February, and returned to below baseline in mid-April; the season lasted 21 weeks,§ making it the longest season in 10 years. Illness attributed to influenza A viruses predominated, with very little influenza B activity. Two waves of influenza A were notable during this extended season: influenza A(H1N1)pdm09 viruses from October 2018 to mid-February 2019 and influenza A(H3N2) viruses from February through May 2019. Compared with the 2017-18 influenza season, rates of hospitalization this season were lower for adults, but were similar for children. Although influenza activity is currently below surveillance baselines, testing for seasonal influenza viruses and monitoring for novel influenza A virus infections should continue year-round. Receiving a seasonal influenza vaccine each year remains the best way to protect against seasonal influenza and its potentially severe consequences.


Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/epidemiologia , Vigilância da População , Adolescente , Adulto , Idoso , Antivirais/farmacologia , Criança , Mortalidade da Criança , Pré-Escolar , Efeitos Psicossociais da Doença , Farmacorresistência Viral , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza B/efeitos dos fármacos , Vírus da Influenza B/genética , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/química , Influenza Humana/mortalidade , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Pessoa de Meia-Idade , Pacientes Ambulatoriais/estatística & dados numéricos , Pneumonia/mortalidade , Estações do Ano , Índice de Gravidade de Doença , Estados Unidos/epidemiologia , Adulto Jovem
12.
Artigo em Inglês | MEDLINE | ID: mdl-31187572

RESUMO

Mutations in the influenza virus neuraminidase (NA) that cause reduced susceptibility to the NA inhibitor (NAI) oseltamivir may occur naturally or following antiviral treatment. Currently, detection uses either a traditional NA inhibition assay or gene sequencing to identify known markers associated with reduced inhibition by oseltamivir. Both methods are laborious and require trained personnel. The influenza antiviral resistance test (iART), a prototype system developed by Becton, Dickinson and Company for research use only, offers a rapid and simple method to identify such viruses. This study investigated application of iART to influenza A viruses isolated from non-human hosts with a variety of NA subtypes (N1-N9).

13.
Virology ; 534: 36-44, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31176062

RESUMO

Bangladesh has reported repeated outbreaks of highly pathogenic avian influenza (HPAI) A(H5) viruses in poultry since 2007. Because of the large number of live poultry markets (LPM) relative to the population density of poultry throughout the country, these markets can serve as sentinel sites for HPAI A(H5) detection. Through active LPM surveillance during June 2016-June 2017, HPAI A(H5N6) viruses along with 14 other subtypes of influenza A viruses were detected. The HPAI A(H5N6) viruses belonged to clade 2.3.4.4 and were likely introduced into Bangladesh around March 2016. Human infections with influenza clade 2.3.4.4 viruses in Bangladesh have not been identified, but the viruses had several molecular markers associated with potential human infection. Vigilant surveillance at the animal-human interface is essential to identify emerging avian influenza viruses with the potential to threaten public and animal health.


Assuntos
Vírus da Influenza A/isolamento & purificação , Influenza Aviária/virologia , Doenças das Aves Domésticas/virologia , Animais , Bangladesh/epidemiologia , Surtos de Doenças , Patos , Evolução Molecular , Gansos/virologia , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/epidemiologia , Filogenia , Doenças das Aves Domésticas/epidemiologia
14.
J Virol Methods ; 270: 95-105, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31004662

RESUMO

Influenza A virus is a negative-sense RNA virus with a segmented genome consisting of eight RNA segments. Avian influenza A virus (AIV) primarily infects avian hosts and sporadically infects mammals, which can lead to adaptation to new species. Next-generation sequencing (NGS) of emerging AIV genomes extracted from respiratory samples collected on sequential days from animal models and clinical patients enables analysis of the emergence of evolutionary variants within the virus population over time. However, obtaining codon complete AIV genome at a sufficient coverage depth for nucleotide variant calling remains a challenge, especially from post-inoculation respiratory samples collected at late time points that have low viral titers. In this study, nasal wash samples from ferrets inoculated with different subtypes of AIV were collected on various days post-inoculation. Each nasal wash sample was aliquoted and extracted using five commercially available nucleic acid extraction methods. Extracted influenza virus RNA was amplified and NGS conducted using Illumina Mi-Seq. For each nasal wash sample, completeness of AIV genome segments and coverage depth were compared among five extraction methods. Nucleic acids extracted by MagNA pure compact RNA isolation consistently yielded codon complete sequences for all eight genome segments at the required coverage depth at each time point sampled. The study revealed that DNase treatment was critical to the amplification of influenza genome segments and the downstream success of codon complete NGS from nasal wash samples. The findings from this study can be applied to improve NGS of influenza and other RNA viruses that infect the respiratory tract and are collected from respiratory samples.

15.
Sci Rep ; 9(1): 2676, 2019 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-30804469

RESUMO

Influenza A(H3N2) viruses evade human immunity primarily by acquiring antigenic changes in the haemagglutinin (HA). HA receptor-binding features of contemporary A(H3N2) viruses hinder traditional antigenic characterization using haemagglutination inhibition and promote selection of HA mutants. Thus, alternative approaches are needed to reliably assess antigenic relatedness between circulating viruses and vaccines. We developed a high content imaging-based neutralization test (HINT) to reduce antigenic mischaracterization resulting from virus adaptation to cell culture. Ferret reference antisera were raised using clinical specimens containing viruses representing recent vaccine strains. Analysis of viruses circulating during 2011-2018 showed that gain of an N158-linked glycosylation in HA was a molecular determinant of antigenic distancing between A/Hong Kong/4801/2014-like (clade 3C.2a) and A/Texas/50/2012-like viruses (clade 3C.1), while multiple evolutionary HA F193S substitution were linked to antigenic distancing from A/Switzerland/97152963/2013-like (clade 3C.3a) and further antigenic distancing from A/Texas/50/2012-like viruses. Additionally, a few viruses carrying HA T135K and/or I192T showed reduced neutralization by A/Hong Kong/4801/2014-like antiserum. Notably, this technique elucidated the antigenic characteristics of clinical specimens, enabling direct characterization of viruses produced in vivo, and eliminating in vitro culture, which rapidly alters the genotype/phenotype. HINT is a valuable new antigenic analysis tool for vaccine strain selection.

16.
MMWR Morb Mortal Wkly Rep ; 68(6): 125-134, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30763296

RESUMO

CDC collects, compiles, and analyzes data on influenza activity and viruses in the United States. During September 30, 2018-February 2, 2019,* influenza activity† in the United States was low during October and November, increased in late December, and remained elevated through early February. As of February 2, 2019, this has been a low-severity influenza season (1), with a lower percentage of outpatient visits for influenza-like illness (ILI), lower rates of hospitalization, and fewer deaths attributed to pneumonia and influenza, compared with recent seasons. Influenza-associated hospitalization rates among children are similar to those observed in influenza A(H1N1)pdm09 predominant seasons; 28 influenza-associated pediatric deaths occurring during the 2018-19 season have been reported to CDC. Whereas influenza A(H1N1)pdm09 viruses predominated in most areas of the country, influenza A(H3N2) viruses have predominated in the southeastern United States, and in recent weeks accounted for a growing proportion of influenza viruses detected in several other regions. Small numbers of influenza B viruses (<3% of all influenza-positive tests performed by public health laboratories) also were reported. The majority of the influenza viruses characterized antigenically are similar to the cell culture-propagated reference viruses representing the 2018-19 Northern Hemisphere influenza vaccine viruses. Health care providers should continue to offer and encourage vaccination to all unvaccinated persons aged ≥6 months as long as influenza viruses are circulating. Finally, regardless of vaccination status, it is important that persons with confirmed or suspected influenza who have severe, complicated, or progressive illness; who require hospitalization; or who are at high risk for influenza complications be treated with antiviral medications.


Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/epidemiologia , Vigilância da População , Adolescente , Adulto , Idoso , Criança , Mortalidade da Criança , Pré-Escolar , Farmacorresistência Viral , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Mortalidade Infantil , Recém-Nascido , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza B/efeitos dos fármacos , Vírus da Influenza B/genética , Vacinas contra Influenza/química , Influenza Humana/mortalidade , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Pessoa de Meia-Idade , Pacientes Ambulatoriais/estatística & dados numéricos , Pneumonia/mortalidade , Prevalência , Estações do Ano , Estados Unidos/epidemiologia , Adulto Jovem
17.
MMWR Morb Mortal Wkly Rep ; 68(6): 135-139, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30763298

RESUMO

In the United States, annual vaccination against seasonal influenza is recommended for all persons aged ≥6 months (https://www.cdc.gov/flu/protect/whoshouldvax.htm). Effectiveness of seasonal influenza vaccine varies by season. During each influenza season since 2004-05, CDC has estimated the effectiveness of seasonal influenza vaccine to prevent laboratory-confirmed influenza associated with medically attended acute respiratory illness (ARI). This interim report uses data from 3,254 children and adults enrolled in the U.S. Influenza Vaccine Effectiveness Network (U.S. Flu VE Network) during November 23, 2018-February 2, 2019. During this period, overall adjusted vaccine effectiveness against all influenza virus infection associated with medically attended ARI was 47% (95% confidence interval [CI] = 34%-57%). For children aged 6 months-17 years, overall vaccine effectiveness was 61% (44%-73%). Seventy-four percent of influenza A infections for which subtype information was available were caused by A(H1N1)pdm09 viruses. Vaccine effectiveness was estimated to be 46% (30%-58%) against illness caused by influenza A(H1N1)pdm09 viruses. CDC recommends that health care providers continue to administer influenza vaccine because influenza activity is ongoing and the vaccine can still prevent illness, hospitalization, and death associated with currently circulating influenza viruses, or other influenza viruses that might circulate later in the season. During the 2017-18 influenza season, in which influenza A(H3N2) predominated, vaccination was estimated to prevent 7.1 million illnesses, 3.7 million medical visits, 109,000 hospitalizations, and 8,000 deaths (1). Vaccination can also reduce the severity of influenza-associated illness (2). Persons aged ≥6 months who have not yet been vaccinated this season should be vaccinated.


Assuntos
Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Vacinas contra Influenza/administração & dosagem , Influenza Humana/prevenção & controle , Vigilância da População , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Vacinas contra Influenza/imunologia , Influenza Humana/epidemiologia , Influenza Humana/virologia , Masculino , Pessoa de Meia-Idade , Estações do Ano , Estados Unidos/epidemiologia , Adulto Jovem
18.
Euro Surveill ; 24(3)2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30670144

RESUMO

The anti-influenza therapeutic baloxavir targets cap-dependent endonuclease activity of polymerase acidic (PA) protein. We monitored baloxavir susceptibility in the United States with next generation sequencing analysis supplemented by phenotypic one-cycle infection assay. Analysis of PA sequences of 6,891 influenza A and B viruses collected during 2016/17 and 2017/18 seasons showed amino acid substitutions: I38L (two A(H1N1)pdm09 viruses), E23G (two A(H1N1)pdm09 viruses) and I38M (one A(H3N2) virus); conferring 4-10-fold reduced susceptibility to baloxavir.

19.
MMWR Morb Mortal Wkly Rep ; 67(49): 1369-1371, 2018 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-30543604

RESUMO

Influenza activity in the United States was low during October 2018, and, although it increased slowly during November, activity remains low across most of the country.* During the week ending December 1, 2018, the percentage of outpatient visits for influenza-like illness† (ILI) was equal to the national baseline§ (Figure) and was at or slightly above the region-specific baseline in four of the 10 U.S. Department of Health and Human Services regions¶ (Regions 4 and 7-9). The majority of jurisdictions experienced minimal or low ILI activity since September 30; however, two experienced moderate ILI activity, and two experienced high ILI activity** during the week ending December 1. The percentage of deaths attributed to pneumonia and influenza remains below the epidemic threshold,†† and the rate of influenza-associated hospitalizations remains low. Five laboratory-confirmed, influenza-associated pediatric deaths occurring since September 30 have been reported to CDC. During the week ending December 1, the majority of jurisdictions (40 states, the District of Columbia, Puerto Rico, and U.S. Virgin Islands) reported sporadic or local geographic spread of influenza activity, nine states reported regional activity, and one state reported widespread activity.§§.


Assuntos
Influenza Humana/epidemiologia , Vigilância da População , Assistência Ambulatorial , Humanos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza B/isolamento & purificação , Influenza Humana/prevenção & controle , Influenza Humana/virologia , Estações do Ano , Estados Unidos/epidemiologia
20.
MMWR Morb Mortal Wkly Rep ; 67(42): 1178-1185, 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30359347

RESUMO

During May 20-October 13, 2018,* low levels of influenza activity were reported in the United States, with a mix of influenza A and B viruses circulating. Seasonal influenza activity in the Southern Hemisphere was low overall, with influenza A(H1N1)pdm09 predominating in many regions. Antigenic testing of available influenza A and B viruses indicated that no significant antigenic drift in circulating viruses had emerged. In late September, the components for the 2019 Southern Hemisphere influenza vaccine were selected and included an incremental update to the A(H3N2) vaccine virus used in egg-based vaccine manufacturing; no change was recommended for the A(H3N2) component of cell-manufactured or recombinant influenza vaccines. Annual influenza vaccination is the best method for preventing influenza illness and its complications, and all persons aged ≥6 months who do not have contraindications should receive influenza vaccine, preferably before the onset of influenza circulation in their community, which often begins in October and peaks during December-February. Health care providers should offer vaccination by the end of October and should continue to recommend and administer influenza vaccine to previously unvaccinated patients throughout the 2018-19 influenza season (1). In addition, during May 20-October 13, a small number of nonhuman influenza "variant" virus infections† were reported in the United States; most were associated with exposure to swine. Although limited human-to-human transmission might have occurred in one instance, no ongoing community transmission was identified. Vulnerable populations, especially young children and other persons at high risk for serious influenza complications, should avoid swine barns at agricultural fairs, or close contact with swine.§.


Assuntos
Surtos de Doenças , Saúde Global/estatística & dados numéricos , Influenza Humana/epidemiologia , Vigilância da População , Farmacorresistência Viral , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H1N2/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N2/genética , Vírus da Influenza A Subtipo H1N2/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/efeitos dos fármacos , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/isolamento & purificação , Vírus da Influenza B/efeitos dos fármacos , Vírus da Influenza B/genética , Vírus da Influenza B/isolamento & purificação , Vacinas contra Influenza/química , Influenza Humana/virologia , Estações do Ano , Estados Unidos/epidemiologia
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