Subtype h1n1 viruses influenza a virus h1n1 subtype. Medical search. Frequent questions

The known SIV strains include influenza C and the subtypes of influenza A known as H1N1, H1N2, H3N1, H3N2 and H2N3. (wikipedia.org)
Influenza A virus subtypes currently endemic in humans are H3N2 and H1N1 viruses. (cdc.gov)
Examples of different influenza A virus subtypes currently endemic in animals include H1N1 and H3N2 in pigs (different strains than those found in humans), H3N8 in horses, H3N2 in dogs, and H5N1 in wild water birds and domestic poultry. (cdc.gov)
However, in 1998, H3N2 viruses from humans were introduced into the pig population and caused widespread disease among pigs. (cdc.gov)
17,599(62%) were influenza A (H3N2) viruses, and 10,946 (38%) were 2009 influenza A (H1N1) viruses. (cdc.gov)
Although influenza A (H3N2) viruses predominated, 2009 influenza A (H1N1) and influenza B viruses also circulated widely. (cdc.gov)
Although during this time influenza A (H3N2) viruses still predominated nationally, 2009 influenza A (H1N1) predominated in five of the 10 regions (Regions 3, 4, 5, 8, and 9) for 5--7 consecutive weeks, ranging from the week ending January 15 to the week ending April 2, 2011. (cdc.gov)
All five cases were infected with swine-origin influenza A (H3N2) viruses. (cdc.gov)
The father had a nasopharyngeal swab positive for swine-origin influenza A (H3N2) virus and had direct swine exposure 6 days before illness onset. (cdc.gov)
The child, whose infection with influenza A (H3N2) virus was confirmed several weeks later by serologic testing, did not have direct swine exposure, and most likely acquired infection from close contact with her father. (cdc.gov)
Those have included 613 2009 influenza A (H1N1) viruses, 1,139 influenza A (H3N2) viruses, and 742 influenza B viruses. (cdc.gov)
A(H3N2) and B/Yamagata viruses are circulating at very low levels," the CDC reports. (medscape.com)
Most (80.7%) influenza A viruses that underwent subtyping were A(H1N1)pdm09 and 19.3% were A(H3N2) viruses. (medscape.com)
62% of all influenza A(H3N2) detections have been reported in adults 65 years of age and older. (canada.ca)
Each year's flu shots contain the scientific community's best estimate of the H1N1, H3N2, and Influenza B strains that will predominate in the coming season. (carnegiecouncil.org)
In sentinel sources, both influenza A subtypes, A(H3N2) and A(H1N1)pdm09, are co-circulating and of the influenza B viruses, the vast majority (97%) are B/Victoria lineage. (flutrackers.com)
Non-structural (NS) 1 proteins from recombinant influenza A/Udorn/72 (H3N2) and influenza A/Finland/554/09 (H1N1pdm09) viruses were purified and used in Western blot analysis to determine specific antibody responses in human sera. (plos.org)
Instead, paired serum samples from patients, who suffered from a laboratory confirmed H1N1pdm09 infection, showed high levels or diagnostic rises (96%) in H1N1pdm virus NS1-specific antibodies and very high cross-reactivity to H3N2 subtype influenza A virus NS1 protein. (plos.org)
The NA genes of H3N2 viruses used for primary infection or vaccination. (wikigenes.org)
Subtypes H1N1, H3N2, and H5N2 were detected. (authorea.com)
Seasonal influenza illness is typically caused by influenza A virus subtypes H1N1 or H3N2, or by influenza B or C viruses. (texas.gov)
Among 144 combinatorial possibilities from 16 subtypes of HA and 9 subtypes of NA, only H1N1, H2N2, and H3N2 are human adapted viruses [ 9 ]. (ijpsonline.com)
While the early start and higher intensity of the 2012/13 influenza A virus (IAV) epidemic was not unprecedented, it was the first IAV epidemic season since the 2009 H1N1 influenza pandemic where the H3N2 subtype predominated. (eurosurveillance.org)
Based on the results of outpatient and hospital surveillance, influenza A(H1N1)pdm09 and A(H3N2) viruses continued to co-circulate in the Region, with very few influenza B detections having been reported during this season. (flutrackers.com)
Of the 1342 influenza A viruses that were subtyped during week 12/2014, 594 (44%) were A(H1N1)pdm09 and 748 (56%) A(H3N2) (Fig. 2a). (flutrackers.com)
Of the 25 143 influenza A viruses that have been subtyped, 14 835 (59%) were A(H1N1)pdm09 and 10 308 (41%) were A(H3N2). (flutrackers.com)
Influenza A(H1N1)pdm09 was the most common strain early in the season, but influenza A(H3N2) predominated later in the season. (health.mil)
Total influenza vaccine effectiveness was low during this season in part because the A(H3N2) strain was antigenically drifted from the vaccine strain. (health.mil)
The 2018-2019 season differed from past seasons in that it was much longer, had a later peak, and the predominant strain of influenza changed from influenza A(H1N1)pdm09 at the beginning of the season to influenza A(H3N2) in the middle of the season. (health.mil)
It was caused by an H3N2 strain of the influenza A virus, descended from H2N2 through antigenic shift, a genetic process in which genes from multiple subtypes reassorted to form a new virus. (searchandrestore.com)
Influenza A(H3N2), the predominant type of influenza virus isolated in the United States during the 1987-88 season, exhibited antigenic drift from previous epidemic strains (1). (searchandrestore.com)
Most commonly, Swine Flu is of the H1N1 Influenza subtype, although they can sometimes come from H1N2, H3N1, and H3N2. (projectswole.com)
Of the 5861 influenza virus isolates reported to CDC, more than 99% were influenza A. Of the influenza A virus isolates subtyped, 81% were influenza A(H3N2), and 19% were influenza A(H1N1). (cdc.gov)
As of April 10, 179 (99%) of the 180 influenza A(H3N2) viruses characterized at CDC resembled A/Beijing/353/89, the A(H3N2) component included in the 1991-92 influenza vaccine. (cdc.gov)
In Asia, outbreaks of influenza A(H3N2) were reported in Japan, Korea, and the People's Republic of China. (cdc.gov)
In these countries, the proportion of influenza A(H1N1) viruses isolated increased during the latter part of the season as influenza A(H3N2) activity declined. (cdc.gov)

Nationally, influenza B/Victoria viruses are predominant, followed by A(H1N1)pdm09 viruses. (medscape.com)
Influenza A(H1N1)pdm09 are the most common viruses among adults aged 25 to 64 years (42% of reported viruses) and those aged 65 years and older (43% of viruses). (medscape.com)
four of these were subtyped and all four were A(H1N1)pdm09 viruses. (medscape.com)
Influenza A(H1N1)pdm09 continues to be the most common influenza virus circulating in Canada. (canada.ca)
Among the 10,014 influenza A viruses subtyped, 92% have been A(H1N1)pdm09. (canada.ca)
86% of all influenza A(H1N1)pdm09 detections have been reported in individuals younger than 65 years of age. (canada.ca)
Here, we assessed the induction of protective immunity to these viruses by infection with A(H1N1)pdm09 virus in a newly developed guinea pig model. (eur.nl)
To this end, ten female 12-16 week old strain 2 guinea pigs were inoculated intratracheally with either A(H1N1)pdm09 influenza virus or PBS (unprimed controls) followed 4 weeks later with an A/H7N9 influenza virus challenge. (eur.nl)
R1a-B6-Fc fusions of both isotypes gave complete protection against lethal challenge with both pandemic A/California/07/2009 (H1N1)pdm09 and avian influenza A/Vietnam/1194/2004 (H5N1). (frontiersin.org)

Major outbreaks of H1N1 strains in humans include the 1918 Spanish flu pandemic, the 1977 Russian flu pandemic and the 2009 swine flu pandemic. (wikipedia.org)
Although it is unusual for people to get influenza A virus infections directly from animals, sporadic human infections and outbreaks caused by certain avian influenza A viruses and swine influenza A viruses have been reported. (cdc.gov)
Earlier this week, the World Health Organization raised its pandemic alert level to 5 (out of 6), indicating widespread human infection of an animal influenza capable of causing community-level outbreaks. (carnegiecouncil.org)
The H5N8 subtype has caused multiple outbreaks in poultry in Europe over the past few winters. (mdpi.com)
Hopefully, the knowledge gained in response to the H5N1 and 2009 H1N1 outbreaks, and continued research to more completely understand influenza virus, as well as improvements in vaccine and drug development, will enable us to minimize the effects of future influenza outbreaks. (bcm.edu)
Influenza A virus (IAV) outbreaks constitute a constant threat to public health and pose a remarkable impact on socio-economic systems worldwide. (authorea.com)
RIDTs can be useful to identify influenza virus infection as a cause of respiratory outbreaks in any setting, but especially in institutions (i.e., nursing homes, chronic care facilities, and hospitals), cruise ships, summer camps, schools, etc. (cdc.gov)
Positive RIDT results from one or more ill persons with suspected influenza can support decisions to promptly implement prevention and control measures for influenza outbreaks. (cdc.gov)
Ongoing avian influenza outbreaks in animals pose risk to humans: read the situation analysis and advice to countries from the Food and Agriculture Organization of the United Nations (FAO), the World Health Organization (WHO), and the World Organisation for Animal Health (WOAH). (eurosurveillance.org)
Although influenza A(H1N1) viruses were isolated less frequently worldwide, Belgium and Japan reported that A(H1N1) viruses constituted the majority of isolates and were isolated from outbreaks. (cdc.gov)

It is an orthomyxovirus that contains the glycoproteins hemagglutinin (H) and neuraminidase (N), antigens whose subtypes are used to classify the strains of the virus as H1N1, H1N2 etc. (wikipedia.org)
So, for example, a virus with version 1 of the HA protein and version 2 of the NA protein would be called influenza A subtype H1N2 (A H1N2, for short). (bcm.edu)
For this reason, they are described as H1N1, H1N2 etc. depending on the type of H or N antigens they express with metabolic synergy. (indiatimes.com)

Hemagglutinin causes red blood cells to clump together and binds the virus to the infected cell. (wikipedia.org)
The resulting new virus might then be able to infect humans and spread easily from person to person, but it could have surface proteins (hemagglutinin and/or neuraminidase) different than those currently found in influenza viruses that routinely circulate in humans-this could make it seem like a "new" influenza virus to people, one that had not been encountered before. (cdc.gov)
The genetic information in these viruses could reassort to create a new influenza A virus with a hemagglutinin and/or neuraminidase gene from the avian virus and other genes from the human virus. (cdc.gov)
Influenza A viruses with a hemagglutinin against which humans have little or no immunity that have reassorted with a human influenza virus are more likely to result in sustained human-to-human transmission and have pandemic potential. (cdc.gov)
The letters H and N stand for hemagglutinin and neuraminidase, two kinds of protein on the surface of the influenza virus. (carnegiecouncil.org)
For example, H1N1 has a coat of the first subtype of hemagglutinin and the first subtype of neuraminidase. (carnegiecouncil.org)
Hemagglutinin helps a virus attach to and insert itself into a target cell, while neuraminidase is what helps the viruses break back out and spread to other cells. (carnegiecouncil.org)
These viruses are classified according to the identity of two of their surface proteins--hemagglutinin (H5 in this subtype) and neuraminidase (N1). (scientificamerican.com)
The subtype behind the 2009 'swine flu' pandemic is H1N1, which has the same version of neuraminidase as H5N1, but a different version of hemagglutinin. (scientificamerican.com)
Kawaoka and his team, whose work has been accepted by Nature, created a chimeric virus with the hemagglutinin protein from H5N1 and the genes from the 2009 pandemic strain of H1N1. (scientificamerican.com)
Disease relevance of na Although differing in their surface hemagglutinin and neuraminidase components, a notable feature of these H9N2 viruses is that the six genes encoding the internal components of the virus are similar to those of the 1997 H5N1 human and avian isolates. (wikigenes.org)
High impact information on NA This was indicated by the ability of viruses bearing the H2- hemagglutinin glycoprotein, regardless of its associated neuraminidase, to induce lymphocyte proliferation in normal spleen cell suspensions and by the ability of antisera with specificity for the H2- hemagglutinin. (wikigenes.org)
Phylogenetic analysis of influenza viruses isolated from wild ducks of the Lerma marshes revealed that hemagglutinin (HA) gene sequences were related to waterfowl, swine, and poultry IAV strains previously isolated in the United States and Mexico. (authorea.com)
The genome of the virus H1N1 2009 consists of eight segments but maximum number of mutations occurs at segments 1 and 4, coding for PB2 subunit of hemagglutinin. (ijpsonline.com)
Similar to other influenza viruses, H1N1 also contains two surface antigens, namely hemagglutinin (HA) and neuraminidase (NA) [ 6 ]. (ijpsonline.com)
We have previously described R1a-B6, an alpaca-derived single domain antibody (nanobody), that is capable of potent cross-subtype neutralization in vitro of H1N1, H5N1, H2N2, and H9N2 influenza viruses, through binding to a highly conserved epitope in the influenza hemagglutinin stem region. (frontiersin.org)

Epstein SL , Tumpey TM , Misplon JA , Lo CY , Cooper LA , Subbarao K , DNA vaccine expressing conserved influenza virus proteins protective against H5N1 challenge infection in mice. (cdc.gov)
People with close or prolonged unprotected contact (not wearing respiratory and eye protection) with infected birds or places that sick birds or their mucous, saliva, or feces have contaminated, might be at greater risk of bird flu virus infection. (cdc.gov)
Five cases of human infection with a novel influenza A virus were reported during the 2010--11 influenza season from three states. (cdc.gov)
Less than 1% were associated with influenza A virus and influenza B virus co-infection and 0.3% had no influenza virus type determination. (medscape.com)
Influenza infection poses a significant public health threat. (atlantis-press.com)
Influenza virus subtypes co-circulate with no reports of co-infection. (atlantis-press.com)
Based on quantitative Western blot analysis, only two of the 45 (4.4%) Pandemrix-vaccinated narcoleptic patients showed specific antibody response against the NS1 protein from the H1N1pdm09 virus, indicating past infection with the H1N1pdm09 virus. (plos.org)
Based on our findings, it is unlikely that H1N1pdm09 virus infection contributed to a sudden increase in the incidence of childhood narcolepsy observed in Finland in 2010 after AS03-adjuvanted Pandemrix vaccination. (plos.org)
It is always a great concern when a new flu virus emerges, because the general population does not have immunity and almost everyone is susceptible to infection and disease. (bcm.edu)
By day 7, only viral antigen positive cells were found after H7N9 virus infection in the nasal turbinates and the lungs of unprimed controls. (eur.nl)
Thus infection with H1N1pdm09 virus induced partially protective heterosubtypic immunity to H7N9 virus in (isogenic) guinea pigs that could not be attributed to cross-reactive virus neutralizing antibodies. (eur.nl)
Two antiviral drugs, oseltamivir and zanamivir are commonly prescribed for treating H1N1 infection. (ijpsonline.com)
The target of neutralizing antibodies that protect against influenza virus infection is the viral protein HA. (jci.org)
However, while heterosubtypic antibodies capable of neutralizing multiple influenza virus subtypes have been recently isolated from phage display libraries, it is not known whether such antibodies are produced in the course of an immune response to influenza virus infection or vaccine. (jci.org)
He said that the biology and epidemiology of the virus itself makes infection extremely difficult to detect in its early stages, because the majority of cases show no symptoms for five days or longer after exposure. (ucla.edu)
However, RIDTs have limited sensitivity to detect influenza virus infection and negative test results should be interpreted with caution given the potential for false negative results. (cdc.gov)
Some RIDTs distinguish between influenza A or B virus infection while others do not. (cdc.gov)
However, due to th e limited sensitivities and predictive values of RIDTs, negative results of RIDTs do not exclude influenza virus infection in patients with signs and symptoms suggestive of influenza. (cdc.gov)
However, negative RIDT results do not exclude influenza virus infection as a cause of a respiratory outbreak because of the limited sensitivity of these tests. (cdc.gov)
Testing respiratory specimens from several persons with suspected influenza will increase the likelihood of detecting influenza virus infection if influenza virus is the cause of the outbreak. (cdc.gov)
Clinical signs and symptoms consistent with influenza o Having clinical signs and symptoms consistent with influenza increases the pre-test probability of influenza virus infection, which increases the reliability of a positive RIDT result. (cdc.gov)
Our findings demonstrate AAV delivery of cross-subtype neutralizing nanobodies may be an effective strategy to prevent influenza infection and provide long-term protection independent of a host induced immune response. (frontiersin.org)
Clinical consultation rates for influenza-like illness (ILI) and/or acute respiratory infection (ARI) returned to pre-season or below baseline levels in most of the countries in the WHO European Region. (flutrackers.com)

Some strains of H1N1 are endemic in humans and cause a small fraction of all influenza-like illness and a small fraction of all seasonal influenza, for instance in 2004-2005. (wikipedia.org)
Genetic analysis of virus from tissue preserved medically or in permafrost suggests that seasonal H1N1 strains of today descend from the 1918 flu pandemic virus, but the result is not conclusive. (wikipedia.org)
The shaded area indicates weeks where the positivity rate was at least 5% and a minimum of 15 positive tests were observed, signalling the period of seasonal influenza activity . (canada.ca)
Her research includes studies on influenza vaccine effectiveness and preventing hospitalization, the use of influenza anti-viral medications in outpatient settings, and the impact of seasonal influenza on children with neurologic disorders. (cdc.gov)
This study aimed to assess the molecular and seasonal pattern of influenza virus subtypes in western Saudi Arabia to inform policy decisions on influenza vaccine. (atlantis-press.com)
Even so, it seems likely that this virus has a greater mortality rate than either ordinary seasonal flu or possibly the 1918 pandemic H1N1 strain . (scientificamerican.com)
Fouchier later added, however, that his mutant virus "does not spread yet like a pandemic or seasonal flu virus" and that the ferrets did not die when infected through aerosol transmission. (scientificamerican.com)
Here we report that, following vaccination with seasonal influenza vaccine containing H1 and H3 influenza virus subtypes, some individuals produce antibodies that cross-react with H5 HA. (jci.org)
These findings reveal that seasonal influenza vaccination can induce polyclonal heterosubtypic neutralizing antibodies that cross-react with the swine-origin pandemic H1N1 influenza virus and with the highly pathogenic H5N1 virus. (jci.org)
Vaccine-binding and H5 pseudotype-neutralizing antibodies in plasma samples collected before and after seasonal influenza vaccination. (jci.org)
Volunteers (A to X) were immunized with seasonal influenza vaccine in 2 consecutive seasons. (jci.org)
E and F ) Correlation between the increase of vaccine binding titers ( E ) and H5-neutralizing titers ( F ) following vaccination in 2007 ( x axis) and 2008 ( y axis) in the 9 donors that received the seasonal influenza vaccine for the 2 consecutive years. (jci.org)
The research offers an explanation for why some people fare much worse than others when infected with the same strain of the flu virus, and the findings could help inform strategies for minimizing the effects of the seasonal flu. (ucla.edu)
In addition, the lineage of 169 influenza B viruses has been determined: 155 (92%) belonged to the B/Yamagata lineage (the lineage of the B virus recommended by WHO for inclusion in trivalent seasonal influenza vaccines) and 14 (8%) to the B/Victoria lineage. (flutrackers.com)

RIDTs that provide results on type of influenza virus (e.g. influenza A or B virus), do not provide information on influenza A virus subtype (e.g. (cdc.gov)

The current H5N1 bird flu, also an Influenza A virus, has a similar effect. (wikipedia.org)
More recently, H5N1 viruses from birds have caused sporadic infections in wild foxes in the U.S. and in other countries. (cdc.gov)
Research describing two mutant strains of H5N1 avian influenza that spread between mammals is likely to be published in its entirety. (scientificamerican.com)
Two teams of scientists, led by Ron Fouchier of Erasmus Medical Center in Rotterdam, the Netherlands, and Yoshihiro Kawaoka of the University of Wisconsin-Madison, have created mutant strains of H5N1 avian influenza. (scientificamerican.com)
One particular strain of H5N1, called highly pathogenic avian influenza (HPAI), is responsible for the 'bird flu' scares. (scientificamerican.com)
Wild H5N1 viruses cannot latch on tothe cells in a person's nose and throat, but the mutant strains created by Fouchier and Kawaoka can spread between ferrets, which are viewed as a good animal model of flu transmission between humans. (scientificamerican.com)
Kawaoka notes that H5N1 viruses already circulate in nature, mutate constantly and could cause pandemics. (scientificamerican.com)
More practically, the research could allow public-health workers to monitor wild viruses for similar mutations that make H5N1 more dangerous to humans. (scientificamerican.com)
Unlike the avian H5N1 flu, the H1N1 swine flu is capable of being transmitted easily from person to person. (bcm.edu)
Fortunately, however, H1N1 is far less deadly than the H5N1 virus. (bcm.edu)

Pigs experimentally infected with the strain of swine flu that caused the human pandemic of 2009-10 showed clinical signs of flu within four days, and the virus spread to other uninfected pigs housed with the infected ones. (wikipedia.org)
The 1918 flu was an unusually severe and deadly strain of H1N1 avian influenza, a viral infectious disease, that killed from 17 to 50 or more million people worldwide over about a year in 1918 and 1920. (wikipedia.org)
Retrospective serologic testing subsequently demonstrated that up to 230 soldiers had been infected with the novel virus, which was an H1N1 strain. (wikipedia.org)
The 1977 Russian flu pandemic was caused by strain Influenza A/USSR/90/77 (H1N1). (wikipedia.org)
The effectiveness of the influenza vaccine for the 2018-19 season is estimated to be 72% against the predominant circulating strain this season, with significant protection observed in all age groups. (canada.ca)
The genome of the airborne strain differed from the original one by just five mutations, which have all been spotted individually in wild viruses. (scientificamerican.com)
The influenza A subtypes are further classified into strains, and the names of the virus strains include the place where the strain was first found and the year of discovery. (bcm.edu)
A global outbreak of a new strain of H1N1-2009 influenza virus, often referred to as "swine flu virus" is well-known for causing a huge number of deaths both in human and swine in recent years. (ijpsonline.com)
The PLoS Pathogens study may help solve a problem that had for decades vexed scientists and health care professionals: why the same strain of the flu virus affects people with various degrees of severity. (ucla.edu)
London flu' was a particular form of influenza caused by an influenza virus which had apparently first been identified in India in 1971, but was first identified as a distinct strain in England early in 1972. (searchandrestore.com)

In 1976, a novel swine influenza A (H1N1) caused severe respiratory illness in 13 soldiers, with one death at Fort Dix, New Jersey. (wikipedia.org)
Influenza A viruses that typically are endemic in one animal species sometimes can cause illness in another species. (cdc.gov)
If this new influenza A virus causes illness in people and is transmitted easily from person to person in a sustained manner, an influenza pandemic can occur. (cdc.gov)
Overall, the percentages of outpatient visits for influenza-like illness (ILI) were lower during the 2010--11 season than the 2009--10 pandemic influenza season. (cdc.gov)
Influenza viruses also can cause pandemics, during which rates of illness and death from influenza-related complications can increase worldwide. (cdc.gov)
Vaccination is associated with reductions in influenza-related respiratory illness and physician visits among all age groups, hospitalization and death among persons at high risk, otitis media among children, and work absenteeism among adults ( 8--18 ). (cdc.gov)
Most of the country is experiencing high influenza-like illness activity and 800 more deaths were reported during the last week of 2019 alone, according to the most recent report from the Centers for Disease Control and Prevention (CDC). (medscape.com)
The percentage of outpatient healthcare provider visits for influenza-like illness (ILI) rose from 5.1% to 6.9% during the week ending December 28 (week 52). (medscape.com)
Influenza-like illness activity was high in the District of Columbia, New York City, Puerto Rico, and 34 states (37 jurisdictions), compared with 28 jurisdictions during the previous week. (medscape.com)
Influenza viruses with reduced in vitro sensitivity have been shown to be transmissible and to cause typical influenza illness. (nih.gov)
Flu, or influenza, is a contagious respiratory illness that spreads from person to person through the air via coughs or sneezes or through contact with infected surfaces. (bcm.edu)
Influenza ("the flu") is a respiratory illness caused by the influenza virus. (texas.gov)
An influenza-associated pediatric death is a death in a child under 18 years of age resulting from a clinically compatible illness that is confirmed to be influenza by an appropriate laboratory or rapid diagnostic test. (texas.gov)
Most people who develop influenza illness will recover on their own with bed rest and do not need medication. (texas.gov)
These medications are usually prescribed to persons who have a severe illness or to those who are at higher risk for developing serious illness or complications due to influenza. (texas.gov)
Some people are more likely to develop complications from their influenza illness, leading to hospitalization or even death. (texas.gov)
Time from illness onset to collection of respiratory specimens for testing o Testing specimens collected within 48-72 hours of illness onset (when influenza viral shedding is highest) is more likely to yield positive RIDT results. (cdc.gov)

The proportion of specimens testing positive for influenza during the 2010--11 season first exceeded 10%, indicating higher levels of virus circulation, during the week ending November 27, 2010. (cdc.gov)
This is consistent with the decline in the percentage of ILI and ARI sentinel specimens testing positive for influenza. (flutrackers.com)

Swine influenza (also known as swine flu or pig flu) is a respiratory disease that occurs in pigs that is caused by the Influenza A virus. (wikipedia.org)
So what, exactly, is Influenza virus A subtype H1N1, commonly known as swine flu? (carnegiecouncil.org)

Amantadine inhibits the replication of influenza A virus isolates from each of the subtypes, i.e. (nih.gov)
It has very little or no activity against influenza B virus isolates. (nih.gov)
Sensitivity test results, expressed as the concentration of amantadine required to inhibit by 50% the growth of virus (ED 50 ) in tissue culture vary greatly (from 0.1 mcg/mL to 25 mcg/mL) depending upon the assay protocol used, size of virus inoculum, isolates of influenza A virus strains tested, and the cell type used. (nih.gov)
The neutralizing antibody response to influenza virus is thought to be specific for a few antigenically related isolates within a given subtype. (jci.org)
Influenza A(H1N1) viruses were isolated most frequently in the mid-Atlantic and South Atlantic regions and accounted for 30% and 52% of influenza A isolates, respectively. (cdc.gov)
Furthermore, the unsampled history of the epidemic means that the nature and location of the genetically closest swine viruses reveal little about the immediate origin of the epidemic, despite the fact that we included a panel of closely related and previously unpublished swine influenza isolates. (duke.edu)

however, 2009 influenza A (H1N1) and influenza B viruses also circulated, and the predominant virus varied by U.S. Department of Health and Human Service (HHS) region and week. (cdc.gov)
Influenza B viruses were predominant in Region 4 from early November through late December. (cdc.gov)
Predominant viruses differ by region and age group, the CDC explains. (medscape.com)
Influenza peaks were observed in October each season, with variant predominant strains. (atlantis-press.com)

Ulmer JB , Donnelly JJ , Parker SE , Rhodes GH , Felgner PL , Dwarki VJ , Heterologous protection against influenza by injection of DNA encoding a viral protein. (cdc.gov)
Please note that questions are limited to clinicians who would like information on CDC's current influenza recommendations for vaccination and anti-viral medications. (cdc.gov)
At the conclusion of today's session the participant will be able to describe the current status of influenza activity in the United States, discuss the circulating influenza strains seen this season and the implications for clinicians, discuss the use of influenza diagnostic tests and the role in clinical care and discuss anti-viral treatment implications for patients evaluation treatment and testing. (cdc.gov)
Her current primary research focuses on influenza anti-viral treatment as well as influenza vaccine effectiveness. (cdc.gov)
A pathogenic swine viral of H1N1 subtype has been proven to cause an outbreak of respiratory disease in both human and swine. (ijpsonline.com)
Rapid influenza diagnostic tests (RIDTs) are immunoassays that can identify the presence of influenza A and B viral nucleoprotein antigens in respiratory specimens, and display the result in a qualitative way (positive vs. negative) (1). (cdc.gov)
Rapid molecular assays are a new type of influenza diagnostic test that use isothermal nucleic acid amplification for viral detection. (cdc.gov)

Therefore, careful evaluation of influenza A viruses recovered from humans and animals that are infected with avian influenza A viruses is important to identify genetic reassortment if it occurs. (cdc.gov)
This cross-protective effect has not yet been demonstrated to the newly emerging avian influenza A viruses of the H7N9 subtype. (eur.nl)

Transmission of the virus from pigs to humans is not common and does not always lead to human influenza, often resulting only in the production of antibodies in the blood. (wikipedia.org)
Influenza A viruses are endemic (can infect and regularly transmit) in 6 animal species or groups (wild waterfowl, domestic poultry, swine, horses, dogs, and bats) in addition to humans. (cdc.gov)
Antigenic shift results when a new influenza A virus subtype against which most people have little or no immune protection infects humans. (cdc.gov)
While a "shift" of this kind has not occurred in relation to avian influenza viruses, such a "shift" occurred in the spring of 2009 when an H1N1 virus with genes from North American Swine, Eurasian Swine, humans and birds emerged to infect people and quickly spread, causing a pandemic. (cdc.gov)
Highly pathogenic influenza A virus H5 subtype remains a risk for transmission in humans. (mdpi.com)
So far, little is known about how this virus evolves and adapts to infect humans. (mdpi.com)
It is a subtype of the influenza A virus--the most virulent of the influenza viruses to affect humans. (scientificamerican.com)
There are three different types of influenza virus - A, B, and C. Type A viruses infect humans and several types of animals, including birds, pigs, and horses. (bcm.edu)
Type B influenza is normally found only in humans, and type C is mostly found in humans, but has also been found in pigs and dogs. (bcm.edu)
In conclusion, the co-circulation of three IAV subtypes in wild ducks close to backyard farms in Mexico, as well as, the local identification of HA gene sequences genetically related to Mexican livestock IAV strains and also to North American waterfowl IAV strains, highlight the importance of the Lerma marshes for influenza surveillance given the close interaction among wild birds, poultry, pigs, and humans. (authorea.com)
While the virus is a major pathogen to humans, it does not disproportionately infect adults older than 60 years, which is an unusual and characteristic feature [ 5 ]. (ijpsonline.com)
We show that it was derived from several viruses circulating in swine, and that the initial transmission to humans occurred several months before recognition of the outbreak. (duke.edu)
Our results highlight the need for systematic surveillance of influenza in swine, and provide evidence that the mixing of new genetic elements in swine can result in the emergence of viruses with pandemic potential in humans. (duke.edu)

In March and early April 2009, a new swine-origin influenza A (H1N1) virus (S-OIV) emerged in Mexico and the United States. (duke.edu)

Epstein SL , Stack A , Misplon JA , Lo CY , Mostowski H , Bennink J , Vaccination with DNA encoding internal proteins of influenza virus does not require CD8(+) cytotoxic T lymphocytes: either CD4(+) or CD8(+) T cells can promote survival and recovery after challenge. (cdc.gov)
Protection of mice against influenza A virus challenge by vaccination with baculovirus-expressed M2 protein. (cdc.gov)
RÉSUMÉ Les informations sur la prévalence de la grippe, les sous-types circulants du virus et la saisonnalité sont essentielles pour la sélection des souches destinées aux vaccins annuels, ainsi que pour la planification des programmes de vaccination. (who.int)
and 5) the assessment of vaccine supply, timing of influenza vaccination, and prioritization of inactivated vaccine in shortage situations. (cdc.gov)
Influenza vaccination is the primary method for preventing influenza and its severe complications. (cdc.gov)
A sudden increase in the incidence of childhood narcolepsy was observed after vaccination with AS03-adjuvanted Pandemrix influenza vaccine in Finland at the beginning of 2010. (plos.org)
Here, we analysed whether the coinciding influenza A H1N1pdm pandemic contributed, together with the Pandemrix vaccination, to the increased incidence of childhood narcolepsy in 2010. (plos.org)
An H1N1 (swine flu) outbreak among recruits at Fort Dix leads to a vaccination program to prevent a pandemic. (searchandrestore.com)
The most important strategy for preventing influenza-associated morbidity and mortality is vaccination of persons in high-risk groups with vaccine closely matched to circulating strains. (cdc.gov)

Pigs can also become infected with the H4N6 and H9N2 subtypes. (wikipedia.org)

Epidemiology and Animal Health Economics category, oral -Matthew Allerson, University of Minnesota, for "The impact of maternally derived immunity on influenza virus transmission in neonatal pig populations," and Heidi Pecoraro, Colorado State University, for "Comparison of virus isolation, one-step real-time reverse transcriptase-PCR assay, and two rapid influenza diagnostic tests for detecting canine influenza virus (H3N8) shedding in dogs. (avma.org)
Testing Methods" and "Table 2: Characteristics of Rapid Influenza Diagnostic Tests" . (cdc.gov)

Modified M2 proteins produce heterotypic immunity against influenza A virus. (cdc.gov)
Okuda K , Ihata A , Watabe S , Okada E , Yamakawa T , Hamajima K , Protective immunity against influenza A virus induced by immunization with DNA plasmid containing influenza M gene. (cdc.gov)
When shifts happen, most people have little or no immunity against the new virus. (cdc.gov)
Heterosubtypic immunity is defined as immune-mediated (partial) protection against an influenza virus induced by an influenza virus of another subtype to which the host has not previously been exposed. (eur.nl)
In a pandemic, a new influenza virus emerges and infects the human population which has little or no pre-existing immunity ( 2 , 3 ). (frontiersin.org)

This report updates the 2004 recommendations by the Advisory Committee on Immunization Practices (ACIP) regarding the use of influenza vaccine and antiviral agents (CDC. (cdc.gov)
99%) of the influenza viruses tested this season are susceptible to the four FDA-approved influenza antiviral medications recommended for use in the US this season. (medscape.com)
NA inhibitor antiviral drugs such as oseltamivir (Tamiflu) and zanamivir (Relenza) are widely used in allopathy to control this influenza virus [ 10 ]. (ijpsonline.com)
Therefore, antiviral treatment should not be withheld from patients with suspected influenza, even if they test negative. (cdc.gov)
Although antiviral drugs such as Oseltamivir are available to control the spread of the virus their effectiveness is limited in treating patients with influenza ( 5 , 6 ). (frontiersin.org)

This type of major change in the influenza A viruses is known as " antigenic shift . (cdc.gov)

The most commonly observed influenza virus subtypes were B followed by A/H3 in ILI cases, and A/H1N1 followed by B in SARI cases. (who.int)
The most commonly isolated virus is respiratory syncytial virus (RSV). (medscape.com)
The novel virus, commonly called swine flu, is named influenza A (H1N1). (bcm.edu)

Influenza infects an estimated 8% of the U.S. population annually, with children and the elderly at highest risk. (health.mil)

The World Health Organization (WHO) reported about 15,174 deaths due to the pandemic influenza virus H1N1 [ 1 ]. (ijpsonline.com)

Influenza A virus M2 protein: monoclonal antibody restriction of virus growth and detection of M2 in virions. (cdc.gov)
Neirynck S , Deroo T , Saelens X , Vanlandschoot P , Jou WM , Fiers W . A universal influenza A vaccine based on the extracellular domain of the M2 protein. (cdc.gov)
Mozdzanowska K , Feng J , Eid M , Kragol G , Cudic M , Otvos JL , Induction of influenza type A virus-specific resistance by immunization of mice with a synthetic multiple antigenic peptide vaccine that contains ectodomains of matrix protein 2. (cdc.gov)
Zharikova D , Mozdzanowska K , Feng J , Zhang M , Gerhard W . Influenza type A virus escape mutants emerge in vivo in the presence of antibodies to the ectodomain of matrix protein 2. (cdc.gov)
Sequence comparison between the extracellular domain of M2 protein human and avian influenza A virus provides new information for bivalent influenza vaccine design. (cdc.gov)
Hydroxyl radicals inside nanoe™ X particles draw out hydrogen from the virus' protein envelope. (panasonic.com)
The numbers refer to protein subtypes-small variations in structure. (carnegiecouncil.org)
The analysis was based on the presence or absence of antibody response against non-structural protein 1 (NS1) from H1N1pdm09 virus, which was not a component of Pandemrix vaccine. (plos.org)

A team that included some of the same UCLA and Arizona scientists reported in 2016 that exposure to influenza viruses during childhood gives people partial protection for the rest of their lives against distantly related influenza viruses. (ucla.edu)
1 Service members may also be at a higher risk for exposure to influenza because of increased crowding and mixing in the recruit setting and duty assignments abroad where influenza subtypes may differ. (health.mil)

Public health authorities should be notified of any suspected institutional outbreak and respiratory specimens should be collected from ill persons (whether positive or negative by RIDT) and sent to a public health laboratory for more accurate influenza testing. (cdc.gov)
During week 12/2014, both the total number of specimens tested for influenza and the influenza positivity rate decreased from those in previous weeks: 13 193 specimens from sentinel and non-sentinel sources were tested for influenza, 2398 (18%) of which were positive: 2212 (92%) influenza A and 186 (8%) influenza B (Fig. 1 and 2). (flutrackers.com)

ABSTRACT Information on the prevalence of influenza, circulating virus subtypes and seasonality is essential for selecting strains for annual vaccines and for planning immunization programmes. (who.int)
The EuroFlu bulletin describes and comments on influenza activity in the 53 Member States in the WHO European Region to provide information to public health specialists, clinicians and the public on the timing of the influenza season, the spread of influenza, the prevalence and characteristics of circulating viruses (type, subtype and lineage) and severity. (flutrackers.com)

This report summarizes influenza activity in the United States during the 2010--11 influenza season (October 3, 2010--May 21, 2011) and describes the components of the 2011--12 Northern Hemisphere influenza vaccine. (cdc.gov)
This report summarizes surveillance for influenza in the United States and worldwide during the 1991-92 season and describes the composition of the 1992-93 influenza vaccine. (cdc.gov)

Molecular surveillance of the influenza viruses should be enhanced continuously for a better understanding of the influenza activity and assessment of vaccine effectiveness. (atlantis-press.com)

The Armed Forces Health Surveillance Branch conducts weekly surveillance of influenza activity among Department of Defense (DOD) populations each influenza season. (health.mil)
Continued weekly surveillance of influenza among DOD populations is crucial to track increases in activity each season and the potential emergence of new and/or severe influenza subtypes. (health.mil)

Influenza B/Victoria viruses are most common among children aged 4 years and younger (48% of reported viruses) and those aged 5 to 24 years (59% of reported viruses). (medscape.com)
Of 27 deaths that have been reported this season, 18 were linked to influenza B viruses (five of these had the lineage determined and all five were B/Victoria viruses). (medscape.com)
Antigenic analysis demonstrated that viruses in the emerging subclade 3C.3 and subgroup 3C-2012/13 were not well inhibited by antisera generated against the 3C.1 vaccine strains used for the 2012/13 (A/Victoria/361/2011) or 2013/14 (A/Texas/50/2012) seasons. (eurosurveillance.org)

A total 2,002 laboratory detections of influenza were reported, of which 98% were influenza A. (canada.ca)
Fewer influenza B detections have been reported this season compared to recent seasons at this time of year. (canada.ca)
For more detailed weekly and cumulative influenza data, see the text descriptions for Figures 2 and 3 or the Respiratory Virus Detections in Canada Report . (canada.ca)
The majority of reported influenza virus detections across the Region were type A, although 5 countries reported type B virus dominance and 2 reported co-dominance of type A and B viruses. (flutrackers.com)
Influenza B accounted for a small proportion of influenza detections, which remained steady over the past weeks. (flutrackers.com)
Since week 40/2013, sentinel and non-sentinel sources have yielded 37 583 influenza detections: 35 897 (95%) were influenza A and 1686 (5%) influenza B viruses (Fig. 2b). (flutrackers.com)

Geographically, influenza activity was widespread in Puerto Rico and 45 states, regional in four states (Kansas, Maine, North Dakota, and Vermont), local in the District of Columbia and Hawaii, and sporadic in the US Virgin Islands. (medscape.com)

The outbreak, which is sometimes called the Hong Kong flu of 1968, was the third influenza pandemic of the 20th century. (searchandrestore.com)
Hong Kong flu was one of the famous influenza pandemics in history. (searchandrestore.com)

A panel of real-time polymerase chain reactions was performed to detect influenza A and B. Extracted RNA from a subset of positive samples was used to determine influenza A subtypes and influenza B lineages. (atlantis-press.com)

Ambulatory data for influenza-like illnesses (ILIs), influenza hospitalization data, and lab data for influenza-confirmed cases were used for the surveillance. (health.mil)

The segmented genome allows influenza A viruses from different species to mix genes (reassortment) and create a new virus if influenza A viruses from two different species infect the same person or animal at the same time. (cdc.gov)
One possible way that virus reassortment could occur is if a pig were infected with a human influenza A virus and an avian influenza A virus at the same time, the new replicating viruses could reassort and produce a new influenza A virus that had some genes from the human virus and some genes from the avian virus. (cdc.gov)
It was an artificial version of the same process through which wild viruses shuffle their genes, known as reassortment. (scientificamerican.com)
genes from some influenza A viruses of the N1 subtype. (wikigenes.org)

Nevertheless, the antigenic drift through several mechanisms that include insertions, deletions, and substitutions are frequent among influenza A and different lineages of influenza B viruses [ 7 - 10 ]. (atlantis-press.com)
viruses, an arrest of significant evolution of the NA discordant with the continuing antigenic drift of HA was found in the 1980- 1983 period. (wikigenes.org)
2 Each influenza season is different because of antigenic drift in the circulating influenza subtypes, the degree of match between vaccine subtypes and circulating subtypes, and vaccine coverage of the population. (health.mil)

In virology, influenza A virus subtype H1N1 (A/H1N1) is a subtype of influenza A virus. (wikipedia.org)

Panasonic's nanoe™ X technology has also been found to inhibit more than 99.9%* of certain viruses during laboratory testing. (panasonic.com)
Medical records and surveillance database of laboratory-confirmed influenza cases were reviewed from October 2015 to 2019. (atlantis-press.com)
This study included a total of 1928 patients with laboratory-confirmed influenza infections. (atlantis-press.com)
These laboratory strains could be passed between mammals more easily than wild strains of the virus. (scientificamerican.com)
The Armed Forces Health Surveillance Branch of the Defense Health Agency utilizes electronic sources of ambulatory medical encounters, hospitalizations, and laboratory data to conduct annual influenza surveillance among all Department of Defense (DOD) beneficiaries across the world. (health.mil)

ECDC and WHO Regional Office published a joint Regional Situation Assessment of the 2019-2020 influenza season up to week 49/2019, which focuses on disease severity and impact on healthcare systems to assist forward planning in Member States. (flutrackers.com)
Influenza activity in the European Region, based on sentinel sampling, first exceeded a positivity rate of 10% in week 47/2019. (flutrackers.com)
The discovery and spread of a novel coronavirus disease in 2019 and 2020 (COVID-19) has led to a plethora of comparisons to the deadly pandemic that occurred a century earlier-the 1918 influenza pandemic, known colloquially as the "Spanish flu. (thegospelcoalition.org)
The 2018-2019 influenza season was longer than the preceding 2 seasons. (health.mil)
This report provides a summary of the data from the 2018-2019 influenza season. (health.mil)
However, there were still 149 influenza-related hospitalizations among service members during the 2018-2019 season. (health.mil)

The "Combined" category is created by adding emergency department patient visits with diagnosed COVID-19 to those visits with diagnosed influenza and those visits with diagnosed Respiratory Syncytial Virus (RSV) for the given week. (cdc.gov)
Diagnostic codes and clinical terms were used to create definitions for diagnosed COVID-19, influenza, and RSV. (cdc.gov)

Viruses are the most common cause of pediatric pneumonia. (medscape.com)
During the 11 influenza seasons from 1977 through 1988, more than 10,000 excess deaths attributed to pneumonia and influenza (P&I) were reported during each of seven seasons, and approximately 45,000 deaths were reported during each of two seasons (CDC, unpublished data, 1992). (cdc.gov)

Findings for each respiratory virus type are presented individually and combined for all three as a percent of total emergency department visits. (cdc.gov)
The data and findings in this report reinforce the importance of the use of up-to-date multivalent influenza vaccines that protect against several different specific virus strains that may become common in the coming influenza season. (health.mil)

Influenza viruses can be spread by large respiratory droplets generated when an infected person coughs or sneezes in close proximity to an uninfected person. (texas.gov)
Similar to other influenza viruses, H1N1 is transmitted through respiratory droplets and not by eating pork or pork products. (ijpsonline.com)

The relative proportion of each type and subtype of influenza virus varied by region and week. (cdc.gov)
The proportion of 2009 influenza A (H1N1) viruses increased nationally, beginning in January, and peaked during the week ending February 20, 2011, when 49% of all subtyped influenza A viruses were 2009 influenza A (H1N1) viruses. (cdc.gov)

Influenza virus continues to be a major public health concern, causing both annual epidemics and occasional pandemics ( 1 ). (frontiersin.org)

Epidemics of influenza typically occur during the winter months in temperate regions and have been responsible for an average of approximately 36,000 deaths/year in the United States during 1990--1999 ( 1 ). (cdc.gov)
Five pediatric deaths associated with influenza occurred during weeks 50 and 51 and were reported to CDC during week 52, bringing the total to 27. (medscape.com)
Three deaths were linked to influenza A viruses and two resulted from influenza B viruses. (medscape.com)
Cite this: Influenza Continues Unabated in US, Deaths in the Thousands - Medscape - Jan 06, 2020. (medscape.com)
Influenza deaths in other age groups are not reportable in Texas. (texas.gov)

Disease relevance of NA Structure of the neuraminidase gene in human influenza virus A/ PR/ 8/ 34. (wikigenes.org)
Disease relevance of NA The complete nucleotide sequence of the neuraminidase gene of influenza. (wikigenes.org)

A quantitative relationship between the in vitro susceptibility of influenza A virus to amantadine and the clinical response to therapy has not been established in man. (nih.gov)
Influenza A variants with reduced in vitro sensitivity to amantadine have been isolated from epidemic strains in areas where adamantane derivatives are being used. (nih.gov)

Genetic and antigenic variation in HA has been used to classify influenza viruses into subtypes (H1-H16). (jci.org)

Anatomy15

Organisms108

Diseases20

Chemicals and Drugs39

Analytical, Diagnostic and Therapeutic Techniques and Equipment26

Phenomena and Processes46

Disciplines and Occupations1

Technology, Industry, Agriculture1

Information Science3

Health Care8

Geographicals3

H3N236

Pdm099

Outbreaks10

H1N23

Hemagglutinin16

Infection23

Seasonal14

Type of influenza virus1

H5N110

Strain10

Illness17

Positive for influenza2

Known as swine flu2

Isolates6

Predominant4

Viral7

Avian influenza A viruses2

Humans13

Swine-origin influenza1

Vaccination9

H9N21

Rapid influenza diagnostic tests2

Immunity5

Antiviral5

Change in the influenza1

Commonly3

Infects1

Pandemic influenza1

Protein8

Exposure to influenza2

Specimens2

Prevalence2

Report summarizes2

Vaccine effectiveness1

Surveillance of influenza2

Victoria3

Detections6

Puerto Rico1

Hong Kong2

Detect influenza1

Hospitalization1

Genes4

Antigenic drift3

Virology1

Laboratory5

20196

Diagnosed COVID-192

Pneumonia2

Findings2

Respiratory droplets2

Proportion2

Pandemics1

Deaths5

Neuraminidase gene2

Vitro2

Classify1