Influenza viruses antiviral therapy and resistance. Author summary influenza viruses can transmit through the air between two hosts. The pandemic is the first since the worldwide spread of an h3n2 flu virus in 196869, when the tools for tracking and identifying influenza viruses were far less sophisticated than today. One form of the vaccine contains a preservative called thimerosal. Ah1n1 influenza b influenza a coronavirus nl63 human rhinovirus enterovirus. Simultaneous detection of influenza a, influenza b, and. The world had been anticipating another influenza pandemic since the last one in 1968. The emergence and transition to pandemic status of the influenza ah1n1ah1n1pdm09 virus in 2009 illustrated the potential for previously circulating human viruses to reemerge in humans and cause a pandemic after decades of circulating among animals. The virus was first recognized in april 2009 and spread quickly to 74 countries worldwide. These aspects of transmission are poorly understood due to a paucity of methods for quantifying infectious virus from airborne particles. Persistence of influenza a h1n1 virus on stainless steel. H1n1 influenza the h1n1 virus is an influenza virus strain causing contagious illness in people, first detected in people in the united states in april 2009. Influenza pandemic h1n1 of 2009, also called h1n1 flu, byname swine flu, the first major influenza outbreak in the 21st century, noted for its rapid global spread, which was facilitated by an unusually high degree of viral contagiousness. Us8835624b1 influenza a h1n1 subtypespecific aptamer.
The pandemic influenza a h1n1 2009 virus a2009h1n1 finally arrived, causing the first pandemic influenza of the new millennium, which has affected over 214 countries and caused over 18,449 deaths. Influenza a h1n1, virus that is best known for causing widespread outbreaks, including epidemics and pandemics, of acute upper or lower respiratory tract infection. Influenza pneumonia incidence was high in 2005, a year when influenza ah3n2 subtype virus strains predominated, low in 2006 when a h1n1 viruses were more common, moderate in 2007 when h3n2 and. An influenza pandemic can happen when a novel flu virus emerges, such as a swine flu. On the basis of sequence analysis, aswinekorea612016 is marked from swine h1n1 influenza virus. In germany, overall 3,720 influenza viruses 66% a h1n1 pdm09, 19% ah3n2 and 15% influenza b circulating between april 2009 and may 2016 were analyzed phenotypically andor genotypically 82. H1n1 influenza synonyms, h1n1 influenza pronunciation, h1n1 influenza translation, english dictionary definition of h1n1 influenza.
Four ferrets were euthanized at each of the time points 1, 3, 5, and 7 days postinoculation dpi and tissue samples. In other flu developments, australian researchers who conducted a 3year study of adults hospitalized for respiratory illnesses found that 2009 h1n1 influenza was associated with more severe illness than h3n2 and other respiratory viruses. Influenza a pandemic h1n1 2009 virus infection in domestic. Less often, a person might become infected with influenza by touching a surface or object contaminated with influenza virus and.
Pandemic h1n1 2009 virus on commercial swine farm, thailand. Ferrets were inoculated intranasally with 10 6 50% tissue culture infectious dose tcid 50 of 1918 h1n1 influenza virus. As annual influenza epidemics continue to cause significant morbidity and economic burden, an understanding of viral persistence and transmission is critical for public health officials and health care workers to better protect patients and their family members from infection. These symptoms typically begin two days after exposure to the virus and most last less than a week. H1n1 was called swine flu at first because it was thought genetically similar to flu viruses normally occurring in pigs. The influenza type a virus, known as h1n1 is a respiratory infection that was popularly named swine flu. Who information for laboratory diagnosis of pandemic h1n1.
Jul, 2009 analysis of a series of clinical isolates of the swineorigin h1n1 influenza virus reveals that in mammalian models mice, ferrets and macaques the current pandemic virus is associated with more. Influenza, commonly known as the flu, is an infectious disease caused by an influenza virus. The a h1n1 influenza virus, which emerged in the human population in 1918, was an aviandescended virus, which appeared to have undergone adaptation to humans by unknown mechanisms. Today, all influenza viruses circulating in the human population carry several gene segments that are direct descendants of the avianlike 1918 a h1n1 pandemic. For influenza a viruses, the hemagglutinin and neuraminidase antigen description are provided in parentheses e. Us8835624b1 influenza a h1n1 subtypespecific aptamer and. Influenza a h1n1 2009 monovalent vaccine is formulated to contain 15 mcg hemagglutinin ha of influenza acalifornia072009 h1n1 vlike virus per. We report here the genome sequence of the influenza a virus strain aswinekorea612016, isolated from swine in the republic of korea. Because this virus is very different from current seasonal influenza viruses, many people will not have protective immunity against it and the seasonal flu vaccine will not protect against it either. Complete genome sequence of h1n1 swine influenza virus. Pigs first became infected with the influenza virus in 1918, and the first swine virus was found in humans in 1974. To better understand this deadly virus, an expert group of researchers and virus hunters set out to search for the lost 1918 virus, sequence its genome, recreate the virus in a highly safe and regulated laboratory setting at cdc, and ultimately study its secrets to better prepare for future pandemics.
Even though human influenza a h1n1 virus had not circulated since 1957 and the swine influenza a h1n1 virus that had been identified at fort dix did not extend outside the base, in. However, just as the common, seasonal flu that affects humans is constantly mutating as our immune systems and vaccines compromise weaker strains, swine flu is always trying to improve itself so that it can become more virulent. Influenza viruses are cultured in chick embryo and cell culture mdck. Additional a h1n1 pdm09 and ah3n2 clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. Global challenges, global solutions aimed to examine the evolutionary origins of the h1n1 virus and evaluate its potential public health and socioeconomic consequences, while monitoring and mitigating the impact of a fastmoving pandemic. Influenza a virus, influenza b virus, and influenza c virus, respectively table 10. A h1n1 pdm09 to distinguish it from the seasonal influenza a h1n1 viruses that circulated prior to the pandemic. That changed several years ago, when a new virus emerged that. The origins of pandemic influenza lessons from the 1918 virus.
The present invention provides an influenza a h1n1 subtypespecific aptamer. The origins of pandemic influenza lessons from the 1918. Because of the persistent threat from the ah5n1 virus since 1997 and the. Additional ah1n1pdm09 and ah3n2 clinical samples are tested for mutations of the virus known to confer oseltamivir resistance. Virus titers, virus antigen, and cytokine expression in 1918 h1n1 influenza virusinoculated ferrets. Characterising viable virus from air exhaled by h1n1. It should be emphasized that these tests will not differentiate seasonal influenza from pandemic h1n1 2009 virus. Historical perspective emergence of influenza a h1n1.
Virus was isolated by using 10dayold specific pathogenfree embryonated chicken eggs. The h1n1 virus that caused that pandemic is now a regular human flu virus and continues to circulate seasonally worldwide. Within a short time of the initial emergence of ah1n1pdm09 virus, novel reassortants were isolated from swine. The world health organization who declared the virus a global pandemic. Rna from a victim of the 1918 pandemic was isolated from a formalinfixed, paraffin. Understanding the origins of the 1918 virus and the basis for its exceptional virulence may aid in the prediction of future influenza pandemics. Influenza a virus h1n1 an overview sciencedirect topics.
Lecture influenza a h1n1 swine influenza influenza. Us flu activity rises again as study highlights h1n1 severity. H1n1 influenza definition of h1n1 influenza by the free. In may 2009, pandemic h1n1 2009 was confirmed in 2 patients in thailand who had a history of travel to mexico. Refresh this list to see the latest articles 22 february. The infectivity and persistence of two influenza a h1n1 virus strains anew.
Swine influenza a virus h1n1 was derived from several viruses circulating in swine, and the initial transmission to humans occurred several months before recognition of the outbreak. Thus, the aptamer can be effective in detection of h1n1 influenza virus. The influenza a h1n1 virus is a member of the family orthomyxoviridae a group of rna. Influenza ah1n1 interim planning considerations for mass gatherings in the context of pandemic h1n1 2009 influenza, november 2009 pdf, 160 kb influenza public health preparedness. The latter are composed of key genes from the 1918 virus, updated by subsequentlyincorporated avian influenza genes that code for novel surface proteins, making the 1918 virus indeed the mother of all pandemics. In vitro and in vivo characterization of new swineorigin. The influenza a h1n1 virus is a member of the family orthomyxoviridae a group of rna viruses. Us flu activity rises again as study highlights h1n1. Pdf effectiveness of common healthcare disinfectants. Pandemic influenza guidance 2 the novel h1n1 influenza was first detected in the united states in midapril 2009. The spanish influenza pandemic killed at least 20 million people in 19181919, making it the worst infectious pandemic in history. Apr 15, 2018 virus titers, virus antigen, and cytokine expression in 1918 h1n1 influenza virusinoculated ferrets. If sick, stay at home until feverfree for at least 24 hours without the use of feverreducing medications e.
A historical perspective of influenza ah1n2 virus volume. The first case of 2009h1n1 influenza a was confirmed in south africa on june, some 2 months after that of the united states and a month or more after other. Effectiveness of common healthcare disinfectants against h1n1 influenza virus on reusable elastomeric respirators article pdf available in infection control and hospital epidemiology 357. Its called swine flu because in the past, the people who caught it had direct contact with pigs. Complete genome sequence of h1n1 swine influenza virus from. Analysis of a series of clinical isolates of the swineorigin h1n1 influenza virus reveals that in mammalian models mice, ferrets and macaques the current pandemic virus is associated with more. The epidemic curve of the 2009h1n1 influenza a pandemic as determined through active surveillance for all laboratoryconfirmed cases nationally in south africa, as of september 29th, is shown in figure a104. Situation updates influenza ah1n1 disease outbreak news. In germany, overall 3,720 influenza viruses 66% ah1n1pdm09, 19% ah3n2 and 15% influenza b circulating between april 2009 and may 2016 were analyzed phenotypically andor genotypically. Because of the persistent threat from the ah5n1 virus since 1997 and the outbreak of the severe acute. Historical perspectiveemergence of influenza a h1n1 viruses, n engl j med 361. The former oseltamivirresistant seasonal ah1n1 virus become to extinct soon after the emergence of the ah1n1pdm09 virus.
For current, updated information on seasonal flu, including information about h1n1, see the cdc seasonal flu website. Reassortment of strains of influenza a h1n1 of avian, porcine and human origin. On june 11, 2009, the world health organization who declared an h1n1 pandemic and on october 24, 2009, president barack obama declared the spread of the h1n1 flu a national emergency. For virus to successfully transmit through the air, it must be exhaled from an infected donor in sufficient quantities and retain infectiousness in the air. Read the domestic and international impacts of the 2009. Influenza pneumonia incidence was high in 2005, a year when influenza ah3n2 subtype virus strains predominated, low in 2006 when ah1n1 viruses were more common, moderate in 2007 when h3n2 and. Global dissemination of the virus was further expedited by the unprecedented rates of passenger travel.
The domestic and international impacts of the 2009 h1n1 influenza a pandemic. Few young people had any existing immunity as detected by antibody response to the h1n1 pdm09 virus, but nearly onethird of people over 60 years old had antibodies against this virus, likely from exposure to an older h1n1 virus earlier in their lives. Influenza bvictoria nrth ecen jeff wcen sern nern swrn mobl influenza a h1n1 influenza b influenza a coronavirus nl63 human rhinovirus enterovirus influenza ah3n2 influenza ah3 adenovirus human metapneumovirus respiratory syncytial virus a. The domestic and international impacts of the 2009h1n1 influenza a pandemic. Preliminary differentiation of pandemic h1n1 2009 virus from other h1 or h3 types of influenza a was performed by using an inhouse rrtpcr assay that distinguishes between pandemic h1n1 2009 eurasian matrix 10 and endemic to north america swine h1n1 influenza viruses north american matrix. Even though human influenza a h1n1 virus had not circulated since 1957 and the swine influenza a h1n1 virus that had been identified at fort dix did not extend outside the base, in november. Testing of influenza a h1n1 pdm09, ah3n2, and influenza b virus isolates for resistance to neuraminidase inhibitors oseltamivir, zanamivir, and peramivir is performed at cdc using a functional assay. Most experts believe influenza viruses spread primarily by droplets made when infected people cough, sneeze, or talk. Swine flu is an influenza virus that usually affects pigs. Three genera exist with this family that pertain to influenza viruses, influenzavirus a, influenzavirus b, and influenzavirus c, each of which contain a single species, or type. A multiplex realtime pcr assay was developed to simultaneously detect and discriminate influenza a virus subtypes, including novel h1n1 2009 and seasonal h3n2 virus, influenza b virus, and respiratory syncytial virus rsv in a single test tube, with detection sensitivity and specificity of 99% and 100%, respectively, for the four pathogens.
Background on h1n1 the 2009 h1n1 influenza virus previously called swine flu is a new strain of influenza virus. The english language content on this website is being archived for historic and reference purposes only. Information for programme managers and clinicians july 2010 about this document pregnant women, especially those with comorbidities, are at increased risk for complications from all forms of influenza virus infection seasonal, zoonotic, and pandemic. Oct 01, 2010 in april 2009, a novel swine origin influenza a h1n1 virus, now referred to as pandemic h1n1 2009 virus, emerged in humans in mexico and the united states and spread worldwide 1. Genetic reassortment in pigs allows for the generation of novel influenza viruses and further demonstrates that pigs can serve as intermediate hosts and. It is believed that the h1n1 flu spreads the same way that seasonal flu does. Yet the h1n1 virus surprised the world by emerging in north america instead of asia and causing mild illness in most people, instead of the severe disease.
The h1n1 pdm09 virus was very different from h1n1 viruses that were circulating at the time of the pandemic. The aptamer is stable, establishing sensitivity about 100 times higher than antibody and high specificity to influenza a h1n1 subtype. It is very contagious and has spread to many areas of the united states and other countries resulting in a pandemic. The team published its report nov 28 in epidemiology and infection. Testing of influenza ah1n1pdm09, ah3n2, and influenza b virus isolates for resistance to neuraminidase inhibitors oseltamivir, zanamivir, and peramivir is performed at cdc using a functional assay. Lecture influenza a h1 n1 free download as powerpoint presentation. Three a h1n1 sivs were obtained, including 2 isolates from pigs in the slaughterhouse and 1 from a pig raised at the familys farm. Influenza virus h1n1 fact sheet morgridge institute for. The pandemic influenza a h1n1 2009 virus a2009 h1n1 finally arrived, causing the first pandemic influenza of the new millennium, which has affected over 214 countries and caused over 18,449 deaths. Apr 25, 2017 the former oseltamivirresistant seasonal a h1n1 virus become to extinct soon after the emergence of the a h1n1 pdm09 virus. Serology hai and microneutralization tests using pandemic h1n1 2009 virus are expected to be able to detect antibody responses following infection. The aptamer was selected in vitro using selex and a microfluidic chip system.
Influenza a h1n1 2009 monovalent vaccine is an inactivated influenza virus vaccine indicated for active immunization of persons ages 6 months. Influenza a h1n1 2009 monovalent vaccines descriptions. Components of the 2009 pandemic virus are thought to have derived from the 1918 influenza pandemic. In april 2009, a novel swine origin influenza a h1n1 virus, now referred to as pandemic h1n1 2009 virus, emerged in humans in mexico and the united states and spread worldwide 1. Pdf in the 4 months since it was first recognized, the pandemic strain of a novel influenza a h1n1 virus has spread to all continents and, after. The three pandemic viruses that emerged in the 20th century the 1918 spanish influenza h1n1 virus, the 1957 asian influenza h2n2 virus, and the 1968 hong kong influenza. It is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. Influenza, or flu, is a respiratory infection caused by a variety of influenza viruses. Human infection from avianlike influenza a h1n1 viruses.
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