It is a triple reassortment virus, meaning that it contains genetic material from an avian influenza virus, two different swine viruses a north american strain and a eurasian strain and a human influenza virus. For this reason, they are described as h1n1, h1n2 etc. Ha genes of ah1n1pdm09 viruses continue to fall within subclade 6b. Influenza a h1n1, virus that is best known for causing widespread outbreaks, including epidemics and pandemics, of acute upper or lower respiratory tract infection. It is important to bear in mind that the ah1n1pdm09 virus is still circulating in. The h1n1 virus that caused that pandemic is now a regular human flu virus and continues to circulate seasonally worldwide.
Files are available under licenses specified on their description page. Although no estimates of scfrs were available from africa and southeast asia, a disproportionate number of estimated pandemic deaths might have occurred in these regions. In the spring of 2009, a new human influenza a h1n1 virus emerged in mexico. Influenza ah1n1v pandemic in the dialysis population. July 20 this document is provided in order to clarify the differences among seasonal. Pdf in the 4 months since it was first recognized, the pandemic strain of a novel influenza a h1n1. Although referred to as swine influenza in many reports, scientific evidence shows that it. Within a short time of the initial emergence of ah1n1pdm09 virus, novel reassortants were isolated from swine. Whole genome sequencing of ah3n2 influenza viruses. In virology, influenza a virus subtype h1n1 ah1n1 is the subtype of influenza a virus that was the most common cause of human influenza flu in 2009, and is associated with the 1918 flu pandemic. Occurrence of ah1n1 viral infection and clinical features.
Although the 1918 ah1n1 pandemic virus appeared in swine and human populations around the same time, it is not known if the first viruses infected. Ecdc surveillance report influenza virus characterisation, september 2016 2 table 1 shows a summary of influenza virus detections in the who european region reported to tessy for the weekly reporting period weeks 402015202016 of the 201516 season. 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. Influenza viruses cause a remarkable disease burden and significant morbidity and mortality worldwide, and these impacts vary between seasons. The virus involved in the spring 2009 global influenza outbreak is a new strain of influenza virus affecting humans. During the 2009 spring epidemic outbreak in mexico, an important research and policy question faced was related to the differences in clinical profile and population characteristics of those affected by the new h1n1 virus compared with the seasonal virus. Ah1n1 and the highly pathogenic avian influenza ah5n1 virus. The pandemic h1n12009 virus h1n12009 is a novel new influenza virus causing illness in people. For online submission, the articles should be prepared in two files first. Pandemicinfluenzaa h1n12009intheenglish anddutch speakingcaribbean anepidemiologicaloverview evboisson1,fdesvignes2,squesnel3,carecfluteam.
Haemagglutinin causes red blood cells to clump together and binds the virus to the infected cell. Estimated global mortality associated with the first 12. Reports of human infections with variant viruses cdc. Serbia reported dominance of type b influenza virus, and two. While most influenza virus infections are selflimiting and do not result in hospitalisation. Influenza virus type a is highly contagious and is the most pathogenic of all human influenza viruses. Influenza was first recognized as a disease of swine during the 1918 pandemic, when it was observed that families infected with the pandemic virus often saw that their swine herds were also infected. Serbia reported dominance of type b influenza virus, and two countries. Influenza virus is the cause of one of the most common infections worldwide. H1n1 influenza or swine flu is a highly contagious acute respiratory disease of pigs caused by type a influenza virus that regularly causes outbreaks of influenza in pigs.
However, sporadic human infections with swine flu have occurred. To understand the mechanisms associated with these differences, a comprehensive approach is needed to characterize the impact of influenza genomic traits on the burden of disease. Ah1n1pdm09 swine flu became an established seasonal influenza virus, alongside. Clinical illness follows a short incubation period and presentation ranges from asymptomatic to fulminant, depending on the characteristics of both the virus and the individual host. Influenza a virus subtype h1n1 is the subtype of influenza a virus that was the most common cause of human influenza in 2009, and is associated with the 1918 spanish flu outbreak. Who information for molecular diagnosis of influenza virus in humans. Its effect on the global population carries important economic, healthcare system, and human suffering consequences.
The pandemic influenza ah1n1 2009 virus was confirmed in all deceased patients. Human antibodies recognize two antigens glycoprotein expressed on the viral. Data from clinical files from all influenza a deaths in mexico between april 10 and july, 2009 were. The hospitalisation rate during the 20092010 season was 5. Influenza a viruses can also cause sporadic infections or spread worldwide. The influenza a h1n1 virus is a member of the family orthomyxoviridae a group of rna viruses.
Our estimate of respiratory and cardiovascular mortality associated with the 2009 pandemic influenza a h1n1 was 15 times higher than reported laboratoryconfirmed deaths. During 20162017, a year with severe ah3n2, we sequenced 176 ah3n2. Influenza a y b, gripe aviar h5n1, virus influenza ah1n1 identificados en eua resistentes a oseltamivir. It is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. But further study has shown that this new virus is very different from what normally circulates in north american pigs.
773 536 1067 777 337 115 571 1144 77 196 384 549 723 1586 950 635 905 887 1439 786 681 147 296 447 1079 956 400 524 626 157 1064 342 1551 501 1008 516 1386 448 1010 1370 447 1494 324 931 497 1338 661 1130