| H5N1 is a type of avian influenza virus (bird | | | | humans. |
| flu virus) that has mutated[1] through | | | | |
| antigenic drift into dozens of highly | | | | A myxovirus of the genus Influenzavirus, |
| pathogenic varieties, but all currently | | | | antigenically varying from influenza virus |
| belonging to genotype Z of avian influenza | | | | type B and influenza virus type C, that |
| virus H5N1. Genotype Z emerged through | | | | causes acute respiratory illness in humans. |
| reassortment in 2002 from earlier highly | | | | |
| pathogenic genotypes of H5N1[2] that first | | | | Influenza caused by infection with a strain |
| appeared in China in 1996 in birds and in | | | | of influenza virus type C. |
| Hong Kong in 1997 in humans[3]. The "H5N1 | | | | |
| viruses from human infections and the closely | | | | People should get vaccine who are: |
| related avian viruses isolated in 2004 and | | | | |
| 2005 belong to a single genotype, often | | | | People 65 years of age or older. |
| referred to as genotype Z." [1] | | | | |
| | | | Resident of nursing home and other |
| The avian influenza subtypes that have been | | | | chronic-care facilities. |
| confirmed in humans, ordered by the number of | | | | |
| known human deaths, are: H1N1 caused Spanish | | | | Adults and adolescents with chronic pulmonary |
| flu, H2N2 caused Asian Flu, H3N2 caused Hong | | | | or cardiovascular disorders, including |
| Kong Flu, H5N1, H7N7, H9N2, H7N2, H7N3, | | | | asthma. |
| H10N7. | | | | |
| | | | Health care workers, care givers and others |
| All avian influenza (AI) viruses are type A | | | | who might transmit influenza virus to persons |
| influenza virus in the virus family of | | | | at high-risk for complications from |
| Orthomyxoviridae and all known strains of | | | | infection. |
| influenza A virus infect birds. | | | | |
| Influenzavirus type A is subdivided into | | | | People who are less able to fight infections |
| subtypes based on hemagglutinin (H) and | | | | because of a disease they are born with, |
| neuraminidase (N) protein spikes from the | | | | infection with Human Immunodeficiency Virus |
| central virus core. There are 16 H types, | | | | (HIV), treatment with medications such as |
| each with up to 9 N subtypes, yielding a | | | | long-term steroids, and/or treatment for |
| potential for 144 different H and N | | | | cancer with X-rays or medications. |
| combinations. | | | | |
| | | | Adults and adolescents who required regular |
| Avian influenza (also known as bird flu, | | | | medical follow-up or hospitalization during |
| avian flu, influenzavirus A flu, type A flu, | | | | the preceding year because of chronic |
| or genus A flu) is a flu due to a type of | | | | illnesses (including diabetes mellitus), |
| influenza virus that is hosted by birds, but | | | | kidney diseases, and blood cell diseases such |
| may infect several species of mammals. | | | | as sickle cell anemia. |
| | | | |
| An influenza pandemic is a large scale | | | | Women who will be in the second or third |
| epidemic of the influenza virus, such as the | | | | trimester of pregnancy during the flu season |
| 1918 Spanish flu. The World Health | | | | (December - March). |
| Organization (WHO) warns that there is a | | | | |
| substantial risk of an influenza pandemic | | | | Persons 6 months to 18 years of age who |
| within the next few years. One of the | | | | receive long-term aspirin therapy and |
| strongest candidates is the A(H5N1) subtype | | | | therefore might be at risk for developing |
| of avian influenza. | | | | Reye syndrome after influenza. |
| | | | |
| A myxovirus of the genus Influenzavirus, | | | | This article is prepared by the editor of on |
| antigenically varying from influenza virus | | | | the basis of current updates and reviews on |
| type A and influenza virus type C, that | | | | avian flu pandemic. |
| causes various respiratory illnesses in | | | | |