Wednesday, November 27, 2019
Avian Influenza and Humans H5N1 Essay Example
Avian Influenza and Humans H5N1 Essay Example Avian Influenza and Humans H5N1 Paper Avian Influenza and Humans H5N1 Paper Abstract            There are three types of influenza virus: A, B, and C. Type A strains are broken down further into low pathogenic (LPAI) and highly pathogenic (HPAI). Some HPAI viruses, such as H5N1, resulted in mild human infections and in some cases, have been fatal. An â€Å"H5N1†virus has an HA 5 protein and a NA 1 protein. There are sixteen known HA subtypes and nine known NA subtypes. There are many combinations of HA and NA proteins that are possible. Only influenza A viruses and all its known subtypes infect birds. Influenza A H5 affects both human and birds. There are nine, potential subtypes of H5 known. â€Å"H5 infections, such as HPAI H5N1 viruses currently circulating in Asia and Europe, have been documented among humans and sometimes cause severe illness or death†(CDC, 2).            In 2006, a new strain of H5N1 bird flu appeared in China. It affected three times as many Chinese poultry than it did the previous year. Researchers say that it is a new â€Å"Fujian-like†strain of virus that came from a duck in Fujian, China in 2005 (MacKenzie, 1). The rate of poultry infections jumped from 3 percent in 2005 to 95 percent by 2006. Vaccine-induced antibodies did not recognize this new Fujian virus.            In 2008, a new strain of H5N1 was detected in Nigeria for the first time. It was found to be different from the strains that were circulating in 2006 and 2007 (Stackyard, 1). The new strain was similar to the strains identified in Italy, Afghanistan, and Iran in 2007. â€Å"Influenza viruses constantly mutate, however, and vaccines are most effective against the highly specific strains that they are made from†(Bardi, 1).            A team of scientist at the National Institute of Allergy and Infectious Diseases (NIAID), which is a part of the National Institute of Health (NIH), report that it is possible to prepare vaccines and therapeutics to target a future mutant strain of H5N1. â€Å"This advance was made possible by creating mutations in the regions of the H5N1 hemagglutinin (HA) protein that directs the virus to bird or human cells and eliciting antibodies to it†(Bardi, 1).            New strains appear and replace older strains. When a new strain of virus emerges, antibody protection that may have developed after infection or vaccination with an older strain may not provide protection against the new strain. For this reason, the influenza vaccine must be updated yearly. References Bardi, Jason Socrates. NIH Scientists Target Future Pandemic Strains of H5N1 Avian Influenza. Retrieved March 12, 2009 from nih.gov/news/pr/aug2007/niaid-09.htm. Centers for Disease Control. Influenza Viruses. Retrieved March 12, 2009 from cdc.gov. MacKenzie, Debora. New Strain of H5N1 Bird Flu Emerges in China. Retrieved March 12, 2009 from newscientist.com. Stackyard, Via. Nigeria: A New Strain of H5N1. Retrieved March 12, 2009 from http://crofblogs.typepad.com.
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