Influenza in humans is often referred to as the seasonal flu. Influenza in birds is often referred to as avian influenza, in pigs as swine influenza, in horses as equine influenza and so on. Influenza d viruses primarily affect cattle and are not known to infect or cause illness in people. Virus influenza e o organismo humano influenza virus. Influenza a can be found in many species, including humans, birds, and pigs. The who collaborating center for reference and research on influenzaat the chinese national influenza center, beijing, has made available attached realchina, time rtpcr protocol for the detection of avian influenza ah7n9 virus. Pdf influenza is a highly contagious acute viral infection of the respiratory tract. About the author influenza d virus in cattle, ireland. Avian influenza ah7n9 virus 8 april 20 updated on 15 april 20.
Influenza a viruses are divided into subtypes based on two proteins on the surface of the virus. Etiology influenza virus c ivc and influenza virus d ivd are enveloped rna viruses in the family orthomyxoviridae. Realtime rtpcr protocol for the detection of avian. They are more closely related to each other than to influenza virus a iva or influenza virus b ivb, containing seven genomic segments and a hemagglutininesterase he. We also determined the distribution of positive and negative samples at county level in ireland online technical appendix figure 2. Cdc protocol of realtime rtpcr for influenza ah1n1 28 april 2009 revision 1 30 april 2009 revision 2 6 october 2009 the who collaborating centre for influenza at. This work is licensed under a creative commons attribution. Type a influenza is a contagious viral infection that can have lifethreatening complications if left untreated. Influenza a symptoms can be confused with signs of other conditions but are usually. Influenza b virus is the only species in the genus betainfluenzavirus in the virus family orthomyxoviridae influenza b virus is only known to infect humans and seals with influenza. This limited host range is apparently responsible for the lack of associated influenza pandemics in contrast with those caused by the morphologically similar influenza a virus as both mutate by both antigenic.
Influenza diagnosis clinical and epidemiological characteristics increase of febrile respiratory illness lab isolation of influenza virus from clinical specimen e. Influenza type c infections generally cause mild illness and are not thought to cause human flu epidemics. Influenza a symptoms can be confused with signs of. Influenza a and b are the two types of influenza that cause epidemic seasonal infections nearly every year.