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Research paper−97−Synthesiology - English edition Vol.8 No.2 pp.97-107 (Sep. 2015) (NA) with different antigenicity. In a new strains of influenza, mutation occurs in the HA and/or NA. Names such as type H1N1 influenza are given according to the type of HA and NA. In a new strain of influenza, new types of HA or NA appear among humans, and the antigenic drift and antigenic shift occur, or the influenza genes pass on from birds to humans. In past fact of research, it was found that the Spanish flu was caused by a hypovirulent H1N1 type derived from the avian flu.There are three reasons why a new strain of influenza is serious. (1) Since a new strain never existed before, no one has immunity. (2) It is highly infectious. It is thought that only an influenza virus that developed the ability for airborne infection causes a pandemic. (3) Since it is an unknown virus, vaccines cannot be made beforehand. Also, as an outstanding characteristic of the Spanish flu, young people developed serious conditions such as systemic infection, multiple organ failure, or a cytokine storm, which is an excessive vital reaction to viral infection. For example, the peak deaths of the Spanish flu occurred in people of ages 24-29. In Japan, there were newspaper headlines that said, “Most productive people were first to fall victims.” The patients spread amongst the most productive people that supported society, and they died and paralyzed the social functions. According to the estimates by the Ministry of Health, Labour and Welfare,[5] if a pandemic equivalent to the strength of the Spanish flu (2.0 % fatality) occurred, 640 thousand people may die. However, since a mutant virus of subtype H5N1 has 60 % fatality rate, there are estimates that greater damage 1 IntroductionHumankind faced three influenza pandemics in the 20th Century and has already experienced the first one in the 21st Century. The pandemics of the 20th Century include the Spanish flu of 1918, the Asian flu of 1957, and the Hong Kong flu of 1968. The 2009 flu pandemic is still fresh in our minds. Influenza is a communicative disease that must be reported to the authorities.Note 1) The Spanish flu developed into a pandemic in seven months, and although estimates of the number of those infected and those who died vary widely, of the affected world population of 1.8 billion people, 1 billion people were infected and 80 million died. In Japan, after the first patient was reported, the disease spread throughout the nation in three weeks, and 42 % of the Japanese citizens were infected and 450 thousand people died. The Spanish flu came to a close in 1920, and economists consider it as the remote cause of the Great Depression that started in 1929.[2] Regarding the 2009 flu that started in the spring of 2009, according to the Center for Disease Control and Prevention (CDC), about 270 thousand people were admitted to the hospital by October 2010 throughout the United States, and 12,000 people died.[3] The reason there were fewer deaths compared to the past pandemics was because the virus was hypovirulent.Note 2) It is reported that in total, 20.68 million people were infected in Japan.[4]Why does such pandemic influenza appear periodically? First, there are three types of influenza: types A, B, and C. Type A has 144 subtypes according to the combinations of 16 types of hemagglutinin (HA) and nine types of neuraminidase - Development of a palmtop sized sensor-We developed a highly sensitive sensor, based on optical waveguide modes, which was reported in the journal, Synthesiology.[1] The first part of the present paper reports the method for reducing sensor size. Applications include identification of influenza virus A H3N2 and other subtypes of influenza viruses. We also found that sialic acid based detection using the waveguide mode sensor system analysis was very useful in distinguishing between H3N2 and H5N1 viruses. Using these techniques, H3N2 and H5N1 strains of influenza viruses have been successfully identified with the waveguide-mode sensor. Sensitivity comparison was also conducted for waveguide-mode sensor, immuno-chromatography, enzyme-linked immunosorbent assay (ELISA), and surface plasmon resonance (SPR). Of these techniques, waveguide mode sensor showed the greatest sensitivity for the H3N2 Udorn strain. The palmtop sized, high sensitive sensor will be useful in border control against intrusion of infections, for example, in aircraft, at airports, and arenas.Detection of influenza viruses with the waveguide mode sensorKeywords : Bio sensor, waveguide mode, influenza virus, palmtop sensor[Translation from Synthesiology, Vol.8, No.2, p.97-106 (2015)]Koichi Awazu*, Makoto Fujimaki, Subash C. B. Gopinath and Xiaomin WangElectronics and Photonics Research Institute, AIST Tsukuba Central 5, 1-1-1 Higashi, Tsukuba 305-8565, Japan* E-mail : Original manuscript received September 22, 2014, Revisions received January 2, 2015, Accepted January 5, 2015

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