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His Ideas 20 ~ Information Center (2)

Frebruary 2, 2021

( ... from the previous story) Human's history of fighting against viruses ・The oldest virus pandemic which there is evidence of is smallpox. There are smallpox-scarring marks in Egyptian mummies from B.C.E. In his country, it is said that 1 million people died of smallpox in the 8th century. The population at that time was about 5 million. It is said that one of the reasons that Inca (13-15C) and Aztec (15-16C) civilizations declined was because of smallpox virus that was brought over by the Spanish invaders. The invaders already had antibodies, and spread it among the native people. In 1796 an English doctor named Edward Janner invented a vaccination for smallpox, and in 1980 WHO declared the eradication of smallpox. Surprisingly smallpox is the only virus that WHO has declared eradicated. Smallpox viruses are preserved in laboratories in America and Russia. ・Other famous viruses are dengue fever, rabies, diphtheria, measles, polio, chicken pox, and type B hepatitis. Other lethal, but novel, viruses are Ebola, AIDS, Zika ... ・Spanish flu (1918~1921) was the deadliest pandemic. The pathogen of it was Influenza Virus H1N1. Influenza Viruses are categorized by its type with the numbers of H(1~16) and N(1~9). Asia Flu (1957, H2N2, Dead: about 1.1 million), Hong Kong Flu (1963, H3N2, Dead: about 1 million), Swine Flu (2009, H1N1, Dead: about 580,000).     ・For recent epidemics, which are of a smaller area than pandemics, SARS (2003, Dead: about 1,700), MARS (2012, Dead: about 300). SARS and MARS are from coronaviruses like COVID-19.   How do pandemics happen? Why did these happen often in recent decades? ・Certain viruses have their own parasitic animals, they have coexisted per se. HIV viruses of AIDS are said to have come from monkeys in Africa. SARS viruses are said to have come from bats. Ebola is also from bats. The MARS virus is said to have come from a one hump camel. Swine Flu in 2009 is said to have come from pigs. Mosquitos seemed to have transmitted them. Zika viruses' transmitters are mosquitos, but the original animals that they have come from are unknown, although it is thought to be the monkey or the mouse. One time, for some reason, some of the viruses happened to mix in with human bodies, and the viruses changed to become stronger and more infectious. The person who got this accidentally might have been a farmer or a peddler, a single source person, and then it started to spread with residents, then tourists ... ・Risks from the chance of new viruses will increase when many people live close to wild animals. The destruction of virgin forests for the development of human living, farming and raising livestock increases risks of new viruses. Global warming will spread mosquitos' active areas. One of the reasons that Mammoths became extinct is thought to be viruses. If the permafrost in Siberia melts more, new viruses might appear from old animals' dead bodies.   Why are there patients who have no symptoms of COVID-19? Why are old people, overweight people, and people who have chronic diseases more at risk? ・After viruses or other pathogens enter in a body, the human body give symptoms, like a fever, a running nose, coughing and sneezing. They are actions of our body to protect ourselves. In the case of fever, high temperature will kill the pathogen. A running nose, coughing, sneezing are the actions to throw out the bad pathogens from our bodies. It is done by chemical's orders in the body. COVID-19 viruses will disrupt the order. Although symptoms stop (remember, symptoms are the protection of the body), the reproducing of the viruses are still proceeding in the body. When the amount of viruses vastly increase after a few days (~5 days), symptoms will appear suddenly, like a high fever. At this points, there are inflammations here and there. Inflammations are an action to kill the pathogens. But if people already have a chronic disease, the inflammations will worsen the already weak organ. The inflammations will make the immune systems weaker, so viruses will increase more; it's a vicious cycle. Obesity is basically an inflammation of one's fat cells, so the inflammation will be accelerated. Old people's immunity is weak, so the viruses' increasing is steeper. Younger people's immunity is stronger, so some of their immune systems can defeat the viruses before the symptoms appear.   (To be continued ...)

No.419



*smallpox :天然痘
*mummy :ミイラ
*antibody :抗体
*eradication :撲滅
*laboratory :研究所
*dengue fever :デング熱
*rabies :狂犬病,
*diphtheria: ジフテリア,
*measles: はしか,
*polio :ポリオ
*chicken pox :水疱瘡
*hepatitis :肝炎
*hump :こぶ
*peddler :行商人
*permafrost :永久凍土
*chronic :慢性の
*inflammation :炎症
*obesity :肥満