[ad_1]
The Spanish flu pandemic of 1918-1919 killed 50-100 million people, ranking it as a 5 on the Pandemic Severity Index. It was caused by an unusually severe influenza A virus strain and affected people in their prime. The immune response, called a cytokine storm, may have killed off the virus. The virus caused bacterial pneumonia and massive bleeding and edema in the lungs. The virus’s genetic material was recovered from a victim in Alaska and used to recreate the virus, causing concern among some technologists.
The Spanish flu was a terrible worldwide epidemic that killed between 50-100 million people in an 18-month period between 1918 and 1919. This ranks it as a 5 on the Pandemic Severity Index, meaning that more than 2% of infected people died. The Spanish flu claimed the lives of 2.5-5% of the world’s population by the time it hit, killing more than World War I, which occurred immediately after. The Spanish flu was in the same severity category as the bubonic plague, which, when it struck as the Black Death, killed an estimated 75 million people, 25-50 million of them in Europe.
The Spanish flu was caused by an unusually severe and deadly influenza A virus strain of the H1N1 subtype. In contrast to most flu outbreaks in history, the Spanish flu hit people in their prime, rather than killing off old and young. People with weaker immune systems, such as children and middle-aged adults, had the lowest death rates, while young adults had the highest death rates.
The pattern of death distribution has led scientists to argue that the Spanish flu was killed off by an excessive immune response, called a cytokine storm. In a cytokine storm, the immune response is so overwhelming that the overabundance of immune cells, such as macrophages, can clog local tissues, causing fluid buildup and ultimately fatal damage. Cytokine storms are normally rare and are thought to be caused as a reaction of the immune system to a highly pathogenic new invader.
Compared to a more typical case of the flu, which kills 0.1% of those infected, the Spanish flu killed between 2-20% of those infected. The main cause of death was a secondary infection of the lungs, bacterial pneumonia. The secondary cause of death was the virus itself, which caused massive bleeding and edema in the lungs.
The genetic material of the Spanish flu virus has been recovered from the corpse of a flu victim in the Alaskan permafrost, a woman who had collapsed in the desert after being stricken with the disease. This genetic material was used to recreate the virus from scratch and to sequence its entire genome, which was posted on the internet. Some technologists, such as inventor Ray Kurzweil and Sun Microsystems co-founder Bill Joy, have expressed dismay at this development.
[ad_2]