Most influenza outbreaks kill juvenile, elders, and already weak patients but the Spanish flu was killing mainly healthy young adults. One of the most shocking complications was hemorrhage coming from the mucous membranes, especially from the stomach, nose, and intestines. There were other complications such as bleeding from the ears and petechial hemorrhages in the skin. A majority of deaths were from bacterial pneumonia. Some people were killed directly from massive hemorrhages and edema in the lung.
January 18, 2008, it was reported, through animal testing, that monkeys infected with the recreated strain exhibited classic symptoms of the 1918 Spanish flu pandemic. The monkeys died from a cytokine storm which is an overreaction of the immune system. This experiment explained why the Spanish flu had a striking effect on healthier and younger people. When infected with the virus, a person with a stronger immune system would have a stronger overreaction.
In June 2010, a team at the school of Medicine in Mount Sinai reported that the 2009 flu vaccine provided some cross protection against the Spanish Flu pandemic strain.
There is not enough historical and epidemiological data to give a definite geographic origin of the pandemic. Modern transportation gave way for the soldiers, sailors, and civilian travelers to spread the disease across the world. An expert of the 1918 flu for the Institut Pasteur, Dr. C Hannoun, stated the former virus was likely to have come from China, mutated in the United States near boston, and spread to Brest, Brittany-France,...