Perhaps you should do some research of the United States Army and the military in biological agents, and warfare and contaminated zones, and infectious diseases.
Maybe you should do research on the Spanish Flu pandemic of 1918 which killed 675,000 Americans and 50 million world wide.
It was US soldiers that brought the disease back home.
Perhaps you should do some research of the United States Army and the military in biological agents, and warfare and contaminated zones, and infectious diseases.