CLINICAL MEDICINE

Detailed explanation-1: -When sores in the mouth break open, the virus infects the trachea and lungs. But before the virus can spread much farther, it needs to replicate. Research suggests this likely happens in the lymphoid organs, specifically the spleen, bone marrow, and lymph nodes.

Detailed explanation-2: -Smallpox can be deadly if the virus attacks the circulatory system, bone marrow or respiratory system. As recently as the 1960s, around 12 million people caught this highly contagious disease and approximately two million people died every year.

Detailed explanation-3: -The Variola virus then invades more macrophages and the cells that cover the inside surfaces of the blood vessels (endothelial cells) in the liver, spleen, lymph nodes and bone marrow.

Detailed explanation-4: -Smallpox can cause a severe rash over the whole body that can leave scars. Other symptoms include high fever and severe headache or body aches. Death occurs in about 30 percent of infected people. Some survivors may suffer blindness.