The main cause of concern was suffocation by this thick, leather-like mucous membrane. Whooping cough was passed through direct transmission. It invaded the lungs when resistance was lowered by other viral infections. Pulmonary complications associated with this disease may lead to death and chronic inflammations of the lung lead to prolonged illnesses. Typhus was carried from man to man.
Small pox is passed directly from host to host with no intermediary carrier and with minimal delay.
Severe headaches, backaches, chills and fevers develop rapidly. Eventually these symptoms are replaced by a rash of hard red lumps that after some time painfully blister. Once the blisters scab over they leave permanent pitted scars on their victims. Many of these were childhood killers that turned into adult killers. It is more deadly than all infectious diseases combined.