The main diseases were smallpox, measles, influenza, and typhus. There were also other diseases such as whooping cough, the mumps, and diphtheria. Each disease has a specific entry into the body, and each can cause various types of symptoms. For example, diphtheria enters the body through the respiratory tract and attaches to the tissue in the throat. This disease can cause a blockage of the air passage to the lungs and can cause suffocation or death.
Whooping cough is also highly contagious and can cause violent coughing.
The person can also turn blue, due to the lack of oxygen, vomit, or go into convulsions. Influenza virus that infects people does not infect other hosts. Influenza is transmitted through air droplets expelled by coughing or sneezing. Measles is a highly contagious viral disease, which can enter the body through the eye or respiratory tract. Symptoms such as a rash, high fever, delirium, and eye pain can occur.