Infectious Disease

Infectious disease is a branch of medicine that deals with the diagnosis, treatment and prevention of infections. Infectious diseases can be caused by bacteria, viruses, fungi or parasites. They can be spread through the air, water, food, or contact with contaminated surfaces. Some infectious diseases, such as the common cold, can be treated at home. Others, such as Ebola, are deadly. Infectious diseases are a major global health problem. In 2015, there were an estimated 1.6 million deaths from infectious diseases, accounting for nearly one in five global deaths. The most common infectious diseases include the flu, tuberculosis, and malaria.