bacteria): A microscopic one-celled organism. Some bacteria are essential for our survival and others may cause disease.

The short name for the disease called diabetes mellitus. Diabetes results when the body cannot use blood sugar as energy because of having too little insulin or being unable to use insulin.

An outbreak of disease that spreads within a specific region and/or country

A state of being protected against infectious diseases by either specific or non-specific mechanisms (i.e., immunization, previous natural infection, inoculation, or transfer of protective antibodies)

The body’s very complex system (made of many organs and cells), which defends the body against infection, disease, and foreign substances

The condition of being immune or protected against infection, disease, and foreign substances

A process or procedure that increases an organism’s reaction to antigens, thereby improving its ability to resist or overcome infection

The period of time after exposure to a disease that it takes for the host to display symptoms of that disease

The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment from it.) A person with an infection has another organism (a “germ”) growing within him or her, drawing its nourishment from the person.

The period of time during which an ill person may pass his or her disease on to another