Part of the human body used for hearing

A brain inflammation of viral or other microbial origin. Symptoms include headaches, neck pain, fever, nausea, vomiting, and nervous system problems. Several types of opportunistic infections can cause encephalitis.

Final period or phase in the course of a disease leading to a person's death. A test commonly used to diagnose HIV infection. The test is based on the detection of antibodies to HIV, and will therefore yield negative results in the first few weeks of HIV infection, when the individual has not yet started to produce antibodies to the virus.

An outbreak of disease (usually infectious) which spreads rapidly in a community.

The study of causes, distribution, prevalence and control of diseases.

A blood test carried out to indicate the level of any infection in the body.