What organism causes AIDS?
The organism that causes AIDS is the human immunodeficiency virus. This virus is more commonly known as HIV. Many people who have HIV/AIDS are more susceptible to other illnesses.
The virus that causes AIDS (HIV) is not the organism that causes the symptoms of AIDS, instead HIV destroys a significant part of the immune system leaving the body open to uncontrolled infections by many other organisms (e.g. bacteria, fungi) and to certain cancers (e.g. Kaposi's Sarcoma) which produce the symptoms of AIDS.