A deficiency of hemoglobin, often accompanied by a reduced number of red blood cells and causing weakness, and breathlessness.

Antiretroviral therapy:
A combination of several antiretroviral medicines used to slow the rate at which HIV makes copies of itself in the body. A combination of three or more antiretroviral medicines is more effective than using just one medicine to treat HIV.

Encephalopathy: Degeneration of brain function, caused by any of various acquired disorders, including infection.

Hepatitis B immune globulin:
Injection used to prevent hepatitis B infection in persons exposed to the virus, including babies born to mothers infected with hepatitis B.

Hepatitis B surface antigen (HBsAg):
An antigen (any substance that can stimulate the production of antibodies and combine specifically with them) of the small spherical and filamentous forms of hepatitis B antibodies.

Hepatitis B virus:
A viral disease transmitted by injection of infected blood or blood derivatives, by use of contaminated needles, lancets, or other instruments, or by sexual transmission. May lead to acute or chronic liver disease.

Hepatitis C virus:
A viral disease transmitted by injection of infected blood or blood derivatives. Today, most people become infected with the hepatitis C virus by sharing needles or other equipment to inject drugs. For some people, hepatitis C is a short-term illness but for more than 50% of people who become infected with the hepatitis C virus, it becomes a long-term, chronic infection.

HIV (human immunodeficiency virus):
A retrovirus that invades and inactivates helper T cells of the immune system and is a cause of AIDS.

Yellow discoloration of the skin, whites of the eyes, etc., due to an increase in bile pigments in the blood, often symptomatic of certain diseases, such as hepatitis.

Inflammation of the meninges caused by a bacterial or viral infection and characterized by high fever, severe headache, and stiff neck or back muscles.

Opportunistic infection:
An organism capable of causing disease only in a host with lowered resistance, e.g., by other disease or by drugs.

Percutaneous exposure:
The passage of substances through unbroken skin, such as absorption, or passage through the skin by needle puncture.

Postexposure prophylaxis:
Means taking antiretroviral medicines after being potentially exposed to prevent becoming infected.

Postvaccination serologic testing:
Helps identify infants to hepatitis B-infected women who do not have an adequate response to an initial hepatitis B vaccine series and might require additional vaccination.

STD (sexually transmitted disease):
Any disease characteristically transmitted by sexual contact, such as gonorrhea, syphilis, genital herpes, and chlamydia.

TB (tuberculosis):
An infection caused by a bacterium called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but TB bacteria can attack any part of the body such as the kidneys, spine, and brain.

Unregulated tattoo:
State and local authorities oversee tattoo practices via regulations, laws, and licensures to ensure the safety of the public. A tattoo received that does not follow these regulations, laws, and licensures is considered unregulated and has been associated with increased risk of infection.

Viral hepatitis:
Inflammation of the liver caused by one of at least seven immunologically unrelated viruses.

Page last reviewed: August 11, 2022