AIDS stands for Acquired Immune Deficiency Syndrome. HIV destroys the body's immune system, leaving the body open to infections that it cannot fight in the normal way. When this happens, a person has AIDS.
Amniocentesis is a test for genetic abnormalities done in hospital. A needle is passed through the abdomen of a pregnant woman and into her uterus, to take a sample of the amniotic fluid surrounding the baby.
Antibodies are produced by the body's immune system in response to an outside organism that causes disease, such as a virus or bacteria. Antibodies are specific to the particular virus or bacteria.
Antiretrovirals (ARV) are drugs that fight the HIV virus.
Artificial feeding means feeding a baby on breastmilk substitutes. These can be any food or drink which is used as a replacement for breastmilk, whether or not it is suitable. Examples are infant formula, cow's milk and goat's milk.
Asymptomatic is when a person has HIV infection, but is well and has no signs or symptoms of HIV-related illness.
CD4 count is a blood test that measures the number of CD4 cells in a cubic millimetre of blood. CD4 cells help to protect the body from getting infections. The CD4 count roughly reflects the state of a person's immune system. The CD4 count in a healthy, HIV-negative adult is usually 600-1200 CD4 cells per cubic millimetre of blood. HIV attacks and destroys CD4 cells, so the CD4 count of people with HIV usually falls over time. If the CD4 count drops below 200 cells per cubic millimetre of blood, there is a high risk of serious infection.
Combination therapy is drug treatment with two or more different ARV drugs.
ELISA stands for enzyme-linked immunosorbent assay. This is one of the blood tests done to find out if somebody is HIV positive.
Exclusive breastfeeding is when a baby is given nothing except breastmilk - no water, no juice, no other food or drink. Exceptions are medicines and vitamins.
HIV stands for Human Immunodeficiency Virus. It is the virus which causes AIDS. There are two types of HIV: HIV-1 and HIV-2. This paper is only about HIV-1, because HIV-2 does not usually pass from mother to child.
HIV-positive is when somebody has become infected with the HIV virus. The virus multiplies rapidly in the blood, and antibodies are produced. A person is then said to be HIV positive. Although she may have no signs of illness, she can still infect others.
MTCT stands for mother-to-child transmission, and means the same as vertical transmission.
Monotherapy is drug treatment with only one ARV drug (not a combination).
Opportunistic infections are the infections which people with HIV/AIDS get because their immune systems are damaged. These are infections which the person's body would normally be able to fight, like thrush, or which are only common among people with HIV/AIDS, like pneumonia caused by pneumocystis carinii.
Perinatal transmission is any transmission from mother to child which happens during pregnancy or delivery or up to one week after birth.
Prophylaxis is the prevention of, or protection against disease. For instance, if women are routinely given antimalarial tablets in pregnancy to prevent, rather than treat, malaria, it is called malaria prophylaxis.
Rapid assay testing is a test for HIV using a kit which clinic staff can be trained to use. It gives an immediate result on a blood test to show whether a person is HIV positive, without the need for a laboratory. Some rapid assay tests need refrigeration.
Resistance to an ARV means that the HIV in a person's body has changed so that the drug no longer works against it.
Symptomatic HIV is when a person with HIV has started to become ill with HIV-related illness.
Sexually transmitted infections (STIs) are infections which can be passed from person to person by sexual contact. HIV is an STI, so are gonorrhoea, syphilis, chlamydia trachomatis, herpes simplex, trichomoniasis, cytomegalovirus (CMV) and hepatitis B.
Unprotected sex means having sexual intercourse without a condom. It also refers to other sexual activities where there is a risk of HIV transmission (oral sex, anal sex).
Vertical transmission is when the HIV virus passes from an HIV positive mother to her baby. This can happen during pregnancy, during labour and delivery, or during breastfeeding.
Viral load is one of the tests done on the blood of an HIV-positive person. It measures the amount of HIV in the blood. If a person is HIV positive, a viral load more than 100,000 is considered to be high, and less than 10,000 is considered to be low. An undetectable viral load means that there is not enough HIV in the blood for it to be measured with the usual tests.
Window period is the time between a person becoming infected with HIV and a blood test showing a positive result. Because the blood tests look for antibodies to HIV, rather than the virus itself, it can be up to three months before the tests show a positive result. During the window period people can transmit the HIV virus to other people.