AIDS
Alternative names:
acquired immune deficiency syndrome
Definition:
AIDS is caused by the HIV (Human Immunodeficiency Virus).
AIDS is the final and most serious stage of HIV
disease. It is characterized by signs and symptoms of
severe immune deficiency. AIDS stands for acquired immune
deficiency syndrome.
Causes, incidence, and risk factors:
In the United States, AIDS is the fifth leading cause of
death among persons between ages 25 and 44. More that 600,000
individuals have been diagnosed with AIDS in the United States
as of January 1998. More than half of these people have died,
most within four years of showing symptoms of the disease.
The CDC estimates that 2.2 million Americans were infected
with the HIV virus and that approximately 30.6 million people
worldwide were infected with HIV. Approximately 41 percent
of the 30.6 million adults living with HIV worldwide were
women and this proportion is growing every day.
High risk groups include homosexual or bisexual men, intravenous
drug users who share needles, the sexual partners of those
in high risk groups, infants born to mothers with HIV, and
persons who received blood transfusions or clotting products
between 1977 and 1985 (prior to standard screening for the
virus in the blood).
The Human Immunodeficiency Virus (HIV) causes AIDS. AIDS
is the final and most serious stage of HIV disease. The virus
attacks the immune system and leaves the body vulnerable to
a variety of life-threatening illnesses. Common bacteria,
yeast, and viruses that would not cause disease in people
with a fully functional immune system often cause these illnesses.
HIV has been found in saliva, tears, nervous system tissue,
blood, semen, breast milk, and female genital tract secretions.
Transmission of the virus occurs:
1) through sexual contact including oral, vaginal, and anal
sex,
2) through blood via blood transfusions or needle sharing
3) from mother to child
When a woman is pregnant, she can passively transmit the
virus to her fetus or a nursing mother can transmit it to
her baby. Other transmission methods are rare and include
accidental needle injury, artificial insemination through
donated semen, and organ transplantation through the donated
organ.
HIV infection is NOT spread by casual contact such as hugging
and touching, by inanimate objects such as dishes or toilet
seats, during participation in sports, or by mosquitoes. It
is NOT transmitted to a person who donates blood. However,
it can be transmitted to the person receiving a blood transfusion,
which is why blood banks screen donors and test donated blood
thoroughly. It is also NOT transmitted to a person that donates
an organ, although a recipient could be at risk.
AIDS is preceded by HIV infection, which may produce no symptoms
for up to ten years before a person is diagnosed with AIDS.
Acute HIV infection progresses over time to asymptomatic HIV
infection and then to early symptomatic HIV infection and
later, to AIDS (very advanced HIV infection). Most individuals
infected with HIV will progress to AIDS if not treated. However,
there is a very small subset of patients who develop AIDS
very slowly or never at all; these patients are called non-progressors.
HIV Infection (acute HIV infection)Žearly asymptomatic HIV
infectionŽearly symptomatic HIV infectionŽAIDS.
Updated Date:02/09/00
Luis A. Diaz, Jr. M.D., Johns Hopkins Medical
Institute, VeriMed Health Network
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