AIDS is an acronym for acquired immune deficiency syndrome, a disease
caused by the human immunodeficiency virus (HIV). This virus attacks
the immune system, the body's line of defense against disease and infections.
When the immune system breaks down, one become susceptible to serious,
often deadly infections and cancers called opportunistic infections,
so named because they take advantage of the body's weakened defenses.
Soon after infection, some people develop short-term flu-like symptoms.
But infected people usually show no other symptoms until the disease
Patients with advancing disease can develop swollen lymph nodes, weight
loss, fatigue, diarrhea, anemia and thrush, as well as various opportunistic
infections, such as Pneumocystis pneumonia.
HIV is spread by sexual contact with an infected person, by needle-sharing
among injection drug users or through transfusions with infected blood.
HIV-infected women can transmit the virus to their newborns before or
during birth, or through breast-feeding after birth. Health-care workers
can become infected with HIV after being stuck with HIV-tainted needles.
People can protect themselves by not engaging in unprotected sex
with those who have HIV or whose HIV status is unknown. The gold standard
in sexual protection is the male latex condom. When used correctly and
consistently, male condoms are 98 to 100 percent effective against infection,
studies show. According to the Centers for Disease Control and Prevention,
the female condom also offers some protection against HIV and may be
used when a male condom cannot be used appropriately. Protection is
also important during oral sex, either with a male condom or dental
dam, which covers the vagina. People who use injection drugs should
use a clean needle each time they inject drugs. Anti-HIV therapy for
pregnant women infected with the virus can reduce the risk of mother-to-infant