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Aids:
AIDS stands for Acquired
immunodeficiency (or immune deficiency) Syndrome. It results from infection
with a virus called HIV, which stands for human immunodeficiency virus. This
virus infects key cells in the human body called CD4-positive (CD4+) T cells.
These cells are part of the body's immune system, which fights infections and
various cancers.
When HIV invades the body's CD4+ T cells, the damaged
immune system loses its ability to defend against diseases caused by bacteria,
viruses, and other microscopic organisms. A substantial decline in CD4+ T cells
also leaves the body vulnerable to certain cancers.
There is no cure for AIDS, but medical
treatments can slow down the rate at which HIV weakens the immune system. As
with other diseases, early detection offers more options for treatment and
preventing complications.
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WHAT IS DIFFERENCE BETWEEN HIV & AIDS |
The term AIDS refers to an advanced stage of HIV
infection, when the immune system has sustained substantial damage. Not
everyone who has HIV infection develops AIDS.
When HIV progresses to AIDS, however, it has
proved to be a universally fatal illness. Few people survive five years from
the time they are diagnosed with AIDS, although this is increasing with
improvements in treatment techniques.
Experts estimate that about half the people with
HIV will develop AIDS within 10 years after becoming infected. This time varies
greatly from person to person, however, and can depend on many factors,
including a person's health status and health-related behaviors.
People are said to have AIDS when they have
certain signs or symptoms specified in guidelines formulated by the U.S.
Centers for Disease Control and Prevention (CDC).
The CDC's definition of AIDS includes:
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All HIV-infected people with fewer than 200
CD4+ T cells per cubic millimeter of blood (compared with CD4+ T cell counts of
about 1,000 for healthy people).
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People with HIV infection who have at least one
of more than two dozen AIDS-associated conditions that are the result of HIV's
attack on the immune system .
AIDS-associated conditions include:
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Opportunistic infections by
bacteria, fungi, and viruses. Opportunistic infections are infections that are
rarely seen in healthy people but occur when a person's immune system is
weakened.
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The development of certain cancers (including
cervical cancer and lymphomas).
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Certain autoimmune disorders.
Most AIDS-associated conditions are rarely
serious in healthy individuals. In people with AIDS, however, these infections
are often severe and sometimes fatal because the immune system is so damaged by
HIV that the body cannot fight them off.
The symptoms of AIDS were
first recognized in the early 1980s:
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In 1981, a rare lung infection called Pneumosystis
carinii pneumonia began to appear in homosexual
men living in Los Angeles and New York.
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At the same time, cases of a rare
tumor called Kaposi's sarcoma were also reported in young
homosexual men. These tumors had been previously known to affect elderly men,
particularly in parts of Africa. New appearances of the tumors were more
aggressive in the young men and appeared on parts of the body other than the
skin.
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Other infections associated with
weakened immune defenses were also reported in the early 1980s.
Groups most frequently reporting these
infections in the early 1980s were homosexuals, intravenous drug users, and
people with hemophilia, a blood disorder that requires frequent transfusions.
Blood and sexual transmission were therefore suspected as the sources for the
spread of the infections.
In 1984, the responsible virus was
identified and given a name. In 1986, it was renamed the human immunodeficiency
virus (HIV).
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Need To Know:
Because many of the first cases of AIDS in the United
States occurred in homosexual men and intravenous drug users, some people
mistakenly believe that other groups of people are not at risk for HIV
infection. However, anyone is capable of becoming HIV-infected, regardless of
gender, age, or sexual orientation.
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HIV is a type of virus called a
retrovirus. Like all viruses, it must invade the cells of other organisms to
survive and reproduce. HIV multiplies in the human immune system's CD4+ T cells
and kills vast numbers of the cells it infects. The result is disease symptoms.
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Nice To Know:
There are two forms of HIV:
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HIV-1 is the more common and more potent form. This
form of HIV has spread throughout the world.
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HIV-2, which is less potent that HIV-1, is found
predominantly in West Africa. It is also more closely related to two HIV-like
viruses found in monkeys.
There also are different strains of the virus, which
makes it difficult to find one single treatment.
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| HOW
IS HIV INFECTION SPREAD |
HIV infection is spread in three ways:
 Sexual
Intercource:
HIV is spread most commonly by sexual contact
with an infected partner. The virus can enter the body through the lining of
the vagina, penis, rectum, or mouth during sexual relations.
Sexual activities that can result in HIV
infection include:
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Need To Know:
Q: Can HIV be spread through kissing?
A: Although studies have found
tiny amounts of HIV in the saliva of some people with HIV, researchers have
found no evidence that HIV is spread to other people through kissing. However,
the CDC recommends against "French" or open-mouthed kissing because of the
possibility of contact with blood if the people kissing have any cuts or sores
in the mouth.
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Direct
Contact With Infected Blood:
HIV can be spread through direct contact with
infected blood:
Through injected drugs. HIV frequently is
spread among users of illegal drugs that are injected. This happens when
needles or syringes contaminated with minute quantities of blood of someone
infected with the virus are shared.
In a health-care setting. Transmission
from patient to health-care worker or vice-versa - via accidental sticks with
contaminated needles or other medical instruments - can occur, but this is
rare.
Through a blood transfusion.
Prior to the screening of blood for evidence of HIV infection and before the
introduction in 1985 of heat-treating techniques to destroy HIV in blood
products, HIV was transmitted through transfusions of contaminated blood or
blood components. Today, because of blood screening and heat treatment, the
risk of acquiring HIV from such transfusions is extremely small.
Form
An Infected Mother To Her Unborn Child:
Women can transmit HIV to their fetuses during
pregnancy or birth. Approximately one-quarter to one-third of all untreated
pregnant women infected with HIV will pass the infection to their babies.
A pregnant woman can greatly reduce the risk of infecting her
baby if she takes the anti-HIV drug AZT (also called zidovudine)
during her pregnancy. Because the risk of transmission increases with longer
delivery times, the risk can be further reduced by delivering the baby by cesarean
section , a surgical procedure in which the baby is delivered
through an incision in the mother's abdominal wall and uterus. Combining AZT
treatment with cesarean delivery can reduce the infection rate to between 1%
and 2%.
HIV also can be spread to babies through the breast milk of
mothers infected with the virus.
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Women who live in countries where safe alternatives to
breast-feeding are readily available and affordable can eliminate the risk of
transmitting the virus through breast milk by bottle-feeding their babies.
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In developing countries, however, where such safe alternatives
are not readily available or economically feasible, breast-feeding may offer
benefits that outweigh the risk of HIV transmission.
| HOW IS HIV
INFECTION NOT SPREAD |
Research
indicates that HIV is NOT transmitted by casual contact such as:
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Touching or
hugging
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Sharing
household items such as utensils, towels, and bedding
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Contact with sweat or tears
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Sharing facilities such as swimming pools, saunas, hot tubs, or
toilets with HIV-infected people
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Coughs or sneezes
In short, studies indicate that HIV
transmission requires intimate contact with infected blood or body fluids
(vaginal secretions, semen, pre-ejaculation fluid, and breast milk). Activities
that don't involve the possibility of such contact are regarded as posing no
risk of infection.
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Need To Know:
Q: Is it safe to share a household with an HIV-infected
person?
A: Studies of families of
HIV-infected people have found that HIV is not spread through sharing utensils,
towels, bedding, or toilet facilities. Behaviors that increase the likelihood
of contact with blood from an HIV-infected person, such as sharing a razor or
toothbrush, should be avoided.
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Many manifestations of HIV disease are
similar in men and women. Both men and women with HIV may have non-specific
symptoms even early in disease, including low-grade fevers, night sweats,
fatigue, and weight loss. Anti-HIV therapies, as well as treatments for other
infections associated with HIV, appear to be similarly effective in men and
women. Other conditions, however, occur in different frequencies in men and
women. HIV-infected men, for instance, are eight times more likely than
HIV-infected women to develop a skin cancer known as Kaposi's sarcoma. In some
studies, women had higher rates of herpes simplex infections than men.
Data from several studies conducted by CPCRA
found that HIV-infected women were also more likely than HIV-infected men to
develop bacterial pneumonia. This finding may be explained by factors such as a
delay in seeking care among HIV-infected women as compared to men, and/or less
access to anti-HIV therapies or preventive therapies for Pneumocystis carinii
pneumonia, or PCP.
Woman-Specific
Symptoms of HIV Infection:
Women also experience HIV-associated gynecologic
problems, many of which occur in uninfected women but with less frequency or
severity.
Vaginal yeast
infections, common and easily treated in most women, often are particularly
persistent and difficult to treat in HIV-infected women. Data from WIHS suggest
that these infections are considerably more frequent in HIV-infected women.
Health care providers commonly use a drug called fluconazole to treat yeast
infections. A CPCRA study demonstrated that weekly doses of fluconazole can
also safely prevent oropharyngeal and vaginal, but not esophageal yeast
infections, without resulting in resistance to the drug.
Other vaginal
infections may occur more frequently and with greater severity in HIV-infected
women, including bacterial vaginosis and common STIs such as gonorrhea,
chlamydia, and trichomoniasis.
Severe herpes simplex
virus ulcerations, which are sometimes unresponsive to therapy with the
standard drug acyclovir, can severely compromise a woman's quality of life.
Idiopathic genital
ulcers, with no evidence of an infectious organism or cancerous cells in the
lesion, are a unique manifestation of HIV infection. These ulcers, for which
there is no proven treatment, are sometimes confused with those caused by
herpes simplex virus.
Human papillomavirus
(HPV) infections, which cause genital warts and can lead to cervical cancer,
occur more frequently in HIV-infected women. A precancerous condition
associated with HPV, called cervical dysplasia, is also more common and more
severe in HIV-infected women and more apt to recur after treatment.
Pelvic inflammatory
disease (PID) appears to be more common and more aggressive in HIV-infected
women than in uninfected women. PID may become a chronic and relapsing
condition as a woman's immune system deteriorates.
Menstrual
irregularities frequently are reported by HIV-infected women and are being
actively studied by NIAID-supported scientists. Although menstrual
irregularities were equally common in HIV-infected women and at-risk
HIV-negative women in a WIHS survey, women with CD4+ T-cell counts below 50 per
cubic millimeter (mm3) of blood were more likely to report no periods than were
uninfected women, or HIV-infected women with higher CD4+ T-cell counts.
CDC
currently recommends that HIV-positive women have a complete gynecologic
evaluation, including a Pap smear, as part of their initial HIV evaluations, or
upon entry to prenatal care, and another Pap smear 6 months later. If both
smears are negative, annual screening is recommended thereafter in asymptomatic
women. The agency also recommends more frequent screenings-every 6 months-for
women with symptomatic HIV infection, prior abnormal Pap smears, or signs of
HPV infection.
Some women in the
United States have poor access to health care. In addition, women may not think
they are at risk for HIV infection. They may not heed symptoms that could serve
as warning signals of HIV infection, such as recurrent yeast infections. PID
and the other symptoms discussed above should signal health care providers to
offer women HIV testing with counseling.
Early diagnosis of
HIV infection allows women to take full advantage of antiretroviral treatments
and preventive medicines for opportunistic infections when their health care
providers think it is appropriate. Both appropriate therapy and preventive
drugs can forestall the development of AIDS-related symptoms and prolong life
in HIV-infected women as well as men. Early diagnosis also allows women to make
informed reproductive choices. Health care providers should be alert to early
signs of HIV infection in women. In addition, all women should consider HIV
testing if they have engaged in behaviors that put them at risk of infection.
| SURVIVAL AMONG
HIV-INFECTED WOMEN |
Women whose HIV
infections are detected early and receive appropriate treatment survive as long
as HIV-infected men. Although several studies have shown HIV-infected women to
have shorter survival times than men, this may be because women are less likely
than men to be diagnosed early.
In an analysis of
several studies involving more than 4,500 people with HIV infection, women were
33 percent more likely than men to die within the study period. The
investigators could not definitively identify the reasons for excess mortality
among women in this study, but they speculated that poorer access to or use of
health care resources among HIV-infected women as compared to men, domestic
violence, homelessness, and lack of social supports may have been important
factors.
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