HIV vs. AIDS

AIDS (also termed acquired immunodeficiency syndrome) is defined as a syndrome or condition that results when HIV damages the human immune system so severely that the person becomes very susceptible to additional problems including different infections.

• The difference between HIV and AIDS is in the strict definition of both words. For example, HIV (also termed human immunodeficiency virus) is defined as a virus that can be transmitted from person to person and damages the human immune system.
• AIDS (also termed acquired immunodeficiency syndrome) is defined as a syndrome or condition that results when HIV damages the human immune system so severely that the person becomes very susceptible to additional problems, including infections like pneumonia or tuberculosis and/or the development of cancers like Kaposi's sarcoma.
• HIV and AIDS are similar only because both of them involve the human immunodeficiency virus. Confusion exists between these two words because both the public and medical literature have tended to use HIV and AIDS interchangeably. Strictly speaking, the use of them interchangeably is incorrect. Consequently, for clarity, HIV should only refer to human immunodeficiency viruses and AIDS should only refer to the relatively end-stage syndromes that develop after HIV has extensively damaged a person's immune system. For example, a person can have HIV, or better termed, an infection caused by the human immunodeficiency virus but not have AIDS. A person can have AIDS caused by the human immunodeficiency virus, but AIDS is a syndrome (that is, a set of signs and symptoms that appear together and characterizes a disease or medical condition), and AIDS is not the human immunodeficiency virus (HIV).

The cause for HIV infection is the human immunodeficiency virus; it is spread by person-to-person contact mainly by body fluids during unprotected sex and/or the use of needles contaminated with the human immunodeficiency virus. Other less frequent ways HIV is transmitted are through contaminated blood or tissue during a transfusion or transplant, to a fetus by an infected mother, or to an infant via breast milk from an infected mother.

The cause of AIDS is infection by human immunodeficiency viruses that eventually damage the person's immune system so severely that the person develops additional medical problems like opportunistic infections or cancers.

The risk factors for HIV and AIDS include

• unprotected sexual contact,
• using contaminated needles,
• mother-to-child transmission,
• having a large number of sexual partners,
• a history of sexually transmitted diseases, and
• receipt of blood transfusions before 1985 in the U.S.

However, AIDS has an additional risk factor; it is increased in people who do not treat HIV infection or live in areas where there is an epidemic or endemic presence of HIV infections without good treatment centers available (for example, in sub-Saharan Africa).

• The initial infection by a human immunodeficiency virus strain may or may not produce symptoms.
• Acute HIV infections may cause flu-like symptoms about two to four weeks after infection.
• HIV infections may produce flu-like illnesses with
  • fever,
  • weakness, and
  • a generalized rash.
• Enlarged lymph nodes commonly occur and are often the first indication of HIV infection.
• There are no specific physical findings for HIV infections; the patient's history is important because if they have had exposure to any risk factors as described above, the doctor will probably do some additional tests for HIV infection, which are listed below.
• AIDS signs and symptoms may include all of the above because these patients are infected first with the human immunodeficiency virus.
• However, AIDS signs and symptoms are more severe and can result in recurrent life-threatening infections with opportunistic viruses and bacteria and/or cancers with worsening symptoms if the patient has additional medical problems like diabetes.
• In addition, patients can develop
  • AIDS-associated dementia,
  • encephalopathy, and
  • a wasting syndrome (severe weight loss and diarrhea).

• Screening tests are recommended for patients who are at risk for developing HIV and AIDS.
• Antibody tests were traditionally used to diagnose HIV.
  • An enzyme-linked immunosorbent assay (ELISA) blood test was used for screening for antibodies to the human immunodeficiency virus as evidence of infection.
  • Another blood test, the Western blot assay, was then used to confirm HIV infections.
• There are also newer combined HIV tests that can detect HIV infection up to 20 days earlier than antibody screening tests. These are called combined antigen/antibody tests that look for the presence of a protein called p24 that's part of the virus that shows up two to four weeks after infection, as well as HIV antibodies. These combined tests are now recommended by the U.S. Centers for Disease Control and Prevention (CDC).
• Another type of diagnostic test, the nucleic acid test (NAT), identifies the genetic material of the human immunodeficiency virus. The NAT can detect HIV infection about seven to 28 days after infection with HIV, but these tests are very expensive and not used for routine HIV screening.
• If a person is diagnosed with an HIV infection, health care providers suggest the patient be screened for additional infectious diseases (for example, syphilis, cytomegalovirus, tuberculosis, and others) and/or other diseases that might indicate AIDS.
• The diagnosis of AIDS is more complex than HIV diagnosis. One major blood test for the diagnosis of AIDS is the CD4 T-cell count.
  • Human immunodeficiency viruses can destroy an immune cell type termed CD4 cells, a T-cell type in our immune system.
  • When an HIV-infected patient has a CD-4 cell count of <200/µl, they are considered to have AIDS; when CD4 counts reach these low levels, patients often show one or more of the symptoms or signs (sometimes termed as an AIDS-defining illness) for AIDS listed above.

• Treatments and medications are best managed by an infectious disease consultant who will design a treatment program for the individual's problems.
• In general, all patients with a history of AIDS with a low CD4 count should be treated with antiviral drugs.
• You and your physicians should discuss treatment and/or medication options that will best fit your circumstances.

• In patients with untreated human immunodeficiency virus infections, the overall prognosis is poor, with a life span ranging about eight to 10 years after the initial infection.
• Once the infection has progressed and the diagnosis of AIDS occurs, the survival time is about two years in untreated patients.
• However, remarkable progress has taken place since HIV infections became common worldwide; treatment with antiviral drug therapy has increased survival times.
• In addition, aggressive antiviral therapy can delay the onset of AIDS for many years.
• Consequently, treated individuals have a much better chance for a relatively longer life span and better prognosis if they undergo and adhere to therapeutic protocols.
• Individuals with HIV can live a long time; however, their life spans average somewhat less than normal.
• Future treatments may allow an HIV-infected person to live a normal life span.

• It is possible to prevent HIV and AIDS by avoiding all of the risk factors that result in transmission of the virus. For example, drug users should never share needles.
• Medical personnel need to follow disease-control methods for disposal of medical instruments and needles.
• Safe sex practices with sexual partners who have HIV infection are some of the methods to prevent both HIV and AIDS.
• According to the CDC, there is no vaccine currently available to prevent HIV and/or AIDS.
• However, research is going on to develop a vaccine; a vaccine trial termed HVTN 072 is currently underway to determine if an experimental vaccine regimen can safely prevent HIV infection among South-African adults.
• Positive results from this trial would be an important step forward in prevention of HIV and AIDS.