Human Immunodeficiency Virus (HIV)

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Original Editors - Holly Grant from Bellarmine University's Pathophysiology of Complex Patient Problems project.

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Definition/Description

AIDS, acquired immunodeficiency syndrome, is a contagious, chronic and life-threatening condition caused by the human immunodeficiency virus (HIV). Acquired means that the diease is not inherited or genetic in nature, but develops as a result of a virus. Immuno refers to the immune system, and deficiency means that the immune system is underperforming or hypoacive.  By damaging your immune system, HIV interferes with your body's ability to fight off viruses, bacteria and fungi that cause disease. HIV makes you more susceptible to certain types of cancers and to infections your body would normally resist. The cytopathogenic virus and the infection itself are known as HIV. "Acquired immunodeficiency syndrome (AIDS)" is the name given to the later and more serious stages of an HIV infection. 

An estimated 40.3 million people have HIV worldwide. And though the spread of the virus has slowed in some countries, it has escalated or remained unchanged in others. The best hope for stemming the spread of HIV lies in prevention, treatment and education.

Prevalence

Prevalence is the number of people living with HIV infection at the end of a given year. According to the CDC, at the end of 2006, an estimated 1,106,400 persons in the United States were living with HIV infection, with 21% of people undiagnosed. Incidence is the number of new HIV infections that occur during a given year. HIV unfection is the 5th leading cause of death for people who are between the ages of 25-44 years old in the United States.  In 2008, the CDC estimated that approximately 56,300 people were newly infected with HIV. Over half of these new infections occurred in gay and bisexual men. Black/African American men and women were also strongly affected and were estimated to have an incidence rate that was 7 times as high as the incidence rate among whites. African-American's represent about 12% of the total United States population, but make up over half of the people known that are suffering from AIDS. AIDS is the leading cause of death for African-American men between the ages of 35-44 years old in the United States. It is thought that approximately 5 million new HIV cases occur each year worldwide.  

Characteristics/Clinical Presentation

The clinical presentation of HIV and AIDS vary depending on which stage of infection the person is in.

Early infection:

When a person first becomes infected with HIV, there are no signs and symptoms at all, although it is common to have the person develop a brief flu-like illness two to four weeks after becoming infected. Early signs and symptoms may include: fever, headache, sore throat, swollen lymph vessels, and rash. GI complaints include change in bowel and bladder function, especially diarrhea. Cutaneous complaints are common and include: dry skin, new skin rashes, and nail bed changes. Because these are very common and present in a number of other diseases, a combination of complaints is more suggestive of HIV infection than any one sign/symptom. In addition, many people with HIV present with back pain, but the underlying cause may differ from person to person. Back pain may be due to: muscle weakness and atrophy that occurs as a result of the disease process. Back muscle weakness and atrophy can alter the person's normal postural alignment and may cause subsuquent backpain as well as a person's response to their medications may contribute to back pain as well. It has been reported that back pain is more likely to occur when the bodies T-cell count drops. Eventhough, the person may or may not exhibit symptoms they can still transmit the virus to others. Once, the virsus enters the person's body, the person's immune system comes under attack. The virus then starts to multiply in the person's lymph nodes and slowly degins to eradicate the helper T- cells, the white blood cells that help the immune system.

Later infection:

A person may remain symptom free for as long as 8-9 years, but as the virus continues to multiply and destroy immune cells, the person may begin to develop chronic symptoms and or acquire mild infections. Chronic symptoms seen in this stage are but not limited to the following: swollen lympth nodes-which is often one of the first signs of HIV infection, diarrhea, weight loss, fever, cough and shortness of breath.

Latest phase of infection:

Usually, after a person has been infected with HIV for 10 years or more the last phase of HIV conmenses. More serious symptoms of the virus start to appear and the infection may then meet the offical definition of AIDS. Some of the signs/symptoms of later infection are: Kaposi's sarcoma, multiple purple blotches and bumps on skin, HTN (pulmonary and or cardiac), dyspnea, syncope, chest pain, non-productive cough, easy bruising, thrush, muscle atrophy and weakness, back pain, poor wound healing, HIV related dementia (memory loss, confusion, behavioral change, imparired gait), and distal symmetric polyneuropathy (pain, numbness, tingling, burning, weakness, and atrophy).    By the time AIDS develops, the person's immune system has been severly damaged, making the person susceptible to many opportunistic infections such as TB, Pneumocystsis carinii, pneumonia, lymphoma, thrush, herpes 1 and 2, toxoplasmosis and cansisiasis. They are called "opportunistic" infections or diseases because they take advantage of the compromised immune system to infect and destroy the person's body. Under normal conditions, a person would not be affected to the degree of severity they are under the presence of these infections with normal immune function.  The signs and symptoms of some of these infections may but not limited to the following: soaking night sweats, shaking chills or fecer higher than 100 degrees F (38 C) for several weeks, dry cough and shortness of breath, chronic diarrhea, persistant white spots or unusual lesions on the person's tongue or in thier mouth, headeaches, blurred and distorted vision, weight loss. In 1993, the CDC redefined AIDS to mean the presence of HIV infection as shown by a positive HIV antibody test with the presense of at least one of the following:

The development of an oppertunistic infection-an infection that occurs when your immune system is impaired such as Pneumocystis Carinii Pneumonia (PCP)

A CD4 lymphocyte, helper T cell count of 200 or less. Normal count ranges from 800 to 1,200.

Associated Co-morbidities

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Medications

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Diagnostic Tests/Lab Tests/Lab Values

Screening for AIDS is done by a fingerstick blood test. The blood test looks for the presence of antibodies to HIV-1. The test only indicates if person has been exposed to the virus. A new quick test has been developed called the OraQuick Rapid HIV Antibody Test and it is almost 100% accurate and the results are available in 20 minutes. A positive OraQuick test requires additional confirmation testing.

Causes

Around the late 1970's and 80's doctors began noticing that an increasing number of people were suffering from serveral unusual and rare illnesses. At first, little was known about what was happening to these inital victims of AIDS. Doctors were unsure as to what was causing the condition. Many of the first people diagnosed with this strange new condition were homosexual men and because of this the condition was labeled GRID, gay related immunodefiency. However, the condition soon started showing up in men and women intravenous drug users and hemophiliacs. The first reported AIDS cases were in the United states in 1981. 1983, the Institut Pasteur in France regonized that the virus that was causing so much panic was the result of AIDS. The virus that resulted from AIDS was then named HIV, human immunodefiency virus. Researchers in France, now understood that the virus passed from each person via the exchange of semen, blood and or vaginal secreations during sexual contact. Researchers also learned that AIDS weakens the immune system by destroying the bodies white blood cells specifically the helper T-cells. Helper T- cells help the body fight off viruses and bacteria that enter the body. In 1985 another breakthrough took place, a blood test for the presence of HIV antibodies in the person's blood stream. The first smaple of HIV infected blood dates back to 1959 but computer analysis dates the emergence date back to the 1930's.  

There has been many theories and much speculation as to where the AIDS virus first orginated. AIDS used to be a very rare and isolated virsus that affected a few types of monkeys and chimpanzees in Africa. AIDS is related to another virus, Simian Immunodefiency virus that affects monkeys and apes. It was thought that humans were first exposed to AIDS when they caught the monkeys for food and kept them as pets and or if they were scratched and bitten by an infected moneky/ape.

We now know that AIDS is caused by the spread of the HIV virus. The virus is spread though sexual contact, needles, or a syringe that is shared by intravenous drug users; transfusion of infected blood or blood products; or perinatal transmission from infected birthing or breastfeeding a child from an infected mother. HIV is not transmitted through casual contact such as: the shared use of utensils, food, cups, towwls, razors, toothbrushes or even kissing. Transmission always involves exposure to some body fluid from an infected client. The greatest concentrations of the virus have been found in blood, semen, cerebrospinal fluid, and cervical/vaginal secreations. HIV has been found to be in low concentrations in tears, saliva, and urine, but no cases of transmisson have been reported via these routes. The primary cause of AIDS is the type 1 retrovirus or HIV and transmission of the HIV virus happens with partaking in high risk behaviors. High risk behaviors are defined and include: unprotected anal and oral sex, having 6 or more sexual partners in the past year, sexual activity with someone known to carry HIV, exchanging sex for money or drugs and  injecting drugs.   

Population groups at the greatest risk are: commercial sex workers (prostitutes) and their clients, homosexual men, injection drug users, blood recipients, dialysis recipients, organ transplant recipients, and fetuses of HIV infected mothers, and people with other sexually transmitted diseases. People who already have a sexually transmitted disease are 3-5 times more likely to come in to contact with the HIV virus compared with people without STDs. Transmission of HIV varies by gender. In 2004, 57% of male infections were related to men who had sex with other men, 19% were related to injection drug users, and 17% were related to heterosexual sex. For females in 2004, 70% of new HIV infections were related to heterosexual sex and 29% resulted from injection drug use.

Systemic Involvement

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Medical Management (current best evidence)

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Physical Therapy Management (current best evidence)

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Alternative/Holistic Management (current best evidence)

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Differential Diagnosis

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Case Reports

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Resources

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Recent Related Research (from Pubmed)

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References

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