Testing for HIV/AIDS
Let’s begin this section of the course with some general information about HIV testing in the United States.
- 54% of American adults have had an HIV test.
- According to AVERT, white Americans are the least likely to have taken an HIV test.
- Immigrant mandatory testing ended in 2010.
- All military personnel are required by law to be tested.
- And in certain states, prison inmates are required by law to be tested.
- HIV testing is done to diagnose those who are newly infected, to identify previously unrecognized infections, and to relieve the minds of those who are not infected.
- It is critical that pregnant women be tested because medications are very effective in reducing transmission of HIV from mother to baby.
- HIV testing is usually a two-step process. The first step is to test for antibodies in blood or saliva. If the test is positive, a second test called a Western blot is done to ensure that the first result was correct.
- If both tests (antibody and Western blot) are positive, the chances are >99% that the patient is infected with HIV.
- HIV antibody tests may miss some infections, resulting in false-negative tests. This often occurs soon after infection when antibodies are just starting to form and are at a level too low to be detected (within about four weeks of infection).
- There are free HIV testing locations in every state.
Over the years, the most common problem and anxiety involved with HIV testing revolved around the length of time that was required for test results. The waiting time of two weeks minimum resulted in not only great anguish for the individual being tested, but also a significant amount of individuals never returned for the results which historically were required to be given in person. As as result of individuals not returning for results, medical testing facilities were spending great amounts of time working to contact individuals to return for test results.
Over time, testing and result time frames have changed significantly and we will cover the most recent updates in this section.
Most common HIV tests look for HIV antibodies in the system and not HIV itself. Below are various tests that can be performed and the time frames for their results:
- EIA (enzyme immunoassay test) – usually requires two weeks for results and utilize blood, oral fluid or urine.
- Rapid HIV antibody test – results are ready in 10-20 minutes and also use blood, oral fluid and urine for testing. This test is performed in a physician’s office or other points of care.
- Antigen test – this test is not used very often, but can detect HIV much earlier (1-3 weeks post infection) and must utilize blood for testing.
- PCR test (Polymerase chain reaction test) – tests the genetic material of HIV itself and recognizes HIV in the blood within 2-3 weeks of infection. PCR is used for newborns whose mother is HIV positive and rules out the mother’s antibodies which remain in the body of the newborn for several months post birth. The PCR is also used to test blood supplies like those of the Red Cross. PRC testing is used for HIV positive individuals to determine the “viral load” or level of infection.
- Home Access HIV-1 Test System – this home testing kit is approved by the FDA. The test is not a true test, but is a collection kit by means of a finger stick. The kit must be sent into lab to obtain results.
- Western Blot Test – this is the 2nd test required for all tests to confirm results. Two weeks are required for results even though the test only takes one day. Most labs do not run these tests everyday which produces a lag time for results.
Treatment and Disease Management
To be very clear, there is no cure for HIV/AIDS. The human body is not capable of ridding itself of the virus and medical science has only been able to develop drugs that help to control the virus. Because there is no known cure for HIV, a single drug is not able to stop HIV from harming the body.
In 1987, the government approved the first drug for use to fight HIV. AZT, azidothymidine, was the first U.S. government-approved treatment for HIV. AZT was marketed under the brand name Retrovir. AZT, as the first breakthrough in AIDS treatment, significantly reduced the replication of the virus in patients and led to clinical and immunologic improvements. By 2009 more than 30 drugs had been approved to treat HIV/AIDS patients.
Due to the mutations of the virus, a combination of drugs makes it less likely that the virus can make copies of itself and stop responding to medication. A combination of 3 drugs has proven to do the best job of “controlling” the viral load or level of infection and protecting the immune system. Common names you may have heard for HIV drugs include: “The Cocktail”; ARVs (antiretrovirals); and HAART (highly active antiretroviral therapy).
HIV drugs are divided into 5 classes based on how each class affects the virus at different points in its lifecycle. The typical HIV patient will take a variety of 3 antiretroviral drugs from 2 different classes. The classifications of the medications (antiretrovirals) are determined by the way that the medication stops HIV from replicating itself.
HIV Medication Classes:
- Nukes (slang) – NRTIs (Nucleoside/Nucleotide Reverse Transcriptase Inhibitors): The medication works by acting as a “faulty” building block of viral DNA production which is a very important step in HIV’s reproduction process. The faulty building block inhibits HIV from using the enzyme, reverse transcriptase, to accurately develop the genetic material that HIV needs to reproduce itself.
- Non-Nukes (slang) – NNRTIs (Non-nucleoside Reverse Transcriptase Inhibitors): Nukes and non-nukes work in very similar ways, except nukes work on genetic material and non-nukes work specifically on the enzyme (reverse transcriptase) to interrupt accurate function.
- PIs (Protease Inhibitors): HIV creates long strands of its own genetic material and to replicate itself, it must have the ability to cut those long strands of genetic material into smaller pieces. Protease is the enzyme that acts as the cutting agent to help HIV multiply or cut the strands. So, protease inhibitors stop the protease from cutting the strands and therefore, block HIV from replicating itself.
- Entry/Fusion Inhibitors: HIV must have a way to attach and bond with CD4 cells in the body. The attachment and bonding occurs through locations/structures on cells called “receptor sites”. HIV and CD4 cells both have these receptor sites. Entry/Fusion Inhibitors target HIV and/or CD4 cells and prevent the docking/bonding from occurring which in turn, blocks the virus from ever reaching the healthy cells.
- Integrase Inhibitors: The HIV virus utilizes the human cell’s genetic material to make its own DNA (a process called “reverse transcription”). For the virus to integrate its genetic material into the human genetic material, the enzyme known as “integrase is required. Integrase inhibitors prohibit the enzyme from integrating the HIV genetic material with the human genetic material, which prevents the virus from replicating.
One last medication we will cover is not a separate class but it is a combination of 2 or more medications from the 5 classes. The healthcare provider determines which of the medications a patient will benefit from and those antiretrovirals are combined into a single pill with fixed doses.
Unfortunately, many HIV patients have more than just the HIV medications prescribed by their physician as part of their overall treatment plan. Patients who are at increased risk for opportunistic infections may be prescribed medications to prevent specific infections. These preventative treatments are referred to as “prophylaxis”.
And lastly, most HIV patients receive medications to prevent the side-effects of other medications.
Due to the extremely high cost of treatment and care involved with HIV/AIDS, the financial burden on patients may be overwhelming. Fortunately, the “National HIV/AIDS Strategy” put a huge emphasis on the “Affordable Care Act” (ACA) to make future provisions for HIV treatment, including, increased Medicaid eligibility and protection for pre-existing conditions to be covered.
Prevention Techniques in HealthCare and Physical Therapy and Emergency Precautions
The most safe attitude a healthcare worker can maintain is that all blood and other bodily fluids from patients can be potentially infectious. AIDs.gov gives a few generic precautions that healthcare workers should follow when there is the potential for interaction with patient bodily fluids and blood. These are:
- Routinely use barriers (gloves, goggles) when anticipating contact with bodily fluids.
- Immediate hand washing and washing of other skin surfaces after contact with blood or bodily fluids.
- Careful handling and disposing of sharp objects.
The Centers for Disease Control established guidelines for healthcare workers in dealing with blood and bodily fluids that are considered “Universal Precautions” which are widely used in the healthcare arena and should not be overlooked. The precautions are listed below:
- Use protective barriers when handling blood, bodily fluids and other infectious fluids.
- Wash hands and mucous membranes.
- Prevent needle sticks.
- Use ventilation devices for resuscitation.
- Do not treat a patient with HIV/AIDS if you have open wounds or skin lesions until lesions have healed.
- If pregnant, take extreme precautions.
The CDC issued extensive guidelines in 2005 for the management of health care worker exposures to HIV and recommendations for post-exposure prophylaxis which can be found at http://www.jstor.org/stable/10.1086/672271
Here are suggestions that should help to prevent accidental exposures:
- Do not recap needles by hand.
- Dispose of used needles in sharps containers.
- Use medical devices with safety features designed to prevent injuries.
- Use of appropriate barriers including gloves, eye and face protectors and gowns.
Emergency Exposure Techniques
To be very clear, most healthcare exposures do not result in infections, but it is important for the healthcare worker to be aware of ways they can become infected and emergency procedures to employee if an accidental exposure does occur. The majority of healthcare exposures occur through needle sticks or cuts from sharp instruments that have been contaminated with an infected person’s blood or contact of the eye, nose, mouth, or skin with the patient’s blood.
Below are some infection statistics provided by the CDC:
- The average risk of HIV infection after a needle stick or cut is 0.3% (1 in 300).
- The risk of exposure of the eye, nose, or mouth to HIV is 0.1% (1 in 1000).
- The risk after exposure to non-intact skin to HIV infected blood is estimated to be < 0.1%.
- Since 1985, there have been 143 possible exposures reported and only 57 of those have been documented to convert to HIV.
- There have been no confirmed exposures that have converted to HIV since 1999.
It is important to note that the risk of infection may vary depending on a variety of factors:
- the pathology involved
- the type of exposure
- the amount of blood involved in the exposure
- the amount of virus in the patient’s blood at the time of exposure
The CDC has provided an emergency procedure to follow if a needle stick exposure occurs and we will provide this procedure verbatim from the CDC.
“If you experience a needle stick or sharps injury or were exposed to the blood or other bodily fluid of a patient during the course of your work, immediately follow these steps”
- Wash needle sticks and cuts with soap and water.
- Flush splashes to the nose, mouth, or skin with water.
- Irrigate eyes with clean water, saline or sterile irrigants.
- Report the incident to your supervisor.
- Immediately seek medical attention.
There is no vaccine that can prevent HIV or AIDS, but Post-exposure prophylaxis (PFS) is recommended for any occupational exposures. The Public Health Services recommends a 4-week course of a combination of either two antiretroviral drugs for most HIV exposures, or three antiretroviral drugs if exposure may pose a greater risk for transmitting HIV. Treatment for exposure should start ASAP (within hours).
Medical Providers Please Note: If you have questions about appropriate treatment for occupational exposures, assistance is available from the Clinician’s Post Exposure Prophylaxis (PEP) Line at 1-888-448-4911 or http://www.nccc.ucsf.edu/