The human immunodeficiency virus, also known as HIV infection, is a retrovirus that causes AIDS (acquired immune deficiency syndrome). The retrovirus primarily attacks the body's immune system, making the patient extremely vulnerable to opportunistic infections (infections that occur in individuals with weakened immune systems).
HIV is transmitted from person to person via bodily fluids including blood, semen, vaginal discharge, and breast milk. It can be spread by sexual contact with an infected person, by sharing needles/syringes with someone who is infected, or, less commonly (and rare in countries, such as the United States, where blood is screened for HIV antibodies), through transfusions with infected blood. HIV has also been found in saliva and tears in very low quantities in some AIDS patients. However, contact with saliva, tears, or sweat has never been shown to result in HIV transmission.
Although healthcare workers are exposed to the virus at work, it is unlikely that they will acquire the virus from a patient, especially if they follow universal precautions, which should be taken with all patients. Healthcare personnel should assume that the blood and body fluids from all patients are potentially infectious.
Since December 2001, there have been 57 documented reports of healthcare workers acquiring HIV from a patient. To prevent transmission of HIV to healthcare personnel in the workplace, the U.S. Centers for Disease Control and Prevention (CDC) offers precautionary guidelines.
For healthcare workers, the main risk of HIV transmission is through accidental injuries from needles or other sharp medical instruments that may be contaminated with the virus. However, even this risk is small. Researchers estimate that about 0.3-1% of healthcare workers exposed to the virus by an accidental needle stick or puncture develop HIV.
This is largely because action can be taken to reduce the risk of transmission immediately after exposure. Healthcare workers who are exposed to the virus can receive post-exposure prophylaxis (PEP), which consists of antiretroviral therapy (ART) to prevent the individual from acquiring HIV. However, antiretrovirals can have serious side effects and patients should evaluate the risks and benefits with their healthcare providers.
Current antiretroviral drugs cannot cure HIV infection or AIDS, and they cannot reduce the risk of transmitting disease to someone else. They can suppress the virus, even to undetectable levels, but are unable to completely eliminate HIV from the body.
RISKS OF TRANSMISSION
Most cases of HIV transmission in occupational settings occur after exposure to HIV-infected blood by a percutaneous injury on the skin. This is most commonly caused by needles, medical instruments, or bites that break the skin. Researchers estimate that about 0.3-1% of healthcare workers who were exposed to the virus via a needle stick or puncture develop HIV.
The virus can also be transmitted if blood from an HIV patient's open sore or wound comes into contact with an open sore or wound on the healthcare provider.
There are a small number of instances when HIV has been acquired through contact with mucous membranes (like the eyes). For instance, if an HIV patient's blood splashes into a healthcare worker's eye, there is a chance of transmission. Research suggests that the risk of HIV infection after mucous membrane exposure is less than 1 out of 1,000.
MANAGEMENT IMMEDIATELY AFTER EXPOSURE
Healthcare workers who are exposed or suspect they were exposed to HIV should follow the protocol of their healthcare facilities.
First Aid should be provided immediately after the injury. Wounds and areas of skin that were exposed to body fluids should be washed thoroughly with soap and water. Mucous membranes (like the eyes) that were exposed to the virus should be flushed with water.
The exposure should be evaluated for potential to transmit HIV infection, based on the severity of exposure (how much bodily fluid the person came into contact with) and specific bodily fluid that the individual was exposed to.
The exposed healthcare worker should be tested for HIV infection if he/she consents to testing. However, it generally takes about two to eight weeks for the body to produce antibodies to the virus, which is needed for an accurate test result. It may take some patients three months or longer to develop the antibodies. Therefore, a protocol called post exposure prophylaxis (PEP) should be provided within 72 hours of exposure if the individual was exposed to an HIV-infected patient or if it is strongly suspected that the patient is HIV-positive.
The patient who is suspected of having HIV should only be tested after obtaining informed consent. Testing should also include appropriate counseling and care referral. The test results must remain confidential.
Exposure risk reduction education should occur with counselors who are evaluating the events that preceded the exposure.
An exposure report should be made and sent to the U.S. Centers for Disease Control and Prevention (CDC).
POST-EXPOSURE PROPHYLAXIS (PEP)
Post-exposure prophylaxis (PEP) is short-term antiretroviral treatment that is administered to reduce the likelihood of HIV infection after potential exposure. Healthcare facilities should provide treatment to personnel as part of a universal precautions program that is designed to reduce staff exposure to infectious hazards at work.
It is estimated that PEP can reduce the rate of infection among exposed healthcare workers by as much as 79%. According to the World Heath Organization (WHO), availability of PEP to healthcare workers will help increase staff motivation to work with HIV-infected patients, and may help to retain staff who are worried about the risk of HIV exposure at work.
PEP should begin as soon as possible after exposure. While there is no time limit in most country recommendations, treatment is most effective when it is initiated within two to four hours of exposure. Combination therapy, usually with two or three antiretrovirals, is recommended because it has shown to be more effective than a single agent.
The specific regimen and dosage depends on the patient's overall health, severity of exposure, availability of antiretrovirals, and known or possible cross-resistance to different drugs. In general, the recommended combination therapy is 250-300 milligrams of zidovudine (Retrovir©) twice daily with 150 milligrams of lamivudine (Epivir©) twice daily. If a third drug is needed, 800 milligrams of indinavir (Crixivan©) three times daily or 600 milligrams of efavirenz (Sustiva©) once daily (not recommended for pregnant women) is recommended.
Treatment should last a minimum of two weeks and no longer than four weeks. Healthcare workers should have access to one month's worth of antiretroviral therapy.
There are many side effects of antiretroviral treatment, including dizziness, confusion, fatigue, headache, difficulty sleeping, nausea, vomiting, and diarrhea. Studies have shown that about 22% of those receiving PEP stopped taking the medications before the four-week course is completed because of the side effects. Treatment is less effective if discontinued prematurely.
Long-term side effects may cause serious medical problems, including changes in metabolism like abnormal lipid and glucose metabolism, which may cause changes in the body shape due to loss and/or accumulation of body fat.
NON-OCCUPATIONAL POST EXPOSURE PROPHYLAXIS (NPEP)
In January 2005, the U.S. Department of Health and Human Services (DHHS) announced that non-occupational post exposure prophylaxis (nPEP) should be available to all individuals who are exposed to HIV, not just healthcare workers.
While the DHHS does not recommend for or against the use to nPEP, it encourages healthcare providers and patients to weigh the risks and benefits with individual patients who may have been exposed to HIV in the last 72 hours. When the risk of transmission is negligible or when patients seek care more than 72 hours after a substantial exposure, nPEP is not recommended because it is not usually effective. The sooner treatment is started, the more likely it will prevent HIV transmission.
However, healthcare providers might wish to consider prescribing nPEP for patients who seek care more than 72 hours after substantial exposure if the benefit of treatment outweighs the risks for side effects from treatment.
Treatment should last a minimum of two weeks and no longer than four weeks. Treatment is less effective if discontinued prematurely.
General: As soon as the virus enters the body, the immune system produces antibodies, which are chemicals that locate invaders and fight off infections. While these antibodies cannot successfully destroy the virus, their presence can be used to detect whether HIV is in the body.
It can take some time for the immune system to produce enough antibodies for the antibody test to detect them. This time period, known as the "window period," varies greatly among patients. Most people will develop detectable antibodies within two to eight weeks (the average is 25 days). However, some individuals might take longer to develop detectable antibodies. Ninety-seven percent of people develop antibodies in the first three months following the time of their infection. In very rare cases, it can take up to six months to develop antibodies to HIV. Therefore, if the initial negative HIV test was conducted within the first three months after possible exposure, repeat testing should be considered at a time longer than three months after the exposure.
Enzyme immunoassay (EIA): The most common HIV tests use blood to detect HIV infection. In most cases, the enzyme immunoassay (EIA) is used to look for antibodies to HIV. A positive (reactive) EIA must be used with a follow-up (confirmatory) test, such as the Western blot test, to make a positive diagnosis. A positive diagnosis means that a person is infected with HIV.
Western blot test: A Western blot test is typically used to confirm a positive HIV diagnosis. During the test, a small sample of blood is taken and used to detect HIV antibodies (not the HIV virus).
Saliva or urine: Tests using saliva or urine are also available. This saliva or urine test is similar to the standard blood EIA test. However, they tend to be less sensitive and accurate than blood and oral fluid tests. A follow-up confirmatory Western Blot uses the same sample.
Oral fluid test: An oral fluid test involves oral fluid (not saliva) that is collected from the patient's gums. This oral fluid test is similar to the standard blood EIA test. A follow-up confirmatory Western Blot uses the same oral fluid sample.
RNA tests look for genetic material of HIV. These tests can be used to screen the blood supply and to detect very early infection in those rare cases when antibody tests are unable to detect antibodies to HIV.
Rapid test: A rapid test produces results in about 20 minutes. Rapid tests use blood from a vein or from a finger stick or oral fluid to look for HIV antibodies. A positive HIV test should be confirmed with a follow-up confirmatory test before a final diagnosis of infection can be made. These tests have similar accuracy rates as traditional EIA screening tests.
Home testing kit:
Consumer-controlled test kits (popularly known as "home testing kits") were first licensed in 1997. The Home Access HIV-1 Test System© is the only home kit that is approved by the U.S. Food and Drug Administration (FDA). The Home Access HIV-1 Test System© is sold at most local drug stores. It is not a true home test, but rather a home collection kit. The test involves pricking a finger with a special device, placing drops of blood on a specially treated card, and then mailing the card in to be tested at a licensed laboratory. Customers receive an identification number to use when calling for the results. Callers may speak to a counselor before taking the test, while waiting for the test result, and/or after the results are given. All individuals who receive a positive test result are given referrals for a follow-up confirmatory test, as well as information and resources on treatment and support services.
POLICIES FOR HEALTHCARE FACILITIES
Institutional guidelines: Institutional guidelines for post-exposure prophylaxis (PEP) should be well established in all healthcare facilities. HIV testing, counseling, and antiretrovirals must be available. All healthcare facilities should train personnel on proper infection control procedures and on the importance of reporting occupational exposures to HIV. These facilities should also develop a system to monitor reporting and management of occupational exposures.
Safety devices: Effective safety devices that can help prevent injuries from needles and other sharp objects used in the hospital should be available. For instance, some needles have built-in safety controls that help reduce the risk of needlestick injuries before, during, or after use. Proper and consistent use of such safety devices should be evaluated.
Monitor the effects of PEP: More data are needed about the safety and efficacy of PEP regimens, especially those regimens that include new antiretrovirals. Improved communication about potential side effects before PEP is started and close follow-up of healthcare workers who are receiving treatment are needed to increase compliance with the PEP.
UNIVERSAL PRECAUTIONS TO PREVENT EXPOSURE
Universal precautions are precautions that are taken with all patients. Healthcare personnel should assume that the blood and body fluids from all patients are potentially infectious. Since everyone is treated the same, healthcare providers do not have to make assumptions about the risks of infection.
The U.S. Centers for Disease Control and Prevention (CDC) recommends that healthcare providers routinely use barriers (like gloves and/or goggles) when contact with blood or body fluids is possible.
If the skin comes into contact with blood or other body fluids, the area should be washed thoroughly with soap and water.
Mucous membranes (like the eyes) that were exposed to the virus should be flushed with water.
Cuts, sores, or breaks on the exposed skin of both the caregiver and patient should be covered with bandages.
Needles and other sharp instruments should be used only when medically necessary and handled appropriately.
Medical instruments and other contaminated equipment should be disinfected.
Safety devices that have been developed to help prevent needlestick injuries should be used whenever possible. For instance, some needles have built-in safety controls that reduce the risk of needle stick injury before, during or after use. If used properly, these types of devices may reduce the risk of exposure to HIV.
Many skin injuries in healthcare settings are related to the disposal of sharp medical equipment. Strategies for safer disposal, including safer design of disposal containers and placement of containers, are currently being developed.
This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).
- AIDS.org. www.aids.org. Accessed April 3, 2007.
- AVERTing HIV and AIDS. www.avert.org. Accessed April 3, 2007.
- Centers for Disease Control. www.cdc.gov. Accessed April 3, 2007.
- National Guideline Clearinghouse. www.guideline.gov. Accessed April 3, 2007.
- Natural Standard: The Authority on Integrative Medicine. www.naturalstandard.com. Copyright © 2007. Accessed April 3, 2007.
- World Health Organization. www.who.int. Accessed April 3, 2007.
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