Post-exposure Prophylaxis (pep)
PEP is any prophylactic (preventive) treatment started immediately after exposure to blood or bodily fluid contaminated with a pathogen (such as a disease-causing virus), in order to prevent infection and the development of disease.
Although multiple diseases can be transmitted from exposure to blood, the most serious infections are hepatitis B virus (HBV), hepatitis C virus (HCV), and HIV. Fortunately, the risk of acquiring any of these infections is low.
In order to be exposed to a blood borne pathogen, you must have contact with blood, a visibly bloody fluid (i.e., phlegm or urine containing blood), or another bodily fluid (i.e., semen or vaginal secretions) that contain an infectious organism (virus or bacteria). The blood or fluid must come in direct contact with some part of your body. A virus can enter your body through the bloodstream, open skin, or mucous membranes, which include the eye, mouth, or genitals. Contact with skin that is intact (without new cuts, scrapes, or rashes) poses no risk of infection.
Thus, exposure to a blood borne pathogen is possible after:
A skin injury such as a needle stick or cut with a sharp object and/or contact with a mucous membrane (including exposure through sexual intercourse, especially if an ulcer is present or vaginal/rectal tissues are injured) or non-intact skin.
What do I do after blood or body fluid exposure?
Wash the area – The first and most important step after being exposed to blood or bodily fluids is to wash the area well with soap and water. You can clean small wounds and punctures with an antiseptic such as an alcohol-based hand gel, since alcohol kills HIV, hepatitis B virus, and hepatitis C virus. However, the alcohol may sting. For mucosal surfaces (mouth, nose), the area should be flushed with copious amounts of water. Eyes should be flushed with saline or water. There is no evidence that expressing fluid by squeezing the wound will further reduce the risk of blood borne infection.
What can the doctor do after implementing first aid measures?
Human immunodeficiency virus (HIV) – Treatments are available to reduce the risk of becoming infected with HIV after exposure. Previous studies have suggested that the use of an anti-HIV medication, reduced the already low risk of healthcare workers becoming infected with HIV by about 81% (but perhaps a higher rate of prevention with the new anti-HIV agents available). The risk of becoming infected with HIV as a result of other types of exposure (i.e., trauma, rape) is probably even lower than the risk of infection after a needle stick.
Anyone who is exposed to potentially infected blood or bodily fluids should be tested for HIV at the time of exposure (baseline) and at six weeks, three months, and six months post exposure. The baseline HIV test is necessary (and required) to document that the HIV infection was not already present at the time of the incident. Experts from the United States Center for Disease Control recommend use of medications to reduce the risk of HIV infection if all of the following criteria are met:
Exposure occurred less than 72 hours previously
One or more of the following areas were exposed: the vagina, rectum, eye, mouth, or other mucous membrane, open skin, through the skin (i.e., from a sharp object or needle)
One or more of the following bodily fluids were involved in the exposure: blood, semen, vaginal secretions, rectal secretions, breast milk, or any body fluid that is visibly contaminated with blood.
However, the CDC also recommends that each situation be considered on an individual basis; preventive treatment may be recommended to people who do not meet these criteria in some situations. The CDC recommends NOT using preventive treatment when: the exposure occurred more than 72 hours prior; when intact skin was exposed; or when the bodily fluid is urine, nasal secretions, saliva, sweat, or tears, and is not visibly contaminated with blood.
The Centers for Disease Control and Prevention (CDC) recommends a combination of two or three medications to prevent developing HIV after exposure; the best regimen should be determined by a healthcare provider who is experienced with HIV prevention and treatment regimens. The optimal length of preventive treatment is unknown, although four weeks is generally recommended.
Hepatitis B – The risk of becoming infected with hepatitis B is greater than the risk of becoming infected with other viruses. Fortunately, there is an effective vaccine that can help to prevent infection.
Hepatitis C – HCV can cause a form of hepatitis that leads to chronic liver disease. There is no known way to prevent this infection following exposure. Blood tests should be done immediately after exposure to measure your liver function and test for the presence of hepatitis C; the tests should be repeated after four to six weeks and again after four to six months, or sooner if symptoms of hepatitis develop. On an individual bases a physician may recommend anti-HCV treatment in patients recently infected with hepatitis C.