Patient information: Blood and body fluid exposure

BLOOD AND BODY FLUID EXPOSURE OVERVIEW

Although more than 200 different 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. Experts have worked to determine the best advice for these situations. However, these guidelines are based upon studies of exposure to bodily fluids within the healthcare system, from needlestick and other exposures of healthcare workers.

This topic review discusses the definition of exposure, the risk of infection, and treatment and follow up recommendations for non-healthcare workers. Recommendations for a person who is exposed to blood or body fluids during a rape or sexual assault are discussed separately. (See "Patient information: Care after sexual assault".)

DEFINITION OF BLOOD OR BODY FLUID EXPOSURE

In order to be exposed to a bloodborne pathogen, you must have contact with blood, a visibly bloody fluid (eg, phlegm or urine containing blood), or another bodily fluid (eg, 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 bloodborne pathogen is possible after:

• A skin injury such as a needlestick or cut with a sharp object
• Contact with a mucous membrane (including exposure through sexual intercourse, especially if an ulcer is present or vaginal tissues are injured) or non-intact skin

RISK OF INFECTION AFTER BLOOD OR BODY FLUID EXPOSURE

Needlestick — Hepatitis B virus (HBV) is the most infectious virus that can be transmitted through the blood or bodily fluids. A healthcare worker who is stuck with a needle containing blood infected with HBV has between a 6 and 30 percent chance of developing HBV. The risk of HCV and HIV in the same situation is 1.8 and 0.3 percent, respectively. This means that 3 people in 1000 who are stuck with a needle containing blood infected with HIV may develop HIV themselves.

Other factors influence the risk of becoming infected, including the amount of blood or bodily fluid involved, the depth of penetration, and the amount of virus in the source's blood or body fluid. It is possible to reduce the risk of becoming infected with hepatitis B and HIV after exposure. (See 'What do I do after blood or body fluid exposure?' below.)

Mucous membrane — The risk of becoming infected from a mucous membrane exposure (mouth, vagina, rectum) is more difficult to define. When healthcare workers were followed after mucous membrane exposure to HIV, no cases of HIV were identified among those who had been exposed. However, no other explanation for HIV has been found in a few cases where mucous membrane exposure occurred in a work setting. This has led most experts to believe that the risk of acquiring HIV following a mucous membrane exposure is quite small, but the risk is not zero.

One versus multiple exposures — There is also a difference in terms of risk if the individual has a one-time exposure or has multiple exposures. Thus, the risk of infection for the victim of a single sexual assault is far less than that of a regular sexual partner of an infected person.

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 bloodborne infection.

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 B vaccine — The hepatitis B vaccine may be given to anyone who is exposed to blood, even if the blood is not known to carry HBV. The vaccine should be given at the time of exposure, and repeated one month and six months later to fully protect you against future infection. (See "Patient information: Hepatitis B".)

Many people have previously received the series of three HepB vaccines. In this case, some experts recommend a single booster dose of the vaccine after being exposed to potentially infected blood.

Hepatitis B immune globulin — If the source of the blood is known to be positive for HBV and you have not previously had the hepatitis B vaccine, treatment with hepatitis B immune globulin (HBIG) is recommended. HBIG contains antibodies that provide temporary protection against the infection. HBIG is an injection, which should be given as soon as possible after exposure, preferably within 24 hours. A dose of hepatitis B vaccine is recommended at the same time.

HBIG is not needed your were previously vaccinated with HepB vaccine. If you are unsure if you had the series of three HepB vaccines, you can have a blood test to determine if there are adequate levels of antibodies to the virus. If antibody levels are low, HBIG and the series of three HepB vaccines are recommended.

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.

Symptoms of hepatitis C include loss of appetite, nausea, abdominal pain, darkening of urine, light stools, or jaundice (yellowing of the skin or whites of the eye). (See "Patient information: Hepatitis C".)

Human immunodeficiency virus (HIV) — Treatments are available to reduce the risk of becoming infected with HIV after exposure. One study suggested that the use of an anti-HIV medication, zidovudine (ZDV), reduced the already low risk of healthcare workers becoming infected with HIV by about 81 percent. This means that the number of people who are likely to become infected from a needlestick that contains HIV-infected blood can be reduced from 3 in 1000 to 0.5 in 1000 as a result of taking anti-HIV medication.

The risk of becoming infected with HIV as a result of other types of exposure (eg, trauma, rape) is probably even lower than the risk of infection after a needlestick. (See "Patient information: Care after sexual assault".)

However, it is often difficult to know if a person (the source of the blood) has HIV. In some situations, it is possible to test the person for HIV later. However, treatment is available even if the person's HIV status cannot be determined.

The benefits of post-exposure treatment (eg, reduced risk of infection) must be weighed against the risks (eg, side effects of treatment, interactions with other medications, cost of treatment). All women of childbearing age should be tested for pregnancy before beginning treatment, although being pregnant does NOT mean that a woman cannot take anti-HIV medications. 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 postexposure (table 1). (See "Patient information: HIV and pregnancy".)

Recommendations — 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 (eg, from a sharp or needle)
• One or more of the following bodily fluids was 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. In all situations, regardless of whether treatment is used, it is important to follow strategies to prevent further spread of the potential infection (see 'Protecting others after exposure' below.

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.

Anyone who is exposed to blood or bodily fluids should consult with a healthcare provider if symptoms of fever, swollen lymph nodes (glands), sore throat, skin lesions, muscle or joint pain, diarrhea, headache, nausea/vomiting, or weight loss develop. The usual time from HIV exposure to the first symptoms of HIV is two to four weeks. (See "Patient information: Symptoms of HIV infection".)

Treatment regimen — Anti-HIV preventive treatments should be started as soon as possible after exposure, within a few hours rather than days. Animal studies suggest that the longer treatment is delayed, the less effective it is. Preventive treatment is not likely to be helpful and is not recommended if more than 72 hours have elapsed since exposure.

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 (table 2). The optimal length of preventive treatment is unknown, although four weeks is generally recommended. Tips for taking HIV medications are available separately. (See "Patient information: Tips for taking HIV medications".)

The cost of preventive HIV treatment is at least $1000 in the United States; not all commercial health insurance companies will cover this cost. It is also important to be aware of the potential side effects of these drugs, possible interactions with other medications, and the proper timing of doses. Because there are a variety of medications and combinations, it is best to discuss these issues with the person who prescribes them. In all cases, it is crucial to take all of the medication exactly as directed.

FOLLOW-UP

Testing — Follow-up testing for hepatitis B, hepatitis C, and HIV should be performed after possible exposure (see above for specific recommendations on frequency of testing). For people who are given the hepatitis B vaccine, it is important to return for the second and third injection to be completely protected.

People exposed to a bloodborne infection during sex are often tested for other sexually transmitted diseases (STDs). In particular, blood tests for syphilis and cultures for gonorrhea and chlamydia are usually performed immediately after exposure and four to six weeks later (table 1).

Anxiety — It is common to feel anxious or scared after being exposed to blood or bodily fluids. These fears are normal but can interfere with your ability to concentrate on normal day to day responsibilities.

However, the risk of becoming infected with hepatitis B, C, and HIV is small in most cases. Following the advice provided here can further decrease the risks. Counseling may be helpful for people who have difficulty coping, especially during the first few weeks and months after exposure.

PROTECTING OTHERS AFTER EXPOSURE

Anyone exposed to a bloodborne pathogen should understand the importance of preventing the spreading of their potential infection to others (for example, family members, sexual partner(s), or a breastfeeding child) during the follow-up period. These measures are especially important during the first three months after exposure, when most people who are infected with HIV become antibody positive.

Precautions include abstaining from sexual intercourse or using condoms every time. Condoms reduce, but do not completely eliminate, the chances of transmitting hepatitis B, hepatitis C, or HIV infection to others. Women who have been exposed to blood or body fluids from a person known to be infected should avoid becoming pregnant during this time.

Individuals who were exposed to HIV-infected fluids should not donate blood, plasma, organs, tissue, or semen during the follow-up period. Women who are breastfeeding should stop breastfeeding due to the risk of passing the infection to their child.

WHERE TO GET MORE INFORMATION

Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two people are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.uptodate.com/patients). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

Some of the most pertinent include:

Patient Level Information:
Patient information: Care after sexual assault
Patient information: Hepatitis B
Patient information: Hepatitis C
Patient information: HIV and pregnancy
Patient information: Symptoms of HIV infection
Patient information: Tips for taking HIV medications

Professional Level Information:
Evaluation and management of sexual assault victims
Management of healthcare workers exposed to hepatitis B virus or hepatitis C virus
Management of healthcare workers exposed to HIV
Nonoccupational exposure to HIV in adults

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable.

• National Library of Medicine

      (www.nlm.nih.gov/medlineplus/healthtopics.html)

• Centers for Disease Control and Prevention (CDC)

      Toll-free: (800) 311-3435
      (www.cdc.gov/ncidod/dhqp/bp.html)

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