In this article, we'll discuss how you can minimize the risk of disease transmission if you or a coworker is accidentally exposed to blood or another potentially infectious body fluid. But first, let's review some key definitions.

Defining terms

Throughout this article, we refer to individuals with the terms source and exposed. For our purposes, the source is the patient whose blood or OPIM has come in contact with a healthcare worker, who is the exposed person. In some cases (such as a sharps injury to a healthcare worker during surgery) the healthcare worker and the surgical patient may be both source and exposed because their blood has mingled, but this unusual circumstance is beyond the scope of this article.

Now let's consider how to minimize the risk of disease transmission if you or a coworker is exposed to potentially infectious body fluid.

Accidents will happen: How to respond

Ada Collins, a nurse in your unit, was just stuck with a needle she'd used to administer a subcutaneous injection. In a panicky voice, she asks for your help. What should you do?

Rule one for responding to accidental exposure to blood or OPIM is to follow facility policy, which is based on guidelines from OSHA, the CDC, the Health Insurance Portability and Accountability Act (HIPAA), and state law. The general principles we discuss here apply at most facilities.

If you're at the scene of an exposure incident (or are exposed yourself), be aware of the emotional component of an occupational exposure. Knowing the risks, an exposed healthcare worker like Ada may panic. So the first step is to calm her by reminding her that disease transmission via blood or OPIM exposure is uncommon. She should take the following steps to minimize transmission risks after a potential exposure:

* If the potential exposure involves a needle stick, puncture injury, cut, or fluid contact with nonintact skin, wash the area with soap and water.

* In the case of a mucous membrane exposure, rinse the site with copious amounts of water or normal saline solution.

* Irrigate the eyes with commercially prepared isotonic solution in eye wash stations, if available, or with saline solution or clean water.

Because some decisions about PEP should be made within hours, urge Ada to immediately seek further care and counseling from the department in your facility responsible for managing occupational exposures, such as the occupational health, infection control, or employee health department. Support her by alerting her manager so her patient-care responsibilities can be delegated to others.

At this time, the source patient must be identified using at least two valid patient identifiers, such as his name, date of birth, or healthcare system medical record number. (These are the same patient identifiers you use before giving a medication.) The patient's room number isn't a valid patient identifier because patients can change rooms.

Occupational health personnel should follow these general guidelines to assess Ada's need for PEP.

Determine if a true exposure to blood or OPIM has occurred. For example, being splashed with blood or any fluid containing blood is considered a potential exposure. Being splashed with urine, feces, or vomitus is not, because these substances aren't OPIMs.

Evaluate the source. If the source patient's HIV, HBV, and HCV status are unknown, occupational health personnel can question him about his status and initiate testing. If he's known to be HIV positive, information should be gathered from him and the medical record about any current HIV antiretroviral therapy and its effectiveness, as determined by viral load or CD4 count.

The rapid HIV test can provide results in 20 to 40 minutes. This is ideal, because PEP for HIV infection should begin within 2 hours after exposure for best results. A negative rapid HIV test can ease the exposed person's anxiety and spare her from unnecessary PEP, which can cause significant adverse reactions.

If the test is positive, it should be confirmed with more definitive HIV testing. In the meantime, starting PEP is indicated for the exposed person. If the source's HIV status can't be quickly determined, the exposed person may start PEP and discontinue it later if the source is negative.

The rapid HIV test may produce a false-negative result if the source has been infected for less than 90 days, the time needed for his body to develop enough telltale antibodies. However, barring unusual circumstances, a negative rapid HIV test on the source is generally accepted as definitive.

Unlike HIV testing, HBV and HCV testing has never required a separate consent, and blood already drawn from the source patient may be used for testing. However, the patient could refuse to have additional blood drawn for testing, and drawing blood against his will could be considered assault.

Hepatitis C antibody testing, also known as an anti-HCV test, has a high false-positive rate, so a positive result must be confirmed with further testing. The preferred approach is to confirm with the recombinant immunoblot assay or HCV RNA. The advantage of the quantitative HCV RNA is that it reveals how infectious the person is, which helps clinicians counsel the exposed person. No PEP is available for HCV.

Assess and test the exposed person. Baseline assessment and testing for an exposed healthcare worker such as Ada is important to determine if she already harbors a bloodborne infection. Her history should include this information:

* current pregnancy or breast-feeding. Pregnancy testing should be considered for women of childbearing potential based on the healthcare professional's assessment of her exposure risk.

* medication reconciliation

* history of HBV vaccination and whether she developed an immune response (more on this shortly)

* history of any liver or kidney problems, dyslipidemia, anemia, pancreatitis, depression, or insomnia

* any other medical or occupational information that affects her risk of infection from bloodborne pathogens.

An exposed person who completed the vaccine series and was never tested for an immune response should have HBsAb and HbsAg testing, because either she may never have developed an immune response to the vaccine or she may be chronically infected with HBV.

If Ada completed HBV vaccination over 10 years ago and wasn't tested afterward, she should be advised that the HBsAb test may be falsely negative because of waning antibodies. If she completed the vaccine series and was tested but doesn't remember the results, refer her to the facility's Occupational Health department for a review of records to determine if additional doses of vaccine are indicated. This information should be shared with her healthcare practitioner.

Some healthcare workers are known nonresponders to the vaccine, many because they've been chronically infected with hepatitis B. These people should also be offered HBsAb and HBsAg testing.

Baseline hepatitis C testing should be done with serum liver enzyme levels (alanine aminotransferase or ALT) as soon as possible after the exposure.

If getting follow-up at the current facility isn't appropriate or feasible, another healthcare provider should be chosen to receive the test results on both the exposed person and the source patient.

Complex decisions about PEP for HIV

If the rapid HIV test on the source patient is positive, Ada should be told that the test can produce false-positive results. She should be asked to maintain confidentiality until confirmatory testing is complete and reminded not to share the information with the source patient. If appropriate, his healthcare provider will discuss test results and their implications with him.

Discussing Ada's treatment options is very important at this point because the 2-hour window for starting HIV PEP began at the time of exposure and decisions about HIV PEP can be complex. Therapy lasts 30 days and can cause many adverse reactions. The clinician working with Ada should call the National Clinicians' Postexposure Prophylaxis Hotline (1-888-448-4911) for advice before proceeding. Given key information about the source and the exposed person, experts can help Ada's clinician make the best treatment recommendations for her.

Teaching your patient about PEP for HIV

A person exposed to bloodborne pathogens who decides to go on HIV PEP should be fully informed about possible adverse reactions, including nausea, diarrhea, abdominal pain, anemia, and neutropenia. Identify follow-up resources to answer her questions, help her manage adverse reactions, or provide additional testing.

Advise Ada that she'll need blood tests to monitor for toxic drug levels: At a minimum, testing should include a complete blood cell count and renal and hepatic function tests at baseline and after 2 weeks of therapy. If her drug regimen includes a protease inhibitor, teach her how to monitor for signs and symptoms of hyperglycemia, such as polydipsia, polyuria, polyphagia, fatigue or weakness, and blurred vision. If the protease inhibitor indinavir is prescribed, she'll also require periodic monitoring for crystalluria, hematuria, hemolytic anemia, and hepatitis. She shouldn't take indinavir if she's pregnant or breast-feeding.

Advise Ada to immediately see her healthcare practitioner if she develops a rash, fever, back or abdominal pain, dysuria, hematuria, or signs and symptoms of hyperglycemia.

If HBsAb and HBsAg testing shows that Ada has no antibodies to HBV, advise her to complete the hepatitis B vaccine series to protect her against this and any future occupational exposures.

Testing positive for HCV

A confirmed positive HCV result would mean that Ada has been exposed to HCV. No PEP regimen is available for HCV, and immune globulin and antiviral drugs aren't recommended. The exposed person should be followed for 4 to 6 months as recommended by CDC guidelines and receive the same counseling that would be given for HBV.

In rare cases, healthcare workers who know they have HIV, HBV, or HCV are reexposed to these diseases while providing care. Ironically, these exposures also carry risk because the source patient's pathogens may have different resistance patterns, affecting the exposed person's response to exposure and treatment. The exposed person should follow the facility's policy and procedure for postexposure care and discuss with the healthcare provider whether additional action is required.

Prevention is the best policy

A quick and appropriate response to a potential exposure can greatly reduce the risk of disease transmission following an occupational exposure to potentially infectious material. But preventing exposures is best of all. Learn your facility's infection control standards and policies, and follow them as though your life depends on it.

After an exposure: What's your risk?

Most people who are exposed to blood or OPIM don't develop an infection. The type of exposure, the amount of blood or body fluid involved, and the viral load in the source patient's blood all affect risk. If the source patient isn't infected with a bloodborne pathogen, only superficial wound care may be needed after a needle-stick or sharps injury. Here's how the risks of disease transmission compare for three bloodborne pathogens.

HIV transmission. Contracting HIV from accidental occupational exposure is quite rare, as indicated by these seroconversion rates.

* sharps injury, 0.3%, or about 1 in 300.

* mucous membrane exposure, 0.09%, or about 1 in 1,000

OSHA regulations require offering the HBV vaccine to all healthcare workers who may be exposed to blood or OPIM on the job. These vaccinations have dramatically decreased transmission of HBV via occupational exposure. However, some healthcare workers don't accept the vaccine or complete the vaccine series, and others who are properly vaccinated don't mount an immune response.

Blood and any visibly bloody body fluids are considered potentially infectious under OSHA guidelines. Other potentially infectious material (OPIM) include:

* semen and vaginal secretions

* cerebrospinal fluid

* synovial fluid

* pleural fluid

* peritoneal fluid

* pericardial fluid

* amniotic fluid.

National clinicians' post-exposure prophylaxis hotline, University of California, San Francisco: 1-888-448-4911