CDC Updates Guideline on HIV Postexposure Prophylaxis in Occupational Setting
Last updated: 01/31/2006
The Centers for Disease Control has updated their 2001 guidelines on management of occupational exposures to human immunodeficiency virus (HIV) and recommendations for postexposure prophylaxis (PEP). Since the previous update in 2001, the U.S. Food and Drug Administration (FDA) has approved new antiretroviral agents, and additional information has become available regarding the use and safety of HIV PEP.
The definition of healthcare personnel (HCP) remains unchanged from previous guidelines and refers to all paid and unpaid persons working in health-care settings who have the potential for exposure to infectious materials. Some examples of infectious materials include blood, tissue and specific body fluids and medical supplies, equipment, or environmental surfaces contaminated with these substances. Feces, nasal secretions, saliva, sputum, sweat, tears, urine, and vomitus are not considered potentially infectious unless they are visibly bloody.
Risk factors play a role in the management of PEP for occupational exposures. An exposure that might place HCP at risk for HIV infections is defined as a percutaneous injury (e.g., needlestick or cut with sharp object) or contact of mucous membrane or nonintact skin (e.g., exposed skin that is chapped, abraded, or afflicted with dermatitis) with blood, tissue, or other body fluids that are potentially infectious. In addition to blood and visibly bloody body fluids, semen and vaginal secretions also are considered potentially infectious. Risks vary with the type and severity of exposure. In prospective studies of HCP, the average risk of HIV transmission after percutaneous exposure to HIV infected blood has been estimated to be approximately 0.3% (95% CI= 0.2%-0.5%) and after a mucous membrane exposure, approximately 0.09% (CI=0.006%-0.5%). Transmission via nonintact skin has been documented; however, the risk has not been quantified but is estimated to be less than the risk for mucous membrane exposures. In a retro-spective case-control study of HCP who had percutaneous exposure to HIV, increased risk for HIV infection was associated with exposure to a larger quantity of blood from the source person as indicated by: 1) a device visibly contaminated with the patient's blood 2) a procedure that involved a needle being placed directly in a vein or artery, or 3) a deep injury. The risk also was increased for exposure to blood from source persons with term-inal illness, possibly reflecting either the higher titer of HIV in blood late in the course of acquired immunodeficiency syndrome (AIDS).
Currently there are five classes of antiretrovirals to treat HIV infection: nucleoside reverse transcriptase inhibitors (NRTIs), nucleotide reverse transcriptase inhibitors (NtRTIs), nonnucleoside reverse tran-scriptase inhibitors (NNRTIs), protease inhibitors (PIs), and a single fusion inhibitor. The recommendations in this report provide guidance for two or more drug PEP regimens on the basis of level of risk for HIV transmission (see tables 1 and 2 on the next page). When percutaneous injuries occur, the exposure type and infection status of the source is needed to indicate which course to follow. Exposure types are defined as less severe (e.g., solid needle or superficial injury) or more severe (e.g., large-bore hollow needle, deep puncture, visible blood on device, or needle used in patient's artery or vein). When HIV status is found to be positive, the source is then differentiated into two classes. Class 1 sources are asymptomatic HIV infection or known low viral load (e.g., <1,500 ribonucleic acid copies/mL). Class 2 sources are symptomatic HIV infection, AIDS, acute sero-conversion, or known high viral load.
When mucous membrane and nonintact skin surfaces are exposed, the exposure type and infection status of source are again needed to indicate which course to follow. Exposure types are defined as small volume (e.g., a few drops) and large volume (e.g., a major blood splash).
PEP should be initiated as soon as possible, preferably within hours rather than days of exposure. If uncertain which antiretroviral agents to use, the basic regimen should be started immediately rather than delay PEP administration. Careful selection should be taken when determining which regimen is appropriate for HCP based upon tolerability and drug interactions because a total course consists of 28 days.
Studies report that between 17-47% of HCP did not complete the total PEP course mainly due to nausea; therefore it is important to minimize side effects and pill burden so that viral suppression can occur. While an extensive overview of the different regimens is available online, the regimens used by Cabell Huntington Hospital are:
Basic 2 drug PEP regimens ? two choices:
- Zidovudine 300mg BID+Lamivudine 150mg BID (also available as Combivir® 1 tablet BID)
- Lamivudine 150mg BID+Stavudine 40mg BID
Expanded 3 drug PEP regimens ? three choices:
- Basic regimen+Kaletra® 3 capsules BID w/ food (Kaletra® is lopinavir/ritonavir 400/100mg)
- Basic regimen+Nelfinavir 750mg TID
- Basic regimen+Efavirenz* 600mg qHS
* contraindicated in pregnancy
HCP that are receiving PEP should be reevaluated in 72 hours regarding the source HIV status and viral load. HIV antibody testing by enzyme immunoassay should be used to monitor seroconversion for greater than 6 months after occupational HIV exposure. Monitoring for drug toxicity should begin two weeks after initiation of PEP and should include complete blood count and renal and hepatic function tests. HCP should report any rash, fever, back or abdominal pain while taking antiretrovirals as to minimize toxicity.
If it's unclear whether PEP is warranted or resistance is detected, an infectious disease specialist should be consulted. Other questions about treat-ment can be directed to the PEPLine, available at: http://www.ucsf.edu/hivcntr/Hotlines/PEPLine or by calling 1-888-448-4911. Occupational HIV exposures should be reported to the CDC at 1-800-893-0485 or to the state health department.
| Exposure Type | HIV-positive, class 1 | HIV-positive, class 2 | Source of unknown HIV status | Unknown source | HIV-negative |
|---|---|---|---|---|---|
| Less severe | Recommend Basic 2-drug PEP | Recommend expanded ≥3-drug PEP | Generally, no PEP warranted; however, consider basic 2-drug PEP for source with HIV risk factors | Generally, no PEP warranted; however, consider basic 2-drug PEP in which exposure to HIV-infected persons is likely | No PEP warranted |
| More severe | Recommend expanded 3-drug PEP | Recommend expanded ≥3-drug PEP | Generally, no PEP warranted; however, consider basic 2-drug PEP for source with HIV risk factors | Generally, no PEP warranted; however, consider basic 2-drug PEP in settings in which exposure to HIV-infected persons is likely | No PEP warranted |
| Exposure Type | HIV-positive, class 1 | HIV-positive, class 2 | Source of unknown HIV status | Unknown source | HIV-negative |
|---|---|---|---|---|---|
| Small volume | Consider basic 2-drug PEP | Recommend basic 2-drug PEP | Generally, no PEP warranted | Generally, no PEP warranted | No PEP warranted |
| Large volume | Recommend basic 2-drug PEP | Recommend expanded ≥3-drug PEP | Generally, no PEP warranted; however, consider basic 2-drug PEP for source with HIV risk factors | Generally, no PEP warranted; however, consider basic 2-drug PEP in settings in which exposure to HIV-infected persons is likely | No PEP warranted |