Much has changed since the previous MASAC Recommendation #43. Since the 1998 HIV exposure guidelines, changes have included newer FDA-approved antiretroviral agents, new information regarding resistance testing of the source of the exposure, and more safety information concerning post-exposure prophylaxis (PEP). A single document now combines all recommendations for HIV, HCV, and HBV exposures. Occupational exposures should be considered urgent and treated in a timely manner with HBIG, hepatitis B vaccine, and/or HIV PEP. Although the changes are summarized briefly below, MASAC strongly recommends that providers refer to the source document referenced below, entitled "Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis," for more specific information.

HBV Postexposure Management
The risk of HBV infection by occupational exposure is 37-62% with HBeAg-positive blood and 23-37% with HBsAg-positive blood. Recommendations include initiation of the hepatitis B vaccine series for any susceptible, unvaccinated person who sustains an occupational exposure. Hepatitis B immune globulin (HBIG) and/or hepatitis B vaccine series should be considered for occupational exposures after evaluation of the HBsAg status of the source and the vaccination and vaccine response status of the exposed person. For those who test positive for hepatitis B antigen or when the source tests positive for hepatitis B antigen, hepatitis B immune globulin (HBIG) and/or the hepatitis B series should be considered. It has been estimated that either alone is 75% effective in preventing HBV infection. Although the effectiveness of using both together is unknown, the increased efficacy observed in the perinatal setting with both HBIG and the hepatitis B series may also apply to the occupational setting. Neither HBIG nor hepatitis B vaccine is contraindicated in pregnancy. Anti-HBs testing should be performed at baseline and 1-2 months after completion of the hepatitis B vaccine series.

HCV Postexposure Management
The risk of HCV infection following occupational exposure is 1.8% (range 0-7%). For HCV postexposure management, the HCV status of the source and exposed person should be determined, and follow-up HCV testing should be performed to determine if infection develops. Neither interferon nor antiviral agents (e.g., ribavirin) is recommended for PEP of hepatitis C. Because there is no recommended PEP for HCV exposure, the goal of PEP management is to identify hepatitis C infection early and refer for treatment. Data show that interferon is not effective until there is an established infection; the earlier interferon is introduced once there is established infection, the higher the rate of resolved infection. Anti-HCV and ALT testing should be performed at baseline and at 4-6 months after exposure. The HCV RNA may be performed earlier for diagnostic confirmation.

HIV Postexposure Management
The risk of HIV infection after percutaneous exposure is 0.3% (range 0.2-0.5%). The risk is increased the larger the quantity of blood, if the exposure was in a vein or artery or by deep-penetrating injury, and the higher the titer of HIV RNA. There is good evidence that antiretroviral agents (e.g., zidovudine) blunt the cytotoxic T-lymphocyte response and inhibit early HIV replication. The PEP regimen should be started preferably within 2 hours of exposure, but at least within 24 hours. PEP includes a 4-week regimen of two drugs that may include the following combinations: zidovudine and lamivudine; or lamivudine and stavudine; or didanosine and stavudine. A third drug should be added for HIV exposures that pose an increased risk of transmission. When the source's virus is known or suspected to be resistant to one or more of the drugs considered for the PEP regimen, the drugs selected should be those to which the source person's virus is unlikely to be resistant. Previously, indinavir or nelfinavir were recommended as first-line agents for PEP, but since 1998, efavirenz, abacavir, and Kaletra have been used, especially when there is known resistance in the source viral strain. HIV antibody testing should be performed at baseline, at 6 weeks, 3 months, and at 6 months, and precautions should be taken to prevent sexual transmission. Drug monitoring for toxicity by chemistry and blood counts should be performed every 2 weeks during PEP treatment. The optimal duration of PEP is not known, but based on animal efficacy data, it should be given for four weeks. If seroconversion occurs, the patient should be evaluated per standard guidelines for antiretroviral treatment (See MASAC Recommendation #124).

References:
1. Centers for Disease Control and Prevention. Updated U.S. Public Health Service Guidelines for the Management of Occupational Exposures to HBV, HCV, and HIV and Recommendations for Postexposure Prophylaxis. MMWR 2001; 50 (No. RR-11); 1-42.

This material is provided for your general information only. NHF does not give medical advice or engage in the practice of medicine. NHF under no circumstances recommends particular treatment for specific individuals and in all cases recommends that you consult your physician or local treatment center before pursuing any course of treatment.

CHAPTERS: Please feel free to distribute to your members.
PHYSICIANS: Please distribute this information to all providers in your area who treat patients with bleeding disorders.