Management of Occupational Exposures to HIV

Abstract & Commentary

By Arathi Rao, MD and Maria D. Mileno, MD

Dr. Mileno is Director, Travel Medicine, The Miriam Hospital, Associate Professor of Medicine and Infectious Diseases, Director, International Travelers’ Clinic, Brown University School of Medicine and Dr. Rao is a Fellow in Infectious Dsiseases at Brown University School of Medicine

Dr. Mileno is a consultant for GlaxoSmithKline, and does research for Merck. Dr. Rao reports no financial relationship relevant to this field of study.

Synopsis: Exposures to blood-borne pathogens continue to pose serious risks to health-care personnel (HCP) and may be especially serious for those working in the developing world. The most likely blood-borne exposures of concern include Hepatitis B, Hepatitis C, and HIV. The field is evolving such that travel medicine specialists advising students and other health providers must take many issues into consideration when advising on appropriate post exposure prophylaxis for potential HIV infection.

Source: Panlilio, AL, et al. Updated US Public Health Service Guidelines for the Management of Occupational Exposures to HIV and Recommendations for Postexposure Prophylaxis. MMWR Recomm Rep. 2005;54:1-17.

Exposure of healthcare personnel to either blood or the bloody secretions of an HIV-seropositive person has only occasionally resulted in HIV infection. This MMWR article cites risks after exposure to HIV-infected blood: transmission of HIV occurs at a rate of approximately 0.3% after percutaneous exposure, 0.1% after mucous membrane exposure, and < 0.1% after exposure to the non-intact skin. We will focus on post-exposure prophylaxis (PEP) and current management strategies, which have been twice updated since 1996, concerning potential exposures to HIV in the healthcare setting.

Commentary

At the moment of exposure to blood or other body fluids, it is imperative to provide both counseling and medical evaluation to delineate the type and degree of exposure encountered. It is also important to obtain as much detail about the source patient’s HIV status as possible. If the source patient is HIV seropositive, one must determine what HIV drug regimens the patient has been using as well. Such information will determine both who should receive prophylaxis and which drugs are likely to be effective.

It is important to understand the types of potentially infectious exposes in the healthcare setting, as well as the degrees of the exposures. Various types of infectious materials include whole blood and bodily fluids that are visibly bloody. Highest risk is associated with a needlestick from a large bore needle that contains blood from a known HIV-infected individual. Percutaneous injury might include a cut with a sharp object, contact of mucous membranes or exposed skin that is chapped, abraded, or affected with dermatitis, by blood, tissue, and open body fluids that are potentially infectious. Fluids that are potentially infectious but for which the risk of HIV transmission is simply unknown include: pleural, cerebrospinal, peritoneal, pericardial, amniotic, and synovial fluids. Those fluids that are considered non-infectious, unless they are visibly bloody, include saliva, tears, urine, feces, vomitus,nasal secretions, sputum, and sweat.1

The level or degree of exposure encountered can help to determine which PEP regimen to utilize. The CDC categorizes less severe vs more severe percutaneous injuries and small versus large volume exposures. The quantity of blood is considered large if a device is visibly contaminated with blood; if a procedure involved a needle placed directly into a vein or artery or if a deep injury occurred. PEP should be initiated within hours depending on the type and degree of exposure. Examples of recommended basic and expanded regimens are provided in the review. Healthcare workers seeking experiences abroad in countries with burgeoning HIV disease should carry an initial phase of a PEP regimen (Combivir one tablet orally twice each day with Kaletra 3 capsules orally twice per day, taken with food) provided with complete instructions for high risk exposures because testing and treatment for HIV infection may not be readily available).

Once PEP has been initiated, it is important to provide a structure for post-exposure monitoring. Baseline HIV antibody tests should be drawn from the healthcare provider (HCP), as well as the source patient. HIV seronegative HCPs should have follow-up testing performed at 6 weeks, 12 weeks, and 6 months after exposure to determine whether transmission has occurred. The average duration of time to seroconversion of exposed individuals who have been infected is within 3 months.2 Some studies have shown 4 weeks of zidovudine to be protective although the optimal duration for PEP is unknown. We suggest 4 weeks of HIV PEP be administered. If it is determined, however, that the HIV status of the source patient is negative, then PEP should be discontinued.

Several additional considerations exist regarding selection of HIV PEP regimens although these complexities should not delay the timing and initiation of PEP. Although choice of agents is primarily empiric, some patients with high body burden of HIV deliver higher levels of viral exposure, and 3 or more drugs may be indicated. Second, resistance of source patients’ HIV virus to antiviral agents is a serious concern when choosing a PEP regimen. Since publication of the last set of guidelines, an additional report of an occupational HIV seroconversion, occurring despite combination therapy HIV PEP, has been published. This exposure was a percutaneous injury sustained by a nurse performing a phlebotomy on a heavily treatment-experienced patient. In addition, all approved antiviral agents may have adverse effects and potentially serious drug interactions when used with certain other medications. During pregnancy, primate data indicate that we should not use efavirenz. Indinavir can lead to hyperbilirubinemia and renal stones. Combination therapy with d4T and ddI should be avoided in treatment of HIV due to reports of mitochondrial dysfunction and fatal lactic acidosis, particularly during pregnancy.

First and foremost, emphasis must be given to providing counseling to HCP who have had exposures, particularly during those weeks of uncertainty requiring both emotional support and monitoring of adverse events, as well as advice for safe sexual practices until viral transmission has been excluded.

References

  1. Bell DM. Occupational Risk of Human Immunodeficiency Virus Infection in Healthcare Workers: An Overview. Am J Med. 1997;102:9-15.
  2. American Academy of Pediatrics. Human Immunodeficiency Virus Infection. In: Pickering LK, ed. Red Book: 2003 Report of the committee on Infectious Diseases. 26th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2003:380-381.