Quiz: Your phlebotomist is injured by HIV needlestick

Gerberding JL. Occupational exposure to HIV in health care settings. N Engl J Med 2003; 348:826-833.

OK. Time for a pop quiz. Here’s the scenario: While obtaining a peripheral venous blood sample from a patient with the AIDS virus, a 35-year-old phlebotomist is injured by a bloody 18-gauge needle attached to a syringe. The patient has been taking didanosine and stavudine for more than six months, but her quantitative plasma HIV RNA titer and CD4 T-lymphocyte count have not been measured for many weeks. What is the appropriate post-exposure treatment for phlebotomist?

Full credit is given for those who answered: Call the U.S. National Clinicians’ Post-Exposure Prophylaxis Hotline (PEPline) at (888) 448-4911 and discuss treatment options and obtain advice about the management of adverse effects of drugs.

For those who ventured a more detailed answer, compare your approach to the following offered by Julie Gerberding, MD, MPH, director of the Centers for Disease Control and Prevention (CDC) and HIV expert since her days at San Francisco General.

"In a case such as that described in the vignette, I would prescribe an antiviral regimen that included at least two drugs. I would choose drugs that were not part of the source patient’s current treatment regimen, even though there is no evidence that this strategy reduces the risk of infection. Since the source patient was being treated with a stable regimen of didanosine plus stavudine, treatment of the exposed health care worker with zidovudine plus lamivudine would be reasonable.

"If the puncture was deep, the needle was visibly bloody before the injury, or the source patient had very advanced HIV infection or a high viral load when last tested, or if other factors suggested an increased risk of HIV transmission, I would discuss with the health care worker the rationale for my recommendation that a third drug, such as a protease inhibitor (e.g., indinavir), be added to the regimen. If I worked in a community where the incidence of primary resistance to zidovudine and lamivudine was known to be high, I would also encourage the use of a third drug.

"If information from recent tests of resistance to antiretroviral drugs was available or became available during treatment, I might adjust the regimen to include at least two drugs to which the virus was susceptible. To do so, I would rely on the strategies that form the basis for selecting empirical salvage therapy’ in persons with HIV infection, even though there is no evidence that this approach is effective."

The most effective and safest antiretroviral regimen for exposed people remains uncertain, the author notes. A combination of three or more antiretroviral agents is usually advised for the treatment of HIV infection, but there is no clinical evidence that such combinations are more effective in preventing infection after occupational exposure than is treatment with a single drug. In fact, of the five health care workers who are known to have acquired HIV infection despite prophylactic treatment with more than one antiretroviral drug, three received three or more drugs, she concluded.

The CDC estimates that more than 380,000 needlestick injuries occur in U.S. hospitals each year; approximately 61% of these injuries are caused by hollow-bore devices.

As of December 2001, the CDC had received voluntary reports of 57 documented cases of HIV seroconversion temporally associated with occupational exposure to HIV among U.S. health care personnel. An additional 138 infections among health care personnel were considered possible cases of occupational HIV transmission.