Tuesday, October 15, 2013

Updates in HIV screening and prevention

- Kenny Lin, MD, MPH

Although the introduction of highly active antiretroviral therapy for HIV has led to substantial declines in AIDS diagnoses and deaths from their peaks in the mid-1990s, an estimated 50,000 persons in the U.S. are infected with HIV each year, and more than 236,000 persons living with HIV are unaware of their diagnoses, according to the Centers for Disease Control and Prevention. Noting that many HIV infections occur in persons without identifiable risk factors, earlier this year the U.S. Preventive Services Task Force recommended that clinicians routinely screen all adolescents and adults ages 15 to 65 years (the American Academy of Family Physicians recommends starting routine screening at age 18).

Identifying infected persons through screening allows for earlier initiation of effective therapy, but there is limited evidence that the diagnosis affects sexual and injection drug use behaviors that could prevent transmission of HIV. Recently, several randomized trials of antiretroviral preexposure prophylaxis in high-risk populations have demonstrated reductions in new HIV infections; a Cochrane review concluded that 56 persons needed to receive prophylaxis to prevent one new infection.

The October 15th issue of AFP includes a STEPS drug review of emtricitabine/tenofovir (Truvada) for HIV preexposure prophylaxis. Although this drug is effective and generally well tolerated in persons with normal renal function, it comes at a steep price: more than $1200 for a one-month supply. Whether it makes sense to prescribe an expensive and potentially toxic drug to uninfected persons who might acquire HIV due to high-risk behaviors such as injection drug use remains a topic of debate. The CDC and other U.S. public health agencies plan to publish comprehensive guidance on the use of antiretroviral preexposure prophylaxis within the next year.

How have the expanded HIV screening recommendations and the availability of preexposure prophylaxis regimens affected your practice?