New HIV drugs offer more tolerable post-exposure regimens for HCWs
A new streamlined approach to PEP
New guidelines provide a simple response to occupational exposure to HIV: Take three anti-retrovirals as soon as possible and re-evaluate after 72 hours.
Remarkable advances in the treatment of HIV have produced anti-retrovirals that have far fewer adverse effects than the older drugs and that means a sea change in post-exposure prophylaxis (PEP). The Centers for Disease Control and Prevention has issued the first new guidelines for PEP since 2005.1
The new guidelines give a streamlined approach to PEP although expert advice will still be required in certain circumstances, says Ronald H. Goldschmidt, MD, director of the National HIV/AIDS Clinicians’ Consultation Center at the University of California-San Francisco, which runs the PEPline advice call line for clinicians (1-888-HIV-4911).
Gone is the need to identify exposures as low-risk and high-risk. "With the new regimens, the adverse effects are quite minimal, and that makes it much easier to recommend PEP and easier for people to complete their course of PEP medications," Goldschmidt says.
For most exposures, CDC now recommends a three-drug combination: emtricitabine plus tenofovir DF (which may be provided with the Truvada combination tablet) plus raltegravir. (See box on p. 112.)
Some hospitals had already begun using the newer anti-retrovirals. The New York State Department of Health was the first to recommend the new regimen earlier this year. Even hospitals in other states used that as a basis for change.
For example, the University of California Los Angeles switched its first-line medications about six months ago. T. Warner Hudson, MD, FACOEM, FAAFP, medical director of Occupational and Employee Health for the UCLA Health System and Campus, welcomed the August 2013 publication of the guidelines.
"It always makes people a little more comfortable when there’s a CDC/HHS [U.S. Department of Health and Human Services] guideline saying this is a good idea," he says. "Thank goodness they’re out."
13 years of no known occupational HIV
Post-exposure prophylaxis for HIV has been an occupational health success story. In the past 13 years, CDC has not reported any new documented occupational transmissions.
Some seroconversions may still have occurred as a result of a sharps injury, cautions David Kuhar, MD, medical epidemiologist with CDC’s Division of Health Care Quality and Promotion and lead author of the guidelines. Reporting is voluntary, and even when a case is suspected, there may be inadequate information to determine whether it was occupational, he says.
"We don’t always receive all the information that we would like to about transmission cases and might not be able to confirm with certainty that it was occupational transmission of HIV versus HIV acquired from another source," he says.
The risk of transmission from a needlestick is still very real, he emphasizes. But post-exposure prophylaxis has been effective in greatly reducing that risk.
UCLA responds to about 300 to 400 bloodborne pathogen exposures a year, many of them involving HIV-positive source patients. There have been no known seroconversions in recent years, Hudson says.
"All the people in this field believe, even though we know there’s underreporting [of exposures], that these meds are much more effective than they were in the early days when they just used AZT [zidovudine]," he says.
Sharps safety technology and greater awareness about bloodborne pathogen risks also have contributed to the decline in seroconversions, Goldschmidt notes.
Quicker diagnosis with better tests
Another advance — rapid HIV testing — has played an important role in PEP improvements. The newer rapid tests provide highly accurate results within 30 minutes or an hour, says Kuhar.
However, even with rapid tests, the prophylaxis should start before the source patient results are in, Kuhar says. "We do not encourage people to wait until the test is back," he says.
In fact, the guidelines suggest having single-dose "starter packets" of the standard PEP regimen so treatment can be given as soon as possible, after some initial evaluation, counseling and baseline HIV testing of the employee.
Yet the rapid test technology promises to reduce some of the fear associated with a needlestick. The new "fourth-generation" tests are so accurate — they detect both the HIV antibody and antigen p24 antibody — they can shorten the entire testing timeframe. Exposed employees would be tested at baseline, six weeks and four months instead of the usual baseline, six weeks, 12 weeks and six months.
"They’re good at detecting HIV earlier than previous tests," says Kuhar. "That’s a very nice option, to finish your testing sooner."
Risk remains with low viral load
There always will be situations that require clinical judgment, but the guidelines provide some direction on common concerns.
Today, HIV patients receive highly sophisticated drug cocktails that keep their infection at bay. Some source patients may have a very low or even undetectable viral load. But there is still latent infection in the source patient’s cells, and employees should still receive post-exposure treatment, explains Kuhar.
"It still constitutes an exposure to HIV and people should be managed appropriately, including being offered post-exposure prophylaxis," he says.
Conversely, source patients who have been treated with various anti-retrovirals may have drug resistance — and that could shape the recommended regimen. The guidelines call for expert consultation if the source patient has known or suspected drug resistance.
PEPline received about 11,000 calls a year related to occupational exposures, says Goldschmidt. By making the standard PEP response simpler, the calls may become more targeted, he says.
But to health care workers who have an exposure, the risk of seroconversion may be low, but it is still very real, he says.
"It’s absolutely normal and appropriate that people are scared," Goldschmidt says. "Even though it’s a small number, people do imagine they are one of the three in a thousand [the estimated rate of seroconversion from a needlestick, based on previous studies2]. People will still remain quite concerned.
"It is reassuring to tell them there haven’t been transmissions in the last 13 years — that we know about," he says.
- Kuhar DT, Henderson DK, Struble KA, et al. Updated US Public Health Service Guidelines for the Management of Occupational Exposures to Human Immunodeficiency Virus and Recommendations for Postexposure Prophylaxis. Infect Control Hosp Epi 2013;34:875-892.
- Cardo DM, ZCulver DH, Ciesielski CA, et al. A case-control study of HIV seroconversion in health care workers after percutaneous exposure. Centers for Disease Control and Prevention Needlestick Surveillance Group. N Engl J Med 1997;337:1485-1490.