Statistics show that more than 100 people are exposed to the human immunodeficiency virus every day in the United States. In the past year, 477 new cases were reported in North Carolina alone.
While most people are infected through consensual sex acts, others are exposed to HIV in the workplace and by sexual assault. The results of such contact cannot be determined absolutely until six weeks later at the very least.
Although the chances of transmission in these situations are quite low-estimates range from one in 250 to one in 1000-medical professionals have at their disposal a "cocktail" style drug regimen that may inhibit the transmission of HIV during that time.
The procedure, known as post-exposure prophylaxis, or PEP, combines a number of medications that are currently used to treat the virus, such as AZT, nevirapine and zidovudine.
The idea for PEP treatment originated in 1994, when the National Institutes of Health, the National Institute of Health and Medical Research and the French National Agency of Research on AIDS published joint research that indicated that certain antiretroviral drugs, when administered to a select group of HIV-infected women and their infants, can reduce the risk for perinatal transmission of HIV by approximately two-thirds. Given that discovery, doctors decided to find out if the risk could also be avoided in other types of exposures.
"Studies are unequivocal that antiretroviral treatments reduce the chance that a baby will be born with HIV," said Dr. Charles Hicks, an associate clinical professor in Duke's Division of Infectious Diseases. "It is logical to consider that it could be used [for other forms of transmission]."
But PEP has not been proven to curb infection rates for victims of rape and on-the-job accidents, and has serious disadvantages such as side effects and high costs. And unlike mother-child transmissions-which have an incidence of infection as high as 25 percent-most occupational HIV exposures do not result in transmission of HIV. Clinicians considering prescribing PEP for exposed patients must balance the risk of transmission against the treatment's costs.
PEP treatment has seen some use in Duke University Medical Center. Last year, 595 Medical Center employees reported potential exposures to bodily fluids of patients with HIV. Of those, 22 were determined to have been exposed to HIV, and 16 procured PEP treatment. But in the sexual assault department of the emergency room, where rape victims are consulted on a variety of matters, PEP treatment is almost never discussed.
"Unfortunately, we don't deal with the HIV question," said Phyliss Briggs, a clinical nurse in emergency medicine. "We treat other diseases, but we don't deal with HIV. We discuss it, but we just don't test for it."
However, sexual assault victims do have access to HIV testing and PEP treatment elsewhere. Briggs said sexual assault victims at risk for HIV infection are urged to see a primary-care physician to discuss possible courses of action, which may include PEP treatments.
Balancing PEP's costs and benefits remains a primary concern. The treatment costs patients $1,000 per week, and the Centers for Disease Control and Prevention recommend a four-week treatment plan. Because the rates of transmission for the exposure types that PEP purports to treat are so low, doctors could be prescribing $2 million worth of medication for every one patient who would otherwise have developed HIV.
PEP treatments also have serious side effects. "Typically the drugs recommended for prevention produce gastrointestinal side effects such as loss of appetite and nausea," Hicks said. "They can make people feel fatigued, give them headaches and make them feel generally off." Some doctors feel that PEP's unpleasant side effects may discourage patients from continuing the treatment-even if it might prevent them from testing positive for HIV.
And because of problems associated with proving the benefits of PEP treatments in sexual assault and workplace scenarios-Bartlett estimated that researchers would need to study 10,000 PEP users to be able to compile identifiable results-wide variance in its use is likely to continue.
"When someone comes in, hopefully the person who is trying to provide the health care will talk to them at length so that they can identify their risk factors and make a balanced decision," Briggs said. "Together, the person and the health-care provider can come to a conclusion as what is best to do."
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