For HCV exposures, it’s still wait and hope

But theoretical’ PEP attempted by some

Citing insufficient and conflicting data, the Centers for Disease Control and Prevention does not recommend attempting post-exposure prophylaxis (PEP) with immune globulin and antiviral agents (e.g., interferon with or without ribavirin) for hepatitis C virus exposures.¹

While the issue has been debated because of increasing success in treating those with HCV infection, the data are too limited to extrapolate into a PEP protocol, the agency decided. In the absence of PEP, the CDC emphasized that the goal of HCV post-exposure management should be early identification of chronic disease and referral for treatment if necessary. The HCV status of the source patient and the exposed person should be determined through testing.

"At this point, there really aren’t data to support PEP recommendations for hepatitis C," says Elise Beltrami, MD, medical epidemiologist in the CDC division of healthcare quality promotion. "These [HCV] drugs have a very different mechanism of action than the antiretroviral agents that we use for HIV. There is some thought that you have to have an infection established to use interferon or ribavirin. There are some data that even show that if you use those, you might increase someone’s chances of getting infected."

However, the CDC conceded that there is "a theoretical argument" that intervention with antivirals when HCV RNA first becomes detectable might prevent the development of chronic infection. Data from studies conducted outside the United States suggest that a short course of interferon started early in the course of acute hepatitis HCV is associated with a higher rate of resolved infection than that achieved when therapy is begun after chronic hepatitis C has been well established, the agency reported.^2-4 HCV RNA can be detected by polymerase chain reaction (PCR) testing.

"That strategy, which I call preemptive therapy’ [involves] monitoring for HCV RNA by PCR, and if it turns positive, then aggressively treating with interferon," says David Henderson, MD, medical epidemiologist at the National Institutes of Health Clinical Center in Bethesda, MD. "There is just not enough experience yet to know if that works or not. For the public health service, you couldn’t possibly make a recommendation yet based on the really limited information that is out there. A lot of [the data] are anecdotal. Even what is in the literature is basically antidotes describing cases where they think it worked."

In addition, no studies have evaluated the treatment of acute HCV infection in people with any evidence of liver disease (i.e., HCV RNA-positive for less than six months with normal ALT levels). The efficacy of antivirals has been demonstrated only among patients who also had evidence of chronic liver disease (i.e., abnormal ALT levels), the CDC guidelines state. Moreover, treatment started early in the course of chronic HCV infection (i.e., six months after onset of infection) might be just as effective as treatment started during acute infection. Because some 15% to 25% of patients with acute HCV infection will spontaneously resolve their infection anyway, treatment of these patients during the acute phase could expose them unnecessarily to the discomfort and side effects of antiviral therapy, the CDC argues.

Reference

1. Centers for Disease Control and Prevention. Updated U.S. Public Health Service guidelines for the management of occupational exposures to HBV, HCV, and HIV and recommendations for post-exposure prophylaxis. MMWR 2001; 50(RR11):1-42

2. Fried MW, Hoofnagle JH. Therapy of hepatitis C. Semin Liver Dis 1995; 15:82-91.

3. Vogel W, Graziadei I, Umlauft F, et al. High-dose interferon-a_2b treatment prevents chronicity in acute hepatitis C: A pilot study. Dig Dis Sci 1996; 41(suppl 12):81S-85S.

4. Quin JW. Interferon therapy for acute hepatitis C viral infection — a review by meta-analysis. Aust N Z J Med 1997; 27:611-617. n