Could HCV Drugs Be Used for Post-exposure Prophylaxis?
With cost, lack of data, it may be best to wait for seroconversion and treat
While there is a proven vaccine for hepatitis B virus and an effective post-exposure prophylaxis (PEP) for HIV, one bloodborne pathogen that threatens healthcare workers has neither: hepatitis C virus (HCV). However, the drugs now available to treat HCV are highly effective, raising the question of whether they could be used in a PEP protocol after needlesticks involving HCV-positive blood.
There certainly is a large contingent of patients who may be carrying the virus. Over the last five years, the number of new HCV infections has nearly tripled, reaching a 15-year high, according to the CDC.1
Because HCV has few symptoms, nearly half of people living with the virus don’t know they are infected and most new infections go undiagnosed. The CDC estimates about 34,000 new hepatitis C infections actually occurred in the U.S. in 2015. The virus takes a devastating long-term toll, and is the No. 1 indication for liver transplant. Some 20,000 people died from HCV in 2015 in the United States, with the majority of those people age 55 and older. That reflects the high HCV prevalence in baby boomers, who may have acquired the virus through past IV drug use and other risk factors. For this reason, the CDC recommends that all people born between 1945 and 1965 be tested for HCV.
Increase in the Young
However, new HCV infections are increasing most rapidly among the young, with the highest overall number of new infections among those in the 20-29 age range.
“This is primarily a result of increasing injection drug use associated with America’s growing opioid epidemic,” the CDC reported.1 “Still, three-quarters of the 3.5 million Americans already living with hepatitis C are baby boomers. [They] are six times more likely to be infected with hepatitis C than those in other age groups and are at much greater risk of death from the virus.”
Testing has never been more important, because there are now highly effective hepatitis C treatments called direct-acting antiretrovirals (DAAs).
“For a person who doesn’t have [co-infection] with HIV, the cure rates are around 97%-98%,” says Gina M. Simoncini, MD, MPH, FACP, assistant professor of clinical medicine at the Lewis Katz School of Medicine at Temple University in Philadelphia. “For patients who have HCV and HIV [the HCV cure rate is] around 95%, depending on the drugs and whether they already have cirrhosis of the liver.”
A question Simoncini and other researchers are exploring is whether the DAA drugs could be used as an HCV PEP regimen by healthcare workers following a needlestick exposure.2
“From a healthcare worker perspective, I think the biggest concern with using hepatitis C PEP is that we don’t really have a national registry for healthcare workers who have a needlestick,” Simoncini says. “Everything we have is basically estimates — (an estimated 385,000 needlesticks a year), but how many of the source patients actually have HCV? What is the conversion rate? We don’t really have any data.”
Simoncini studied four hospitals in Philadelphia, interviewing employee health nurses and other staff about needlesticks and hepatitis C. The CDC estimates that the incidence of HCV transmission after a needlestick is 1.8%. The CDC does not currently recommend using DAA drugs for HCV PEP, and Simoncini and colleagues hypothesized that this is due to the the lack of data, the low incidence of HCV seroconversion among healthcare workers, and the potential cost of the DAA drugs when used as PEP. They reviewed bloodborne pathogen policies at three hospitals (one institution declined to share its policy), and interviewed occupational health directors and infection preventionists at all four hospitals. For the three hospitals that reported seroconversion data over the last 10 years, there was only one case of HCV infection following a needlestick.
“Anecdotally, they say we don’t see that many seroconversions over a 10-year period,” she says. “I just don’t think we know enough about how a big a problem it is.”
Cases Missed?
In particular, it is likely that HCV cases are missed because sharps injuries go unreported and the virus may remain dormant for years.
“Underreporting is a major issue,” Simoncini says. “You can imagine you have trainees, medical students, who get a needlestick. They are embarrassed and they don’t want to go and seek care because it makes them look like they are not a good student or resident. It makes them feel like they have messed up. For nurses, they are sometimes so committed to patient care they don’t have an opportunity or the [staff] coverage to run downstairs to occupational health and get this taken care of. So I think that underreporting is certainly an issue.”
The interviewees in the study highlighted the need for data regarding the use of DAAs as HCV PEP and/or published updated guidelines from the CDC or another regulatory agency that recommended HCV PEP, she reported. They mentioned that given the effectiveness of DAAs, HCWs who did seroconvert after an occupational exposure could be cured, which obviates the need to use PEP for all exposures. Simoncini notes that one healthcare worker told the researchers, “Experts say the treatment is so good. Why not wait until seroconversion to avoid potential adverse effects or cost?”
With the DAA drugs making HCV essentially a treatable disease, perhaps it is time to refocus research on treatment of HCV seroconversion instead of HCV PEP, she says.
“About 20% of people who pick up hepatitis C clear themselves naturally with their immune systems [within about six months],” she says. “So, this has come up in this discussion — why not wait the six months to see if people [test positive]. You may have the relatively rare seroconversion that actually amounts to chronic infection, but why not just wait that six months and see if it clears and if they are one of of those 20%. Then, if not, do the [DAA treatment] and that should be covered by the occupational health workers’ compensation.”
Given the low seroconversion rate and other factors, it would be extremely challenging to assess DAA drugs for PEP and establish a concise protocol for the timing and duration of the intervention.
“We don’t have any idea of what that [a PEP] protocol would look like, and so there is a need for guidance to say how long the treatment should be,” she says. “I think for that reason most occupational health practices are not using PEP. I think from a physician/public health standpoint, we have limited resources. The drugs cost a lot of money. If we were to put every single [healthcare worker] who has had a bloodborne pathogen exposure to HCV on PEP, we would probably bankrupt workers’ compensation insurance. We are in a limited resource time, and the data that we do have suggest there is a relatively low [probability] of seroconversion. It is a hard argument to make to spend $50,000 to $100,000 on every single person who gets an [HCV-positive] needlestick. That’s a ton of money and there is not really evidence that they need it.”
Other researchers recently came to the same conclusion, citing similar arguments of low risk, cost-effectiveness, and lack of guidance to support HCV PEP.3
“Any studies of or recommendations for PEP would have to acknowledge that this intervention is not cost-effective,” the study concluded. “In addition, the clinical application of these results would need to consider differences in efficacy across genotypes and use a pan-genotypic regimen when feasible. The lack of understanding of the appropriate length of therapy for PEP and the lack of feasibility of conducting an adequately powered clinical trial to assess efficacy further solidify this argument. Instead, appropriate follow-up and post-exposure testing, reassurance, and early treatment of acquired HCV infection with potent DAA combination therapies should be recommended.”
In an accompanying editorial, researchers expanded the authors’ decision analysis to factor in the anxiety and lost quality of life in the “no PEP” strategy. Under nearly all circumstances, the “no PEP” strategy was preferable, suggesting that DAA drugs are not an efficient use of resources even when one does explicitly incorporate anxiety into the analysis.
“Close follow-up, post-exposure testing, continued reassurance, and early treatment with direct-acting antiviral combination therapy in the event that HCV transmission occurs continue to be the paradigm for HCV post-exposure care,” they reported.4
REFERENCES
- CDC. New Hepatitis C Infections Nearly Tripled over Five Years. May 11, 2017: http://bit.ly/2qErNrP.
- Simoncini GM, Jessop AB. Hepatitis C Post-Exposure Prophylaxis for Healthcare Personnel: Policy Analysis Among Philadelphia’s Large Teaching Institutions. Infect Control Hosp Epidemiol 2017;38:246–248.
- Naggie S, Holland DP, Sukowski MS, et al. Hepatitis C Virus Postexposure Prophylaxis in the Healthcare Worker: Why Direct-Acting Antivirals Don’t Change a Thing. Clin Infect Dis 2017;64(1): 92-99.
- Barocas, JA, Linas BP. Decision Science at Work: The Case of Hepatitis C Virus Postexposure Prophylaxis. Clin Infect Dis 2017;64(1): 100-101.
The drugs now available to treat HCV are highly effective, raising the question of whether they could be used in a PEP protocol after needlesticks involving HCV-positive blood.
Subscribe Now for Access
You have reached your article limit for the month. We hope you found our articles both enjoyable and insightful. For information on new subscriptions, product trials, alternative billing arrangements or group and site discounts please call 800-688-2421. We look forward to having you as a long-term member of the Relias Media community.