Despite – or perhaps because of -- the incredible cure rates being achieved by new drugs for hepatitis C virus, experts say post-exposure prophylaxsis for exposed healthcare workers is not the path to pursue. Given a host of undermining variables, it is better to repeatedly test a worker who suffers a needlestick, ready to treat as soon as a seroconversion occurs, experts concur.

As IPs are well aware, there is no vaccine for HCV. However, the drugs now available to treat HCV are highly effective, raising the question whether they could be used in a PEP protocol after healthcare worker exposures.

There is certainly 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 Centers for Disease Control and Prevention (CDC). While the majority of those cases are in people age 55 and older -- “baby boomers” – HCV infections are increasing most rapidly among in those in the 20 to 29 year 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 antiretroviral (DAA) drugs.

“For a person who doesn’t have [co-infection] with HIV the cure rates are around 97%-98%,” says Gina M. Simoncini, MD, MPH, 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 that is being explored by Simoncini and other researchers is whether the DAA drugs could be used as an HCV PEP regimen by healthcare workers following a needlestick exposure.²

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. However, it is likely that that HCV cases are being 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.”

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.”

Confounding Variables

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. 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,” they 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 postexposure 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 till 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

1. CDC. New Hepatitis C Infections Nearly Tripled over Five Years. May 11, 2017: http://bit.ly/2qErNrP
2. 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.
3. 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.
4. Barocas, JA, Linas BP. Decision Science at Work: The Case of Hepatitis C Virus Postexposure Prophylaxis. Clin Infect Dis 2017;64(1): 100-101