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The Dangers of HCV Transmission: How the Infection Spreads Today

Issue: March 2015

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Many patients with hepatitis C virus are cured using novel treatments, and many more flood the system due to increased screening protocols, but the clinical community also must remember to keep a watchful eye on trends in how the disease is transmitted.

HCV Next spoke to several experts on HCV transmission in this era of increased awareness of HCV. Although some high-profile cases have hit the mainstream media and caused a certain degree of misinformation — one involved a man spitting blood into a police officer’s face and telling the officer he was HCV-positive — most experts agree that HCV is largely being transmitted through injection drug use, hazards in the health care setting and unsafe sexual practices.

But the nuances of those transmissions may be evolving. Harm reduction programs and prison interventions may be affecting rates among people who inject drugs. As improved technology and raised awareness have reduced the number of needle sticks and blood exposures in health care facilities, an increasing number of non-HCV experts, including primary care physicians and drug and alcohol counselors, may be forced to deal with the disease. This, in turn, could bring about an increase in transmission at the hospital or the clinic. And although the safe sex message was promoted to near saturation during the height of the HIV epidemic, some experts believe that the impact of that message has worn off, and unsafe sexual practices are increasing in prevalence.

Jason Grebely, BSc, PhD, associate professor and NHMRC Career Development Fellow at the Kirby Institute at the University of New South Wales in Australia, discussed the issue of transmission in terms of the reality of eradicating HCV in people who inject drugs. He and colleagues recently published research on the feasibility of reducing HCV in people who inject drugs through various interventions, including treatment as prevention.

Jason Grebely

“Essentially … elimination of HCV among people who inject drugs is probably much more feasible than HCV eradication,” Grebely said. “Any strategy to eliminate HCV might be able to reduce the incidence of HCV infection to zero in defined geographical areas with continued interventions to prevent re-emergence of infection — such as needle and syringe programs and opioid substitution treatment — but it will be difficult to achieve eradication, a complete and permanent worldwide reduction to zero.”

Injection Drug Users

Roux and colleagues investigated factors associated with HCV risk practices in a cohort of 195 patients on methadone maintenance. They aimed to assess the feasibility of initiating methadone in the primary care setting as opposed to initiation in specialized facilities. Patients were followed for 12 months and queried about HCV risk prevention practices such as sharing needles, syringes, toiletry items or other drug paraphernalia, getting a tattoo or having a piercing in a nonprofessional context.

Results indicated that 19% of the cohort engaged in HCV risk practices at baseline, whereas 15% engaged in these practices at month 12. Adjusted analysis results indicated that living as a couple with a nondrug user and being in a couple with a drug user both predicted engagement in HCV risk practices.

“Innovative prevention approaches tailored to couples are also urgently needed and could decrease HCV-risk in this population,” the researchers concluded.

“The issue of HCV transmission among people who inject drugs is particularly important among many high-income settings, given that the majority of new cases (70% to 80%) occur among this group,” Grebely said. “While HCV transmission among injection drug users is also important among many low- and middle-income countries, this varies according to geographic region.”

Alexis M. Roth, PhD, MPH, assistant professor of community health and prevention at the Drexel University School of Public Health, agreed. “There are harm reduction programs, such as syringe exchange programs [SEPs], in many major cities, but there are plenty of places where these services are not covered,” she said. “Because there is a federal ban on funding for SEPs, provision of these services varies state-to-state.” According to a 2013 report by amfAR, the Foundation for AIDS Research, 20 states do not have SEPs and those who do are vastly underfunded despite evidence these programs are both effective and cost-saving, Roth added.

Roth said that poor funding may increase risk in a number of ways because these programs often provide a host of other supportive services such as linkages to drug treatment, overdose prevention, prevention education for HIV, HCV, and sexually transmitted infections, housing, social services and medical care. “While injection drug users might know that sharing needles can lead to transmission of diseases, they may not know that unsafe sexual practices, especially among [men who have sex with men] living with HIV, or sharing works such as cookers, cottons or rinse water also can transmit infectious disease. Quite simply, HCV is more prevalent among persons who inject drugs and much heartier than HIV,” she said. “We need programs to raise this kind of awareness.”

Another complicating factor is that the epidemiology of injection drug use is shifting, according to Roth. “We are seeing the rise of prescription opioid addiction as these drugs become unobtainable or unaffordable, individuals may initiate heroin use because it is cheaper and more available,” she said.

Younger individuals from higher socioeconomic backgrounds with little history of injection drug use are transitioning to needles and are at increased risk for overdose. Roth suggested that these uninitiated populations may need targeted interventions to both decrease the likelihood that they begin injecting and prevent the spread of disease among those who do.

Grebely highlighted the risk for reinfection among injection drug users. With so many patients achieving cure on novel DAA combinations, individuals prone to high-risk behaviors may acquire HCV again, even after successful treatment or intervention.

In the Health Care Setting

Many recent papers have looked at HCV transmission in the health care setting.

Eskandarani and colleagues investigated 2,274 exposures to blood and body fluids among health care workers in Denmark between 2003 and 2012. Although they reported a prevalence of anti-HCV/HCV-RNA of 3.8% among source patients, there was a 0% incidence and prevalence of HIV, HCV and hepatitis B virus.

“Despite a high rate of exposure to [blood and body fluids] among health care workers, the risk of infection was low,” they concluded.

Douglas T. Dieterich, MD, professor of medicine in the division of liver disease at the Icahn School of Medicine at Mount Sinai, offered perspective on these findings. “In the last 5 or 10 years, there have been so many new ways to prevent needle sticks in blood drawing that it is hard to get a significant needle stick that way,” he said. “So this is not particularly a worry right now.”

Douglas T. Dieterich

Scheller and colleagues estimated bloodborne infection risk in emergency rooms in Germany and investigated the extent to which trauma team members are complying with prevention protocols. They sent a questionnaire to 100 trauma team members. Results indicated insufficient knowledge of bloodborne infection risk and overestimation of HCV infection risk.

In another study, Caciari and colleagues investigated biological risk among 254 health care workers at a single center in Rome. Four percent of health care workers with exposure to high-risk situations were positive for HBV and HCV. Among those in the low-exposure risk group, the prevalence of HCV positivity was 2.6%.

“We found a small numbers of positive cases of hepatitis B and C in people exposed to biological agents,” the researchers concluded. “We did not find alterations of the average values of transaminases, total protein, alkaline phosphatase, gamma GT, total bilirubin and albumin in positive cases, so that we can say that the proper use of personal protective equipment, training and information of workers and the observance of universal precautions are effective in protecting workers.”

“In the OR, there still will be sticks due to scalpels and other instruments,” Dieterich said. “However, it is still relatively difficult to transmit HCV.”

Yet, this is not the case worldwide, according to Grebely.

“Iatrogenic transmission still is a major source of transmission in many countries with inadequate infection control practices in the health care setting,” Grebely said.

Serdar and colleagues reviewed occupational exposures to infections at the University Hospital Dubrava in Croatia between 2002 and 2011. The analysis included 451 cases of exposure, of which 55.4% occurred among nurses and medical technicians. Needle stick injuries occurred in 77.6% of the cohort, whereas 27.9% occurred during blood sampling and 23.5% occurred during surgery.

Positive serology for HIV was reported in 2.2% of patients. However, “cases of professionally acquired infections were not recorded in the registry,” the researchers wrote. “The most important preventive action in respect to HBV, HCV and HIV infections is nonspecific pre-exposure prophylaxis.”

One positive to take away from health care-related infections is that those individuals are likely to be treated in a timely fashion. With highly curative direct-acting antiviral agents readily available, the long-term effects of these infections will be mitigated.

MSM

Marina Daskalopoulou, a PhD student at the University College London, and colleagues studied associations between self-reported sexual behaviors and drug use in men who have sex with men (MSM) with HIV. They found that recreational and injection drug use, along with unprotected sex and multiple new sexual partners, were factors associated with pre-existing HCV incidence. All of these factors except injection drug use predicted new HCV infection among MSM with HIV.

Dieterich summed up the issue succinctly. “Unsafe sex is back,” he said.

Roth said sexual transmission has been considered a rare and inefficient mechanism of HCV transmission. However, she echoed the conclusions seen in the Daskalopoulou study. “There appears to be very little transmission of HCV except in situations where one of the individuals has HIV,” she said. “Recent studies have linked greater numbers of sexual partners, drug use, and sexual practices that damage rectal tissues … to HCV seroconversion among MSM.”

Then there is the issue of HIV serosorting among MSM with HIV engaging in unprotected sex with other HIV-infected partners, which could lead to increased risk for transmission of HCV.

“If men are not aware of the risks and mechanisms associated with sexual transmission, clinicians must include consciousness raising and routine testing for HCV as part of their standard of care,” Roth said.

Prisons

“The availability of simple, tolerable and highly efficacious interferon-free HCV therapies has the potential to substantially broaden access to simplified regimens, which will expand the potential settings for delivery of treatment,” Grebely said. Some of these settings include prisons.

However, the issue is not as simple as administering pills for 12 weeks, nor has this kind of intervention been proved. Complicating factors include economics and adherence, among others.

“Mathematical modeling has suggested that with relatively moderate HCV treatment uptake rates, that HCV treatment among people who inject drugs could have a substantial prevention benefit, with the potential impact on reducing HCV transmission,” Grebely said. “This may be particularly feasible in settings such as prisons or in drug and alcohol clinics, if sufficiently high HCV treatment uptake could be achieved.”

Treatment as Prevention

Another approach addressed by Grebely and colleagues is treatment as prevention. “As newer interferon-free HCV therapies become available, HCV treatment as prevention may be an attractive option to reduce the future burden of HCV-related disease,” he said.

However, most clinicians agree that treatment as prevention may be feasible, but could prove difficult in settings where HCV prevalence is high. Grebely added that this strategy will need to be compatible with other existing interventions and treatment platforms.

For Roth, cost is a major obstacle to treatment as prevention. “All of this is predicated on people being able to access these drugs,” she said. “Medication can only be as effective as people getting access to it.”

Roth added that the requirements related to being able to receive DAA therapies are stringent and include everything from being sober to undergoing fibrosis screening. “These requirements create further obstacles to life-saving treatment,” she said.

The general consensus among most experts is that the cost of DAA therapy will come down. Whether that will occur because of competition, or because of elective decisions in the pharmaceutical industry, or because of intervention by government or nongovernment organizations remains to be seen. Grebely suggested that programs such as the Global Fund to Fight AIDS, Tuberculosis and Malaria may serve as a model for controlling costs of HCV medications. From there, treatment as prevention may become a reality and the clinical community may have another weapon in the arsenal for reducing HCV transmission. – by Rob Volansky