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For many years the only available treatment for chronic hepatitis C virus (HCV) infection was an injectable formulation of interferon-alpha. This had modest effectiveness and generally caused many side effects. Interferon-alpha works by mobilizing the immune system against the virus.
About a decade ago pharmaceutical companies began to develop drugs that could specifically attack HCV-infected cells. These drugs are called direct-acting antivirals (DAAs). The first generation of DAAs were taken orally but had to be used together with interferon. The second generation of DAAs are far more potent and can be used in combination with each other. Combinations of second-generation DAAs are now the standard of care for HCV in Canada and other high-income countries. DAAs are generally well tolerated, result in cure rates of 95% or greater in many people, and, depending on the combination used, can be taken for only eight weeks.
Although healthcare services are universally available in Canada, coverage of medications varies from one province/territory to another. When DAAs were first approved by regulatory authorities, most provinces rationed subsidized access to these drugs as prices were high. The rationing mechanism was to enable access of the drugs only to people with severe liver injury. As more DAAs became approved in Canada, bargaining between the provinces/territories and pharmaceutical companies eventually resulted in substantial price reductions. As a result, over time, the rationing of access to subsidized DAAs was lifted, allowing for universal access.
A team of scientists across Canada has been monitoring the health of people co-infected with HCV and HIV. They assessed the trends in use of DAAs before and after the lifting of access restrictions. The scientists found that the cessation of rationing resulted in almost a doubling of the use of these drugs. Among people who injected drugs, the use of DAAs rose almost four-fold.
However, the scientists found that the increase in use was not sustained. A year after universal access to DAAs, rates of treatment declined. The scientists stated that vulnerable populations—particularly people who inject drugs, Indigenous people and those “disengaged from care”—were more likely to remain co-infected with HCV.
Commenting on future steps, the scientists stated that “the minimization of structural barriers and adoption of tailored interventions are needed to engage and treat all vulnerable populations [with HCV].”
Scientists collected and analysed information from a prospective observational study called the Canadian Coinfection Cohort Study (CCC). They focused on data collected between 2010 and 2018. Participants were enrolled from 18 clinics across Canada. For the present analysis, scientists zeroed in on information collected from 1,130 people, distributed as follows:
The scientists found that before all-oral DAAs became available, rates of HCV treatment were low. Once such drugs became subsidized, rates of use initially increased but then fell somewhat.
When provinces ceased rationing DAAs, HCV treatment rates doubled. Among people who injected street drugs, rates of treatment use increased nearly four-fold. However, a year after DAA rationing was lifted, rates of HCV treatment fell, particularly among the following groups who were more likely to remain co-infected:
In contrast, the following populations or factors were associated with being cured of HCV:
The scientists advanced this explanation for the changes in rates of HCV treatment:
“…physicians were aware of those existing patients who were eligible and likely to adhere to treatment, and treated them as soon as access [to DAAs] was expanded. Once most [of these patients] had been treated, the people remaining were those who continued to be more difficult to reach, inconsistently engaged in health care, or perceived to be socially unstable, resulting in a reluctance to initiate treatment.”
The present study was not designed to interview participants as to why some of them did not seek HCV care. However, the scientists pointed to a survey of Canadian infectious disease physicians in which the issue of barriers to HCV care was raised. The physicians suggested that “poor access” to the following served as barriers to HCV care:
Now that subsidized access to DAAs is generally available across Canada, more research with vulnerable populations is needed to help understand barriers to HCV care and how such barriers can be overcome.
Resources
Hepatitis C Treatments – CATIE
Harm reduction programs and resources – Prevention in Focus
Hepatitis C treatment in harm reduction programs for people who use drugs – Prevention in Focus
Blueprint to Inform Hepatitis C Elimination Efforts in Canada: What do service providers need – Prevention in Focus
Opioid agonist therapy: Does it have a role to play in helping to prevent hepatitis C and HIV? – Prevention in Focus
Assessing the cascade of care for opioid use disorder in British Columbia – CATIE News
Trends in deaths among people with hepatitis C virus in British Columbia – CATIE News
Prescribed opioids associated with increased risk of pneumonia – CATIE News
Canadian study finds hepatitis C virus treatment effective in HIV co-infection – CATIE News
—Sean R. Hosein
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