Hepatitis C (HCV) and HIV are two of the most devastating, chronic diseases afflicting Americans. The two viruses share many characteristics. Both infect healthy human cells (HIV targets immune cells, while HCV goes after the liver). Both can be passed from person to person via sexual contact or blood exposure, and both can cause life-long illness.
Despite their similarities, HIV and HCV differ dramatically when it comes to detection, treatment and care. Although HCV is more than three times as prevalent as HIV in the United States, the federal government allocates a fraction of federal funding (see, for example, the 2015 budget summary and 2016 budget request for the Centers for Disease Control and Prevention [CDC]) to viral hepatitis programs relative to HIV programs.
Another major difference is that HCV can be cured with direct-acting antivirals (DAAs), while HIV is treated with life-long antiretroviral therapy. It is easy to assume that health care providers could quickly tackle a disease for which they can offer patients a cure. However, in reality, far more HCV patients fall through the cracks in the health care system.
Much of the disparity has to do with lack of funding, said Ryan Clary, executive director of the National Viral Hepatitis Roundtable. HCV lacks sufficient surveillance and outreach programs needed to tackle the disease. No one really knows the true number of infected patients in the United States -- all figures reported are rough estimates based on patchy surveillance. Accurate figures are desperately needed, as HCV is 10 times more infectious than HIV. Approximately four million people are thought to have HCV in the Unites States, compared to 1.2 million with HIV.
A concept called the care continuum, or treatment cascade, has significantly bolstered detection and control efforts of HIV in the United States. The care continuum was developed by Edward Gardner, M.D., and his colleagues in 2011. The CDC -- as well as other federal and local health agencies -- now follow the five steps of this model to track a patient's journey through the health care system: (1) diagnosis, (2) linkage to care (visiting a health care provider within three months of diagnosis), (3) engagement in care, (4) prescription of ART drugs and (5) viral suppression.
The CDC tracks the number of patients passing through each step, enabling it to identify if and when patients are dropping out. In 2013, President Obama issued an executive order called the HIV Care Continuum Initiative, which instructs federal programs to prioritize the care continuum in the roll out of the National HIV/AIDS Strategy.
Drawing inspiration from the HIV care continuum, experts have proposed that one be codified for HCV treatment. Scott Holmberg, M.D., chief of the epidemiology and surveillance branch in the CDC's division of viral hepatitis, proposed one model in 2013. Holmberg's findings were stark: of the 3.2 million people estimated to have HCV in 2013, 50% had been diagnosed, 32% to 38% had been referred to care, 7% to 11% had started treatment and 5% to 6% had been successfully cured.
Another model was published in 2014 by Baligh R. Yehia, M.D., from the department of medicine at the University of Pennsylvania Perelman School of Medicine. Yehia's analysis offered slightly different figures but the same general conclusion. He found that of the 3.5 million people estimated to have HCV, only 9% had moved through all seven steps of his proposed care continuum to achieve a cure.
Among HIV practitioners and advocates, the care continuum packed a punch. It is a simple model for tracking a patient's progress and identifying weaknesses in health care delivery. Since its introduction in 2011, it has become an integral tool for promoting patient engagement. Holmberg noted that for HCV the CDC supports campaigns to increase the numbers of people being tested, linked to care and treated. Nevertheless, implementation of an HCV care continuum is far less robust, Clary said.
Right now, the two ends of the HCV continuum need the most work, said Gardner, the architect of the HIV care continuum: "We need to increase the number of patients aware of their diagnosis and we need to start increasing access to modern Hepatitis C treatment regimens in order to cure Hepatitis C for the individual and prevent forward transmission in the community."
According to Clary, the weakest link in the HCV care continuum is step 1: diagnosis. Experts estimate that of the millions of infected patients, between 50% and 75% have no idea that they carry the virus, he said. Because at least half of those infected with HCV are not aware of their infection, testing is a vital first step for connecting those in need with effective treatment and care, agreed Holmberg. However, even when patients are diagnosed, progressively fewer are evaluated for their infections and for receipt of effective therapy, so every step along the care continuum loses some patients, Holmberg continued.
In 2012, the CDC tried to address this dismal lack of screening with new guidelines. The new guidelines recommend that all baby boomers (the so-called "birth cohort") be tested at least once. The guidelines also call for testing of people who engage in high-risk behaviors such as needle sharing or tattooing. By contrast, every patient who walks into a doctor's office -- regardless of age or risk behavior -- will likely be offered an HIV test at least once.
Even inside a clinical setting such as a hospital or doctor's office, HCV testing is not as emphasized as HIV testing, said Clary. As a result, birth cohort and high-risk patients can often be overlooked. HCV has been regarded as a disease primarily affecting baby-boomers, but alarmingly, the epidemic has flared up in a younger population. In the last few years, the CDC has documented a sharp increase of HCV among young people in rural and suburban areas who inject drugs, Holmberg said.
"I agree with the CDC that screening by birth cohort is necessary and needs to increase," said Gardner. "However, HCV prevalence, while lower in other age groups, is still higher than HIV prevalence in most general U.S. populations. While younger individuals may be less likely to have advanced liver disease, diagnosis and treatment of younger individuals is more likely to prevent ongoing HCV transmission in the community," Gardner said.
Better screening could build a sense of community among HCV-positive individuals, Clary pointed out. For HIV, patient advocates have come together in the last few decades to identify with their status, and this community has emerged as a powerful force supporting funding initiatives, said Clary.
"If we can successfully go out to identify new patients, not only would we be able to help them through the continuum, but we would also be developing a stronger advocacy base to go petition Congress for additional funding," Clary said.
This fiscal year, the CDC was allocated $31.4 million for its entire viral hepatitis department, including hepatitis A, B, C, D and E. By contrast, the CDC was allocated $796.2 million for its HIV-prevention efforts and an additional $363.8 million for HIV surveillance, research and other programs.
The CDC is requesting an additional $31.5 million for viral hepatitis prevention for fiscal year 2016, but even a doubling of the budget would provide resources that pale in comparison to those that have benefited the HIV community. With a bigger budget to codify a care continuum in HCV, fewer patients would be allowed to fall through the cracks, Clary said.
The tide may be turning for HCV. A new class of antiretroviral drugs has revolutionized treatment -- partially because of its incredible cure rate, and partially because of its eye-popping price tag. These drugs have been steeped in controversy because of the extraordinary cost -- up to $95,000 per course of treatment -- which has prompted insurance companies to deny coverage to many patients. Recent media attention on these pricey drugs has illuminated the fact that most HCV patients remain unaware of their status -- making them perfect candidates for step 1 of a codified care continuum.