By Dr. Karine Lacombe, IAS 2013 Plenary Session Speaker
Initially associated with blood transfusions and hospital care, the Hepatitis C virus (HCV) epidemic has since moved rapidly onwards to intravenous drug users, where it remains a major problem. Despite numerous harm reduction programmes, such as needle exchange, opiate substitution, and controlled shooting galleries, drug addiction remains the number one route of HCV transmission around the world. However, in HIV-infected patients, the HCV epidemic experienced a major shift in the mid-1990s, with sexual transmission, particularly among men who have sex with men (MSM), surfacing as a major route of HCV acquisition. Around 25% of HIV-infected patients are also chronic carriers of HCV and, because of the intricate and deleterious influence both viruses have upon one another, liver-related morbidity and mortality have been increasing among those who are co-infected.
Identifying HCV-infected persons is imperative and, without suitable HCV screening campaigns, it will continue to be a major hurdle towards getting infected persons into appropriate care. Patients at-risk of HCV infection, such as those reporting the use of recreational drugs and having traumatic sexual practices, are generally tested once but not regularly during their lifetime. Furthermore, screening tests have been for a long time based on Elisa, which is mainly available in medical settings, thus restricting the development of community-oriented screening campaigns.
The advent of point-to-care tests (either salivary or capillary) should help increase infection awareness in outreach campaigns geared towards more at-risk populations. Increasing the effectiveness of identifying HIV-HCV co-infected patients with end-stage liver disease is another crucial issue when it comes to increasing the life expectancy associated with broad-use HAART.
Therapeutic options in HCV infection had been quite limited and based largely on the use of combined Peg-Interferon and ribavirin. In HCV-treatment naïve HIV -nfected patients the rate of efficacy does not exceed 50% at best, with a 48 to 72 week-treatment duration and numerous serious adverse events that often lead to treatment interruption.
With the recent, exciting developments in HCV research, new targets on the virus replication cycle have been discovered and the first two molecules specifically targeting HCV protease, telaprevir and boceprevir have been marketed in 2011. Used in combination with peg-interferon and ribavirin, they have led to an increase of 20% to 30% in the treatment response rate. However, their effectiveness is affected by the high rate of side effects (anemia, skin toxicities) and factors such as the prior response to peg-interferon and ribavirin or fibrosis level. Sustained virological response rates in cirrhotic patients with a prior null response may not exceed 10%.
Therefore, the next steps of the revolution in HCV care and management are highly awaited. New drugs are currently being evaluated and may greatly change the course of treatment: once daily, highly active and easily-tolerated regimens, administered for a short period of time with HCV eradication in more than 90% of patients, independently of prior treatment, level of fibrosis, and comorbidities such as HIV co-infection. This definitely has the potential to curb the HCV epidemic, provided that advocacy for broad-access to treatment is successful for those most in need. The use of these treatments in resource-constrained settings may also be the next political challenge for HCV in the future.