During 2014, the 25th anniversary of the identification of the hepatitis C virus (HCV), it became clear that a spate of new antiviral drugs and novel treatment strategies heralded a future in which a significant proportion of patients can be cured of HCV infection. The evolving saga is highlighted by efforts at enhanced early recognition, the development of better-tolerated and more effective therapeutic regimens, and the emergence of ever-changing management guidelines.
The current and highly successful strategic treatment approach is similar to that used for the treatment of HIV infection. Antiretroviral agents with different mechanisms of action are combined in order to increase efficacy and prevent resistance. However, not all eligible patients with HCV have been tested and identified, and even fewer have been referred for care or offered treatment. Thus, HCV infection remains a significant problem worldwide, with risk for progression to cirrhosis, liver failure, and hepatocellular carcinoma (HCC).
At this year's Digestive Disease Week, investigators discussed issues related to screening efforts, the natural history of HCV infection, the safety and efficacy of the next wave of antiviral agents, access to care, and affordability of treatment.
Variability of Hepatitis C Screening in Veterans
In August 2012, the Centers for Disease Control and Prevention (CDC) and the US Preventive Services Task Force called for all Americans in the baby-boomer generation (born between 1945 and 1965) to undergo a one-time screening test for HCV. The response to this call is unclear because relevant data regarding screening practice patterns are limited.
The US Department of Veterans Affairs (VA) is the largest provider of HCV care in the United States. Using their national database, Sarkar and colleagues quantified the variability in screening for HCV across the VA. They queried the database to identify HCV screening rates and predictors of screening among all birth cohort veterans (> 6.6 million) presenting for care within the VA between 2000 and 2013. HCV screening was defined as completion of any diagnostic test, such as anti-HCV, HCV genotype, or HCV RNA viral load.
Overall, 52% of patients had completed HCV testing. The odds of testing were higher by twofold among those with elevated alanine aminotransferase (ALT) levels. The mean (± standard deviation) time to screening from first VA encounter was 784 ± 1121 days. The overall rate of testing for HCV varied across 130 VA centers, ranging from 6.5% to 84.6%, with 41.5% of the centers having a testing rate < 50%. Thus, approximately one half of a large national cohort of US veterans born between 1945 and 1965 completed a qualifying HCV screening test from 2000 to 2013.
The significant variation in HCV testing among centers signals the need for broader policies and interventions to improve screening in target populations. These results also have implications for the implementation of HCV screening based on birth age cohort in large healthcare systems.
Screening Results From Baby Boomers
Smyth and colleagues analyzed HCV screening rates in more than 100,000 clinical practices nationwide and found that in the year after the CDC call, screening rates rose significantly in the baby-boomer cohort but decreased significantly in non–baby-boomer cohorts. Using data from the nationwide Medivo Lab Exchange Database, they analyzed laboratory test results from almost 5 million adults who were screened for HCV antibody between August 2011 and July 2014.
Overall, the anti-HCV positivity rate was 8.5%: 12.7% among baby boomers and 4.4% among non-baby boomers. Logistic regression analysis showed that baby boomers were 250% more likely than non-baby boomers to have a positive anti-HCV test. However, over time, HCV positivity rates among baby boomers fell in comparison with non-baby boomers.
The investigators confirmed that HCV positivity rates were indeed significantly higher among baby boomers than non-baby boomers and that HCV genotype 1 continues to be the most common genotype in the United States. They suggested ongoing studies to continue to examine the results and success of HCV screening and positivity rates across birth cohorts.
Hepatitis C in Immigrants and Refugees From Endemic Countries
HCV infection is a significant global health issue, leading to 350,000 preventable deaths annually due primarily to HCV-associated cirrhosis and HCC. Immigrants and refugees originating from countries with an intermediate to high prevalence of HCV are more likely to have been exposed to HCV and thus have increased mortality from HCV-related cirrhosis and HCC.
Christina and colleagues performed a systematic review and meta-analysis to estimate HCV seroprevalence rates in a migrant population. Multiple data sources were assessed, including original observational studies reporting the seroprevalence of anti-HCV in migrants leaving countries with low to intermediate income and intermediate to high HCV prevalence and arriving in countries with high income and intermediate to low HCV prevalence
Fifty studies representing 38,635 migrants were included. The overall anti-HCV prevalence rate was 1.9%. Older age and region of origin, particularly sub-Saharan Africa, Asia, and Eastern Europe, were the strongest predictors of positivity. No statistically significant difference in HCV seroprevalence was found between immigrants and refugees. The estimated HCV seroprevalence of migrants living in countries with low HCV prevalence was at least twofold higher than in most host populations.
The investigators estimated that approximately 1.3 million migrants living in countries with low HCV prevalence are positive for anti-HCV and account for > 15% of HCV seroprevalence in the majority of host countries. They concluded that because migrants originating from countries with intermediate to high HCV prevalence have a higher seroprevalence of HCV, they may benefit from targeted HCV screening.
Medscape Gastroenterology © 2015 WebMD, LLC
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Cite this: William F. Balistreri. Hepatitis C: 25 Years Old, and Fading - Medscape - Jun 15, 2015.