Chronic hepatitis C virus (HCV) infection typically takes years or decades to progress to severe liver disease. Many people now developing cirrhosis or liver cancer were infected as young adults in the 1960s-1970s, when HCV was not yet identified and experimentation with drugs was more common.

Healthcare providers generally offer HCV testing to people thought to be at risk, including current or recent injection drug users, people who received blood transfusions before donated blood was adequately screened, and others with known or suspected exposure. The U.S. Preventive Services Task Force does not recommend screening for low-risk populations.

But this approach may not identify everyone at risk, leaving a significant number of people with undiagnosed and untreated infection, according to a study by Lisa McGarry and colleagues presented at the Digestive Disease Week meeting (DDW) this week in Chicago. Funding for the research was provided in part by Vertex Pharmaceuticals, which is developing the new HCV protease inhibitor telaprevir (Victrelis).

Approximately three-quarters of people with HCV are not aware they are infected, and many will not be diagnosed until they are symptomatic, at which point treatment is less effective, the researchers noted as background. It is estimated that less than 3% percent of infected individuals are screened each year.

McGarry's team compared mathematical models of targeted HCV screening based on birth year versus current risk-based screening. The birth cohort screening model assumed that everyone born between 1946 and 1964 -- the "baby boomer" generation -- would be screened once over a 5-year period, regardless of risk factors or liver disease symptoms. Another model looked at a larger "baby boomer plus" cohort of people born between 1946 and 1970. The researchers assumed that 24% of people would be treated with standard interferon-based therapy at the time of diagnosis, about one-third would be ineligible for treatment, and 10% of untreated people would start therapy each year.

Results

	The 1946-1964 birth cohort approach would screen about 79 million people vs 8 million using the risk-based approach.
	More than 1.3 million people would be diagnosed as having HCV using the former approach compared with about 427,000 using the current approach.
	About 472,000 vs 234,000 people, respectively, would undergo hepatitis C treatment.
	About 404,000 vs 124,000, respectively, would achieve sustained virological response, or a cure.
	Rates of liver disease outcomes would decrease with expanded screening:
	Compensated cirrhosis: 112,881 fewer cases; Decompensated cirrhosis: 52,787 fewer cases; Hepatocellular carcinoma: 28,634 fewer cases; Liver transplants: 5,914 fewer cases; HCV-related deaths: 47,953 fewer cases.
	Screening the "baby boomer plus" cohort would result in approximately 106,000 fewer cases of advanced liver disease and about 59,000 fewer HCV-related deaths.
	Birth-cohort screening would cost more than risk-based screening ($45.1 billion vs $32.0 billion), but would reduce expenses related to advanced liver disease ($21.7 billion vs $25.8 billion).

Use of new direct-acting anti-HCV drugs, which increase the cure rate when added to pegylated interferon/ribavirin, would lead to even greater reductions in advanced liver disease and death if age-based screening were implemented, the researchers noted.

"Screening is potentially a smart investment, comparable to widely accepted preventive health practices," McGarry said in a press release issued by DDW. "In particular, screening for HCV now may reduce future costs to Medicare."

Investigator affiliations; i3 Innovus, Medford, MA; Baylor University Medical Center, Dallas, TX; Inova Health System, Falls Church, VA; DiVita Clinical Research, Boston, MA; Harvard School of Public Health, Boston, MA.

5/13/11

Reference
L McGarry, GL Davis, ZM Younossi, et al. The Impact of Birth-Cohort Screening for Hepatitis C Virus (HCV) Compared with Current Risk-Based Screening on Lifetime Incidence of and Mortality from Advanced Liver Disease (AdvLD) in the U.S. Digestive Disease Week (DDW 2011). Chicago. May 7-11, 2011. Abstract 477.

Other Source
Digestive Disease Week. Investigators Make Great Strides in Identifying and Improving Screening Practices and Treatment for Liver Related Diseases. Press release. May 8, 2011.