Alanine aminotransferase elevation. This can be considered screening or part of the diagnostic work-up of transaminitis. Regardless of the classification, this is a cohort of people with a high prevalence of HCV antibody. For individuals with one isolated alanine aminotransferase elevation, the prevalence is 3.2%.4 With two or more elevated aminotransferase results, the prevalence rises to 8.2%.4
Hemodialysis. Two major studies have estimated the prevalence of HCV antibody-positive in end-stage renal disease individuals on hemodialysis to be 7.8% and 10.4%.11,12 This prevalence can reach 64% at some dialysis centers.11 The risk of HCV infection has been associated with blood transfusions, longer duration of hemodialysis, and higher rates of HCV infection in the dialysis unit.13 With implementation of infection control practices in dialysis units, the incidence and prevalence of HCV infection are declining.13
Born in the U.S. between 1945 and 1965. The CDC and USPSTF recommend a one-time screening for HCV infection for people born in the U.S. between 1945 and 1965, regardless of the presence or absence of risk factors.6,14 This age group has an increased prevalence of HCV antibodies, at 3.25%.6
Human immunodeficiency virus (HIV). HCV has a prevalence of 30% in people infected with HIV.15 The rate of co-infection is likely secondary to shared routes of transmission. For example, 72.7% of HIV-infected individuals who used IV drugs had HCV antibodies, but only 3.5% of “low-risk” HIV-infected individuals had HCV antibodies.16
Born in a high prevalence country. In the U.S., a significant number of immigrants are from areas with a high endemic rate of HCV infection. High prevalence areas (greater than 3.5%) include Central Asia and East Asia, North Africa, and the Middle East.7 Of note, Egypt is thought to have the highest prevalence of chronic HCV infection in the world, with well over 10% of the population being antibody-positive.17 Although major guidelines do not currently recommend it, the high prevalence of chronic HCV infection in this population may warrant screening.
Other high-risk or high-prevalence populations. The prevalence of HCV infection in people who have had over 10 lifetime sexual partners (3% to 9%), those with a history of sexually transmitted disease (6%), men who have had sex with men (5%), and children born to HCV-infected mothers (5%) is increased compared with the general population.8 Incarcerated people in the U.S. have an HCV antibody prevalence of 16% to 41%.18 In addition, people who have sustained needle-stick injury or mucosal exposure, or those with potential exposures in unregulated tattoo or piercing salons, may also benefit from HCV antibody screening.14
Table 1 reviews HCV screening recommendations for the CDC, AASLD, and USPSTF.1,6,8,14
The most common initial screening test for the diagnosis of chronic HCV infection is the HCV antibody test. A positive antibody test should be followed by an HCV RNA test. In an individual with recent exposure, it takes between four and 10 weeks for the antibody to be detectable. HCV RNA testing can be positive as soon as two to three weeks after infection.8