for Health Care Providers
Acute HCV - Hepatitis C
Acute hepatitis C (HCV) infection is defined as the 6-month time period following exposure to the hepatitis C virus. After initial infection, the virus clears spontaneously in an estimated 20 to 35% of patients. These patients never develop chronic hepatitis C infection.
The CDC tracks confirmed cases of acute hepatitis C virus infection each year, which are reported by each state on a voluntary basis. The CDC requires that a confirmed case of acute HCV meet both clinical criteria (discrete onset of symptoms such as nausea or malaise plus either jaundice or a peak elevated serum alanine aminotransferase (ALT) level >200 IU/L) and laboratory criteria (positive HCV RNA). The HCV antibody can be negative during the first 6 weeks after exposure. A case can also be classified as acute HCV if the patient has a documented negative HCV test followed by a positive test within 12 months. The CDC also computes an estimate of the true number of new HCV infections per year after taking into account the fact that acute infections are likely to be asymptomatic and underreporting by clinicians is high.
During the 1980s, the estimated total of new HCV infections was 180,000-290,000 cases per year in the United States. During the early 1990s, the number of new infections sharply declined by more than 80% to 36,000 per year in 1995, and then slowly declined until 2005. From 2005-2010 there was a plateau at 16,000-21,000 cases per year. However, since 2011, the incidence has been steadily rising from 16,500 cases per year in 2011 to 33,900 cases per year in 2015. Acute HCV infections have increased notably among intravenous drug users and men who have sex with men (MSM), especially MSM who have HIV infection.
Since acute HCV can resolve spontaneously within the first 6 months, it is recommended that clinicians initially monitor patients with acute HCV infection for at least 3 months after time of infection to allow for the possibility of spontaneous clearance. If spontaneous clearance occurs with HCV RNA becoming undetectable, then antiviral treatment is not recommended. If spontaneous clearance has not occurred by 3 months, treatment should be considered. Direct-acting antivirals (DAAs) are also under study for acute hepatitis C. If a DAA regimen is considered, the same regimen that is recommended for chronic HCV is also recommended for acute HCV.
Before the availability of DAAs, there was a stronger recommendation to treat those with acute HCV with PEG-RBV immediately after diagnosis, without a waiting period. That is because PEG-RBV is more effective for treating acute HCV than for chronic HCV. However, monitoring for spontaneous clearance before initiating treatment became a more viable option after the introduction of DAAs as a highly effective treatment for chronic HCV. In sum, PEG-RBV or an appropriate DAA regimen could be considered for treatment of acute hepatitis C to prevent development of chronic HCV infection.