Treatment duration in acute hepatitis C: the issue is not solved yet

Diagnosis and treatment of acute hepatitis C virus infection

The first 6 months after exposure to hepatitis C virus (HCV) are regarded as acute hepatitis C (AHC). Two patient populations worldwide share the highest prevalence of AHC virus infection: injection drug users and HIV-positive men who have sex with men. Diagnosis of AHC is often difficult in both patient populations as the acute inflammatory phase can be clinically asymptomatic and patients at highest risk for acquiring AHC (injection drug users) tend to evade regular medical care. This article addresses similarities and differences in the epidemiology, diagnosis, and management of AHC monoinfection and coinfection.

Treatment of acute HCV infection

In developed nations, the majority of new HCV infections are acquired by injection drug users. Acute HCV infection is generally asymptomatic and is followed by spontaneous viral clearance in approximately 25% of individuals. However, given the asymptomatic nature of infection and difficulties in identifying and following those at risk of acquiring infection, our knowledge of treatment for acute HCV infection has been hampered. Much of what is known about the timing, optimal regimen and duration of therapy comes from small, prospective, observational studies and randomized, controlled trials in selected populations. Furthermore, data on the treatment of acute HCV infection among injection drug users and patients co-infected with HCV and HIV are limited. Genetic testing for variations in IL28B may provide an additional diagnostic tool for the optimal management and treatment of acute HCV infection. This Review highlights current knowledge of the epidemiology, diagnosis, natural history and treatment of acute HCV infection, including proposed recommendations for the assessment and treatment of this infection.

Acute hepatitis C

Symptomatic acute hepatitis C occurs in only about 15% of patients who are infected with hepatitis C virus (HCV). Acute hepatitis C is most often diagnosed in the setting of post-exposure surveillance, or seroconversion in high-risk individuals (eg, health-care professionals or injecting drug users) previously known to be seronegative. Although transmission via transfusion and injecting drug use has declined in developed countries, unsafe blood products and medical practices continue to increase transmission of HCV in many developing countries. Clinically, acute hepatitis C can increase concentrations of alanine aminotransferase to ten times the upper limit of normal but almost never causes fulminant hepatic failure. Diagnosis of HCV infection in the acute phase is difficult since production of antibodies against HCV can be delayed by up to 12 weeks, and about a third of infected individuals might not have detectable antibody at the onset of symptoms. Therefore, testing for HCV RNA by PCR is the only reliable test for the diagnosis of acute infection. Symptomatic patients with jaundice have a higher likelihood of spontaneous viral clearance than do asymptomatic patients, and thus should be monitored for at least 12 weeks before initiating antiviral therapy. By contrast, asymptomatic patients have a much lower chance of spontaneous clearance, and might benefit from early antiviral therapy. Antiviral therapy for 12 weeks is generally effective in treating patients who are HCV RNA negative after 4 weeks of treatment; lengthier courses could be needed for those who relapse or fail to show early virological clearance.