The incubation period (the amount of time that elapses between infection and
the development of symptoms) varies for the different hepatitis
viruses. Hepatitis A and E may develop as few as two weeks after
exposure, but usually appear after four weeks. For hepatitis B and C it
may take up to six months before symptoms develop. (The average
incubation period is two to three months for hepatitis B and six to nine
weeks for hepatitis C.) In experiments on chimpanzees, hepatitis D
developed two to ten weeks after infection.
After initial exposure, HCV RNA can be detected in blood in 1-3 weeks. Within
an average of 50 days (range 15-150 days), virtually all patients
develop liver cell injury, as evidenced by elevation of serum alanine
aminotransferase (ALT)—[an enzyme which leaks out of the damaged cells
into the bloodstream]. The majority of patients are asymptomatic and
anicteric [whites of the eyes are clear]. Only 25-35 percent develop
malaise, weakness, or anorexia, and some become icteric [whites of the
eyes are jaundiced]. Fulminant [rapid onset] liver failure following
HCV infection has been reported but is a rare occurrence. Antibodies to
HCV (anti-HCV) almost invariably become detectable during the course of
illness. Anti-HCV can be detected in 50-70 percent of patients at the
onset of symptoms and in approximately 90 percent of patients in 3
months after onset of infection. HCV infection is self-limited in only
15 percent of cases. Recovery is characterized by disappearance of HCV
RNA from blood and return of liver enzymes to normal. - National
Institutes of Health Statement on Hepatitis C 1997.
