A 22-year-old man who recently immigrated to the United States comes to the physician for routine care. He has no current symptoms. He takes no medications and has no known allergies. Laboratory testing yields the following results:
Anti-hepatitis A IgM Negative Anti-hepatitis A IgG Positive
The patient's country of origin does not offer universal immunization against hepatitis A, and he says he has not been vaccinated against the virus. Which of the following do these laboratory findings most likely suggest?
This asymptomatic patient with immunoglobulin G (IgG) antibodies against hepatitis A virus (HAV) likely had a prior infection with HAV. In children age <6, HAV infection is most often (>80%) silent or subclinical ("anicteric," with no jaundice observed). Less frequently, it can present as an acute, self-limited illness characterized by jaundice, malaise, fatigue, anorexia, nausea, vomiting, and right upper-quadrant pain. Clinical disease is typically more severe (70% of symptomatic patients with jaundice) in adults (some of whom develop an aversion to smoking, for unclear reasons), although in the United States most adults with anti-HAV IgG antibodies have never experienced an icteric illness. Liver failure and death due to HAV are extremely rare (<0.5% of cases) (Choice E).
(Choices B, C, and F) Unlike hepatitis B or C, HAV infection is a self-limiting disease that is not associated with an asymptomatic viral carrier state and does not progress to chronic hepatitis, cirrhosis, or hepatocellular carcinoma.
(Choice D) Immunity against hepatitis D virus (HDV) infection would be signaled by anti-HDV IgG antibodies, not anti-HAV IgG antibodies.
(Choice G) Reinfection with HAV would be associated with the presence of anti-HAV IgM antibodies. Individuals who have persistent anti-HAV IgG antibodies typically enjoy immunity to repeat HAV infection.
(Choice H) Acute hepatitis B infection is sometimes associated with a window period where hepatitis B surface antigen (HBsAg) is no longer present but anti-HBsAg is not yet detectable in serum.
Educational objective:
Hepatitis A virus infection is most commonly silent or subclinical ("anicteric") in young children but can also present as an acute, self-limited illness characterized by jaundice, malaise, fatigue, anorexia, nausea, vomiting, right upper-quadrant pain, or an aversion to smoking.