A 33-year-old man has never been vaccinated for hepatitis B

A 33-year-old man has never been vaccinated for hepatitis B. Serologic tests reveal negative hepatitis B surface antigen (HBsAg) and positive antibody to surface antigen. Which of the following conditions does this serologic pattern best fit with?
(A) previous hepatitis B infection
(B) chronic active hepatitis
© acute hepatitis B infection
(D) poor prognosis
(E) need for vaccine to hepatitis B

solution

The antibody can be demonstrated in 80–90% of patients, usually late in convalescence, and indicates relative or absolute immunity. In contrast, HBsAg occurs very early and disappears in <6 months. Persistence of HBsAg indicates chronic infection. The pattern in this patient is also seen postvaccination, and perhaps
as a consequence of remote infection.