A 20-year old female student represents with a 1-week history of nausea, vomiting and anorexia. She returned 2-weeks ago from a trip to Guatemala. On physical examination, her temperature was 100.3 F, clear chest and she has mild jaundice and a palpable tender liver. Her CBC was normal and her liver function tests are as follows: Serum total bilirubin 3.1 mg/dL. Serum aspartate aminotransferase 1100. Serum alanine aminotransferase 1900. Serum alkaline phosphatase 112. What is the most likely lab test to confirm your diagnosis?
A- IgM antibody to hepatitis A virus
B- Antibody to hepatitis B surface antigen
C- Antibody to hepatitis C virus
D- DNA for Epstein-Burr virus
E- Serum anti-mitochondrial antibodies
This patient has typical presentation of hepatitis A virus infection. His recent travel, short incubation period and mode of infection in addition to lab results confirm this diagnosis. The only option that is almost always positive in hepatitis A virus recent infection is IgM antibody to hepatitis A virus.
The correct answer is A
2 thoughts on “Repeated USMLE Questions Step 1- 168”
Awesome. Thank you for explanation.
The answer A… Considering the symptoms, the incubation period (1 week ), Recent travel history and the laboratory investigation’s results given in the question…