Repeated USMLE Questions Step 1- 168

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”

  1. Awesome. Thank you for explanation.

  2. The answer A… Considering the symptoms, the incubation period (1 week ), Recent travel history and the laboratory investigation’s results given in the question…

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