Explanations for the 2019 Official Step 1 Practice Questions

The 2019 set was recently updated in February. Of the 117 questions in the PDF, only two have been changed, which I’ve answered below. The order and content otherwise appear unchanged, including the three multimedia questions at the end of the online version.

Please see last year’s 2018 explanations for the remainder.

The many comments at the bottom of that page may prove helpful for those with additional questions. You’re never the only one to struggle.

48. E – When people go camping, you should be thinking of zoonotic infections. Fun fact, New Mexico leads the country in cases of plague. Yes, that plague: Yersinia pestis. The “bubonic” part of bubonic plague refers to the swollen infected nodes (“buboes”) characteristic of the disease, which often involve the groin (bubo is the Greek word for groin, who knew?). In this case, they’re also describing a necrotic epitrochlear node. Classic treatment is with aminoglycosides, which bind to the 30s ribosomal subunit. (Note that Tularemia, caused by another gram-negative bacteria Francisella tularensis can present similarly but is more common in the midwest. Regardless, the two are often lumped together, the antimicrobial treatment is similar, and the answer in this case would be the same).

69. E – Catalase and coagulase-positive gram-positive cocci = staph aureus. mecA-positivity means the bacteria carry the gene that confers methicillin-resistance, hence MRSA. Of the choices, MRSA is treated with vancomycin.


becca 05.23.19 Reply

what does “*” mean at the the end of the answers for some of the questions?

Ben 05.23.19 Reply

New from last year’s practice set. It facilitates those who want to do multiple years in order to have more free questions.

Ahmed Saber 04.24.23 Reply

Dear Ben, Can you please provide me (or shall I say students) with the questions for 2019 and 2020 ? The official link only shows the 2021 sample questions. I love your work and explanations and I need the questions to make use of your explanations :))

Thanks, Regards, Respect

Ben 04.24.23 Reply

I’ve just updated the link to the archived version of the PDF available via the Wayback Machine.

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