An asymptomatic 36-year-old male Catholic missionary has returned to the United States following 12 years in rural Mexico. His routine physical examination shows elevated transaminases. His medical history in Mexico was unremarkable except for an auto accident requiring a blood transfusion of 3 pints of blood. What definitive lab test should be performed to determine what effective treatment should be prescribed?
An emerging pathogen has been linked to severe lower respiratory tract illness. Both amprenavir and saquinavir have shown efficacy in treating the infection. What stage in the pathogenesis of the infectious agent is impacted by these medications?
A young patient presents with an inflamed itchy groin area. What antifungal would work as long as it is a dermatophyte but might make it worse if it is a yeast infection?
A-B subunit structure as it relates to bacterial pathogenesis refers to the structure of what?
After a trip to Peru to adopt a 7-month-old baby, a 33-year-old woman and her new baby both develop profuse, watery diarrhea with flecks of mucus. Both are hospitalized because of the severity and rapidity of the dehydration, but neither one is febrile. What is the most likely causative agent?
After extensive oral surgery, a 67-year-old patient who had rheumatic fever as a child and who did not take the prescribed perioperative prophylactic antibiotics subsequently developed subacute infective endocarditis. Which of the following is the most likely causative agent?
A typically healthy 9-year-old boy from Florida is visiting friends on a farm in Iowa during the month of July. He presents on July 28 with a fever, cough, and lower respiratory symptoms (no upper respiratory tract symptoms). He has been ill for 4 days. His chest sounds are consistent with pneumonia, so a chest radiograph is obtained. The radiograph shows small, patchy infiltrates with hilar adenopathy. His blood smear shows small, nondescript yeast forms inside monocytic cells. What is the most likely causative agent?
A woman who imports food from Mexico and spends several months per year in rural Mexico had to have a compound leg fracture pinned and set in Mexico and has returned 5 days later. She now has signs of acute appendicitis and is taken to surgery in Houston. When her appendix is removed, it is found to contain a light-colored, 20.5-cm-long roundworm as well as bile-stained, knobby eggs consistent with Ascaris. How did she acquire this infection?
A woman who is an intravenous drug abuser and who has been a prostitute for the past 25 years now has an aortitis. She has no mucosal ulcerations or exanthems. Her VDRL (Venereal Disease Research Laboratory) test is negative and her fluorescent treponemal antibody absorption test is positive. What is the most likely diagnosis?
A severely neutropenic patient presents with pneumonia. Bronchial alveolar fluid shows dichotomously branching (generally with acute angles), septate hyphae. What is the most likely causative agent?