A 67-year-old woman presents to her primary care physician with a viral infection. She has a 45 pack-year history of smoking, and past medical history includes COPD. The virus causing her infection has a specific M2 ion channel that can be blocked by certain antivirals. With which virus is she infected?

A 67-year-old woman presents to her primary care physician with a viral infection. She has a 45 pack-year history of smoking, and past medical history includes COPD. The virus causing her infection has a specific M2 ion channel that can be blocked by certain antivirals. With which virus is she infected?

A 32-year-old G2P1 woman in her third trimester presents to the ambulatory care clinic with dysuria and urgency. Urine is nitrite positive and leukocyte esterase positive. A drug commonly used to treat urinary tract infections is trimethoprim-sulfamethoxazole, but the physician is reluctant to use it. What risk is the physician worried about?

A 23-year-old woman who underwent a laparoscopic appendectomy is later found to have a wound infection. A culture grows methicillin-resistant Staphylococcus aureus (MRSA). What is the principle mechanism this strain uses to avoid the bactericidal properties of methicillin and methicillin-related drugs?

A 43-year-old woman who is obese undergoes laparoscopic cholecystectomy following repeated episodes of right upper quadrant pain caused by cholelithiasis. Over the next 48 h, she is found to have an MRSA wound infection. Her physician administers daptomycin. Which of the following laboratory values should she follow most closely as a result of daptomycin administration?

A 34-year-old immigrant with HIV disease complains of a productive cough with hemoptysis and night sweats. A sputum smear is positive for acid-fast bacilli. He is placed in isolation and started on isoniazid, rifampin, pyrazinamide, and ethambutol. A few months later, he complains of a loss of his ability to discriminate certain colors. What is causing his vision impairment?