The correct answer is A. You answered C.

The answer is A. (Chap. 192) This patient is suffering from classic traveler’s diarrhea (of which, Campylobacter is a common cause). A prodrome of fever, headache, myalgia, and/or malaise often occurs 12–48 hours before the onset of diarrheal symptoms. The most common signs and symptoms of the intestinal phase are diarrhea, abdominal pain, and fever. The degree of diarrhea varies from several loose stools to grossly bloody stools; most patients presenting for medical attention have ≥10 bowel movements on the worst day of illness. Abdominal pain usually consists of cramping and may be the most prominent symptom. Pain is usually generalized but may become localized; Campylobacter jejuni infection may cause pseudoappendicitis. Fever may be the only initial manifestation of C jejuni infection, a situation mimicking the early stages of typhoid fever. Even among patients presenting for medical attention with Campylobacter enteritis, not all clearly benefit from specific antimicrobial therapy. Indications for therapy include high fever, bloody diarrhea, severe diarrhea, persistence for >1 week, and worsening of symptoms. Macrolides are generally the empirical treatment of choice with <10% of isolates demonstrating resistance. A single dose of azithromycin 500 mg is effective and is the regimen of choice; a 5- to 7-day course of erythromycin (250 mg orally four times daily or—for children—30–50 mg/kg/d in divided doses) is also effective. Resistance to quinolones as well as to tetracyclines is substantial; approximately 22% of U.S. isolates in 2010 were resistant to ciprofloxacin. Except in infection with Campylobacter fetus, bacteremia is uncommon, developing most often in immunocompromised hosts and at the extremes of age. Due to its proclivity to cause bacteremia and distant organ involvement, C fetus has a far worse prognosis than other subtypes. Systemic infection with C fetus is much more often fatal than that due to related species; this higher mortality rate reflects in part the population affected.

The correct answer is A. You answered A.

Age-related macular degeneration is a major cause of painless, gradual bilateral central visual loss. It occurs as nonexudative (dry) or exudative (wet) forms. Recent genetic data have shown an association with the alternative complement pathway gene for complement factor H. The mechanism link for that association is unknown. The nonexudative form is associated with retinal drusen that leads to retinal atrophy. Treatment with vitamin C, vitamin E, beta-carotene, and zinc may retard the visual loss. Exudative macular degeneration, which is less common, is caused by neovascular proliferation and leakage of choroidal blood vessels. Acute visual loss may occur because of bleeding. Exudative macular degeneration may be treated with intraocular injection of a vascular endothelial growth factor antagonist (bevacizumab or ranibizumab). Blepharitis is inflammation of the eyelids usually related to acne rosacea, seborrheic dermatitis, or staphylococcal infection. Diabetic retinopathy, now a leading cause of blindness in the United States, causes gradual bilateral visual loss in patients with long-standing diabetes. Retinal detachment is usually unilateral and causes visual loss and an afferent pupillary defect.

The correct answer is A. You answered A.

The answer is A. (Chap. 282) Bicuspid aortic valve is among the most common of congenital heart cardiac abnormalities. Valvular function is often normal in early life and thus may escape detection. Due to abnormal flow dynamics through the bicuspid aortic valve, the valve leaflets can become rigid and fibrosed, leading to either stenosis or regurgitation. However, pathology in patients with bicuspid aortic valve is not limited to the valve alone. The ascending aorta is often dilated, misnamed “poststenotic” dilatation; this is due to histologic abnormalities of the aortic media and may result in aortic dissection. It is important to screen specifically for aortopathy because dissection is a common cause of sudden death in these patients.