A 74-year-old tourist from Bangladesh presents with anorexia, nausea, vomiting, and intermittent upper abdominal pain for 3 weeks. His medical history is significant for gram-negative meningitis 12 months ago, and chronic obstructive pulmonary disease for 15 years with numerous exacerbations, the most recent of which was 2 months earlier. He is currently on inhaled corticosteroid therapy, and also consumes antacid tablets frequently due to recurrent dyspeptic symptoms. He does not drink, and stopped smoking 13 years ago, with a total pack-history of 11 years.