A 64-year-old man comes to the office due to 3 days of diarrhea. He began to have nausea, vomiting, abdominal cramps, and diarrhea 24 hours after eating chicken salad at a fast-food restaurant. The patient continues to have 4-6 episodes of diarrhea per day with no blood in the stool. His wife, who ate the same food, had a few loose stools but felt well afterward. The patient takes a tumor necrosis factor inhibitor for psoriatic arthritis and a proton pump inhibitor for gastritis. Temperature is 38 C (100.4 F), blood pressure is 120/70 mm Hg, and pulse is 88/min. Abdominal examination reveals mild diffuse tenderness to palpation and increased bowel sounds. Cultures of the stool yield gram-negative bacilli that are non-lactose fermenting and oxidase negative. Which of the following is the most likely complication associated with this patient's current infection?

Question

A 64-year-old man comes to the office due to 3 days of diarrhea.  He began to have nausea, vomiting, abdominal cramps, and diarrhea 24 hours after eating chicken salad at a fast-food restaurant.  The patient continues to have 4-6 episodes of diarrhea per day with no blood in the stool.  His wife, who ate the same food, had a few loose stools but felt well afterward.  The patient takes a tumor necrosis factor inhibitor for psoriatic arthritis and a proton pump inhibitor for gastritis.  Temperature is 38 C (100.4 F), blood pressure is 120/70 mm Hg, and pulse is 88/min.  Abdominal examination reveals mild diffuse tenderness to palpation and increased bowel sounds.  Cultures of the stool yield gram-negative bacilli that are non-lactose fermenting and oxidase negative.  Which of the following is the most likely complication associated with this patient's current infection?

Quizplus · Accepted Answer

11ec160b_3806_bdec_9249_af4d3cb46ff5_MD0001_00 Salmonella species are enteric gram-negative bacilli that are oxidase negative and generally non-lactose fermenting. Nontyphoidal strains such as S enterica are a major cause of foodborne gastroenteritis; there are an estimated 2-4 million cases in the United States annually. Transmission typically occurs after the consumption of contaminated poultry products (eg, chicken salad), including eggs. However, handling amphibians and reptiles can also lead to infection. Ingested Salmonella must survive the acidic environment of the stomach prior to traveling to the small intestine to cause disease. Therefore, patients on acid suppression (eg, proton pump inhibitors) require smaller infectious doses and are generally at greater risk. In the small intestine, the organism swims through the mucus barrier, attaches to and penetrates enterocytes, and then travels within vacuoles from the apical end to the basolateral membrane and on to the lamina propria. Here, the pathogen is phagocytosed by macrophages and neutrophils and elicits a profound inflammatory response. Manifestations may be quite mild or may feature fever, nausea, vomiting, and watery diarrhea. Most cases resolve spontaneously within 3-4 days, but a minority of individuals develop invasive disease with spread through the bloodstream and reticuloendothelial system. Long-bone osteomyelitis is a common complication, particularly at sites of prior bone injury/prosthesis or in those with sickle cell disease. Endocarditis, mycotic aneurysm, and visceral abscesses can also occur. The risk of invasion is greatest in patients at the extremes of age and in those with impaired immunity (eg, AIDS, tumor necrosis factor-alpha inhibitor). (Choice A) Chronic malabsorption can occur with Giardia infection due to blunting of the small intestine villi. Giardia is usually acquired from contaminated water, and symptoms (watery diarrhea, foul-smelling stool, bloating, nausea) typically begin >7 days after transmission. (Choice B) Generalized seizures are often seen in children infected with Shigella and are thought to be due to the systemic absorption of Shigella enterotoxins. Shigella is often transmitted in day care centers but may be passed via contaminated vegetables. Infections are typically marked by high fever, abdominal pain, and hemorrhagic colitis. (Choice C) Guillain-Barré syndrome is most often caused by preceding Campylobacter jejuni infection. Although Campylobacter is often transmitted by poultry and can cause a clinical illness similar to Salmonella, the organism is oxidase positive. (Choice D) Hemolytic uremic syndrome is characterized by the triad of acute renal insufficiency, thrombocytopenia, and microangiopathic hemolytic anemia. It is frequently linked to infections with enterohemorrhagic Escherichia coli, a gram-negative, lactose-fermenting organism. E coli is typically transmitted through consumption of contaminated, undercooked ground beef and is usually associated with bloody diarrhea. Educational objective: Nontyphoidal Salmonella is a leading cause of foodborne gastroenteritis. Most cases are marked by 3-4 days of self-limited fever, nausea, vomiting, and watery diarrhea. A minority of individuals develop subsequent invasive disease with spread to the long bones (osteomyelitis), vasculature (mycotic aneurysm), or heart (endocarditis). Risk of invasion is greatest in those with sickle cell disease or impaired immunity or at the extremes of age.

A 64-Year-Old Man Comes to the Office Due to 3