A 10-year-old boy is brought to the emergency department due to sudden-onset nausea, abdominal cramps, and several episodes of vomiting over the last 2 hours. He has not had diarrhea. His mother notes that the patient's 6-year-old sister has similar symptoms. The children ate barbecued chicken with potato salad at a community lunch 4 hours before the symptoms began. They also swam in the community pool and played with a pet turtle. The patient has a history of upper respiratory infections and received antibiotics a month ago for acute otitis media. Temperature is 36.8 C (98.2 F), blood pressure is 112/70 mm Hg, and pulse is 88/min. Abdomen is soft and nontender. Which of the following is the most likely cause of this patient's symptoms?

Question

A 10-year-old boy is brought to the emergency department due to sudden-onset nausea, abdominal cramps, and several episodes of vomiting over the last 2 hours.  He has not had diarrhea.  His mother notes that the patient's 6-year-old sister has similar symptoms.  The children ate barbecued chicken with potato salad at a community lunch 4 hours before the symptoms began.  They also swam in the community pool and played with a pet turtle.  The patient has a history of upper respiratory infections and received antibiotics a month ago for acute otitis media.  Temperature is 36.8 C (98.2 F), blood pressure is 112/70 mm Hg, and pulse is 88/min.  Abdomen is soft and nontender.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d278_034f_bc81_f18ad5c84096_MD0003_00 This boy and his sister developed concomitant acute gastrointestinal symptoms after attending a community lunch, suggesting a foodborne illness. Approximately 50 million cases of foodborne illness occur in the United States each year. Pathogens include bacteria, viruses, and parasites. Suspicion for a specific etiologic organism is often suggested by the food consumed, length of time to symptoms, and symptom complex. Staphylococcus aureus is found in the nose and on the skin of ~25% of the population. Most people are asymptomatic, but colonized food handlers can transmit S aureus to food during preparation. Dairy items, meats, eggs, produce, and salads (eg, potato salad) are particularly vulnerable. S aureus produces enterotoxins in the contaminated food that rapidly cause symptoms after ingestion (often within 1-6 hours). Vomiting is the primary symptom; diarrhea may or may not be present. Illness is usually self-limited, resolving completely within 24-48 hours. (Choice A) Bacillus cereus also causes rapid-onset vomiting due to a toxin formed outside of the body. However, B cereus is usually transmitted via rice that has been reheated or left at room temperatures for extended periods. In this patient, potato salad was likely the culprit. (Choices B and H) Campylobacter jejuni and nontyphoidal salmonella directly attack colonic epithelial cells and usually cause watery diarrhea (with blood/mucus), severe abdominal pain, and fever. Both organisms are transmitted by poultry (salmonella is also associated with turtles). This patient had a vomiting-predominant illness (not diarrhea-predominant). (Choice C) Clostridium difficile causes antibiotic-associated colitis (watery diarrhea, abdominal pain). Although this patient had antibiotics a month ago, vomiting is his primary symptom (not diarrhea). (Choices D, E, and I) Clostridium perfringens, enterotoxigenic Escherichia coli (ETEC), and Shiga toxin-producing E coli (STEC) produce toxins after the organism is ingested. As such, symptoms are typically delayed >1 day (not 4 hours). Both C perfringens and ETEC cause watery diarrhea; STEC causes watery diarrhea that becomes bloody, often with renal failure (O157:H7). (Choice F) Giardia is transmitted primarily by contaminated water. Incubation takes 7-14 days, and symptoms include foul-smelling, watery diarrhea. (Choice G) Listeria monocytogenes is a foodborne illness that occasionally causes self-limited, febrile gastroenteritis (watery diarrhea). Patients who are immunocompromised, pregnant, or at the extremes of age (<2, >50) may develop invasive disease (bacteremia, meningoencephalitis). This patient did not have diarrhea or fever. Educational objective: Staphylococcus aureus causes foodborne illness due to the ingestion of preformed toxins. Vomiting is the preeminent symptom and usually begins 1-6 hours after exposure. Diarrhea may or may not be present. Colonized food handlers usually transmit S aureus to food during preparation. References: Diagnosis and management of foodborne illnesses: a primer for physicians. (http://www.ncbi.nlm.nih.gov/pubmed/11214980) Staphylococcal enterotoxins. (http://www.ncbi.nlm.nih.gov/pubmed/11028954)

A 10-Year-Old Boy Is Brought to the Emergency Department Due