A 5-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. The patient ate barbecue chicken with potato salad at a community lunch 4 hours before the symptoms began. His mother says that 2 other children who ate at the lunch have similar symptoms. The patient lives with his 3-year-old sister. Temperature is 36.8 C (98.2 F), blood pressure is 112/70 mm Hg, and pulse is 88/min. The abdomen is soft and nontender. Which of the following is the most appropriate next step in management of this patient?
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After a community lunch, this patient, as well as other children who consumed the same meal, developed acute-onset vomiting, nausea, and abdominal pain. These findings are suggestive of a foodborne illness. Common organisms that cause vomiting-predominant foodborne illness include Staphylococcus aureus and Bacillus cereus; some viruses can lead to a similar presentation (eg, norovirus).
In this case, the patient developed symptoms within hours of the meal, which suggests a pathogen producing a preformed toxin (eg, S aureus, B cereus). Because B cereus is typically transmitted via reheated rice, the most likely cause in this case is S aureus, which is typically spread via contaminated raw or prepared foods, such as dairy, meats, eggs, produce, and salads (eg, potato salad). Asymptomatic skin colonization with S aureus is common, and colonized food handlers can transmit S aureus to food during preparation; the bacterium proliferates at room temperature or in heat, resulting in high levels of toxin production.
Gastrointestinal infection with S aureus leads to rapid-onset vomiting as the primary symptom, as seen here; watery diarrhea may or may not be present. Diagnosis is clinical (ie, no testing required), and management is fluid repletion. Because symptoms are caused by a preformed enterotoxin, person-to-person spread does not occur, and contact precautions are unnecessary (Choice B). The illness is usually self-limited, and symptoms resolve within 24-48 hours.
(Choice A) Clinical features suggestive of invasive disease (eg, bloody diarrhea, ill-appearance, persistent fevers) may warrant blood culture due to risk of bacteremia with certain pathogens (eg, Shigella). In contrast, gastroenteritis presumed to be caused by S aureus does not warrant cultures because this self-limited illness is not associated with invasive disease.
(Choice C) Testing of vomitus is not recommended for suspected S aureus gastroenteritis because the diagnosis is clinical and symptoms self-resolve. Moreover, multiplex PCR testing is typically performed on stool samples in patients with prolonged or bloody diarrhea, not vomitus in patients with emesis alone.
(Choice E) Stool toxin assay is performed for suspected Clostridioides difficile, which typically presents with profuse watery diarrhea after antibiotic exposure or hospitalization, features that are not seen in this case.
Educational objective:
Vomiting-predominant acute gastroenteritis is often caused by Staphylococcus aureus or Bacillus cereus. S aureus should be suspected with a recent history of ingestion of raw or prepared foods (eg, potato salad); ingestion of preformed toxin leads to symptoms within hours. Diagnosis is clinical.