Review Question - QID 212839

A 4-year-old boy presents to the emergency department with diarrhea. Several days ago, he experienced a fever which has progressed to vomiting and diarrhea. He has had multiple episodes of non-bloody diarrhea and states that he feels fatigued. He is not up to date on his vaccinations and takes many different herbal supplements from his parents. His temperature is 101°F (38.3°C), blood pressure is 100/55 mmHg, pulse is 111/min, respirations are 19/min, and oxygen saturation is 100% on room air. Physical exam is notable for dry mucous membranes and a fatigued appearing child. Which of the following is the most likely etiology of this patient’s symptoms?