A 15-month-old girl was brought to the emergency department with a 7-day history of diarrhea, vomiting, pancytopenia, and bleeding. The patient was born in Mexico City, Mexico, where she lived with her parents and two elder preschoolaged siblings, all in good health. All the members of the family were poorly fed and slept in the same room under unhygienic conditions. Her vaccination scheme was up-to-date, and her previous medical history was unremarkable.