Review Question - QID 109963

A 9-year-old girl presents to the emergency department with a fever and a change in her behavior. She presented with similar symptoms 6 weeks ago and was treated for an Escherchia coli infection. She also was treated for a urinary tract infection 10 weeks ago. Her mother says that last night her daughter felt ill, and her condition has been worsening. Her daughter experienced a severe headache and had a stiff neck. This morning she was minimally responsive, vomited several times, and produced a small amount of dark cloudy urine. The patient was born at 39 weeks and met all her developmental milestones. She is currently up to date on her vaccinations and did not have infections during early childhood. Her parents are divorced and her father has noted she does not seem to get sick when he takes care of her. Her temperature is 99.5°F (37.5°C), blood pressure is 60/35 mmHg, pulse is 190/min, respirations are 33/min, and oxygen saturation is 98% on room air. The patient is started on intravenous fluids, vasopressors, and broad-spectrum antibiotics. Which of the following is the most appropriate underlying explanation for this patient's presentation?