The RN is caring for a 6-month old child who is hospitalized undergoing IV antibiotic treatment for bacterial blood infection. Upon bedside assessment, the RN notes the patient's rectal temperature is 103.4F, capillary refill is > 4 seconds, the patient is listless, the blood pressure is 50/30 mmHg and heart rate 190 BPM. Considering the background and situation, the nurse is most likely to suspect that this presentation is