MS-1830

A 5-year-old child presents to the emergency department with a fever and difficulty breathing, accompanied by a sore throat. The mother reports that the symptoms started within the past 24 hours. On examination, the child is observed to be leaning forward with audible stridor and drooling around the mouth. There is no rash on the body, and the face is not swollen. The child’s medical records indicate that they are not up to date with their immunisation schedule. What is the probable pathogen responsible for this diagnosis?