1. A computer-implemented method performed on a dispatch center computer to assist a dispatcher when communicating with a caller via telephone regarding a medical emergency of a patient, comprising: providing on the dispatch center computer system an emergency dispatch protocol to assist the dispatcher, the protocol presenting a plurality of pre-scripted interrogatories for the dispatcher to ask the caller to gather information regarding the emergency and generate an emergency dispatch response by emergency responders; initiating a diagnostic tool on the dispatch center computer, the diagnostic tool configured to assist the dispatcher in guiding the caller to obtain information that can be used by the diagnostic tool to diagnose whether the patient has meningitis; the diagnostic tool presenting to the dispatcher a user interface; the diagnostic tool providing one or more questions via the user interface for the dispatcher to vocally relay to the caller over the telephone to guide the caller in identifying signs and symptoms that the patient has meningitis; the diagnostic tool receiving dispatcher-entered input indicative of caller-relayed information concerning the caller's observations of the patient, including signs and symptoms that indicate whether the patient has meningitis, wherein the caller's observations are vocally relayed over the telephone to the dispatcher; and the diagnostic tool determining a likelihood that the patient has meningitis based on the dispatcher-entered input indicative of the caller-relayed information.