This is the same germ (Neisseria meningitidis) which causes meningitis, but if it’s only in the blood stream & not the brain, the patient may not look sick at first. Then full-blown Shock rapidly ensues, mortality rates are high. The telltale sign are petechiae — tiny reddish-purple spots which by definition don’t blanche (“blanche” = turn white for a split second when you push on them, then resume their color). But often in the first few hours they don’t blanche.
New fever with non-blanching petechiae gets rushed to an ER by ambulance. But we must never dismiss new, discrete, blanching spots in a patient with fever. If ER clinicians ignore the concern, we wait around a few more hours, for any petechiae to develop that don’t blanche. If the spots remain, always blanching, or go away, they won’t be petechiae.
Diagnosis is made by blood cultures, which take a few days for final results. In the meantime, if we suspect Meningococcemia, we treat with IV antibiotics. The best one is Penicillin, but others may be used instead, to cover other germs too, since we can’t be sure.