Sentence:  Meningococcal meningitis <WSD>defervesces</WSD> quickly over one to three days whereas "Haemophilus influenzae" meningitis resolves over three to five days, and severe pneumococcal meningitis may take a week or longer for the fever to decrease/become afebrile. Viral causes of meningitis or encephalitis <WSD>defervesce</WSD> very slowly over a seven-day period, and by monitoring the fever defevescence pattern a clinician can easily differentiate viral meningitis/encephalitis from bacterial meningitis. 
Meaning of the word marked with <WSD> tags:  To experience an abatement or resolution of fever.