A 50-year-old man presents with persistent headache, low-grade fever, night sweats, and difficulty concentrating that have been present for the past 6 weeks. He denies photophobia or seizures. His medical history includes HIV with a low CD4 count. A lumbar puncture is performed, and cerebrospinal fluid (CSF) analysis shows lymphocytic pleocytosis, decreased glucose, and elevated protein. Which of the following criteria best confirms the diagnosis of chronic meningitis?
