Table 2.

Primary Infective Etiologies

Meningitis Etiology	No. (%)
Cryptococcal meningitis, first episodea	509 (60.5)
Cryptococcal meningitis, second episode—relapse	54 (6.4)
Cryptococcal meningitis, second episode—IRIS	8 (1.0)
Prior cryptococcal meningitis, persistent ↑ICP	5 (0.6)
Symptomatic cryptococcal antigenemiab	33 (3.9)
Definite tuberculous meningitisa	45 (5.3)
Probable tuberculous meningitisb	13 (1.5)
Empirically treated TBM	66 (7.8)
Acute bacterial meningitisc	11 (1.3)
Viral meningitis, confirmed	6 (0.7)
No etiology with normal CSFd	42 (5.0)
No etiology identified	54 (6.4)
Total cohort	842 (100)

Eight hundred forty-two Ugandan adults with HIV presenting with meningitis underwent a structured, stepwise diagnostic algorithm to diagnose infective etiologies. Cryptococcal meningitis was the most common cause of HIV-associated meningitis followed by tuberculous meningitis. Total etiologies n = 846 due to 4 participants with TB+ cryptococcal co-infection. Supplementary Table 4 lists the Marais et al. uniform criteria for TB meningitis.

Abbreviations: CSF, cerebrospinal fluid; ICP, Intra cranial pressure; IRIS, immune reconstitution inflammatory syndrome; TB, tuberculosis; TBM, tuberculous meningitis.

^aThree patients were co-infected with cryptococcal and TB meningitis.

^bOne patient had symptomatic cryptococcal antigenemia and probable TB meningitis.

^cOne patient had acute bacterial meningitis and a history of cryptococcosis, being CSF CrAg positive.

^dCSF WBC <5 µL and protein <45 mg/dL, of whom n = 6 had prior cryptococcal meningitis, of whom n = 4 were CSF CrAg negative.