Central nervous system tuberculosis: characteristics, risks, and outcomes in California adults, 2010-2022

Background Central nervous system (CNS) tuberculosis (TB) is rare and causes substantial morbidity and mortality. We quantified the frequency, characteristics, outcomes, and risks associated with CNS TB. Methods We performed a retrospective analysis of culture-confirmed TB in adults reported to the California TB Registry during 2010-2022 to compare individuals with CNS TB vs. non-CNS TB. We used a causal diagram and modified Poisson model with robust variance to estimate the adjusted relative risk of CNS TB vs. non-CNS TB among people with TB caused by Mycobacterium bovis vs. non- M. bovis M. tuberculosis complex. We also identified risk factors for death with CNS TB. Results There were 21,117 TB cases reported; 382 (1.8 %) involved the CNS. Compared to those without CNS TB, those with CNS TB were more likely younger, of Hispanic ethnicity, born in Mexico, infected with M. bovis , co-infected with HIV, immunosuppressed, and to have had normal chest radiography. The adjusted relative risk of M. bovis (vs. non- M. bovis ) causing CNS TB was 2.86 (95 % CI 2.04-4.02). A large number of CNS TB patients died, 108 (28.3 %). Among people with CNS TB, death was associated with older age, end-stage renal disease, and immune suppression. Conclusion More than one quarter of patients with CNS TB died. People with TB caused by M. bovis , were more likely to have CNS TB than people with TB caused by non- M. bovi s forms of the M. tuberculosis complex. Further efforts to prevent, rapidly diagnose, and effectively treat CNS TB is warranted.