Background: Subacute meningitis can be caused by several etiologies such as tuberculosis, fungal, viral, autoimmune, and neoplastic. Tuberculous meningitis represents a diagnostic challenge, as cultures are not sensitive and slow to grow. The Lancet and the Thwaites criteria are utilized to differentiate tuberculosis from bacterial meningitis but the utility in subacute meningitis is unknown.
Methods: We conducted a retrospective study of 235 adults with subacute meningitis, defined by symptoms of greater than 5 days, hospitalized between January 1, 2008 and January 1, 2015 in Houston, Texas. The Lancet and Thwaites criteria were applied to these patients on the day of admission. The Thwaites and the Lancet criteria suggest a high probability of tuberculous meningitis with scores of less than 4, and with scores of 12 or above, respectively. The etiology of the meningitis was categorized as tuberculosis, viral, bacterial, fungal, unknown and other (non-infectious).
Results: 235 patients were identified; 54% were male. The median age was 39 years (18 to 78). The most common etiologies were unknown (126,53.6%), fungal (41,17.4%), viral (29,12.3%), tuberculosis (16,6.8%), other (16,6.8%), and bacterial (7,2.9%). Both the Lancet and the Thwaites criteria were able to distinguish tuberculosis from bacterial meningitis but only the Lancet score was able to differentiate tuberculosis from fungal, viral, and unknown etiologies (p≤0.001). There was significant overlap between the different etiologies in the Lancet scores.
Conclusion: In subacute meningitis, both the Lancet and the Thwaites criteria are helpful in distinguishing tuberculosis from bacterial meningitis but only the Lancet score can help to differentiate it from fungal, viral and unknown etiologies.
Horizontal bars = median values; Vertical bars = absolute range
*Denotes a significant difference (P value <0.05) in median scores between TB and corresponding etiology
L. Salazar, None
R. Hasbun, None