Clinical value of a uniform research case definition of tuberculous meningitis
Thesis (MMed)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: BACKGROUND: Tuberculous meningitis (TBM) research remains important but obtaining adequate sample sizes of microbiologically-confirmed TBM cases is difficult, therefore clinical cases of TBM need to be included. A uniform research case definition for TBM was developed to assist diagnostic standardization. METHODS: Our study evaluated the proposed uniform research case definition in a group of children diagnosed with TBM. A subgroup of 66 children with cultureconfirmed TBM was compared to culture-confirmed bacterial meningitis controls. RESULTS: The uniform case definition was applied to 554 TBM patients. Sixty-six (11.9%) patients had definite TBM, 408 (73.6%) had probable TBM and 72 (13.0%) had possible TBM. Symptom duration >5 days, weight loss or persistent cough >2 weeks, recent TB contact, focal neurological deficit, clear cerebrospinal fluid (CSF) appearance and basal meningeal enhancement predicted TBM when compared to definite bacterial meningitis with a sensitivity and specificity of 97.0% and 93.7%, respectively. When using a probable TBM score as the diagnostic measure, sensitivity was 86% and specificity was 100%. When using a possible TBM score as the diagnostic measure, sensitivity was 100% but specificity was 56%. CONCLUSION: The uniform research case definition for TBM performed well when using a probable TBM score as the diagnostic marker. A regression model also differentiated TBM from bacterial meningitis with good accuracy, but caution is needed in its application to early TBM.