Tuberculous meningitis in BCG vaccinated and unvaccinated children

A modified clinical presentation of tuberculous meningitis (TBM) in children vaccinated with BCG has been described in the literature. However, most reports are old and not based on actual comparisons and tests of significance. Also, neuroimaging features were not compared. With large scale BCG coverage, it becomes pertinent to describe the "modified" presentation and identify any significant differences between vaccinated and unvaccinated children with TBM.

A total of 150 consecutive hospitalised children (96 unvaccinated, 54 vaccinated) were enrolled. They all satisfied predefined criteria for diagnosis of TBM. Clinical and radiological features of children with/without a BCG scar were compared.

Univariate analysis revealed that the vaccinated children with TBM had significantly lower rates of altered sensorium (68.5% v 85.4% unvaccinated; OR 2.2 (1.1 to 6.2); p = 0.019) and focal neurological deficits (20.3% v 39.5% unvaccinated; OR 2.6 (1.1 to 6.0); p = 0.016), and higher mean (SD) Glasgow Coma Scale score (10.2 (3.4) v 8.76 (2.7) unvaccinated; p = 0.010) and cerebrospinal fluid cell count (210.9 v 140.9 unvaccinated; p = 0.019). No significant radiological differences were seen. Short term outcome was significantly better in the vaccinated group with 70% of the total severe sequelae and 75% of the total deaths occurring in the unvaccinated group (p = 0.018).

Children with TBM who have been vaccinated with BCG appear to maintain better mentation and have a superior outcome. This may in part be explained by the better immune response to infection, as reflected in the higher CSF cell counts in this group in the present study.