Effectiveness of BCG vaccination against tuberculous meningitis

Abstract

Objective: To assess the protective effectiveness of BCG vaccination against tuberculous meningitis, while controlling for age, nutrition and socio-economic status, in children 1 month to 12 years of age.

Design: Case-control study.

Setting: Secondary care referral and teaching hospital.

Methods: Cases were those conforming to the definition of tuberculous meningitis and controls were patients admitted after every third consecutive case included in the study from September 1995 till the end of August 1997 and who did not suffer from any central nervous system disorder.

Results: Among the 192 cases and 70 controls, BCG scar was present in 57.8% and 75.7%, respectively. The crude odd's ratio (OR)for tuberculosis meningitis with a BCG scar was 0.44 (95% CI, .24-0.81; p = 0.008), while the adjusted OR was 0.53 (95% CI, 0.26-1.06; p value = 0.07) after controlling for weight, age, sex and place of residence. Higher weight for age and urban residence were associated with a decreased risk of tuberculous meningitis in the logistic model.

Conclusions: BCG vaccination offers protection against tuberculous meningitis. Since improvement in weight for age was associated with a decreased risk of disease, further studies are needed to evaluate the association, if any, between nutritional status and vaccine efficacy.