Diagnostic value of latex agglutination test in diagnosis of acute bacterial meningitis

Objectives: To know the incidence of bacterial meningitis in children below five years of age. To compare conventional culture and antigen detection methods (Latex agglutination test). Materials and Methods: 100 CSF samples of clinically suspected meningitis cases in children below 5 years of age were included. The samples were subjected to cell count, Gram stain, culture and LAT. The organisms isolated in the study were characterized according to standard procedures. Results: Of the 100 cases studied, 31 cases were diagnosed as ABM by Gram stain, culture and latex agglutination test as per WHO criteria. The hospital frequency of ABM was 1.7%. 15 (48.38) cases were culture positive. Gram stain was positive in 22(70.96) cases and LAT in 17(54.83) cases. Haemophilus influenzae was the most common causative agent of acute bacterial meningitis followed by S. pneumoniae. Case fatality rate was 45.16%. The sensitivity and specificity of LAT was 66.66% and 87.91% respectively. Conclusion: Bacterial meningitis is a medical emergency and early diagnosis and treatment is life saving and reduces chronic morbidity. LAT was more sensitive compared to conventional Gram stain and Culture technique in identifying the fastidious organisms like H. influenzae, S. pneumoniae and Group B Streptococcus. However, the combination of Gram stain, Culture and LAT proved to be more productive than any of the single tests alone.