Etiology of central nervous system infections in the Philippines and the role of serum C-reactive protein in excluding acute bacterial meningitis.

OBJECTIVES

The value of measurements of serum C-reactive protein (CRP) in differentiating central nervous system (CNS) infections of varying etiologies in the Philippines was investigated.

METHODS

A wide array of bacteriologic and virologic methods as well as computed tomography, typical clinical presentation, and autopsy were used for etiologic diagnosis.

RESULTS

Among 103 patients with CNS infection, etiology was identified in 60 (58%) cases. Bacteria were found in 19 (including 7 Streptococcus pneumoniae, 5 Haemophilus influenzae, 3 Neisseria meningitidis), tuberculosis in 4, viruses in 38 (including 20 coxsackievirus, 8 measles, 4 adenovirus, and 4 poliovirus infections), and brain abscess in 3 patients. C-reactive protein was elevated on admission in all 18 cases of bacterial meningitis tested, exceeding 50 mg/L in 17 (94%), and was not affected by prior antibacterial treatment. The mean CRP was significantly higher in the bacterial group than in the viral group (207 +/- 111 mg/L vs. 39 +/- 34 mg/L; P < 0.001). In the viral group one third had CRP above 50 mg/L. In patients with tuberculous meningitis, brain abscess, or cryptococcal meningitis, CRP was moderately to highly elevated.

CONCLUSIONS

In the presence of a normal CRP concentration (below 10 mg/mL) acute bacterial meningitis is excluded even in a developing country setting and antimicrobial therapy is not warranted.