PCR of cerebrospinal fluid for diagnosis of bacterial meningitis during meningococcal epidemics; an example from Sudan.

Meningococcal disease is feared due to its rapid progression and high case fatality rate, especially in the African meningitis belt, where epidemics of meningococcal meningitis appear cyclically. Culture, direct microscopy and antigen detection are the basic methods for diagnosis and species identification of bacterial meningitis. These methods are known to have limitations, especially in developing countries. The aim of the present study was to document the application of PCR technology for the diagnosis of bacterial meningitis in cerebrospinal fluid (CSF) samples (n = 52) collected during epidemics in Sudan. In the application of PCR for detection of the causative agent of bacterial meningitis (based on the 16S rRNA gene), bacterial DNA was identified in 49 samples. Common bacterial species causing bacterial meningitis could be detected in 31 of the CSF samples (27 meningococci), while 18 contained DNA, mainly from normally contaminating bacteria. A specific PCR for group A meningococci (based on the sacC gene) was positive in 27 of the CSF samples. The results show that PCR technology is a sharp-edged tool for confirmation of a diagnosis of meningococcal meningitis and for obtaining a direct genogrouping of group A meningococci in CSF. It is important to stress the use of direct and specific PCRs to avoid interference by contaminating bacteria, a great problem in samples from areas in the meningitis belt.