[Comparative study of meningitis due to Staphylococcus aureus and coagulase-negative Staphylococci in adults].

INTRODUCTION: Staphylococcus spp. rarely cause community-acquired acute bacterial meningitis (ABM), but they are a frequent cause of nosocomial meningitis. AIMS. We describe and conduct a comparative analysis of ABM due to S. aureus and coagulase-negative (CoN) Staphylococci in adults. PATIENTS AND METHODS: We reviewed the medical records of patients aged 14 or over who had been diagnosed with ABM, including those with a positive cerebrospinal fluid (CSF) culture for Staphylococcus spp.
RESULTS: Forty cases were included (28% of the ABM), 12 due to S. aureus and 28 due to CoN Staphylococci. Incidence increased over time: 1.9% in the first third of the study, 22.9% in the second and 19.4% in the third (p = 0.003). In 67% of cases it was nosocomial and post-operative in 95%. Neurosurgical devices (74%) and recent neurosurgery (26%) were the risk factors, and both associated 61%. Clinical signs and symptoms and alterations to CSF were similar in both groups, but bacteraemia (60% versus 20%) and the development of complications were more frequent in infections due to S. aureus. Overall mortality rate was above 15%, and was higher in infections due to S. aureus (67% versus 0%). Mortality was also associated with spontaneous acquisition of the infection (25% versus 0%), the development of septic complications (37% versus 6%), bacteraemia (62% versus 19%) and not withdrawing or changing the neurosurgical device (60% versus 0%).
CONCLUSIONS: Staphylococcus spp. are a frequent cause of ABM in hospitals with neurosurgery, especially in the post-operative period following neurosurgical procedures and/or in carriers of CSF drainage devices. Prognosis in infections caused by CoN Staphylococci is favourable, in contrast to the high mortality rate caused by S. aureus.