PURULENT meningitis resulting from the introduction of bacteria into the subarachnoid space during procedures requiring lumbar puncture is rare. Most cases reported in the literature are caused by Pseudomonas aeruginosa.1,2 Anesthetic solutions, medications used in intrathecal therapy, and various instruments may become contaminated with this organism and act as either a reservoir or direct source of the infection. Other gram-negative enteric bacilli1 and the Staphylococcus aureus3 are the major causative agents in the remainder of the reported cases. These organisms are commonly found on skin surfaces and during lumbar puncture may be carried into the cerebrospinal fluid (CSF) by the exploring needle.
Iatrogenic meningitis caused by bacteria that are normal inhabitants of the respiratory tract is extremely rare. Majka4 described two cases of Streptococcus salvarius meningitis that followed pneumoencephalography. Both patients were thought to be infected by droplet contamination of the spinal needle from the respiratory