Which bodily fluid is examined to diagnose meningitis definitively?

The examination of cerebrospinal fluid is the definitive method for diagnosing meningitis. When meningitis is suspected, a lumbar puncture (spinal tap) is performed to collect this fluid, which bathes the brain and spinal cord. Analyzing the cerebrospinal fluid provides critical information about the presence of infectious organisms such as bacteria or viruses, as well as other characteristics like glucose levels and white blood cell count. These findings can distinguish between types of meningitis (e.g., bacterial versus viral) and guide appropriate treatment.

In contrast, urine, serum, and saliva are not used as primary diagnostic fluids for meningitis. Urine may be tested for various infections but not for meningitis itself. Serum can indicate the presence of infection in general but does not provide the specific details required to diagnose meningitis. Saliva may contain pathogens but lacks the cerebrospinal fluid’s direct insight into the condition of the central nervous system. Hence, cerebrospinal fluid analysis is crucial for a definitive diagnosis of meningitis.