From the Guidelines
Screening for meningitis should involve a lumbar puncture (spinal tap) as the definitive method, along with blood cultures and empiric antibiotics if bacterial meningitis is strongly suspected, as recommended by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) guideline 1. When meningitis is suspected, a thorough clinical assessment should be conducted, including checking for fever, headache, neck stiffness (Kernig's and Brudzinski's signs), altered mental status, and photophobia.
- Additional screening tools include:
- Blood tests for inflammatory markers (CRP, procalcitonin)
- Complete blood count
- Imaging studies like CT or MRI if there's concern about increased intracranial pressure or to rule out other conditions
- Rapid diagnostic tests for specific pathogens may also be used The ESCMID guideline advises to start empiric treatment within one hour of arrival in all suspected meningitis cases, and the choice of antibiotics needs to be differentiated according to the patient's age, risk factors, and local resistance rates of pneumococci 1. Cerebrospinal fluid (CSF) analysis remains the principal contributor to the final diagnosis of meningitis, with the CSF leucocyte count being the best diagnostic parameter for differentiating bacterial meningitis from other diagnoses 1. In cases where bacterial meningitis is suspected, empiric antibiotics like ceftriaxone or vancomycin should be administered without waiting for test results, as delayed treatment can lead to serious complications or death 1. The UK Joint Specialist Societies guideline also recommends sending blood for culture, pneumococcal and meningococcal PCR, and storing samples for serological testing if a cause is not identified 1. Prompt screening is crucial as meningitis can progress rapidly, potentially leading to serious complications or death if treatment is delayed.
From the Research
Screening for Meningitis
To screen for meningitis, the following methods can be used:
- Clinical examination: The absence of fever, neck stiffness, and altered mental status can effectively eliminate meningitis, with a sensitivity of 99%-100% for the presence of one of these findings 2
- Jolt accentuation of headache: This is a useful adjunctive maneuver, with a sensitivity of 100%, specificity of 54%, positive likelihood ratio of 2.2, and negative likelihood ratio of 0 for the diagnosis of meningitis 2
- Lumbar puncture: This is a crucial test for diagnosing meningitis, especially in high-risk patients 2, 3
- Blood cultures: Positive blood cultures can establish the diagnosis of bacterial meningitis, even in cases with negative culture of cerebrospinal fluid 3
Laboratory Tests
The following laboratory tests can be used to aid in the diagnosis of meningitis:
- Cerebrospinal fluid (CSF) analysis: This can help identify the presence of bacteria, viruses, or other pathogens in the CSF 2, 3, 4, 5, 6
- CSF protein concentration: This can affect the distribution of antibiotics such as ceftazidime and ceftriaxone in the CSF 5
- CSF cell count and glucose concentration: These can also be useful in diagnosing meningitis, although their correlation with antibiotic concentrations is not significant 5
Antibiotic Therapy
The following antibiotics can be used to treat meningitis:
- Ceftriaxone: This antibiotic has been shown to have excellent therapeutic efficacy against bacterial meningitis, and its concentration in CSF is not significantly affected by concomitant dexamethasone use 2, 4, 6
- Ceftazidime: This antibiotic has also been shown to be effective against bacterial meningitis, and its concentration in CSF correlates with protein concentration in CSF 5