From the Guidelines
Viral meningitis is typically self-limiting and requires only supportive care, whereas bacterial meningitis is a medical emergency that necessitates immediate empiric antibiotic therapy. The distinction between viral and bacterial meningitis is crucial due to differences in treatment and prognosis. Viral meningitis is more common and usually less severe, caused by viruses like enteroviruses, herpes simplex virus, and arboviruses, presenting with fever, headache, neck stiffness, and photophobia 40. In contrast, bacterial meningitis is caused by bacteria such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae, and it presents with similar symptoms but often more severe, including altered mental status, seizures, and focal neurological deficits.
Key Differences
- Viral meningitis:
- Typically self-limiting
- Requires supportive care with rest, fluids, and pain management
- May use specific antivirals like acyclovir for herpes infections
- Bacterial meningitis:
- Medical emergency
- Requires immediate empiric antibiotic therapy (typically vancomycin plus a third-generation cephalosporin like ceftriaxone)
- Higher risk of complications and mortality if not treated quickly According to the ESCMID guideline on the diagnosis and treatment of acute bacterial meningitis 1, diagnostic algorithms are not 100% sensitive and may fail to recognize a proportion of bacterial meningitis patients, highlighting the importance of clinicians' judgement in estimating the risk of bacterial meningitis and initiating empiric antibiotic and adjunctive therapy. Lumbar puncture findings can help distinguish between the two types of meningitis, with viral meningitis typically showing clear CSF with lymphocytic predominance and normal glucose, and bacterial meningitis showing cloudy CSF with neutrophil predominance, elevated protein, and low glucose.
From the Research
Viral vs Bacterial Meningitis
- Bacterial meningitis is a serious infection that requires prompt treatment with antibiotics, as seen in studies 2, 3, 4, 5, 6.
- The use of empiric vancomycin plus a third-generation cephalosporin for suspected bacterial meningitis has been recommended since 1997 2.
- Ceftriaxone is a preferred drug for bacterial meningitis caused by H. influenzae, meningococci, and pneumococci, and it reaches a high bactericidal titer in the cerebrospinal fluid 3.
- Ceftriaxone given once daily produces results equivalent to those obtained with ampicillin plus chloramphenicol in the treatment of bacterial meningitis 4, 6.
- Prophylaxis with antibiotics such as ciprofloxacin, rifampin, and ceftriaxone can be effective in preventing secondary cases of meningococcal disease after contact with someone with the disease 5.
Treatment Options
- Ceftriaxone is effective in infants and children three months to 18 years old, but it is not yet recommended in neonates due to concerns about bilirubin displacement 3.
- In adults, ceftriaxone is effective therapy for presumed bacterial meningitis, but it must be combined with ampicillin initially to cover L. monocytogenes meningitis 3.
- Vancomycin should still be included as empiric therapy for bacterial meningitis, despite the decreased prevalence of ceftriaxone-nonsusceptible pneumococcal meningitis 2.
Comparison of Antibiotics
- Ceftriaxone, ciprofloxacin, and rifampin are effective in eradicating N. meningitidis, but rifampin may lead to the circulation of resistant isolates 5.
- Ceftriaxone is more effective than rifampin after one to two weeks of follow-up, and it may be considered as an alternative to rifampin in outbreak settings 5.