Suspected meningitis
The clinical presentation of viral meningitis is often indistinguishable from that of acute bacterial meningitis. If the patient is very ill, is immunocompromised, or has received prior antibiotics, empiric antibiotic therapy is justified as delay in administration of antibiotics is associated with a poor outcome. If the patient appears well it may be appropriate to observe without antibiotics while the cerebrospinal fluid (CSF) is analyzed.
The choice of empiric antibiotics depends on the patient's age, which determines the most likely organisms. Although adjunctive therapy with dexamethasone, prior to the administration of antibiotics, has not been shown to significantly reduce mortality in people with bacterial meningitis, it has been shown to reduce hearing loss and neurologic sequelae in patients living in high-income countries.[57]de Gans J, van der Beek D; European Dexamethasone in Adulthood Bacterial Meningitis Study Investigators. Dexamethasone in adults with bacterial meningitis. N Engl J Med. 2002 Nov 14;347(20):1549-56.
https://www.nejm.org/doi/10.1056/NEJMoa021334
http://www.ncbi.nlm.nih.gov/pubmed/12432041?tool=bestpractice.com
[58]van de Beek D, de Gans J, McIntyre P, et al. Steroids in adults with acute bacterial meningitis: a systematic review. Lancet Infect Dis. 2004 Mar;4(3):139-43.
http://www.ncbi.nlm.nih.gov/pubmed/14998499?tool=bestpractice.com
[59]Brouwer MC, McIntyre P, Prasad K, et al. Corticosteroids for acute bacterial meningitis. Cochrane Database Syst Rev. 2015 Sep 12;(9):CD004405.
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD004405.pub5/full
http://www.ncbi.nlm.nih.gov/pubmed/26362566?tool=bestpractice.com
Typically, adjuvant dexamethasone is recommended in all previously well and nonimmunosuppressed adults and children over 3 months.[3]McGill F, Heyderman RS, Michael BD, et al. The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J Infect. 2016 Apr;72(4):405-38.
https://www.journalofinfection.com/article/S0163-4453(16)00024-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/26845731?tool=bestpractice.com
[60]Chaudhuri A, Martinez-Martin P, Kennedy PG, et al; EFNS Task Force. EFNS guideline on the management of community-acquired bacterial meningitis: report of an EFNS Task Force on acute bacterial meningitis in older children and adults. Eur J Neurol. 2008 Jul;15(7):649-59.
http://www.ncbi.nlm.nih.gov/pubmed/18582342?tool=bestpractice.com
[61]National Institute for Health and Care Excellence. Meningitis (bacterial) and meningococcal disease: recognition, diagnosis and management. Mar 2024 [internet publication].
https://www.nice.org.uk/guidance/ng240
The use of acyclovir may reduce the severity and duration of symptoms in viral meningitis caused by herpes simplex virus (HSV) or varicella zoster virus.[62]Bergstrom T, Alestig K. Treatment of primary and recurrent herpes simplex virus type 2 induced meningitis with acyclovir. Scand J Infect Dis. 1990;22(2):239-40.
http://www.ncbi.nlm.nih.gov/pubmed/2162558?tool=bestpractice.com
Efficacy has not been established in prospective randomized trials.
Confirmed viral meningitis
Antibiotics may be stopped following confirmation of viral infection.[3]McGill F, Heyderman RS, Michael BD, et al. The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J Infect. 2016 Apr;72(4):405-38.
https://www.journalofinfection.com/article/S0163-4453(16)00024-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/26845731?tool=bestpractice.com
Patients who develop severe illness, or who are at risk for developing severe illness, may require continued hospital admission for monitoring and supportive care, including airway management and oxygen if required, adequate analgesia for headaches, antipyretics if fever is present, antiemetics if vomiting, and intravenous fluids if dehydrated.[3]McGill F, Heyderman RS, Michael BD, et al. The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J Infect. 2016 Apr;72(4):405-38.
https://www.journalofinfection.com/article/S0163-4453(16)00024-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/26845731?tool=bestpractice.com
[4]Centers for Disease Control and Prevention. About viral meningitis. Jan 2024 [internet publication].
https://www.cdc.gov/meningitis/about/viral-meningitis.html
Antiviral medication is recommended if infection with herpes simplex, varicella zoster, or cytomegalovirus (CMV) is confirmed. Patients with confirmed viral meningitis who are afebrile and clinically improving may be appropriate for discharge following specialist review, with outpatient therapy as needed.[3]McGill F, Heyderman RS, Michael BD, et al. The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J Infect. 2016 Apr;72(4):405-38.
https://www.journalofinfection.com/article/S0163-4453(16)00024-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/26845731?tool=bestpractice.com
Most patients with mild viral meningitis get better on their own in 7-10 days.[4]Centers for Disease Control and Prevention. About viral meningitis. Jan 2024 [internet publication].
https://www.cdc.gov/meningitis/about/viral-meningitis.html
Acyclovir or valacyclovir is typically given first line for HSV and varicella zoster. Valacyclovir is better absorbed orally but is much more expensive. Foscarnet may be used for severe acyclovir-resistant infections.
For CMV, ganciclovir or valganciclovir is used as first-line agent; second- and third-line agents include foscarnet and cidofovir, respectively.
Recurrent benign lymphocytic meningitis (also known as Mollaret meningitis) is a rare condition thought to be due to viral infection.[3]McGill F, Heyderman RS, Michael BD, et al. The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J Infect. 2016 Apr;72(4):405-38.
https://www.journalofinfection.com/article/S0163-4453(16)00024-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/26845731?tool=bestpractice.com
Herpes simplex type 2 is most commonly implicated. Treatment decisions should always be made by a specialist. Acyclovir and valacyclovir should not routinely be given as prophylaxis.[3]McGill F, Heyderman RS, Michael BD, et al. The UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults. J Infect. 2016 Apr;72(4):405-38.
https://www.journalofinfection.com/article/S0163-4453(16)00024-4/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/26845731?tool=bestpractice.com
A randomized controlled trial of secondary prophylaxis with valacyclovir in patients with either primary or recurrent HSV-2 meningitis found no effect on the risk of recurrence.[63]Aurelius E, Franzen-Röhl E, Glimåker M, et al. Long-term valacyclovir suppressive treatment after herpes simplex virus type 2 meningitis: a double-blind, randomized controlled trial. Clin Infect Dis. 2012 May;54(9):1304-13.
http://www.ncbi.nlm.nih.gov/pubmed/22460966?tool=bestpractice.com
The study also found an increased risk of recurrence in the valacyclovir group once treatment was stopped.[63]Aurelius E, Franzen-Röhl E, Glimåker M, et al. Long-term valacyclovir suppressive treatment after herpes simplex virus type 2 meningitis: a double-blind, randomized controlled trial. Clin Infect Dis. 2012 May;54(9):1304-13.
http://www.ncbi.nlm.nih.gov/pubmed/22460966?tool=bestpractice.com
If a specialist initiates antiviral treatment, this should be stopped after 1 year as Mollaret meningitis tends to resolve.