Community-acquired acute meningitis and encephalitis: a narrative review

Miles H Beaman
Med J Aust 2018; 209 (10): . || doi: 10.5694/mja17.01073
Published online: 15 October 2018



  • Meningitis and encephalitis are medical emergencies. Patients need prompt evaluation and immediate empiric therapy to reduce the likelihood of fatal outcomes and chronic neurological sequelae.
  • Conjugate bacterial vaccines have significantly reduced the incidence of bacterial meningitis, especially in children.
  • As the results of changes in patterns of bacterial drug sensitivity, ceftriaxone is now part of the recommended empiric treatment for bacterial meningitis and should be administered as early as possible.
  • Neuroimaging delays the treatment of meningitis and is not needed in most cases.
  • Adjunctive corticosteroid therapy is of benefit for many patients with meningitis and should be initiated in most adults before antibiotic therapy.
  • Molecular testing can assist the specific diagnosis of encephalitis and should be based on the exposure history and geographic risk factors relevant to the patient, but non-infectious causes of encephalitis are also common.
  • Empiric therapy for encephalitis should be directed at the most frequently identified infectious pathogen, herpes simplex virus type 1 (ie, intravenous aciclovir).
  • Vaccines can protect against the major pathogens of childhood infections (measles, mumps, rubella, polio, varicella viruses), influenza viruses, and exotic pathogens that cause meningitis and encephalitis (rabies, Japanese encephalitis, dengue, yellow fever, tick-borne encephalitis viruses, Mycobacterium tuberculosis).


  • Western Diagnostic Pathology, Perth, WA


Competing interests:

No relevant disclosures.

  • 1. Costerus JM, Brouwer MC, Bijlsma MW, van de Beek D. Community-acquired bacterial meningitis. Curr Opin Infect Dis 2017; 30: 135-141.
  • 2. Mailles A, De Broucker T, Costanzo P, et al. Long-term outcome of patients presenting with acute infectious encephalitis of various causes in France. Clin Infect Dis 2012; 54: 1455-1464.
  • 3. Mailles A, Stahl JP, Bloch KC. Update and new insights in encephalitis. Clin Microbiol Infect 2017; 23: 607-613.
  • 4. Antibiotic Expert Groups. Central nervous system infections. In: Therapeutic guidelines: antibiotic; version 15. Melbourne: Therapeutic Guidelines, 2014; pp. 267-268.
  • 5. van de Beek D, Cabellos C, Dzupova O, et al. ESCMID guideline: diagnosis and treatment of acute bacterial meningitis. Clin Microbiol Infect 2016; 22 Suppl 3: S37-S62.
  • 6. Britton PN, Eastwood K, Brew BJ, et al. Consensus guidelines for the investigation and management of encephalitis. Med J Aust 2015; 202: 576-577. <MJA full text>
  • 7. Beaman MH, Wesselingh SL. Acute community-acquired meningitis and encephalitis. Med J Aust 2002; 176: 389-396. <MJA full text>
  • 8. GBD 2013 Mortality and Causes of Death collaborators. Global, regional, and national age-sex specific all-cause and cause-specific mortality for 240 causes of death, 1990–2013: a systematic analysis for the Global Burden of Disease Study 2013. Lancet 2015; 385: 117-171.
  • 9. Sharma S, Sneath E, Cheng AC, Friedman NB. Community-acquired syndromes causing morbidity and mortality in Australia. Commun Dis Intell Q Rep 2017; 41: e49-e57.
  • 10. Australian Government Department of Health. Pneumococcal disease (invasive): public dataset. (viewed July 2018).
  • 11. Communicable Diseases Network Australia. Invasive pneumococcal disease in Australia, 2011 and 2012. Comm Dis Intell 2016; 40: E267.
  • 12. Lahra MM, Enriquez RP; National Neisseria Network. Australian Meningococcal Surveillance Programme annual report, 2015. Commun Dis Intell Q Rep 2016; 40: E503-E511.
  • 13. Australian Government Department of Health. Meningococcal disease (invasive): public dataset. (viewed July 2018).
  • 14. Koopmans MM, Bijlsma MW, Brouwer MC, et al. Listeria monocytogenes meningitis in the Netherlands, 1985–2014: a nationwide surveillance study. J Infect 2017; 75: 12-19.
  • 15. McGill F, Griffiths MJ, Solomon T. Viral meningitis: current issues in diagnosis and treatment. Curr Opin Infect Dis 2017; 30: 248-256.
  • 16. Communicable Diseases Network Australia. Invasive meningococcal disease: CDNA National guidelines for public health units. Updated: 4 July 2017. (viewed Sept 2018).
  • 17. Britton PN, Eastwood K, Paterson B, et al.; Australasian Society of Infectious Diseases; Australasian College of Emergency Medicine; Australian and New Zealand Association of Neurologists; Public Health Association of Australia. Consensus guidelines for the investigation and management of encephalitis in adults and children in Australia and New Zealand. Intern Med J 2015; 45: 563-576.
  • 18. van de Beek D, de Gans J, Tunkel AT, Wijdicks EF. Community-acquired bacterial meningitis in adults. N Engl J Med 2006; 354: 44-53.
  • 19. Viale P, Scudeller L, Pea F, et al. Implementation of a meningitis care bundle in the emergency room reduces mortality associated with acute bacterial meningitis. Ann Pharmacother 2015; 49: 978-985.
  • 20. Brouwer MC, Wijdicks EF, van de Beek D. What’s new in bacterial meningitis. Intensive Care Med 2016; 42: 415-417.
  • 21. Lebel MH, Freij BJ, Syrogiannopoulos GA, et al. Dexamethasone therapy for bacterial meningitis. Results of two double-blind, placebo-controlled trials. N Engl J Med 1988; 319: 964-971.
  • 22. Brouwer MC, McIntyre P, de Gans J, et al. Corticosteroids for acute bacterial meningitis. Cochrane Database Syst Rev 2010; (9): CD004405.
  • 23. van de Beek D, de Gans J, McIntyre P, Prasad K. Corticosteroids in acute bacterial meningitis. Cochrane Database Syst Rev 2003; (3): CD004405.
  • 24. van de Beek D, de Gans J, McIntyre P, Prasad K. Corticosteroids for acute bacterial meningitis. Cochrane Database Syst Rev 2007; (1): CD004405.
  • 25. Charlier C, Perrodeau É, Leclercq A, et al; MONALISA study group. Clinical features and prognostic factors of listeriosis: the MONALISA national prospective cohort study. Lancet Infect Dis 2017; 17: 510-519.
  • 26. Cunningham AL, Taylor R, Taylor J, et al. Prevalence of infection with herpes simplex virus types 1 and 2 in Australia: a nationwide population based survey. Sex Transmiss Infect 2006; 82: 164-168.
  • 27. Aurelius E, Franzen-Rohl 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; 54: 1304-1313.
  • 28. Tunkel AR, van de Beek D, Scheld WM. Acute meningitis. In: Mandell GL, Bennet JE, Dolin R, editors, Mandell, Douglas, and Bennett’s Principles and practice of infectious diseases, 7th edition. Philadelphia: Elsevier/Churchill Livingstone, 2010; pp. 1189-1230.
  • 29. Desmond RA, Accortt NA, Talley L, et al. Enteroviral meningitis: natural history and outcome of pleconaril therapy. Antimicrob Agents Chemother 2006; 50: 2409-2414.
  • 30. Wildenbeest JG, van den Broek PJ, Benschop KS, et al. Pleconaril revisited: clinical course of chronic enteroviral meningoencephalitis after treatment correlates with in vitro susceptibility. Antivir Ther 2012; 17: 459-466.
  • 31. Benschop KS, Wildenbeest JG, Koen G, et al. Genetic and antigenic structural characterization for resistance of echovirus 11 to pleconaril in an immunocompromised patient. J Gen Virol 2015; 96: 571-579.
  • 32. Castelblanco RL, Lee MJ, Hasbun R. Epidemiology of bacterial meningitis in the USA from 1997 to 2010: a population-based observational study. Lancet Infect Dis 2014; 14: 813-819.
  • 33. The Australian Meningococcal Surveillance Programme; Tapsall J. Annual report of the Australian Meningococcal Surveillance Programme, 2008. Commun Dis Intell 2009; 33: 259-267.
  • 34. Granerod J, Cunningham R, Zuckerman M, et al. Causality in acute encephalitis: defining aetiologies. Epidemiol Infect 2010; 138: 783-800.
  • 35. Granerod J, Ambrose HE, Davies NW, et al. Causes of encephalitis and differences in their clinical presentations in England: a multicentre, population-based prospective study. Lancet Infect Dis 2010; 10: 835-844.
  • 36. Huppatz C, Durrheim DN, Levi C, et al. Etiology of encephalitis in Australia, 1990–2007. Emerg Infect Dis 2009; 15: 1359-1365.
  • 37. Davison KL, Crowcroft NS, Ramsay ME, et al. Viral encephalitis in England, 1989–1998: what did we miss? Emerg Infect Dis 2003; 9: 234-240.
  • 38. Cag Y, Erdem H, Leib S, et al. Managing atypical and typical herpetic central nervous system infections: results of a multinational study. Clin Microbiol Infect 2016; 22: 568.e9-568.e17.
  • 39. Ward KN. Child and adult forms of human herpesvirus 6 encephalitis: looking back, looking forward. Curr Opin Neurol 2014; 27: 349-355.
  • 40. De Broucker T, Mailles A, Chabrier S, et al. Acute varicella zoster encephalitis without evidence of primary vasculopathy in a case-series of 20 patients. Clin Microbiol Infect 2012; 18: 808-819.
  • 41. Beaman MH. Toxoplasmosis. In: Rakel RE, Bope ET, editors, Conn’s Current therapy. Philadelphia: WB Saunders, 2001; pp 155-162.
  • 42. Misbah SA. Progressive multi-focal leukoencephalopathy: driven from rarity to clinical mainstream by iatrogenic immunodeficiency. Clin Exp Immunol 2017; 188: 342-352.
  • 43. Thakkar R, Chavan A. Acute encephalitis: a brief review of its types and clinical management. Pharmagene 2015; 2: 1-7.
  • 44. Deverell M, Phu A, Zurynski YA, Elliott EJ; chief investigators of Australian Paediatric Surveillance Unit surveillance studies. Australian Paediatric Surveillance Unit annual report, 2015. Commun Dis Intell Q Rep 2017; 41: E181-E185.
  • 45. Graus F, Titulaer MJ, Balu R, et al. A clinical approach to diagnosis of autoimmune encephalitis. Lancet Neurol 2016; 15: 391-404.
  • 46. Granerod J, Davies NW, Mukonoweshuro W, et al. Neuroimaging in encephalitis: analysis of imaging findings and interobserver agreement. Clin Radiol 2016; 71: 1050-1058.
  • 47. Ben-Harari RR, Goodwin E, Casoy J. Adverse event profile of pyrimethamine-based therapy in toxoplasmosis: a systematic review. Drugs R D 2017; 17: 523-544.
  • 48. Hernandez AV, Thota P, Pellegrino D, et al. A systematic review and meta-analysis of the relative efficacy and safety of treatment regimens for HIV-associated cerebral toxoplasmosis: is trimethoprim–sulfamethoxazole a real option? HIV Med 2017; 18: 115-124.
  • 49. Nishida K, Morioka I, Nakamachi Y, et al. Neurological outcomes in symptomatic congenital cytomegalovirus-infected infants after introduction of newborn urine screening and antiviral treatment. Brain Dev 2016; 38: 209-216.
  • 50. Martinez-Torres F, Menon S, Pritsch M, et al; GACHE Investigators. Protocol for German trial of acyclovir and corticosteroids in herpes-simplex-virus-encephalitis (GACHE): a multicenter, multinational, randomized, double-blind, placebo-controlled German, Austrian and Dutch trial [ISRCTN45122933]. BMC Neurol 2008; 8: 40.
  • 51. Canivet C, Menasria R, Rhéaume C, et al. Valacyclovir combined with artesunate or rapamycin improves the outcome of herpes simplex virus encephalitis in mice compared to antiviral therapy alone. Antiviral Res 2015; 123: 105-113.
  • 52. Ginsburg AS, Meghani A, Halstead SB, Yaich M. Use of the live attenuated Japanese Encephalitis vaccine SA 14-14-2 in children: a review of safety and tolerability studies. Hum Vaccin Immunother 2017; 13: 2222-2231.
  • 53. Kessels JA, Recuenco S, Navarro-Vela AM, et al. Pre-exposure rabies prophylaxis: a systematic review. Bull World Health Organ 2017; 95: 210-219C.
  • 54. Iro MA, Sadarangani M, Goldacre R, et al. 30-year trends in admission rates for encephalitis in children in England and effect of improved diagnostics and measles–mumps–rubella vaccination: a population-based observational study. Lancet Infect Dis 2017; 17: 422-430.
  • 55. Neuzil KM, Griffin MR. Preventing shingles and its complications in older persons. N Engl J Med 2016; 375: 1079-1080.
  • 56. Dutmer CM, Asturias EJ, Smith C, et al. Late onset hypomorphic RAG2 deficiency presentation with fatal vaccine-strain VZV infection. J Clin Immunol 2015; 35: 754-760.
  • 57. Watanabe D, Mizukami A, Holl K, et al. The potential public health impact of herpes zoster vaccination of people aged ≥ 50 years in Japan: results of a Markov model analysis. Dermatol Ther (Heidelb) 2018; 8: 269-284.
  • 58. Middleton D, Pallister J, Klein R, et al. Hendra virus vaccine, a one health approach to protecting horse, human, and environmental health. Emerg Infect Dis 2014; 20: 372-379.
  • 59. Si D, Marquess J, Donnan E, et al. Potential exposures to Australian bat lyssavirus notified in Queensland, Australia, 2009–2014. PLoS Negl Trop Dis 2016; 10: e0005227.


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