From the Guidelines
Viral meningitis is most commonly caused by enteroviruses and herpes viruses, particularly HSV-2 and VZV, as stated in the UK joint specialist societies guideline on the diagnosis and management of acute meningitis and meningococcal sepsis in immunocompetent adults 1. The causes of viral meningitis can be broken down into:
- Enteroviruses, which are transmitted via the faecal-oral route and account for a significant proportion of cases
- Herpes viruses, including HSV-2 and VZV, which can be transmitted through sexual contact or the respiratory route
- Other less common causes, such as cytomegalovirus, Epstein-Barr virus, and mumps virus, which should be considered if initial tests do not reveal a cause 1 It is essential to note that the precise incidence of viral meningitis is unknown, but it is estimated to account for at least 50% of the meningitis burden and possibly up to 80% 1. The transmission of these viruses typically occurs through:
- Direct contact with respiratory secretions, fecal matter, or contaminated surfaces
- Certain risk factors, such as compromised immune systems, crowded living conditions, and seasonal factors, can increase susceptibility to viral meningitis Unlike bacterial meningitis, viral meningitis is generally less severe and often resolves without specific treatment, though antiviral medications may be used for certain causative viruses like HSV 1. Prevention measures include good hygiene practices, avoiding close contact with infected individuals, and vaccination against viruses like mumps that can cause meningitis.
From the Research
Causes of Viral Meningitis
- Viral meningitis can be caused by various viruses, including enteroviruses, herpesviruses, and influenza viruses 2
- Enteroviruses are the most common cause of viral meningitis worldwide 3, 2, 4
- Other viruses that can cause viral meningitis include:
- Arboviruses (e.g., West Nile virus, Japanese encephalitis, Tick borne encephalitis, Dengue, Zika, Toscana) 3
- Parechoviruses 3
- Respiratory viruses (e.g., severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza, metapneumoviruses, measles, mumps) 3
- Herpes viruses (e.g., herpes simplex virus (HSV) type 1 (HSV-1), HSV-2, human herpes (HV) 6, varicella zoster virus (VZV)) 3, 4, 5, 6
- Epstein-Barr virus (EBV) and Cytomegalovirus (CMV) 6
Common Causative Agents
- Enteroviruses are the underlying cause of most viral meningitis cases worldwide 2, 4
- Herpes simplex virus type 2 (HSV-2) is more likely to cause the clinical syndrome of viral meningitis, while HSV-1 is more likely to cause a meningoencephalitis with serious brain dysfunction 4
- Varicella-zoster virus (VZV) can infect the meninges by means of spread from cervical and dorsal root ganglia in a retrograde fashion 4
Diagnosis and Treatment
- The diagnosis of viral meningitis is based on the identification of a specific viral agent in body fluids, especially the cerebrospinal fluid (CSF) 4, 5, 6
- Polymerase chain reaction (PCR) testing provides a rapid and specific etiological diagnosis 5
- Treatment of viral meningitis depends on the causative agent and may include antiviral therapy, supportive care, and prevention of complications 3