Viruses That Cause Meningitis Beyond HSV
Besides herpes simplex virus (HSV), the most common viruses that cause meningitis are enteroviruses, varicella zoster virus (VZV), and less commonly cytomegalovirus, Epstein-Barr virus, and mumps virus. 1
Primary Viral Causes of Meningitis
Most Common Causes
- Enteroviruses are the predominant cause, accounting for 85-95% of all viral meningitis cases, with over 90 different serotypes transmitted via the fecal-oral route 1, 2
- Herpes viruses, particularly HSV-2 (more common than HSV-1 for meningitis) and VZV (varicella zoster virus), are the second most common causes 1
- Both VZV and HSV-2 meningitis can occur with primary infection or as reactivation of disease 1
Less Common Viral Causes
- Cytomegalovirus (CMV) can cause meningitis, particularly in immunocompromised patients 1, 3
- Epstein-Barr virus (EBV) is another less common herpesvirus cause of meningitis 1, 4
- Mumps virus, though rare since widespread vaccination, can still cause meningitis 1, 5
Emerging and Re-emerging Viral Causes
Arboviruses
- West Nile virus, Japanese encephalitis virus, and Tick-borne encephalitis virus can cause meningitis 5
- Dengue, Zika, and Toscana viruses are other arboviruses associated with meningitis 5
Other Viral Pathogens
- Respiratory viruses including SARS-CoV-2, influenza, metapneumoviruses, and measles can cause meningitis 5
- Human herpesvirus type 6 (HHV-6) is a rare but documented cause of viral meningitis 2, 5
- Lymphocytic choriomeningitis virus (LCMV) is an uncommon cause of viral meningitis 2
- Parechoviruses have been identified as causes of meningitis, particularly in pediatric populations 5, 6
Diagnostic Considerations
Testing Recommendations
- When viral meningitis is suspected, CSF should be tested for enteroviruses, HSV-1, HSV-2, and VZV by PCR 1
- Additional PCR testing or serological assays for other viruses should be guided by specific features in the history and examination, such as immune compromise and travel history 1
- Stool and/or throat swabs should be tested for enterovirus by PCR to aid diagnosis 1
Clinical Presentation
- Patients typically present with meningism (neck stiffness, headache, and photophobia), though fever is not always present 1, 7
- Other non-specific symptoms may include diarrhea, vomiting, muscle pain, and sore throat 1, 7
- Patients with HSV-2 meningitis rarely have concurrent genital ulcers, and VZV meningitis can occur with or without the characteristic rash 1
Prevention Strategies
- Ensure up-to-date vaccinations, including measles-mumps-rubella (MMR) and varicella vaccines, which can prevent some causes of viral meningitis 8
- Practice good hygiene including frequent handwashing, especially after using the toilet or changing diapers 8
- Avoid close contact with people who are sick with viral illnesses and avoid sharing personal items 8
Treatment Approach
- Most viral meningitis cases require supportive care focusing on symptom management 7
- For HSV-2 meningitis, aciclovir 10 mg/kg IV every 8 hours may be used until resolution of symptoms 7
- For VZV meningitis, intravenous aciclovir at 10-15 mg/kg three times daily for 10-14 days is recommended 4
Clinical Pitfalls to Avoid
- Failing to distinguish between viral meningitis and encephalitis, which requires different management approaches 7
- Missing altered consciousness, which suggests an alternative diagnosis such as bacterial meningitis, encephalitis, or other intracranial pathology 1, 7
- Overuse of antibiotics in confirmed viral meningitis cases, as identifying the viral pathogen allows for appropriate management and reduction of unnecessary antibiotic use 1