From the Guidelines
Viral meningitis typically presents with symptoms of meningism, including neck stiffness, headache, and photophobia, as well as non-specific symptoms such as fever, diarrhoea, vomiting, muscle pain, and sore throat. These symptoms often develop rapidly over 24-48 hours 1. Some patients may also experience rash, muscle pain, and irritability. Unlike bacterial meningitis, viral meningitis symptoms are usually less severe, though they can still be quite uncomfortable. The illness is caused by viruses that inflame the meninges (protective membranes covering the brain and spinal cord), most commonly enteroviruses, but also herpes viruses, mumps virus, or West Nile virus.
Key Symptoms
- Severe headache
- Fever
- Neck stiffness
- Sensitivity to light (photophobia)
- Nausea
- Vomiting
- Fatigue
- Confusion
- Rash
- Muscle pain
- Irritability
Diagnosis and Treatment
Diagnosis of viral meningitis is typically made through CSF examination and PCR testing for viral pathogens 1. CSF PCR is the gold standard for confirmation of viral meningitis, and most laboratories will test for enterovirus, HSV-1, HSV-2, and VZV. Treatment focuses on managing symptoms with rest, adequate fluid intake, and over-the-counter pain relievers like acetaminophen or ibuprofen (typically 400-600mg every 6 hours for adults) 1. Most cases resolve within 7-10 days without specific antiviral treatment, though recovery can sometimes take weeks. Medical attention should be sought immediately if symptoms appear, as early diagnosis is important to rule out bacterial meningitis, which requires prompt antibiotic treatment and can be life-threatening.
Important Considerations
- Viral meningitis should be assessed by an infection or neurological specialist 1.
- No cause is found in 30-50% of patients with presumed viral meningitis 1.
- Identifying a viral pathogen allows the patient to be given a diagnosis and antibiotics to be stopped, reducing the number of investigations performed and the duration of hospital stay 1.
From the Research
Viral Meningitis Symptoms
The symptoms of viral meningitis can vary depending on the causative agent, but they are generally similar across different viruses.
- The clinical manifestations and symptoms associated with viral meningitis are similar for the different causative agents, which makes it difficult to diagnose the disease at early stages 2.
- Enteroviruses account for 85 to 95% of all cases of aseptic meningitis, but the arboviruses and herpes simplex virus are also important etiologic agents 3.
- Mumps, lymphocytic choriomeningitis virus, herpes zoster, human herpesvirus type 6, and influenza viruses are rare causes of meningitis 3.
Diagnosis and Treatment
- Molecular diagnostics can improve the rate of pathogen detection, reduce unnecessary antibiotics use, and length of hospitalization 4.
- Despite improvements in diagnostics, many laboratories do not use molecular methods and even when they are used, many cases still remain without a proven viral aetiology identified 4.
- There are no established treatments for viral meningitis, and the one potential treatment, aciclovir, which is effective in vitro for herpes simplex virus, has never been subjected to a clinical trial 4.
- Early administration of antiviral drugs such as acyclovir, valaciclovir, or famciclovir can shorten the duration of an episode of aseptic meningitis 5.
- Daily prophylactic administration of any of these medicines also reduces the frequency of future episodes 5.
Patient Outcomes
- Neurologic outcomes were significantly improved with antiviral therapy in immunocompromised patients with herpes meningitis, but not in immunocompetent patients 6.
- Most patients with HSV meningitis rapidly improve, but immunocompromised hosts have more neurologic sequelae and may benefit from antiviral therapy 6.