Aseptic Meningitis Causes and Diagnosis

Definition and Epidemiology

Aseptic meningitis is defined as a syndrome characterized by acute onset of meningeal symptoms, fever, cerebrospinal fluid pleocytosis, and bacteriologically sterile cultures, according to the Centers for Disease Control and Prevention (CDC) 2, 3, 4
The condition is the most common form of meningitis, with viral meningitis accounting for at least 50% and possibly up to 80% of all meningitis cases, as reported by the Journal of Infection 1
In the UK, enteroviruses and herpes viruses (predominantly HSV-2 and VZV) are the most common causes of aseptic meningitis, with an annual incidence of 7.6 per 100,000 adults 1

Enteroviruses are the most common cause of aseptic meningitis, accounting for more than half of all cases, with over 90 different enterovirus serotypes existing, according to the Journal of Infection 1
Herpes viruses, including Herpes simplex virus type 2 (HSV-2) and Varicella zoster virus (VZV), are the second most common cause of aseptic meningitis, with HSV-2 being more common than HSV-1 for meningitis 1
Other viral causes, such as Cytomegalovirus (CMV) and Epstein-Barr virus (EBV), can also contribute to aseptic meningitis, as reported by the Journal of Infection 1

Distinguishing between viral meningitis and bacterial meningitis is crucial due to differences in treatment and outcomes, with viral meningitis generally being self-limited with a good prognosis, according to the Journal of Infection 1
Diagnosis relies on examination of cerebrospinal fluid obtained from lumbar puncture, with CSF testing for enteroviruses, HSV-1, HSV-2, and VZV by PCR when viral meningitis is suspected, as recommended by the Journal of Infection 1
Specific antiviral therapy, such as intravenous aciclovir, is indicated for certain causes, including VZV meningitis, with a recommended dosage of 10-15 mg/kg three times daily for 10-14 days, according to Praxis Medical Insights 5
Corticosteroids may be considered for VZV meningitis with a vasculitic component, as suggested by Praxis Medical Insights 5

Systemic illnesses, such as autoimmune disorders and inflammatory conditions, can also contribute to aseptic meningitis, as reported by MMWR Recommendations and Reports 4 and Praxis Medical Insights 5