Most cases of meningitis are caused by a viral infection, but bacterial and fungal infections also can lead to meningitis. Non-bacterial meningitis is often referred to as ‘aseptic meningitis’ – eg.viral meningitis. Bacterial meningitis may be referred to as ‘purulent meningitis’.
Viral meningitis can occur at any age. Those at increased risk of contracting viral meningitis:
*Children < 5 years of age
*People with weakened immune system due to disease, medications
*Babies < 1 month old
Enteroviruses (Coxsackie or Echovirus groups) are the most common cause of viral meningitis across all age groups; parechoviruses are also common in children. Herpesviruses that cause meningitis include herpes simplex virus (HSV) 1 and 2, varicella-zoster virus (VZV), cytomegalovirus, Epstein-Barr virus, and human herpesvirus 6.
Viral meningitis is usually mild and often clears on its own within two weeks. A group of common viruses known as enteroviruses are responsible for about 90 percent of viral meningitis in the United States
Three major pathways exist by which an infectious agent gains access to the central nervous system (CNS) and causes disease.
The infectious agent colonizes or establishes a localized infection in the host. From this site, the organism invades the submucosa by circumventing host defenses and gains access to the CNS. Clinical manifestations of viral meningitis: headache, fever, photophobia, less neck stiffness
Viral meningitis
