Viral meningitis is an infection occuring mostly in children under age 5.
It happens when certain viruses invade the meninges which are the tissues that cover and protect the brain and spinal cord.
The meninges are arranged in three layers.
The layer that actually touches the brain and spinal cord is called the pia mater.
The spider web-like middle layer is called the arachnoid mater.
The outermost and toughest layer is called the dura mater.
Cerebrospinal fluid, which also protects the brain and spinal cord,
flows between the meninges and over the surface of the brain.
The most common cause of viral meningitis is a type of virus called enteroviruses.
Other viruses that can cause meningitis include: the mumps virus, the measles virus,
herpes viruses, and a variety of viruses spread by blood –feeding insects, such as mosquitos and ticks.
Viruses that cause meningitis may be spread through the bite of an infected insect.
However, the two most common ways the viruses spread are through fecal contamination,
which can happen when hands are not washed after using the toilet or changing a diaper,
and through contact with the body fluids from an infected person, such as through sneezing or coughing.
Once inside the body, the viruses make copies of themselves, and enter the bloodstream.
Viruses travel through the bloodstream to the brain,
where they cross the border between the bloodstream and the brain into the cerebrospinal fluid.
The viruses spread throughout the cerebrospinal fluid and infect the cells of the meninges.
The meninges become inflamed as the immune system begins to fight off the infection.
Symptoms of viral meningitis in infants and young children include: fever, irritability, loss of appetite, and trouble waking up.
Symptoms in older children and adults include: fever, headache, stiff neck, sensitivity to light,
sleepiness, trouble waking up, nausea, vomiting, and loss of appetite.
The symptoms of viral meningitis are similar to those of bacterial meningitis, but usually less severe.
Doctors may recommend acetaminophen, or other non-steroidal anti-inflammatory drugs for fever and headache.
For meningitis caused by a type of herpes virus, doctors may prescribe an antiviral medication, such as acyclovir.
There is no treatment for most viruses that cause meningitis, though most people recover on their own within two weeks.