Meningitis is inflammation of the thin tissue that surrounds the brain and spinal cord, called the meninges.
There are several types of meningitis. The most common is viral meningitis, which you get when a virus enters the body through the nose or mouth and travels to the brain. Bacterial meningitis is rare, but can be deadly. It usually starts with bacteria that cause a cold-like infection. It can block blood vessels in the brain and lead to stroke and brain damage. It can also harm other organs.Pneumococcal infections and meningococcal infections can cause bacterial meningitis. Anyone can get meningitis, but it is more common in people whose bodies have trouble fighting infections.
Certain vaccines can help prevent some types of bacterial meningitis:
- Haemophilus vaccine (HiB vaccine) given to children helps
- Pneumococcal vaccine is given to children and adults
- Meningococcal vaccines is given to children and adults; some communities hold vaccination campaigns after an outbreak of meningococcal meningitis.
Household members and others in close contact with people who have meningococcal meningitis should receive antibiotics to prevent becoming infected.
The most common causes of meningitis are viral infections. These infections usually get better without treatment. But, bacterial meningitis infections are very serious. They may result in death or brain damage, even if treated.
Meningitis may also be caused by:
- Chemical irritation
- Drug allergies
Many types of viruses can cause meningitis:
- Enteroviruses: These are viruses that also can cause intestinal illness.
- Herpes viruses: These are the same viruses that can cause cold sores and genital herpes. However, people with cold sores or genital herpes do not have a higher chance of developing herpes meningitis.
- Mumps and HIV viruses can cause aseptic meningitis.
- West Nile virus: This virus is spread by mosquito bites and has become a cause of viral meningitis in most of the United States.
Viral meningitis occurs more often than bacterial meningitis, and is milder. It usually occurs in the late summer and early fall. It most often affects children and adults under age 30.
Bacterial meningitis is an emergency. You will need immediate treatment in a hospital.
Symptoms usually come on quickly, and may include:
- Fever and chills, especially in newborns and children
- Mental status changes
- Nausea and vomiting
- Sensitivity to light (photophobia)
- Severe headache
- Stiff neck (meningismus)
Other symptoms that can occur with this disease:
- Bulging fontanelles in babies
- Decreased alertness
- Poor feeding or irritability in children
- Rapid breathing
- Unusual posture, with the head and neck arched backwards (opisthotonos)
You cannot tell if you have bacterial or viral meningitis by how you feel. Your health care provider must find out the cause. Go to the hospital emergency department right away if you think you have symptoms of meningitis.
Early diagnosis and treatment of bacterial meningitis is essential to prevent permanent neurological damage. Viral meningitis is usually not serious, and symptoms should disappear within 2 weeks with no lasting complications.
Antibiotics are used to treat bacterial meningitis. Antibiotics do not treat viral meningitis. But antiviral medicine may be given to those with herpes meningitis.
Other treatments will include:
- Fluids through a vein (IV)
- Medicines to treat symptoms, such as brain swelling, shock, and seizures