The brain and the spinal cord are covered by a protective membrane. This membrane is made up of three layers called the dura mater, arachnoid mater and Pia mater. These layers are together called as is called as meninges. They help in protecting the central nervous system from infection. However, there are certain microorganisms as well as drugs that can cause inflammation of the meninges. This leads to a life-threatening condition called meningitis.
What is Meningitis?
The inflammation of the meninges around the brain and spinal cord is called as meningitis. It leads to swelling around the brain and spinal cord, leading to headache, stiff neck and fever. In some cases, the infection can get cured after a few weeks of treatment. However, it may turn into a serious life-threatening condition in some cases. Thus, anyone suffering from meningitis requires immediate medical attention.
Causes of Meningitis
Meningitis is caused by viral, bacterial, protozoal and fungal infections. It can even occur due to non-infectious causes like effects of certain drugs, antibiotics, etc. In some cases, inflammation of the meninges can occur due to spread of cancerous cells to the membrane, systemic lupus erythrmatous, dermoid cysts, and other similar conditions affecting the central nervous system. Infectious causes that is, meningitis caused by microorganisms is more common than non-infectious meningitis.
Types of Meningitis
There are different types of meningitis infection, based on the causes. These include:
The less severe form of meningitis that is controllable with treatment is viral meningitis. It is usually caused by viruses belonging to the enterovirus family.
Some of the other causes of viral meningitis include:
Herpes simplex virus
West Nile virus
La Crosse virus
Varicella zoster virus
Lymphocytic choriomeningitis virus (LCMV)
Causes of Viral Meniningitis
Viral meningitis can strike anyone of any age. However, it is common in people with weak immune system like children under the age of 5 years or very old people. It can spread from person to person due to fecal contamination. This occurs when people do not wash hands after using the toilet, changing diapers, etc. The virus can also spread through respiratory secretions released by an infected person. In some cases, certain virus can spread through direct as well as indirect contact. Like, shaking hands, touching objects contaminated by the virus or sharing towels, clothes and napkins.
Bacterial meningitis is a severe infection that requires medical attention. If left untreated, it could lead to many complications. There are several bacteria that can cause meningitis. Some of these infectious agents are as follows:
Haemophilus influenza type B
Group B Streptococcus
Causes of Bacterial Meningitis
Bacterial meningitis do not spread like viral meningitis. Some bacterial infections spread through kissing. Some infections spread when people live in close quarters with an infected person. They can even spread by sharing infected or contaminated glasses, spoons, towels, etc. Bacterial meningitis usually attacks people who have a weak immune system and their bodies cannot offer resistance to the invading bacteria.
One of the rare types of meningitis is fungal meningitis. It tends to affect people with a weak immune system like those suffering from cancer or HIV/AIDS. It is caused by a fungus called as Cryptococcus. This infection is not contagious and does not spread from an infected person to a healthy one. It tends to spread by inhalation of the fungal spores present in soil or bird droppings.
An extremely rare form of meningitis is primary amebic meningoencephalitis (PAM). This infection is caused by an amoeba called Naegleria fowleri. It only infects people who swim in freshwater rivers and lakes or poorly maintained or unchlorinated swimming pools. The parasite enters the body only through the nose. One cannot get meningitis by drinking water contaminated by Naegleria fowleri. The parasite tends to destroy the brain tissues and causes symptoms similar to bacterial meningitis. The disease tends to progress very fast and can lead to death of the infected person within 12 days of infection.
Noninfectious meningitis is caused by reasons other than microorganisms. It can be due to a brain surgery, injury, systemic lupus erythematosus (SLE), reaction to certain drugs, cancer, etc.
Symptoms of Meningitis
Viral meningitis usually lasts for about a week. Bacterial meningitis can turn into a serious condition. The symptoms of meningitis in children are different from the symptoms observed in adults.
Children tend to show the following symptoms of meningitis:
Difficult to wake up a sleeping child
- Tends to eat less
- Becomes very irritable
- Suffers from high fever
- Sore throat
- Bulging soft spot on the fontanelle
Adults develop the following signs of viral meningitis:
- Poor appetite
- Nausea and vomiting
- High fever
- Sore throat
- Joint pain
- Unexplained headaches
- Stiffness in neck
- Problems waking up from sleep
- Light sensitivity (photophobia)
- Sound sensitivity (phonophobia)
- Memory loss
Diagnosis of Meningitis
Meningitis is diagnosed based on medical history and the reports of certain tests.
These tests include:
- Blood test: Blood samples are taken and blood cultures are prepared to find the type of bacterial infection.
- Lumbar puncture to take a sample of the cerebro-spinal fluid to identify the organism infecting the meninges.
- CT Scan to check the extent of inflammation and spread of infection.
Treatment of Meningitis
Viral meningitis does not have any specific treatment. As it is a viral infection, antibiotics are of not much help. Vaccines too are not available to prevent viral meningitis. In most cases, viral meningitis are cured within 8 – 10days. One should be given plenty of fluids and bed rest to overcome the infection.
It is very important to treat bacterial meningitis. The doctors may suggest antibiotic treatment to cure the infection as soon as possible. Also, doctors may suggest treatment to overcome the seizures, shock and swelling on the brain.
Fungal meningitis is treated with antifungal medications. Parasitic meningitis can be treated with the help of several medications. However the prognosis is very poor as almost all patients with parasitic meningitis have succumbed to the infection.
Complications of Meningitis
There are many complications of meningitis. Meningitis can lead to long-term effects such as:
- Cognitive defects
- Gangrene of limbs leading to amputation
- Low blood pressure
- Visual impairment
- Learning disabilities
- Kidney failure
- Brain damage
- Loss of speech
Prevention of Meningitis
Meningitis spreads from an infected person to healthy individuals. Thus, one should always cover their nose and mouth while coughing and sneezing. Never share utensils, towels, napkins and toothbrushes. Also, make sure you wash your hands and maintain all precautions when tending a sick individual. Eat a healthy diet to keep your immune system strong and increase body’s resistance to infections. Wash your hands after using toilets and before cooking or eating. There are many vaccines available against bacteria that causes meningitis.
These vaccines include:
- Meningococcal conjugate vaccine (MCV4)
- Pneumococcal polysaccharide vaccine (PPSV)
- Haemophilus influenzae type b (Hib) vaccine
Maintain hygiene and if you find any child or adult not being their normal self, drowsy, falling into deep sleep, fever, visit a doctor immediately. Timely medical intervention can help treat meningitis as soon as possible.
Written by: Batul nafiasa
Date last updated: January 30, 2015