Meningitis: Causes, Types, Risk Factors, Clinical Features, Diagnosis, Treatment, Prevention, Vaccines

Meningitis is an infection of the membranes (meninges) that cover the brain and the spinal cord. In meningitis, there occurs swelling and inflammation of the membranes and the characteristic presenting features of the infection are fever, headache and stiff neck.

While the most common types of meningitis may get better on their own, some types need special attention. The severity of the infection as well as the treatment varies greatly with the types of meningitis.

Meningitis is primarily of five types and is based on their causes. These are:

• Bacterial Meningitis – It is caused by a bacterial infection and needs immediate attention or else it can be life-threatening. Vaccines may help to prevent some types of bacterial meningitis. This is often contagious and spreads through nasal and oral discharges from affected person to another.
• Viral Meningitis – This is caused by viruses and the infection is serious but not commonly fatal depending on the patient status and the causative virus. Some vaccines may help to prevent some types of viral meningitis. The most common causes are enteroviruses, which often spread by the fecal-oral route from person to person.
• Parasitic Meningitis – This type is caused by parasitic infections, which mainly spread through contaminated water, food and soil. These types are comparatively less prevalent in developed countries.
• Fungal Meningitis – It is caused by fungi and usually spreads due to inhalation of fungal spores. Also, those having illnesses like cancer, HIV or diabetes are at an increased risk of fungal type of meningitis.
• Non-Infectious Meningitis – This type of meningitis is non-infectious and does not spread via persons. It may be caused by lupus, head injury, cancers or certain drugs.

• Younger children
• Persons living in communities like hostels, child care centers, camps, etc. where chances of infection spread are more.
• Persons with compromised immune system like those with other infections or those taking immunosuppressive drugs and pregnant women.
• Missing out the recommended vaccinations for he particular age group can also increase the risk.

Meningitis signs and symptoms may take some time to develop or may even show up in few hours. The most commonly observed symptoms include:

• Very severe headache
• Sudden high fever
• Neck stiffness
• Headache may be associated with nausea, vomiting, confusion and increased sensitivity to light.
• There may be seizures, confusion, difficulty in concentrating and reduced alertness.
• Unusual postures with arching of head and neck backwards may be seen.
• Sometimes drowsiness, difficulty in waking up or less interest in eating and drinking, may be noted.
• In newborns, along with high fever, excessive irritability, poor feeding and crying may be seen. Also, a bulge may be noted in the fontanel.

While the physician examines the patient and takes a detailed history of the illness, certain diagnostic investigations may also be ordered.

• Laboratory Tests – Blood tests to find the causative organism and other infection related parameters.
• Imaging Tests – X-rays, CT scans can help in detecting location and extent of inflammation and examine head and other related areas.
• Lumbar Puncture – When meningitis is suspected, the cerebrospinal fluid (CSF) is collected by lumbar puncture or spinal tap and CSF analysis is done.

Treatment of meningitis depends on the cause and type of infection. Antibiotics are given in case of bacterial meningitis, but these may not be useful for viral meningitis. However, till the cause is unclear, a broad spectrum antibiotic may be prescribed. In some viral infections like herpes meningitis, anti-viral treatment may be given.

In addition, symptomatic treatment is given. These include treating fever, seizures, inflammation, headache and shock. Intravenous fluids may also be given. For some cases, corticosteroid medications may be helpful in recovery and to reduce the chances of complications.

Drainage of accumulated fluid may be required in certain cases.

Complications of meningitis can be severe if not treated in time and can also affect the neurological functioning. Some of the possible complications include hearing loss, brain damage, memory problems, learning disabilities, seizures or gait problems. Timely diagnosis and treatment in bacterial meningitis can help to prevent complications. Viral meningitis usually resolves within 2 weeks without causing much damage.

Meningitis can be contagious and can spread through the commonest means, by which other bacterial and viral infections spread. Preventive measures, if adopted can be helpful in controlling the spread of many types of meningitis. Some suggested measures include

Hand Washing – Proper hand washing methods should be practiced and the entire family, particularly children should be trained. Washing hands with soap and running water before eating, in crowded places, after handling pets and animals, before and after using toilet should be practiced.

Personal Hygiene – Measures like covering nose and mouth while sneezing or coughing, wearing masks, avoiding sharing of personal items, keeping surroundings clean should be followed.

In general, staying healthy, consuming fresh food and exercising can help in boosting the immune system. Pregnant women can be more cautious about their food and drink and follow their physician’s advice.

For some types of meningitis, vaccines are available; so it is important to follow the recommended immunization schedule for children, pregnant women and other adults. Some vaccinations are now a regular part of the childhood immunization schedule and those specified for older children and adults should be accordingly taken at the physician’s advice.

• Haemophilus influenzae (HiB) vaccine
• Pneumococcal conjugate vaccination
• Meningococcal vaccination– for older children and later booster doses.

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Also Read About Other Types Of Meningitis:

• Bacterial Meningitis
• Viral Meningitis
• Tuberculous Meningitis
• Fungal Meningitis