Meningitis is the 10th leading cause of mortality in Africa. Nigeria has a long history of meningitis epidemic and there was an outbreak early this year as well.
Meningitis is an inflammation of the meninges. The meninges are the three membranes that cover the brain and spinal cord. Meningitis can occur when fluid surrounding the meninges becomes infected.

Types of Meningitis

Viral Meningitis

Viral meningitis is the most common type of meningitis. Viruses in the Enterovirus category cause 85% of cases.
• coxsackievirus A
• coxsackievirus B
• echoviruses
• West Nile virus
• influenza
• mumps
• HIV
• measles
• herpes viruses
• Coltivirus, which causes Colorado tick fever
Viral meningitis typically goes away without treatment.

Noninfectious Meningitis

Causes include:
• Cancers
• Systemic lupus erythematosus (lupus)
• Certain drugs
• Head injury
• Brain surgery
This type of meningitis is not spread from person to person.

Parasitic Meningitis

Various parasites can cause meningitis or can affect the brain or nervous system in other ways. Overall, parasitic meningitis is much less common than viral and bacterial meningitis.
Main causes are;
• Angiostrongylus cantonensis (neurologic angiostrongyliasis)
• Baylisascaris procyonis (baylisascariasis; neural larva migrans)
• Gnathostoma spinigerum (neurognathostomiasis).

Amebic Meningitis

Primary amebic meningoencephalitis (PAM) is a very rare form of parasitic meningitis that causes a brain infection that is usually fatal. PAM is caused by the microscopic ameba (a single-celled living organism) Naegleria fowleri when water containing the ameba enters the body through the nose.

Bacterial Meningitis

Bacterial meningitis is contagious and caused by infection from certain bacteria. It’s fatal if left untreated. Between 5-40% of children and 20-50% adults with this condition die. This is true even with proper treatment.
The most common types of bacteria that cause bacterial meningitis are:
• Streptococcus pneumoniae, which is typically found in the respiratory tract, sinuses, and nasal cavity and can cause what’s called “pneumococcal meningitis”
• Neisseria meningitidis, which is spread through saliva and other respiratory fluids and causes what’s called “meningococcal meningitis”
• Haemophilus influenza, which can cause not only meningitis but infection of the blood, inflammation of the windpipe, cellulitis, and infectious arthritis
• Listeria monocytogenes, which is a foodborne bacteria

Fungal Meningitis

Fungal meningitis is rare and usually caused by fungus spreading through blood to the spinal cord. Although anyone can get fungal meningitis, people with weakened immune systems, like those with an HIV infection or cancer, are at increased risk.
The most common cause of fungal meningitis for people with weak immune systems is Cryptococcus. This disease is one of the most common causes of adult meningitis in Africa.
Different types of fungus are transmitted in several ways.
• Cryptococcus is thought to be acquired through inhaling soil contaminated with bird droppings.
• Histoplasma is found in environments with heavy contamination of bird or bat droppings, particularly in the Midwest near the Ohio and Mississippi Rivers.
• Blastomyces is thought to exist in soil rich in decaying organic matter in the Midwest United States, particularly the northern Midwest.
• Coccidioides is found in the soil of endemic areas (Southwestern US and parts of Central and South America).
When these environments are disturbed, the fungal spores (small pieces of fungus) can be inhaled. Meningitis results from the fungal infection spreading from the lungs to the spinal cord. Unlike the fungi above, Candida, which can also cause meningitis, is usually acquired in a hospital setting.

Symptoms of Meningitis

• Sudden high fever
• Stiff neck
• Severe headache that seems different than normal
• Headache with nausea or vomiting
• Confusion or difficulty concentrating
• Seizures
• Sleepiness or difficulty waking
• Sensitivity to light
• No appetite or thirst
• Skin rash (sometimes, such as in meningococcal meningitis)

Complications

• seizures
• hearing loss
• brain damage
• hydrocephalus
• a subdural effusion, or a buildup of fluid between the brain and the skull

Risk Factors

• Skipping vaccinations.
• Age. Most cases of viral meningitis occur in children younger than age 5. Bacterial meningitis is common in those under age 20.
• Living in a community setting.This is probably because the bacterium is spread by the respiratory route, and spreads quickly through large groups.
• Pregnancy.
• Compromised immune system.
Diagnosis
• Complete health history and physical examination
• a fever
• an increased heart rate
• neck stiffness
• reduced consciousness
• lumbar puncture test
• Blood cultures
• A complete blood count with differential
• Chest X-rays
• A CT scan of the head

Treatment

• Treatment is determined by the cause of meningitis.
• Bacterial meningitis requires immediate hospitalization. Early diagnosis and treatment will prevent brain damage and death. Bacterial meningitis is treated with intravenous antibiotics. There’s no specific antibiotic for bacterial meningitis. It depends on the bacteria involved.
• Fungal meningitis is treated with antifungal agents.
• Viral meningitis isn’t treated. It usually resolves on its own.
Prevention
• Wash your hands.
• Practice good hygiene.
• Stay healthy.
• Cover your mouth. When you need to cough or sneeze.
• If you’re pregnant, take care with food. Cook meat properly. Avoid cheeses made from unpasteurized milk.
• Go for Immunizations.
• Get prompt treatment if symptoms are noticed.

Sources:
https://www.cdc.gov/meningitis/non-infectious.html

http://www.healthline.com/health/meningitis#Symptoms3
http://www.mayoclinic.org/diseases-conditions/meningitis/symptoms-causes/dxc-20169522