Bacterial meningitis is the most common form of meningitis (approximately 80% of all cases are acute bacterial meningitis). This disease can be life-threatening with the infection causing the tissues surrounding the brain to swell. This in turn interferes with the blood flow, resulting in paralysis or even stroke.

In some cases, bacterial meningitis starts when bacteria get into the bloodstream from the throat, ears, or sinuses; which then travels through the bloodstream into the brain. This is true of meningococcal meningitis.

Children are at increased risk for bacterial meningitis compared to people in other age groups. However, people of any age can develop bacterial meningitis. Due to the severity of bacterial meningitis, treatment should commence as soon as symptoms begin to surface because meningitis has a very high mortality rate if left untreated.

In Nigeria, there are three most common forms of bacterial meningitis:

• Meningococcal Meningitis (Neisseria meningitides)
• Pneumococcal Meningitis (Diplococci pneumoniae)
• Tuberculosis Meningitis (Microbacteria tuberculosis)

Epidemic of Bacterial Meningitis: Meningococcal Meningitis

Meningococcal meningitis affects all countries of the world but primarily Africa, especially the "Meningitis belt" that extends from Senegal near the Atlantic coast to Ethiopia and Somalia on the seashores of the Red Sea and the Indian Ocean. Over 1.2 million cases of meningococcal meningitis are estimated to occur worldwide each year. The incidence and case-fatality rates for meningitis vary by region, country, pathogen, and age group. Without treatment, the case-fatality rate can be as high as 70 percent, and 1 in 5 survivors of meningitis may be left with permanent sequelae including hearing loss, and neurologic disability.

Even when the disease is diagnosed early and adequate treatment is started, 8–15% of patients may die, often within 24 to 48 h after the onset of symptoms, or may result in brain damage, hearing loss, or disability in 10% to 20% of survivors.

Meningococcal meningitis causes the membranes that cover the brain and spinal cord to become inflamed. It can cause severe brain damage and is fatal in 50% of cases if untreated.

In children, meningococcus is the most common cause of bacterial meningitis and the second most common cause in adults. Five serogroups of Neisseria meningitides – A, B, C, W, and X are found across the ‘meningitis belt’ that stretches across Africa, thus cutting across Northern Nigeria where the disease is endemic.

In these areas during the dry season, from December to June, populations in the meningitis belt are at high risk of an outbreak of this disease. This is due to the dry Harmattan winds in Western Africa; which is a transporter of dust and sand particles that may irritate the mucous membranes of the upper respiratory tract for people living in these areas.

Neisseria Meningitidis only infects humans and cannot be contracted through animals. The bacteria are carried in the throat, sometimes with no signs or symptoms, then transmitted from one person to another through droplets of respiratory secretions as a result of prolonged, close contact.

What are the Symptoms of Meningococcal Meningitis?

The signs and symptoms of meningococcal meningitis may vary from one person to another, but some common ones indicate that a person could have the disease. These symptoms include:

• Sudden high fever
• Neck stiffness
• Nausea or vomiting
• Severe and persistent headache
• General weakness
• Drowsiness or difficulty awakening
• Joint pain
• Confusion or other mental changes

How Can Meningococcal Meningitis Be Treated?

Tests can confirm a diagnosis of meningococcal meningitis. Examination under a microscope of the cerebrospinal fluid, taken from a lumbar puncture can help to detect the presence of the bacterial (infection). Medical doctors can start with antibiotics for treating the infection, including penicillin, ampicillin, chloramphenicol, and ceftriaxone. During epidemics in sub-Saharan Africa, ceftriaxone by injection is recommended as first-line treatment for a minimum of five days. Dexamethasone a powerful steroid is also given to treat the inflammation of the meninges.

Prevention of Meningococcal Meningitis?

There are vaccines that can prevent meningococcal meningitis.

In Nigeria, there are three types of vaccines available:

• Meningococcal polysaccharide vaccines
• Meningococcal conjugate vaccines against group C
• Meningococcal A conjugate vaccine

Who Are Those at Risk of Meningococcal Meningitis?

Children under the age of 5 years are most at risk of meningococcal C disease. That is why vaccines, especially the meningococcal conjugate vaccine, are targeted at the following groups:

• Children at 3 and 12 to 13 months of age
• Children between the ages of 2 - 10 years
• College students, particularly those living in dormitories or residence halls
• Military personnel
• Visitors or residents of countries with hyper-endemic or epidemic meningococcal disease (e.g., West Africa during the dry season from December to June, Saudi Arabia during the annual Hajj)
• People who might have come in contact with an infected person
• Unvaccinated household members

Chemoprophylaxis During an Epidemic

The occurrence of meningitis in any patient always raises concerns about the risk of infection to other persons especially family members and other close contacts. So, in the Neisseria meningitides epidemic situation, chemoprophylaxis should be aimed at eliminating any form of nasal carriage so as to prevent secondary cases of meningococcal meningitis.

Chemoprophylaxis should only be administered to individuals who frequently eat or sleep in the same dwelling as the patient at least 7 days prior to the disease onset.

It is also recommended for unvaccinated persons during epidemic of meningococcal meningitis, and cannot be substituted by vaccination which takes 1 – 2 weeks for good antibody production.

There are certain drugs that are used to administer chemoprophylaxis, and they include:

• Ciprofloxacin 500mg orally stat
• Azithromycin 500mg orally stat
• Rifampicin 600mg 112hourly for 2 days

NOTE: It should be understood that Rifampicin and Ciprofloxacin should not be used in pregnancy, and Ciprofloxacin should not be used by children and adolescents.