Meningococcal Meningitis

Meningococcal Meningitis
Communicable Disease Control

Definition
Meningitis is an infection of the meninges, the thin lining that surrounds the brain and the spinal cord. Several different bacteria can cause meningitis and Neisseria meningitidis is one of the most important because of its potential to cause epidemics.

Causes
Several different bacteria can cause meningitis and Neisseria meningitidis is one of the most important because of its potential to cause epidemics.

Bacteria – Most serious, can cause severe disease that can result in brain damage and even death- most commonly caused by one of three types of bacteria:

Neisseria meningitidis-MENINGOCOCCAL MENINGITIS
streptococcus pneumoniae-PNEUMOCOCCAL MENINGITIS
Haemophilus influenzae type b (Hib).

Viruses - Commonest, rarely serious:common intestinal viruses, mumps or herpes virus,Mosquito-borne viruses & unknown viruses.

Fungi - Cryptococcal meningitis is a fungal form of the disease that affects people with immune deficiencies, such as AIDS

Other causes - drug allergies, some types of cancer and inflammatory diseases such as lupus, protozoa.

Transmission

person to person through droplets of respiratory or throat secretions.
Close and prolonged contact (e.g. kissing, sneezing and coughing on someone, living in close quarters or dormitories (military recruits, students), sharing eating or drinking utensils, etc.) facilitate the spread of the disease.
N. meningitidis only infects humans; there is no animal reservoir. The bacteria can be carried in the pharynx and sometimes, for reasons not fully known, overwhelm the body’s defences allowing infection to spread through the bloodstream and to the brain.

Incubation period

The average incubation period is 4 days, ranging between 2 and 10 days

Signs and Symptoms

High fever
Severe headache, Vomiting or Nausea with Headache
Generalised malaise, Confusion
Seizures
Sleepiness or Difficulty waking up
Stiff neck
Sensitivity to light
Lack of interest in drinking and eating
Newborns and young infants may not have the classic signs and symptoms of headache and stiff neck. Instead, they may cry constantly, seem unusually sleepy or irritable, and eat poorly. Sometimes the soft spots on an infant's head may bulge. A very late sign may be a spasm consisting of extreme hyperextension of the body (opisthotonos).

Diagnosis
The diagnosis of meningococcal meningitis is suspected by the clinical presentation and a lumbar puncture showing a purulent spinal fluid.
Sometimes the bacteria can be seen in microscopic examinations of the spinal fluid.
The diagnosis is confirmed by growing the bacteria from specimens of spinal fluid or blood.

Epidemiology
Meningitis in South Africa has sporadic outbreaks, which are most prevalent during droughts, dry and dusty or winter seasons
The number of cases increases in winter and spring.

During the dry season, between December and June, because of dust winds and upper respiratory tract infections due to cold nights, the local immunity of the pharynx is diminished increasing the risk of meningitis.

At the same time, the transmission of N. meningitidis is favoured by overcrowded housing at family level and by large population displacements due to pilgrimages and traditional markets at regional level.

Treatment

Meningitis is potentially fatal, always a medical emergency.
Admission to a hospital is necessary.
Isolate patient.
Antimicrobial therapy must be commenced as soon as possible after the lumbar puncture has been carried out
A range of antibiotics may be used for treatment, sensitivity dependent . This includes penicillin, ampicillin, chloramphenicol, and ceftriaxone. Under epidemic conditions in Africa, oily chloramphenicol is the drug of choice in areas with limited health facilities because a single dose of this long-acting formulation has been shown to be effective.
Other medications may be needed depending on the condition prevailing.

Prophylaxis

Currently recommendations for chemoprophylaxis in South Africa are as follows:
Contacts :

Adults: Non-pregnant Ciprofloxacin 500mg po. (single dose)
or Ceftriaxone 250mg imi. (single dose)
Pregnant women Ceftriaxone 250mg imi (single dose)
Children > 12 years Ceftriaxone 250mg imi (single dose)
Children < 12 years Ceftriaxone 125mg imi (single dose)

Prevention

Several vaccines are available to prevent the disease.
All these vaccines have been proven to be safe and effective with infrequent and mild side effects.
The vaccines may not provide adequate protection for 10 to 14 days following injection.
The duration of protection through vaccination is limited (3 to 5 years).
Travellers to areas affected by meningococcal outbreaks are advised to be vaccinated.
Includes: educating the public on the need to reduce direct contact and exposure to droplet infection (using disposable paper tissues to wipe your nose and to cover both nose and mouth when coughing, not sharing cigarettes and glasses and minimizing close body contact, e.g. kissing)
reduce overcrowding in living quarters and workplaces, such as barracks, schools and camps.

Mainstay of Control of Disease

Clinical vigilance
early treatment
prompt notification
appropriate chemoprophylaxis of close contacts

For further information on Meningitis, please contact the Communicable Disease Component on 033 395 2051

Compiled by: Premi Govender (STA-CDC)

Notes courtesy of World Health Organisation & Dr. Ayo Olowolagba

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