Introduction

Sporadic cases are found worldwide. In temperate zones, most cases occur in the winter months. Localized outbreaks occur in enclosed crowded spaces (e.g dormitories, military barracks or during pilgrims performing Hajj).

In Sub-Saharan Africa, in a zone stretching across the continent from Senegal to Ethiopia (the African ‘meningitis belt’), large outbreaks and epidemics take place during the dry season (November – June).

Causative agent: The bacterium meningitides, of which 12 serogroups are known. Most cases of meningococcal disease are caused by serogroups A, B and C; less commonly, infection is caused by serogroups Y and W-135. Epidemics in Africa are usually caused by N. meningitides type A.

Transmission: Direct person-to-person contact, including aerosol transmission and respiratory droplets from the nose and pharynx of infected persons, patients or asymptomatic carriers. There is no animal reservoir or insect vector.

Incubation period: Varies from 2 – 10 days, commonly 3 – 4 days

Sign & Symptoms

The symptoms may come on quickly. Many infected people (5-10%) become asymptomatic carriers of the bacteria and serve as a reservoir and source of infection for others.

Meningococcal meningitis has a sudden onset of intense headache, fever, nausea, vomiting, photophobia and stiff neck, plus various neurological signs.

The disease is fatal in 5-10% of cases even with prompt antimicrobial treatment.

Complication

Among individuals who survive, up to 20% have permanent neurological sequelae.

Meningococcal septicaemia is less common characterized by circulatory collapse, haemorrhagic skin rash and high fatality rate.

Treatment

Specific treatment: Penicillin given parenterally in adequate doses is the drug of choice for meningococcal meningitis. Others like ampicillin and chloramphenicol are also effective.

Patients with meningococcal or Hib disease should be given rifampicin prior to discharge from the hospital to assure elimination of the organism.

Prevention & Precautions

Recommendation –

A single-dose tetravalent vaccine containing contains capsular polysaccharides for serogroups A, C, Y, and W135 is advisable. Duration of immunity is unknown, but repeat dose is recommended every two years. Protective efficacy is estimated at 90%.

Vaccination for prophylaxis

Type of vaccine: Purified bacterial capsular polysaccharide

Number of doses: One

Booster: Every 3 years, protection lasts at least 2 years after infancy

Contraindications: Serious adverse reaction to previous dose

Before departure: 2 weeks

Consider for:

• Travellers visiting sub-Saharan Africa during dry season, between December and June, especially if close contact with locals is anticipated.
• Pilgrims performing Umrah / Hajj where there is large congregation of people.
• Travellers to other countries where epidemics of meningococcal disease are recognized.
• Elderly Travellers, those with pre-existing disease or ill persons who have had a splenectomy or have a nonfunctioning spleen
• In UK, students entering higher education or college are recommended to receive meningococcal vaccination

Special precautions for vaccine: Children under 2 years of age are not protected by the vaccine

Precautions: Avoid overcrowding in confined spaces. Following close contact with a person suffering from meningococcal disease, medical advice should be sought regarding chemoprophylaxis