Meningococcal Infection

What is Meningococcal Infection?

Meningococcal Infection is caused by the bacteria Neisseria meningitidis. The disease is mainly transmitted by droplets via coughing or sneezing or by direct contact through respiratory secretions from infected persons. The incubation period varies from 2 – 10 days, commonly 3 – 4 days. The clinical picture may be variable. It may result in severe illness when the bacteria invade the bloodstream (meningococcaemia) or the membranes that envelop the brain and spinal cord (meningococcal meningitis).

Common symptoms of meningococcal meningitis are fever, severe headache, stiff neck, altered mental status, vomiting and fear of bright light; it can cause brain damage or even death. The brain damage may lead to intellectual impairment, mental retardation, hearing loss and electrolyte imbalance. Symptoms of meningococcaemia can include sudden onset of fever, vomiting, diarrhea, purpura, shock, and even death in severe cases.

How common is meningococcal infection?

In general, the risk of acquiring meningococcal infection while travelling is low (< 0.1 per 100,000 travellers per month of travel). However, the disease incidence is higher in sub-Saharan Africa extending from Senegal to Ethiopia (African meningitis belt), particularly during the dry season (December to June) and hence a higher risk of contracting the disease. Moreover, travellers attending mass gatherings (e.g. religious pilgrimages like Hajj and Umrah) and long-stay travellers who live in close contact with the indigenous population face a higher risk as well.

How can you prevent it?

Meningococcal infection is transmitted by droplets via coughing or sneezing or by direct contact through respiratory secretions from infected persons. Therefore, travellers should pay attention to the following points:

• Wash hands properly and frequently, and observe good personal and environmental hygiene;
  
• Avoid going to crowded or poorly ventilated places; high-risk individuals may consider putting on surgical masks while in such places;
  
• Avoid close contact with patients having fever or severe headache;
  
• Cover the nose and mouth when coughing or sneezing and dispose of nasal and mouth discharge in lidded rubbish bin; wash hands immediately afterwards.
• Travellers to high-risk areas should consult their doctor before the trip to determine the need for meningococcal vaccination.

Meningococcal vaccines, including quadrivalent polysaccharide conjugate vaccines (MenACWY) and a recombinant protein vaccine (MenB), are available in Hong Kong. Based on the risk of infection, the following groups of travellers are recommended to receive meningococcal vaccines for personal protection:

• Travellers to sub-Saharan regions of Africa during the dry season (i.e. December to June) should consult their doctors to receive quadrivalent MenACWY vaccine;
• Travellers to Mecca in Saudi Arabia for Hajj and Umrah should receive quadrivalent MenACWY vaccine. For more information on health requirements, please visit the Saudi Arabia Ministry of Health website (https://www.moh.gov.sa/en/Pages/Default.aspx).;
• Travellers to other areas with reported meningococcal disease epidemics or outbreaks should receive vaccine that aligns with the destination’s prevalent serogroups;
• Long-term travellers, such as those studying abroad, should receive meningococcal vaccination per the recommendations by the health authorities in the destination country.

Travellers should seek professional advice from doctors for vaccination in view of the individual’s age and health condition, and details of the journey such as place, duration and nature.

How is it treated?

Meningococcal infection is a serious illness. Patients must be treated promptly with antibiotics. Close contacts should be placed under surveillance to observe for early symptoms of the disease and may need to take preventive medications as necessary.