Meningococcus (Neisseria meningitidis) is one of the common bacteria causing invasive meningococcal disease. The main serogroups include A, C, W-135, Y, B, and X. Infants and young children (0-4 years old) have a higher incidence rate compared to other age groups. Common pathogens causing bacterial meningitis include meningococcus, Haemophilus influenzae type b, Streptococcus pneumoniae, and Group B Streptococcus.

Transmission Routes

Meningococcus resides in the human nasopharynx and can spread through droplets or close contact. Even among healthy individuals, 5-10% may carry the bacteria in their nasopharynx. Invasive meningococcal disease can be fatal within 24 hours!

• First 4-6 hours: No obvious symptoms.
• 6-13 hours: Possible septicemia symptoms, such as leg pain, cold hands and feet, abnormal skin color.
• 13-22 hours: Possible hemorrhagic rash, meningitis signs, and impaired consciousness.

Risks and Mortality

Infected individuals may die within 24 hours, with a mortality rate up to 10%. One in every 10 patients dies from the infection. 10-20% of survivors may suffer long-term sequelae, including:

• Intellectual disability
• Deafness
• Epilepsy
• Other neurological disorders

Local Data in Hong Kong (2013-2018)

As of June 20, 2018, 83% of confirmed cases were locally acquired. ACWY serogroups accounted for 66% of confirmed cases.

• Y: 38.10%
• B: 28.60%
• W: 14.30%
• C: 14.30%
• X: 4.70%

The mortality rate of C + W + Y types is at least 50% higher than that of type B.

Prevention Methods

Maintaining good hygiene practices and getting vaccinated are effective ways to prevent infection. Early recognition of symptoms can lead to timely medical attention and save lives!