Neisseria meningitidis in a primary school

Area of Science:

• Microbiology
• Epidemiology
• Public Health

Background:

• A cluster of four meningococcal infections, including two fatalities, occurred in an inner London primary school over three years.
• This prompted a study on the nasopharyngeal carriage of sulphonamide-resistant Neisseria meningitidis, group B, type 15 P1.16.

Purpose of the Study:

• To investigate the carriage and transmission dynamics of a specific strain of Neisseria meningitidis following an outbreak in a primary school.
• To compare carriage rates and serum bactericidal activity between the affected school and a control group.

Main Methods:

• Prospective study of nasopharyngeal carriage in children over one year.
• Comparison of carriage and acquisition rates with a control group of similar age and ethnic origin.
• Serum bactericidal assays against the outbreak strain in children from selected classes.

Main Results:

• Overall meningococcal carriage and acquisition rates were below 6% and 1% respectively, similar to controls.
• The outbreak strain was isolated from three children in the study school but not in the control school.
• No lack of serum bactericidal activity against the outbreak strain was observed in the study school.

Conclusions:

• Low carriage and acquisition rates, alongside specific bactericidal activity, suggest prolonged colonization with infrequent child-to-child transmission.
• This pattern is consistent with the observed distribution of meningococcal infection cases within the school.
• The findings highlight complex transmission dynamics of Neisseria meningitidis in a school setting.