Neisseria meningitidis, Serogroup A
Meningococci, Serogroup A
Meningococcus, Serogroup A
Strains of Neisseria meningitidis responsible for most outbreaks of meningococcal disease in Western Europe and the United States in the first half of the 20th century. They continue to be a major cause of disease in Asia and Africa, and especially localized epidemics in Sub-Sahara Africa.