Meningococcemia and Purpura Fulminans

Abstract

Meningococcemia is an invasive bacterial infection by the gram-negative diplococcus, Neisseria meningitidis, which is often rapidly fatal if not detected and treated early. Neisseria meningitidis infections occur both endemically and epidemically. Sporadic disease occurs more commonly during winter and early spring months, and affects predominantly children. The highest rate of infection is in infants six months to one year, with a steady decline in infection rate with age. This is likely explained by passive maternal immunity providing protection in the first six months, and gradual onset of acquired immunity with age. Approximately two-thirds of invasive meningococcal disease occurs in children (1). The human bacterial reservoir is the upper respiratory tract. In the general population, the carrier state is quite common, but in only rare cases do carriers develop invasive disease. There are many different serotypes of Neisseria meningitidis, but types A, B, C, W-135, and Y account for nearly all invasive disease. Worldwide, type A is responsible for most large epidemics, but in the United States, serotypes B and C account for approximately 90% of invasive infections.