Invasive Meningococcal Disease in a Patient With Complement 7 Deficiency

<i>Neisseria meningitidis</i> can cause invasive meningococcal disease (IMD). Individuals with primary complement deficiencies are at a higher risk of developing IMD. However, cases of IMD associated with complement deficiency have rarely been reported in Japan. In this case, a 35-year-old Japanese man presented with fever and a spreading skin rash. Blood culture identified <i>N. meningitidis</i> serogroup B. The patient was treated with antibiotics and fully recovered. Genetic analysis revealed a deficiency in complement component 7. This case highlights that IMD can occur in young, otherwise healthy individuals, some of whom may have underlying complement deficiency.