# Invasive Meningococcal Disease in a Patient With Complement 7 Deficiency

## TL;DR

A 35-year-old Japanese man with a complement 7 deficiency developed invasive meningococcal disease, highlighting the risk in otherwise healthy individuals.

## Contribution

This case report adds to the limited understanding of invasive meningococcal disease in Japan associated with complement deficiency.

## Key findings

- A Japanese man with complement component 7 deficiency developed invasive meningococcal disease caused by Neisseria meningitidis serogroup B.
- The patient, who was otherwise healthy, fully recovered after antibiotic treatment.

## Abstract

Neisseria meningitidis
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
N. meningitidis
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.