Adult dies from meningococcal disease as WA records third case this yearAdult dies from meningococcal disease as WA records third case this year Credit: 7NEWSA young adult is recovering in a Perth hospital after being diagnosed with invasive meningococcal serogroup B disease. The latest diagnosis is the fourth confirmed case of invasive meningococcal disease recorded in the State this year. Of the four cases reported in 2026, three have been caused by serogroup B and one by serogroup Y. Last year, WA recorded 13 cases of invasive meningococcal disease, including 12 caused by serogroup B and one by serogroup Y. Health officials stressed that while meningococcal disease is rare, it remains a medical emergency because it can deteriorate with alarming speed.