An adult has become the 25th person in WA to be diagnosed with meningococcal disease this year.
The Department of Health said the elderly person is recovering in hospital after contracting the W strain of the infection.
Meningococcal disease is an uncommon, life-threatening illness caused by a bacterial infection of the blood and/or the membranes that line the spinal cord and brain.
Invasive meningococcal infection is most common in babies and young children, and older teenagers and young adults, but infection can occur at any age.
Symptoms may include high fever, chills, headache, neck stiffness, nausea and vomiting, drowsiness, confusion, and severe muscle and joint pains.
Young children may not complain of symptoms, so fever, pale or blotchy complexion, vomiting, lethargy (blank staring, floppiness, inactivity, being hard to wake, or poor feeding) and rash are important signs.
Sometimes – but not always – symptoms may be accompanied by the appearance of a spotty red-purple rash that looks like small bleeding points beneath the skin or bruises.
Although treatable with antibiotics, meningococcal infection can progress very rapidly, so it is important that anyone experiencing these symptoms seeks medical attention promptly.
Date set for Mandurah's Town Ward Extraordinary Election
Elderly North Pinjarra woman hands over $10k cash to scammers
'Gale' the whale heads back to sea after 19 days in Peel-Harvey Estuary
Secret Harbour by-election: Former Rockingham councillor Craig Buchanan endorsed as Legalise Cannabis WA Party candidate
Gang of youths remain on run after Warnbro servo break-in
Mandurah flooded as rainfall total tops state
Aerial firefighter loses Serpentine home in devastating blaze
Rumours Rockingham councillor Ryan Robertson to be announced as Liberal candidate for Secret Harbour by-election
Baldivis man fined for throwing ex-wife's elderly dog