A WA teenager has been diagnosed with meningococcal disease but has made a good recovery after receiving treatment.
The WA Health Department says close contacts of the student - the fifth West Australian to be diagnosed this year - have been given information and where necessary antibiotics to reduce the risk of the organism being passed on to others.
It comes three weeks after a child was diagnosed with the infection and hospitalised.
Meningococcal disease is an uncommon, life-threatening illness due to a bacterial infection of the blood and/or the membranes that line the spinal cord and brain.
Bacteria are usually carried harmlessly in the back of the nose and throat by about 10-20 per cent of the population at any one time but rarely they invade the bloodstream and cause serious infections.