A Canberra teenager is being treated for the deadly meningococcal B disease, the first such case in two years.
The school student was admitted to Canberra Hospital on the weekend with a headache, fever and body pains.
Doctors soon confirmed the teen was suffering from the disease.
The teen is said to be recovering well, and people who have come into contact have been given antibiotics.
ACT chief health officer Paul Kelly is encouraging anyone worried about similar symptoms - or others such as sore eyes or a big rash - to seek treatment as quickly as possible.
Dr Kelly warned the consequences of failing to act could be extremely serious.
"There's a high rate of ongoing disability after meningococcal disease and also death," he told reporters on Monday.
The incident comes after a 16-year-old girl died from meningococcal B in Tasmania in July, with another five cases confirmed on the island state last month.
Dr Kelly said young people are more susceptible to meningococcal, and those aged 16 to 19 in the territory can get free vaccines from their GP for a different strain of the disease.
A vaccination against meningococcal B is available in the ACT on the private market.
The federal government has been under pressure to list the vaccine on the National Immunisation Program, which distributes free vaccines.
But the prime minister has said the change can not occur until the vaccine earned the recommendation of an expert committee.
He has urged the company that makes the vaccine, GlaxoSmithKline, to have another attempt at becoming listed on the program.
The company confirmed last week it would consider the move but only after it had the results of a South Australian study on the impact of the vaccine, Bexsero, on meningococcal B immunity in 2019.