Notifications of tuberculosis in the ACT have hit their highest levels in 25 years.
There have been 31 notifications of the bacterial infection reported in the ACT so far this year – the highest number since 1989, according to the data from the National Notifiable Diseases Surveillance System.
The only other times when there have been more cases was in 1962 when there were 45 notifications and in 1989 when there were 35 notifications.
Tuberculosis is not a very common condition in the territory, according to ACT Health acting chief health officer Dr Andrew Pengilley, who said it was difficult to know why notifications in the ACT were so high this year.
“Tuberculosis is quite a complicated disease. It is caused by a bacterial infection but the majority of people infected by it will not develop any active signs of disease,” he said.
“In parts of the world where there is a lot of tuberculosis which is a lot of south east Asia and a lot of Africa, people can be exposed to tuberculosis in early life and not develop any (signs of the) disease and still be carrying latent tuberculosis and they then move to Australia.”
“The thing with the latent condition is that as you go throughout life, there is a small chance that the disease will reactivate and (when) it becomes reactivated, then you are sick.”
Dr Pengilley said tuberculosis could be reactivated by things such as age, illnesses affecting the immune system such as HIV and immuno-suppressive drugs.
He said most of the tuberculosis notifications in the ACT were not newly acquired infections.
“When we see a new case, it isn’t normally the fact that they’ve just been infected, they have been carrying the condition for a number of years and it’s been reactivated and that’s when they’re diagnosed,” he said.
Dr Pengilley said the risk of getting tuberculosis in Australia and the ACT was “extraordinarily low” and the community should not be concerned.
“We have some people in aged care homes that reactivate every year and that tends to explain our cases,” he said.
“Most of them (cases in the ACT) will be reactivations. Importantly this does not reflect an increase in the rate of people getting infected in Canberra.”
The ACT recorded the country’s second highest rate of notifications of tuberculosis this year with 7.6 cases per 100,000 people, according to the data.
The Northern Territory was the only other jurisdiction with a higher notification rate this year where the rate was 10.8 per 100,000. The national notification rate was 5.2 per 100,000.
Tuberculosis is not highly contagious, and is spread by close contact with an infected person for long periods of time, Dr Pengilley said.
“It’s spread largely by droplets so it’s something in coughing essentially,” he said.
“Historically and in the rest of the world still, it’s often a matter of people being exposed in crowded conditions with poor ventilation.”
Dr Pengilley believed the ACT figures were indicative of patients who had come from areas where tuberculosis was more prevalent, rather than the infections being acquired locally.
“Those people in Canberra and in Australia are identified and followed up well in a way that means they don’t pose a risk of infection to others,” he said.
“I think the risk that people should be concerned about is if they go overseas and acquire tuberculosis, then it may be one of the nastier forms, there’s a bit of drug-resistance around the place so I think people need to be careful about what they’re exposed to when they’re travelling and that’s true of a lot of diseases.”