The number of Legionella cases has risen to over 100 as the outbreak in Melbourne continues to grow.
According to an update from the Victorian Department of Health, there have now been 100 confirmed and 10 probable cases as of July 26, mainly in adults aged 40 and over.
Most people who have been infected with the bacteria have had to go to hospital. People with severe community-acquired pneumonia require intensive care.
A 90-year-old woman and a man in his 60s have died in hospital since the outbreak began in Melbourne’s west.
All infected people lived in or were visiting the Melbourne region, the health department said.
In more hopeful news, Victoria’s Chief Health Officer Clare Looker said on Friday that genomic sequencing results had proven what authorities had hoped: that all the confirmed cases of Legionnaires’ disease were linked to one location, a cooling tower in Laverton North in Melbourne’s west, which they have already treated.
“I can confirm that these sequences are all closely related genomically and in fact form a single genomic cluster,” said Dr. Looker.
‘That sequence was compared to the genomic sequence of a number of human samples taken as part of this outbreak, to look for links between that specific cooling tower and those cases.
The number of cases of Legionnaires’ disease has passed 100 as the outbreak in Melbourne continues to grow. Victoria’s Chief Health Officer Clare Looker is pictured
“This means that I can now say with a high degree of confidence that we have identified and already treated the source of this outbreak.”
Legionnaires’ disease can cause a chest infection with fever, chills, cough, headache and muscle aches.
Other atypical symptoms may include nausea, vomiting, diarrhea, and confusion.
The bacteria that cause the disease are common in the environment and in natural waters such as rivers, lakes, creeks, and hot springs.
They are also found in spas, hot water systems, and man-made systems that use water for cooling, heating, or industrial processes, such as cooling towers, and in potting soil.
An update from the Victorian Department of Health said there have now been 100 confirmed and 10 probable cases up to July 26, mainly in adults over 40. Legionella bacteria are pictured
Only a small number of people become infected when they come into contact with the bacteria.
In this outbreak, most cases are occurring in people who would normally be at greater risk of infection. This may include people over the age of 40, smokers, people with chronic lung disease or a weakened immune system, and other underlying conditions such as chronic heart, liver or kidney disease, and diabetes.
But there have also been known cases in otherwise active and normally healthy adults, the health service said.
The bacteria is not often transmitted from person to person or through drinking contaminated water.