Legionnaires’ Disease Outbreak Source Likely a Cooling Tower

Legionella pneumophila bacteria which are responsible for causing the pneumonic disease Legionnaires' disease in a 1978 electron microscope image. Francis Chandler/CDC via AP

Victorian authorities have identified a cooling tower as the likely source of a Legionnaires Disease outbreak in the state.

The health department confirmed 78 cases and 10 suspected cases of Legionnaires  disease in just a week and a half as of 5 p.m. Aug. 5.

Two people have died from this outbreak, including a man in his 60s and a woman in her 90s. 

Health authorities have been working to identify the source of the outbreak for a days in Melbourne’s western suburbs.

Chief Health Officer Dr. Clare Looker confirmed on Aug. 5 that Legionella bacteria had been detected in a sample from a cooling tower in the suburb of Laverton North.

“The tower was visited early on in our investigations, on July 30. And it was disinfected within 24 hours of that visit,” Looker said in comments provided to The Epoch Times. 

“This is a direct result of our rapid investigation, which saw the likely source located, tested and disinfected, within a matter of days.”

Legionnaires’ disease is an urgent notifiable condition in Victoria, requiring doctors to notify the Health Department upon initial diagnosis.

In an health alert issued by the chief health officer, the Victorian Health department revealed the majority of individuals with Legionnaires disease have gone to hospital.

“Most cases have required hospitalisation, with multiple admissions to intensive care for severe community acquired pneumonia,” the alert states.

“All cases have visited or reside in metropolitan Melbourne. Those most at risk are adults aged over 40 years, especially people with other medical conditions or immune compromise, or who smoke. People who develop symptoms should seek urgent medical care.”

The Victorian health department has observed a significant increase in case numbers since July 26.

Testing Recommended

The Victorian health department said healthcare professionals should have a “high index of suspicion” for Legionnaires disease in patients with symptoms and recommended testing.

“If Legionnaires’ disease is suspected, request urgent urinary antigen testing through your normal pathology provider,” Looker advised.

“As a priority, order Legionella culture and PCR on sputum or other respiratory fluid samples.”

Further, cooling tower operators in Melbourne have been asked to stay “compliant” with cooler tower testing, servicing, and auditing.

What are the Symptoms?

Legionnaires disease is a severe type of pneumonia caused by infection with Legionella bacteria. This bacteria can be found in water systems including hot tubs, cooling towers, fountains, and plumbing systems.

Common symptoms of the disease, which can appear two to 10 days after exposure, include chest infection, fever, chills, cough, headache, and muscle aches and pains.

In addition, the disease can cause less common symptoms such as nausea, vomiting, diarrhoea, and confusion.

High risk groups for the disease after exposure to the bacteria include smokers, those aged over 40, people with chronic lung disease, a weakened immune system or other underlying medical conditions including chronic heart, liver or kidney disease and diabetes.

A fact sheet issued by the Victorian health department (pdf) notes there is no vaccine for the disease.

“Legionnaires’ disease is not known to be transmitted between people. You won’t catch it from someone who has it,” the health department recommends.

“The symptoms are like those for other infectious diseases that can spread from person to person like COVID-19 the flu or RSV—so if you have symptoms, wear a mask until you have your test results so you can protect those around you from respiratory viruses.”

The health department noted Victoria regularly sees a number of cases of Legionnaires disease, but there has been a significant increase in those numbers in a short period of time.

“When this occurs, it triggers local public health units and the fepartment to investigate the cause of the increase and analyse the information to determine public health measures to reduce the case numbers and the risk to the public,” Victoria Health said.

Cooling towers can provide an ideal environment for Legionella bacteria to grow. This increases if the water is allowed to stay stagnant. The health department regulates cooling systems in Victoria.

Meanwhile, the New South Wales Health department states about 10 percent of people who get  Legionnaires’ disease die despite treatment.

“The proportion of people who die with Legionnaires disease is not related to whether or not the person acquired the infection as part of an outbreak or not,” the department said.

“The extent and severity of an outbreak is usually measured by the number of patients who have been affected, rather than the number of deaths.”

The U.S. Centers for Disease Control and Prevention (CDC) concurs that one out of every 10 people who get sick with Legionnaires’ disease will die due to complications from the illness.

It added that most healthy people exposed to Legionella bacteria don’t get sick.