Status:
Resolved
Health alert:
AL180004
Date Issued:
28 Feb 2018 (update to Alert issued 23 February 2018)
Issued by:
Dr Brett Sutton, Deputy Chief Health Officer (Communicable Disease)
Issued to:
Health professionals and laboratories

Key messages

  • There has been an increase in the number of cases of Legionnaires’ disease (Legionella pneumophila, serogroup 1) associated with an outbreak in Melbourne’s Central Business District. As of midday on 28 February 2018 there were eight confirmed cases, and one probable case.
  • All cases involve individuals who have spent time in the south eastern area of Melbourne’s Central Business District (CBD). Be alert for Legionnaires’ disease in patients with influenza-like symptoms, particularly those with severe pneumonia, who have been around the Melbourne CBD since late January 2018.
  • If you suspect Legionnaires' disease, request urinary antigen testing through your normal pathology provider. As a priority, order Legionella culture on sputum, and undertake serology on blood at baseline and 14 days later.
  • Legionnaires' disease is a Group A notifiable condition which requires immediate notification on suspicion to the Department of Health and Human Services on 1300 651 160. Immediate notification of all suspected cases is essential to assist in the management of this outbreak.

What is the issue?

The Department of Health and Human Services has now identified eight confirmed cases and one probable case of Legionnaires’ disease involving individuals who have spent time in the south eastern area of Melbourne’s CBD, including Flinders Street station. All cases have required treatment in hospital. All had onset of symptoms within a similar timeframe between February 6 and February 18, 2018.

The department is continuing to investigate notified cases of Legionella infection to identify the possible source of their illness. A number of cooling towers in the CBD have already been sampled and disinfected and additional sampling and disinfecting will be taking place over the coming days.

There have been no positive results for Legionella bacteria in the tested towers to date, however some results are still pending.

It is important that all suspected cases of Legionella infection are immediately notified to the department to ensure that appropriate control measures are in place. 

Who is at risk?

People aged over 50 years, smokers, heavy drinkers, people with diabetes or chronic lung disease and those with an impaired immune system are most at risk. However, we have seen cases in individuals less than 50 years of age.

While those hospitalised spent time in the CBD, their possible exposures have been across greater metropolitan Melbourne, so clinicians should consider testing for Legionella pneumophila in any patient with a compatible illness. 

Symptoms and transmission

Legionnaires’ disease often presents with initial influenza-like symptoms such as myalgia, headache, fever and cough, and may progress to atypical pneumonia, sometimes with confusion. Rapid confirmation of the diagnosis of Legionella pneumophila serogroup 1, which makes up the majority of Victorian cases, can be obtained by urinary antigen testing. Sputum for culture should be sought in all cases if possible. A four-fold rise in titre between acute and convalescent sera is also diagnostic, however, this may take two to four weeks to develop.

Prevention and treatment

Early diagnosis and treatment with appropriate antibiotics is important in reducing the severity of illness and the risk of severe complications. Referral to hospital is often required for confirmed cases. Empirical treatment of moderate or severe community-acquired pneumonia (as per the current edition of the Therapeutic Guidelines) is recommended to cover Legionella bacteria.

More information

Clinical information

  • Legionnaires' disease is a Group A notifiable condition which requires immediate notification to the department by telephone on initial diagnosis (presumptive or confirmed) with written notification to follow within five days.
  • For further information or to notify a case please contact the Communicable Disease Prevention and Control Unit at the Department of Health and Human Services on 1300 651 160 or visit health.vic's information on Legionellosis (Legionnaires' disease).

Consumer information

Contacts

For more information please contact the Communicable Disease Prevention and Control section at the Department of Health and Human Services on 1300 651 160 (24 hours).