Five recent cases of confirmed infection with Legionella pneumophila have all spent time in
the Sydney CBD during their exposure period.
• Have a high index of suspicion for people presenting with features of pneumonia. Collect a
legionella urinary antigen and sputum culture

Current situation
There is a cluster of 5 patients with Legionella pneumophila serogroup 1 infection, with symptom onsets
between 30 March and 4 April. All visited Sydney CBD during their incubation periods. No single source for
the cases has been identified, and it is possible that they are unrelated.
An investigation of a potential source in the area is underway.
Legionella pneumophila
• Legionella pneumophila bacteria can contaminate air conditioning cooling towers, whirlpool spas,
shower heads and other bodies of water. People walking outside or driving past may be exposed if they
inhale aerosolised contaminated water.
• Legionnaires’ disease is not spread from person to person.
• The typical incubation period is 2 to 10 days, but more commonly 5 to 6 days.
Symptoms
• Symptoms usually include fever, chills, cough and dyspnoea. Cases may also have muscle aches,
headache, fatigue, loss of appetite and diarrhoea.
• Cases may be critically unwell with pneumonia. Most people recover but the disease is occasionally
fatal, particularly when it occurs with co-morbidities or immune suppression.
Diagnosis
• Consider Legionella pneumophila in patients presenting with consistent symptoms, especially those
with travel to Sydney CBD in the 10 days prior to symptom onset.
• It is difficult to distinguish Legionnaires’ disease from other types of pneumonia by symptoms alone.
Chest X-rays help diagnose pneumonia, but the diagnosis of Legionnaires’ disease requires special
tests including:
o urine for Legionella urinary antigen testing
o sputum for Legionella culture and PCR
Note: Sputum culture should always be collected if possible, to enable matching of any isolates with
environmental samples.
Management
• Treat as per Therapeutic Guidelines: Antibiotic guidelines for Legionella pneumonia (low-moderate
severity: azithromycin, ciprofloxacin or doxycycline).
• For further management advice discuss with your local infectious disease specialist.
• Notify your local public health unit of any suspected case - phone 1300 066 055.
Further information:
https://www.health.nsw.gov.au/Infectious/legionnaires/Pages/default.aspx
Dr Jeremy McAnulty
Executive Director, Health Protection NSW