Situation
NSW Health surveillance has detected public health signals for two causes
of atypical bacterial pneumonia: Legionella pneumophila and Mycoplasma
pneumoniae.
Legionella pneumophila
As of 3 January 2024, seven confirmed cases of Legionella pneumophila
have been notified in NSW over the past 10 days. These cases developed
symptoms in late December 2023. All cases spent time in the Sydney CBD
area in mid to late December 2023. Investigations to identify a possible
common environmental source are ongoing.
Mycoplasma pneumoniae
Pneumonia presentations to public hospital emergency departments, as well
as subsequent admissions, have started to increase, particularly in people
aged 5 to 16 years.
While the majority of childhood pneumonias are caused by a variety of
viruses and bacterial infections, the proportion of presentations and
admissions due to mycoplasma pneumonia and atypical pneumonia is
starting to increase.
Background
Legionella pneumophila
Legionella pneumophila can contaminate air conditioning cooling towers,
whirlpool spas, shower heads and other bodies of water. People outside may
be exposed if they inhale aerosolized contaminated water.
The incubation period is 2 to 10 days, but more commonly 5 to 6 days.
Symptoms usually include fever, chills, cough, and shortness of breath.
Cases may also have muscle aches, headache, fatigue, loss of appetite and
diarrhoea.
Mycoplasma pneumoniae
Globally, there has been an increase in cases of Mycoplasma pneumoniae
circulation. Such increases usually occur every 3 to 7 years as population
immunity wanes.
Symptoms may develop over 1 to 3 weeks and include fever, dry cough,
headache, sore throat, and malaise. Mycoplasma pneumoniae commonly
causes mild respiratory infections and generally resolves without serious
complications. Cough and lethargy may persist for more than 1 month.
Infection is most common in age groups 5 to 20 years but can occur at any
age.
Issue date
04 January 2024
Distributed to:
Chief Executives
Directors of Clinical
Governance
Director, Regulation and
Compliance Unit
Action required by:
Chief Executives
Directors of Clinical
Governance
We recommend you
also inform:
Directors, Managers
and Staff of:
• Emergency
Departments
• Infectious Diseases
• Paediatric
Emergency
department
• General paediatric
• PHU
• Nursing
Deadline for
completion of action
07/01/2024
Expert Reference
Group
Content reviewed by:
Executive Director
Health Protection NSW
Clinical Excellence
Commission
Tel: 02 9269 5500
Email
Internet Website
Intranet Website
Review date
January 2025

Assessment
It can be difficult to distinguish Legionella pneumonia from other types of pneumonia by symptoms alone.
In adults, consider Legionella as a possible cause of pneumonia.
People with Mycoplasma pneumonia may appear well, often referred to as “walking pneumonia”.
In children, consider a diagnosis of Mycoplasma pneumoniae.
Atypical pneumonia can present with a characteristic bilateral lower lobe reticulonodular pattern or patchy
infiltrates on chest x-ray.
Clinical Recommendations
In adults presenting with pneumonia consider Legionella pneumophilia among other causes.
In children, the commonest cause of pneumonia is viral, followed by streptococcal pneumonia, but
consider Mycoplasma pneumoniae infection among other causes in those with clinically compatible
symptoms.
In patients presenting with an illness that is clinically compatible with Legionella or Mycoplasma infection,
consider the following investigations:
• chest x-ray
• atypical respiratory PCR (to detect Mycoplasma pneumoniae and Legionella)
• urinary antigen testing (to detect Legionella)
• sputum culture and/or PCR testing
• atypical pneumonia serology (acute and convalescent sera)
Manage as per treatment guidelines (penicillins e.g., amoxicillin) for typical pneumonia.
For patients with clinically consistent disease and/or epidemiological suspicion of pneumonia caused by
an atypical pathogen, consider including treatment with appropriate antimicrobial cover e.g., doxycycline
(children 8 years and over), azithromycin or clarithromycin.
Refer to clinical guidelines or the relevant local specialty team for further advice on antimicrobial
selection.
Required actions for the Local Health Districts/Networks
1. Distribute this Safety Alert to all relevant clinicians and clinical departments.
2. Include this Safety Alert in relevant handovers and safety huddles.
3. Confirm receipt and distribution of this Safety Alert within 72 hours to cec-recalls@health.nsw.gov.au