Department of Health

Increase in Mycoplasma pneumoniae infections in Victoria

Health advisory

Advisory number:
Date issued:
12 Mar 2024
Issued by:
Dr Clare Looker, Chief Health Officer
Issued to:
Health professionals

Key messages

  • In recent months, the number of mycoplasma infections in Victoria has increased.
  • Mycoplasma pneumoniae is a common respiratory pathogen that typically causes mild respiratory symptoms however it can lead to severe pneumonia.
  • Clinicians should consider the possibility of Mycoplasma pneumoniae infection in people presenting with pneumonia, particularly children and adolescents.
  • If mycoplasma infection in suspected, send a PCR for atypical bacteria, and provide appropriate antimicrobial cover.

What is the issue?

Mycoplasma pneumoniae infection is caused by the bacterium Mycoplasma pneumoniae (M. pneumoniae). The number of confirmed cases of M. pneumoniae infection in Victoria has been increasing, particularly in children and adolescents. An increase in emergency department presentations and hospital admissions has also been reported. Similar increases have also been reported interstate.

Globally there has been an increase in M. pneumoniae infections in many countries and regions, including the United Kingdom, Europe, China and North America. This typically occurs every 3-7 years as population immunity wanes.

Who is at risk?

Mycoplasma infections are most common in those aged 5 to 20 years but can occur at any age.

Symptoms and transmission

M. pneumoniae infection usually causes mild self-resolving respiratory illness, however in some cases it can cause severe pneumonia and rarely other atypical presentations. Symptoms include fever, sore throat, dry cough, headache, and malaise and typically develop over 1-3 weeks. Cough and fatigue can persist for more than one month. People may also appear well, as it is sometimes referred to as “walking pneumonia”. Signs of atypical pneumonia on a chest x-ray may include a bilateral lower lobe reticulonodular pattern or patchy infiltrates.

M. pneumoniae is transmitted from person-to-person through respiratory droplets.


For health professionals

Whilst viral pneumonia is the most common cause of pneumonia in children, in those with disease clinically consistent with M. pneumoniae infection consider the following investigations:

  • Nose and throat swab PCR for atypical bacteria including mycoplasma.
  • Chest x-ray
  • Sputum culture and/or PCR testing

In patients suspected of having atypical pneumonia consider appropriate antimicrobial cover. Refer to clinical guidelines or seek advice from an infectious diseases specialist.

M. pneumoniae infection is not a notifiable condition in Victoria.

Reviewed 13 March 2024


Contact us

Communicable disease prevention and control Department of Health

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