Reviewed by Dr Chris Armstrong, Director of the Melbourne ME/CFS Collaboration, University of Melbourne.
Australian swimmer Kaylee McKeown withdrew from the 2026 Commonwealth Games in Glasgow while recovering from glandular fever, citing the risk of chronic fatigue. University of Melbourne researcher Dr Chris Armstrong, who studies the chronic outcomes of infectious disease, called it a smart decision. Around 1 in 10 people who get glandular fever go on to develop ME/CFS.
Key points
- Glandular fever (mono) is usually caused by the Epstein-Barr virus, and most people recover in two to three weeks.
- For around 1 in 10 people, it can lead to ME/CFS, a serious long-term illness.
- Resting properly, rather than pushing through a lingering infection, is one of the few things known to lower that risk.
Why did Kaylee McKeown withdraw from the Commonwealth Games?
McKeown withdrew after competing unwell at the Australian selection trials and failing to recover from glandular fever. She said she was worried about pushing herself so hard that she ended up with chronic fatigue. Dr Chris Armstrong described the decision as a smart one for her long-term health.
"Kaylee has made a smart decision. There are real dangers to anyone's long-term health if they try to push through a lingering infection like this, particularly when sleep has stopped being refreshing, fatigue persists and symptoms worsen after exertion."
Can glandular fever cause chronic fatigue syndrome (ME/CFS)?
Yes, in a minority of cases. Glandular fever (infectious mononucleosis) is usually caused by the Epstein-Barr virus. Most people recover within two to three weeks. For some, symptoms persist and develop into ME/CFS, a serious long-term illness. Post-infectious onset is one of the most consistently documented triggers of ME/CFS.
What percentage of people with glandular fever develop ME/CFS?
Around 1 in 10. Australian prospective research (the Dubbo Infection Outcomes Study) found roughly 9 to 12 per cent of people still met criteria for a chronic fatigue syndrome six months after glandular fever, and about 9 per cent at twelve months.
How can you reduce the risk of long-term fatigue after glandular fever?
The evidence points to rest. Pushing through a lingering infection, especially once sleep stops being refreshing and symptoms worsen after exertion, carries real risk.
"Resting properly is one of the few things we know can avoid a longer-term fatigue syndrome."
This is general information, not medical advice. Anyone concerned about a lingering infection should speak with their doctor.
What is ME/CFS?
ME/CFS (myalgic encephalomyelitis / chronic fatigue syndrome) is a serious, long-term condition defined by unrefreshing sleep, persistent fatigue, and symptoms that worsen after exertion (known as post-exertional malaise). It is not improved by rest. At its most severe, people can be housebound or bedbound.
"The term 'chronic fatigue syndrome' fails to give a true impression of how profoundly disabling and severe this condition can be. Around a quarter will be unable to leave their homes, and only about 13 per cent can maintain a full time job."
How many people have ME/CFS in Australia?
Australian government sources estimate up to 250,000 people may have ME/CFS, though the true figure is uncertain because the condition is widely underdiagnosed.
Who is Dr Chris Armstrong?
Dr Chris Armstrong is a biochemist and medical researcher at the University of Melbourne and Director of the Melbourne ME/CFS Collaboration. The Collaboration runs a broad research program that spans the underlying biology of ME/CFS and Long COVID through to precision medicine and treatment-matching research, including TOTEM (Tracking to Optimise Treatment Matching). It is the primary scientific partner of Open Medicine Foundation Australia and part of the global Open Medicine Foundation research network, which also includes centres at Stanford, Harvard, Uppsala and Montreal.
Open Medicine Foundation Australia funds biomedical research into ME/CFS and Long COVID as part of the global OMF network. Donations support this research.
Source: Dr Armstrong's comments appeared in The Australian (23 July 2026).
Australian swimmer Kaylee McKeown withdrew from the 2026 Commonwealth Games in Glasgow while recovering from glandular fever, citing the risk of chronic fatigue. University of Melbourne researcher Dr Chris Armstrong, who studies the chronic outcomes of infectious disease, called it a smart decision. Around 1 in 10 people who get glandular fever go on to develop ME/CFS.
Open Medicine Foundation Australia funds biomedical research into ME/CFS and Long COVID as part of the global OMF network. Donations support this research.
Open Medicine Foundation Australia funds and supports ME/CFS and Long COVID research as part of Open Medicine Foundation’s global network of Collaborative Research Centres. The Melbourne ME/CFS Collaboration, led by Dr Chris Armstrong at the University of Melbourne, is the Australian research engine within that network.