Catherine O. Morrissey is an Infectious Disease Specialist based in Prahran, VIC, at 55 Commercial Rd. She looks after people with tricky infections, especially when the usual germs need extra care to treat properly.
Her work often involves patients with long-term immune challenges. This can include people living with immune system conditions such as common variable immune deficiency, or those with chronic problems that make infections more likely. At times, she also helps with infections that can affect the brain, lungs, skin, and other parts of the body.
Catherine’s patients may come to her when there are concerns about fungal infections, including aspergillosis, mucormycosis, cryptococcosis, and coccidioidomycosis. She also supports people dealing with infections linked to immune changes, like cytomegalovirus infection and cryptococcal meningitis.
In many cases, her care is part of a larger team plan. For example, she works with transplant teams and oncology services when someone has had a lung transplant or a heart transplant, or when someone has had a bone marrow transplant. People with blood cancers such as leukaemia may also need this kind of close infectious disease support.
She also looks at lung infections linked to specific organisms, including Pneumocystis jiroveci pneumonia and nocardiosis, as well as pulmonary nocardiosis and related conditions. Some patients are referred after tests and imaging, when the cause is not clear straight away and the treatment plan needs careful checking.
There are times when infections show up as sudden, serious illness. Catherine helps guide treatment in situations like febrile neutropenia, where someone’s immune defences are low and any fever needs urgent attention. She may also be involved in care where there are more complex underlying problems, such as severe acute respiratory syndrome (SARS), tetanus, and other serious infections.
Depending on the case, she may organise or interpret investigations like tissue biopsy, so the right treatment can be chosen. Her goal is to help make sense of what’s happening, keep the body as safe as possible, and support the broader medical team with practical, up-to-date infection care.
If you’re being treated for an infection that feels complicated, or you’ve had ongoing symptoms despite initial treatment, Catherine can help assess the situation and work out the next steps with you and your healthcare team.
