Six patients in the transplant unit of Royal Prince Alfred Hospital in Sydney's inner west developed fungal infections between October and December 2025, with a NSW Health report finding that a balcony accessible to the patients likely led to their exposure, as it opened to a nearby construction area.
The cause of the infection was Aspergillus, a common mould found in soil, dust and damp environments whose concentration in the air often increases during construction. While Aspergillus moulds are usually harmless to healthy people, the vulnerability of transplant patients to severe infection is stark. Transplant patients are particularly vulnerable because their immune system must be deliberately weakened to stop their body rejecting the transplanted organ; if they inhale Aspergillus spores, the fungus can more easily take hold in their lungs.
Though most people are unlikely to become unwell from Aspergillus, invasive fungal infections are often fatal for transplant patients, who often take medications that suppress their immune system. Beyond the Royal Prince Alfred outbreak, about half of all healthcare-associated Aspergillus outbreaks are caused by construction or renovation activities in or around hospitals, highlighting a systemic vulnerability in hospital planning during major works.
The outbreak's timeline reveals a concerning gap between warning signs and institutional response. Construction work began near the transplant ward in March 2025 as part of a $940 million redevelopment; six months later, a nurse unit manager raised concerns about mould growth and water damage in patient rooms and bathrooms, but they did not receive a response with a clear plan to address the issues. A month later, three infection cases were diagnosed; by December the group had doubled to six, though the rising number was reviewed by an infectious disease specialist but was not considered out of the ordinary or linked.
The hospital's initial response to escalating infections was slow. The hospital executive were notified two days later about the increase in infections due to Aspergillus and that a preliminary review was underway. While the investigation team was unable to determine a single conclusive cause of the outbreak, the balance of evidence indicates the balcony and nearby construction activities posed the greatest exposure risk.
Of the six infected patients, outcomes varied significantly. Two deaths were referred for serious adverse event review. The ward subsequently closed and was only reopened after an expert panel, headed by NSW Chief Health Officer Kerry Chant, declared it safe on February 9. One patient was found to have died from unrelated causes; another remains in intensive care months after diagnosis.
The NSW Health investigation has prompted concrete change. The health district has accepted four recommendations: updating its infection control management plan, ensuring documents required before construction work include all known impacted areas and proposed risks, establishing a process to prioritise maintenance and repair requests in high-risk areas, and creating a formal governance process to respond to any increases in infections during construction. These reforms aim to prevent a recurrence of the failures that exposed vulnerable patients to preventable harm.