Two additional cases of Legionnaires’ disease have been reported in people who spent time Sydney’s CBD in late April in areas in common with three other recently reported cases, according to NSW Health.
All five cases were due to infection with the Legionella pneumophila strain. This type of Legionnaires’ disease most commonly develops after breathing in contaminated water vapour. Outbreaks of the disease can be associated with contaminated cooling tower air conditioning systems used in many large buildings.
City of Sydney and NSW Health public health units have undertaken extensive inspections and testing of 89 cooling towers and water features in the CBD in the area of possible common exposure (concentrating on the blocks bounded by Margaret, Kent, King and George streets). Results to date indicate that 5 cooling towers have tested positive for legionella bacteria. Final testing results are not yet available for all of the samples collected.
NSW Health is reminding building owners in the CBD to ensure their cooling tower systems are properly cleaned and maintained. Penalties may apply to owners of these systems if they do not meet prescribed requirements.
The five patients each spent time in the CBD during the period they likely contracted the infection, with the onset of symptoms from 25 April to 3 May 2016. At this stage, there is no evidence that these cases are linked to the Sydney CBD outbreak in March, although investigations are continuing.