The role of poorly maintained ventilation ductwork in spreading airborne infections is largely ignored because it is ‘out of sight out of mind’, but recent analysis by healthcare professionals confirms that the risks are increasing. Ghasson Shabha will identify particular threats in healthcare facilities from dirty ductwork. He also points out that fewer than 5% of building air-conditioning systems have been inspected despite regulations making this mandatory. Dr Shabha will look at how planned cleaning strategies can reduce risks and how hospitals can use 3D building information modelling software to identify ‘infection hotspots’. The healthcare environment can be described as a reservoir for potentially infective agents which can spread unpredictably in a whole array of ways particularly in ventilation and air-conditioning systems making it difficult to effectively control and manage, for those seeking timely information about the patterns of cross-infection. The severity of the problem has been highlighted extensively over the past decade, as part of wider umbrella of what was known as health care acquired infections (HCAIs). Airborne transmission extends over a wide spectrum, and includes many prevalent agents, inter alia Mycobacterium tuberculosis (TB),nosocomial MRSA, Aspergillus fumigatus, Serratia marcescens, norovirus, and other airborne infection. Dr Shabha was speaking live from Birmingham and this CIBSE ASHRAE Group (www.cibseashrae.org) webinar was co-sponsored by the B&ES; Ventilation Hygiene Group and the Institute of Healthcare Engineering and Estate Management (IHEEM).