Healthcare-associated infections (HAIs) cause risk to patients and have a financial impact on healthcare services due to increased length of hospital treatment, and the costs of isolating patients or closing wards. As antimicrobial resistance increases, the prevention of the spread of pathogens which cause HAIs has become of increasing importance. This paper describes a new project which aims to produce a tablet-based training tool for healthcare staff using digital visualisations of data on pathogens: how they behave in the ward context and how to prevent their spread. Crucial to the success of the tool will be to understand the training needs of staff, and the key preventable errors which lead to the spread of infection. The planned co-design and evaluation process for the project is described in the paper, including the different considerations for the design of the workshops to facilitate effective inputs from key hospital staff stakeholder groups – doctors, nurses and cleaning staff.