Abstract for:Cryptosporidium and ‘code brown’ – a participatory modelling approach to clearing the pool water

Cryptosporidium, an enteric pathogen that is commonly transmitted through swimming pool water, is a persistent public health problem in South East Queensland, Australia. Despite the introduction of swimming pool management guidelines, cases of Cryptosporidium infections continue to rise. This study used a participatory process to map, and subsequently model, the dynamic processes driving transmission in the region. Stakeholders identified six main processes contributing to local disease dynamics including international travel, person-to-person contact, the use of public swimming pool, the use of healthcare services, the operation and maintenance of public aquatic facilities, and the public health sector response to outbreaks. Simulation results identified a number of key insights such as the random nature of the ‘cyclic’ pattern of cryptosporidiosis notifications in SEQ, the larger-than expected role of overseas acquired cases in local disease dynamics, the relative effectiveness of management techniques applied to small vs. large public swimming pools, the unexpected role of primary care in the dynamics of Cryptosporidium transmission, an unclear threshold for action for swimming pool water quality issues, and the broader need to rethink the role of primary and secondary outbreak prevention in the design of intervention strategies.