Water heating and new bacteria: Emerging infections in healthcare facilities

Literature data assert that climatic conditions are changing, and physical-chemical factor may influence the proliferation of waterborne pathogens in drinking waters. Aim of study is the evaluation of water temperature influencing the opportunistic pathogens growth in hospital water networks. Between 2010 and 2018 in an Italian hospital hot water networks treated with monochlorammine, Legionella spp. and Nontuberculous Mycobateria (NTM) were researched and temperature values were measured during the sampling procedure. Temperature lowering has been observed during Legionella colonization in hot water networks, while NTM were detected after the temperature increase. We observed moderate correlations between the presence of waterborne pathogens (Legionella spp. and NTM) and the water increase/decrease. In conclusion, temperature changing is a risk factor for the occurrences of waterborne pathogens proliferation in water networks, and we highlight the need of microbiological tests aimed to ensure the water safety for patients.