Are liquids an efficient vehicle of healthcare associated infections? A review of reported cases in Italy (2000-2014)

Introduction. In the field of healthcare-associated infections (HCAIs), one of the most reported, studied and discussed sources of infections is water, partly due to its controllability, but also because healthcare facilities, especially hospitals, require a significant quantity of water per day. In addition to water, during healthcare procedures, other liquids can serve as source of infections. The present study reports a review of those HCAIs associated to liquid vehicles occurred in Italy during the period 2000-2014. Method. The review focused on cases of liquid-associated HCAIs in both sporadic cases and outbreaks according to the definition provided by both Word Health Organization and United States' Centers for Disease Control and Preventions in 2011. The review included all original papers published in peer-reviewed journals, in which the association between the infection and the exposure to contaminated water/other fluid was demonstrated by epidemiological and/or molecular methods. Articles describing cases due to parenteral transmitted pathogens (by blood or blood-derived fluids) were excluded. Results. During the period 2000-2014, 34 episodes have been described for a total of about 400 cases of infection. Isolations included genus Legionella, Pseudomonas, Serratia, Ralstonia, Burkolderia, Klebsiella and other pseudomonadaceae. The results confirm that HCAIs can be associated also to liquids other than piped water. The large majority of articles refers to hospital wards where patients with high risk of infections are usually admitted. Discussion. The review highlights a great number of HCAIs, but if we consider that the large part of HCAIs are not reported in literature, it is clear that the burden of this phenomenon is by far higher. Many cases of HCAI were identified in the context of local surveillance systems, demonstrating their role in HCAI control. With regard to diagnosis, the isolation and identification of the etiological agent is critical to reach the source of infection and to plan the necessary disinfection measures. Therefore, it is possible to conclude that, through a multiple approach of engineering and hygiene measures, as well as surveillance ad management of hospital liquids, the risk for contracting "water born" HCAIs may be controlled.