The role of intra and inter-hospital patient transfer in the dissemination of healthcare-associated multidrug-resistant pathogens

Abstract

Healthcare-associated infections cause significant patient morbidity and mortality, and contribute to growinghealthcare costs, whose effects may be felt most strongly in developing countries. Active surveillance systems,hospital staff compliance, including hand hygiene, and a rational use of antimicrobials are among the importantmeasures to mitigate the spread of healthcare-associated infection within and between hospitals. Klebsiellapneumoniae is an important human pathogen that can spread in hospital settings, with some forms exhibitingdrug resistance, including resistance to the carbapenem class of antibiotics, the drugs of last resort for suchinfections. Focusing on the role of patient movement within and between hospitals on the transmission andincidence of enterobacteriaceae producing K. pneumoniae Carbapenemase (KPC, an enzyme that inactivatesseveral antimicrobials), we developed a metapopulation model where the connections among hospitals are madeusing a theoretical hospital network based on Brazilian hospital sizes and locations. The pathogen reproductivenumber, R_0 that measures the average number of new infections caused by a single infectious individual, wascalculated in different scenarios defined by both the links between hospital environments (regular wards andintensive care units) and between different hospitals (patient transfer). Numerical simulation was used to il-lustrate the infection dynamics in this set of scenarios. The sensitivity of R_0 to model input parameters, such ashospital connectivity and patient-hospital staff contact rates was also established, highlighting the differentialimportance of factors amenable to change on pathogen transmission and control.