The impact of healthcare-associated infections on patient care and the role of diagnostic molecular technology in infection prevention and control practice

Healthcare-associated infections (HCAIs) are a public health challenge in Ireland and pose a patient safety risk. The emergence of multi-drug resistant (MDR) Grampositive organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococci (VRE), Panton-Valentine leucocidin toxin-positive S. aureus (PVL-SA), and Gram-negative organisms, such as extended-spectrum betalactamase (ESBL)-producers and carbapenemase-producing Enterobacteriaceae (CPE), have made HCAIs more complex and diverse. Clinical microbiologists are an integral part of a hospital infection prevention and control (IPC) team, providing clinical guidance and expertise, assisting with the implementation of national and international IPC practices, managing outbreaks, and analysing rates of HCAIs. An efficient microbiology laboratory is an integral component of a hospital’s IPC strategy to facilitate the timely identification of pathogenic organisms from clinical specimens. In order to provide this service, a combination of skilled scientists who can perform traditional ‘bench’ tests and also utilise newer molecular diagnostics is required. Matrix-Assisted Laser Desorption/Ionisation Time of Flight Mass Spectrometry (MALDI-TOF MS) has facilitated the identification of bacteria, viruses and fungi in a convenient and time efficient manner and negated the need to employ older methodologies such as biochemical identification techniques. Faster identification of multi-drug resistant organisms (MDROs) is crucial for the timely management of HCAIs. Gradually, more laboratory work is becoming semi-automated and total laboratory automation (TLA) has become reality in many laboratories in Europe. To date, no Irish laboratory has installed a TLA system. Through greater public awareness of HCAIs, patients are more informed than ever regarding the risks associated with the acquisition of a HCAI and the concepts of patient safety and risk management have become key objectives for hospital management teams. As presented in this thesis, HCAIs have occurred in the Mid-West of Ireland across all age groups, despite the successful implementation of recommended IPC practices. Between 2009 and 2015, two outbreaks of CPE, an ESBL outbreak in a neonatal intensive care unit, the first reported case of neonatal mastitis secondary to PVL-SA, the first Irish outbreak of linezolid-resistant S. epidermidis and a rare case of daptomycin and vancomycin resistant enterococcal infective endocarditis have all occurred in the region. The Mid-West of Ireland currently has the highest national rates of CPE and higher than average national rates of ESBL-producing Escherichia coli in blood cultures. Future work to track the progression of these trends is needed. Infection prevention and control practices currently employed within the region are in line with national and international guidelines but despite this the rates of HCAIs remain problematic both clinically and practically, with regard to allocation of isolation facilities in acute hospitals. Leadership and support are required from hospital management to implement measures to reduce rates of HCAIs including providing funding for the purchase of laboratory equipment that can facilitate the rapid diagnosis of microorganisms, staff education and training including incentivising and rewarding wards to reduce rates of HCAIs, thoroughly investigating outbreaks as they occur and managing hospital beds in a safe and efficient manner. HCAIs have a negative impact on patient care and staff morale. A hospital-wide approach with input from all key stakeholders is needed for a sustained reduction in HCAI rates to be achieved.