First experience of implementing Candida auris real-time PCR for surveillance in the UK: detection of multiple introductions with two international clades and improved patient outcomes.

BACKGROUND: Candida auris has been associated with rapid transmission and high mortality. A novel PCR-based surveillance programme was initiated at a London teaching hospital from January 2018. The results of this implementation until March 2019 are presented along with the clinical, transmission and phylogenetic characteristics encountered in that setting. METHODS: A real-time PCR assay for C. auris was developed, validated, and implemented for direct use on skin swabs and urine. Environmental swabs were also tested by PCR as an emergency outbreak-control measure. Clinical risk factors and outcomes of patients were determined. Environmental dispersal was assessed using 24 h settle plate cultures around nine colonized patients followed by air sampling around one colonized patient during high- and low-turbulence activities. Sequencing was performed using Illumina HiSeq and maximum likelihood phylogenies were constructed using rapid bootstrap analysis. RESULTS: Twenty-one C. auris colonized patients were identified. Median turnaround time of colonization detection reduced from 141 h (5.8 days) to approximately 24 h enabling rapid infection-control precautions. Settle plates detected 70-600 cfu/m2 around colonized patients over 24 h and air sampling suggested dispersal during turbulent activities. C. auris DNA was detected from 35.7% environmental swabs. Despite being in a high-risk setting, no patients developed invasive infection. Sequencing analysis of isolates from this centre identified two introductions of the South Asian (Clade I) and one of the South African (Clade III) strain. CONCLUSION: The PCR offers a rapid, scalable method of screening and supports clinical risk reduction in settings likely to encounter multiple introductions.

Incidence and outcomes of healthcare-associated COVID-19 infections: significance of delayed diagnosis and correlation with staff absence.

BACKGROUND: The sudden increase in COVID-19 admissions in hospitals during the SARS-CoV-2 pandemic of 2020 led to onward transmissions among vulnerable inpatients. AIMS: This study was performed to evaluate the prevalence and clinical outcomes of healthcare-associated COVID-19 infections (HA-COVID-19) during the 2020 epidemic and study factors which may promote or correlate with its incidence and transmission in a Teaching Hospital NHS Trust in London, UK. METHODS: Electronic laboratory, patient and staff self-reported sickness records were interrogated from 1st March to 18th April 2020. HA-COVID-19 was defined as COVID-19 with symptom onset within >14 days of admission. Test performance of a single combined throat and nose swab (CTNS) for patient placement was calculated. The effect of delayed RNA positivity (DRP, defined as >48 h delay), staff self-reported COVID-19 sickness absence, hospital bed occupancy, and community incidence of COVID-19 was compared for HA-COVID-19. The incidence of other significant hospital-acquired bacterial infections (HAB) was compared with previous years. RESULTS: Fifty-eight HA-COVID-19 (7.1%) cases were identified. When compared with community-acquired admitted cases (CA-COVID-19), significant differences were observed in age (P=0.018), ethnicity (P<0.001) and comorbidity burden (P<0.001) but not in 30-day mortality. CTNS-negative predictive value was 60.3%. DRP was associated with greater mortality (P=0.034) and incidence of HA-COVID-19 correlated positively with DRP (R = 0.7108) and staff sickness absence (R = 0.7815). For the study period HAB rates were similar to the previous 2 years. CONCLUSIONS: Early diagnosis and isolation of COVID-19 patients would help to reduce transmission. A single CTNS has limited value in segregating patients into positive and negative pathways.

Transmission of multi-drug resistant Pseudomonas aeruginosa between two flexible ureteroscopes and an outbreak of urinary tract infection: the fragility of endoscope decontamination.

OBJECTIVES: Flexible endoscopes are difficult to decontaminate, and endoscope-associated infections are increasing. This report describes an outbreak of multi-drug resistant Pseudomonas aeruginosa identified following an increase in incidence of clinical infections associated with flexible ureteroscopy at a tertiary care centre in the UK. METHODS: Clinical, laboratory and central decontamination unit (CDU) records were reviewed to determine the extent of the problem, and links to the used endoscopes. Audits of the ureteroscopy procedure, endoscopy unit and CDU were performed. Endoscopes were sampled, cultured and examined for structural integrity. All available isolates were typed. RESULTS: Thirteen patients developed clinical infections linked to two flexible ureteroscopes. The first ureteroscope was likely colonized from a known infected patient and the second ureteroscope after use on another patient infected by the first. Risk factors identified include surface cuts, stretching and puckering of the outer cover in both ureteroscopes, absence of bedside cleaning, overnight delay between the ureteroscopy and decontamination, inadequate drying after decontamination and non-traceability of connector valves. CONCLUSIONS: The adequacy of flexible endoscope decontamination depends on numerous steps. With the increasing global incidence of multi-drug resistant organisms, stringent monitoring of the flexible endoscopy process by users and decontamination units is essential.

Cluster of non-tuberculous mycobacteraemia associated with water supply in a haemato-oncology unit.

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms but rarely cause infections. Clinical, microbiological and epidemiological investigations and subsequent management of a cluster of NTM bacteraemia on a haemato-oncology unit are reported. From October 2007 to July 2008, five patients being managed for haematological malignancies developed pyrexia and general malaise. Mycobacterium mucogenicum (four patients) and Mycobacterium neoaurum (one patient) were identified from their blood cultures. The environment, in particular the water system, was investigated to identify the source of the infection and multiple water samples were cultured according to established criteria. NTM were also isolated from the hospital water system. Central venous catheters (CVCs) were removed and the patients were successfully treated with antibiotics. Environmental measures and changes in CVC care were introduced to prevent further episodes of NTM bacteraemia in these patients. Despite these measures, NTM continued to be present in the water system, but new clinical cases were not identified. NTM are common environmental organisms and are recognized as being difficult to remove from water systems. CVCs were presumed to be the portal of entry in this cluster of NTM bacteraemia, and the implementation of changes to CVC care protocols was successful in preventing further infections in this immunocompromised patient group.