The epidemiology of enterococci in a tertiary hospital and primary healthcare facilities in Fiji (2019-2022).

OBJECTIVES: We analysed 4 y of laboratory data to characterise the species and determine the antimicrobial susceptibility profiles of enterococci as human pathogens in Fiji. The study also investigated the molecular epidemiology amongst the subset of vancomycin-resistant enterococci (VRE). METHODS: This retrospective study reviewed bacteriological data from Colonial War Memorial Hospital (CWMH) and other healthcare facilities in the Central and Eastern divisions of Fiji. Phenotypic, antimicrobial susceptibility and vanA and vanB PCR testing were performed using locally approved protocols. The first clinical isolates per patient with antimicrobial susceptibility testing results in a single year were included in the analysis. Data was analysed using WHONET software and Microsoft Excel. RESULTS: A total of 1817 enterococcal isolates were reported, 1415 from CWMH and 402 from other healthcare facilities. The majority of isolates, 75% (n = 1362) were reported as undifferentiated Enterococcus spp., 17.8% (n = 324) were specifically identified as Enterococcus faecalis and 6.7% (n = 122) as E. faecium. Overall, 10% of the enterococci isolates were from blood cultures. Among isolates from CWMH, <15% of E. faecium were susceptible to ampicillin, and 17.2% were vancomycin resistant. Overall, 874 enterococcal isolates (including the undifferentiated species) were tested against vancomycin, of which 4.8% (n = 42) were resistance. All of the VRE isolates tested (n = 15) expressed vanA genes. CONCLUSIONS: This study demonstrates the clinical importance of VRE, particularly van A E. faecium in the national referral hospital in Fiji. Enhanced phenotypic and molecular surveillance data are needed to better understand enterococci epidemiology and help guide specific infection prevention and control measures and antibiotic prescribing guidelines.

The changing epidemiology of antimicrobial resistance in Fiji: a descriptive analysis of antimicrobial susceptibility and trends of endemic and emerging pathogens, 2019-2022.

Background: There is a paucity of data on antimicrobial resistance in Fiji. The aim of this study was to determine the antimicrobial susceptibility profile of bacterial isolates from clinical samples at Colonial War Memorial Hospital in Fiji. Methods: This retrospective study reviewed four-year of data from January 1, 2019, through December 31, 2022. Laboratory testing was carried out using locally approved protocols. Selective antimicrobial susceptibility testing was performed whereby only isolates resistant to first line antimicrobials were tested against second line antimicrobials. Only the first isolate of a given species per patient in a single year were included in the analysis. WHONET software and Microsoft Excel were used for analysis. Findings: A total of 29,222 bacterial isolates were included, 62% (n = 18,084) were Gram-negative bacteria. K. pneumoniae was the most common (n = 5363), followed by E. coli (n = 4321). Extended spectrum beta lactamase (ESBL) production increased from 30% in 2019 to 43% in 2022 amongst K. pneumoniae, and 10%-23% in E coli. There were 733 carbapenem-resistant isolates identified from clinical samples, 61% (n = 445) were A. baumannii, 15% (n = 110) E. coli and 14% (n = 101) P. aeruginosa. Amongst the E. coli isolates tested, susceptibility to meropenem declined from 99% (272/274) in 2019 to 79% (255/325) in 2022. The rate of methicillin resistance amongst Staphylococcus aureus was steady, remaining between 11% and 13%. Interpretation: This study demonstrated a high rate of MDR amongst Gram-negative bacteria, especially ESBL producing K. pneumoniae and E. coli and carbapenem-resistant A. baumannii. The emergence and rapid spread of carbapenemase producing E. coli in Fiji's largest hospital is of particular concern. There is an urgent need to allocate resources to improve existing capacity and to develop effective multimodal strategies to detect, manage and control the spread of MDR organisms. Funding: This study was supported by the Medical Research Future Fund through the Australian government (grant number APP 1200970).

Attributable mortality and excess length of stay associated with third-generation cephalosporin-resistant Enterobacterales bloodstream infections: a prospective cohort study in Suva, Fiji.

OBJECTIVES: There are scant primary clinical data on antimicrobial resistance (AMR) burden from low- and middle-income countries (LMICs). We adapted recent World Health Organization methodology to measure the effect of third-generation cephalosporin resistance (3GC-R) on mortality and excess length of hospital stay in Fiji. METHODS: We conducted a prospective cohort study of inpatients with Enterobacterales bloodstream infections (BSIs) at Colonial War Memorial Hospital, Suva. We used cause-specific Cox proportional hazards models to estimate the effect of 3GC-R on the daily risk (hazard) of in-hospital mortality and being discharged alive (competing risks), and we used multistate modelling to estimate the excess length of hospital stay. RESULTS: From July 2020 to February 2021 we identified 162 consecutive Enterobacterales BSIs; 3GC-R was present in 66 (40.7%). Crude mortality for patients with 3GC-susceptible and 3GC-R BSIs was 16.7% (16/96) and 30.3% (20/66), respectively. 3GC-R was not associated with the in-hospital mortality hazard rate (adjusted hazard ratio [aHR] 1.13, 95% confidence interval [CI] 0.51-2.53) or being discharged alive (aHR 0.99, 95% CI 0.65-1.50), whereas Charlson comorbidity index score (aHR 1.62, 95% CI 1.36-1.93) and Pitt bacteraemia score (aHR 3.57, 95% CI 1.31-9.71) were both associated with an increased hazard rate of in-hospital mortality. 3GC-R was associated with an increased length of stay of 2.6 days (95% CI 2.5-2.8). 3GC-R was more common among hospital-associated infections, but genomics did not identify clonal transmission. CONCLUSION: Patients with Enterobacterales BSIs in Fiji had high mortality. There were high rates of 3GC-R, which was associated with increased hospital length of stay but not with in-hospital mortality.

Epidemiology, antimicrobial resistance and outcomes of Staphylococcus aureus bacteraemia in a tertiary hospital in Fiji: A prospective cohort study.

Background: Staphylococcus aureus bacteraemia (SAB) is one of the commonest bloodstream infections globally and is associated with a high mortality rate. Most published data comes from temperate, high-income countries. We describe the clinical epidemiology, microbiology, management and outcomes of patients with SAB treated in a tropical, middle-income setting at Fiji's largest hospital. Methods: A prospective, observational study was performed of consecutive SAB cases admitted to Colonial War Memorial Hospital (CWMH) in Suva, between July 2020 and February 2021. Detailed demographic, clinical and microbiological data were collected, including the key outcome of in-patient mortality. To estimate the population incidence, all SAB cases diagnosed at the CWMH laboratory were included - even if not admitted to CWMH - with the population of Fiji's Central Division used as the denominator. Findings: A total of 176 cases of SAB were detected over eight-months, which equated to an incidence of 68.8 cases per 100,000 population per year. Of these, 95 cases were admitted to CWMH within 48 h of index culture. Approximately 8.4% (8/95) of admitted cases were caused by methicillin-resistant Staphylococcus aureus (MRSA). All cause in-patient mortality was 25.3%, increasing to 55% among patients aged 60 or older. Interpretation: This reported incidence of SAB in central Fiji is one of the highest in the world. SAB was associated with significant mortality, especially in those over 60 years of age, despite a relatively low frequency of methicillin resistance. Funding: Supported by the National Health and Medical Research Council (Australia) and the GRAM (Global Research on Antimicrobial Resistance) Project, Oxford University (United Kingdom).