Molecular epidemiology and clinical impact of Klebsiella spp. causing bloodstream infections in Hong Kong.

BACKGROUND: The epidemiological features of the Klebsiella pneumoniae causing bloodstream infections in Hong Kong and their potential threats to human health remained unknown. METHODS: K. pneumoniae strains collected from four hospitals in Hong Kong during the period of 2009-2018 were subjected to molecular typing, string test, antimicrobial susceptibility testing, whole genome sequencing and analysis. Clinical data of patients from whom these strains were isolated were analyzed retrospectively using univariate and multivariate logistic regression approaches. FINDINGS: The 240 Klebsiella spp. strains belonged to 123 different STs and 63 different capsule loci (KLs), with KL1 and KL2 being the major type. 86 out of 212 BSI-KP (40.6%) carried at least one of the virulence genes iuc, iro, rmpA or rmpA2. Virulence plasmid correlated well with the string test positive result, yet 8 strains without rmp genes were also hypermucoviscous, which was due to wzc mutation. The mortality rate of bloodstream infection patients was 43.0%. Univariant analysis showed that factors including renal replacement therapy (FDR adjusted p = 0.0007), mechanical ventilation (FDR adjusted p < 0.0001) and respiratory sepsis (FDR adjusted p < 0.0001) were found to pose the highest risk of death upon infection by Klebsiella spp. INTERPRETATION: This study revealed the high mortality rate and risk factors associated with bloodstream infections caused by K. pneumoniae in Hong Kong, which warrants immediate action to develop effective solution to tackle this problem. FUNDING: Theme Based Research Scheme (T11-104/22-R), Research Impact Fund (R5011-18 F) and Postdoctoral Fellowship (PDFS2223-1S09).

Population sepsis incidence, mortality, and trends in Hong Kong between 2009-2018 using clinical and administrative data.

BACKGROUND: Sepsis surveillance using electronic health record (EHR)-based data may provide more accurate epidemiologic estimates than administrative data, but experience with this approach to estimate population-level sepsis burden is lacking. METHODS: This was a retrospective cohort study including all adults admitted to publicly-funded hospitals in Hong Kong between 2009-2018. Sepsis was defined as clinical evidence of presumed infection (clinical cultures and treatment with antibiotics) and concurrent acute organ dysfunction (≥2 point increase in baseline SOFA score). Trends in incidence, mortality, and case fatality risk (CFR) were modelled by exponential regression. Performance of the EHR-based definition was compared with 4 administrative definitions using 500 medical record reviews. RESULTS: Among 13,550,168 hospital episodes during the study period, 485,057 (3.6%) had sepsis by EHR-based criteria with 21.5% CFR. In 2018, age- and sex-adjusted standardized sepsis incidence was 759 per 100,000 (relative +2.9%/year [95%CI 2.0, 3.8%] between 2009-2018) and standardized sepsis mortality was 156 per 100,000 (relative +1.9%/year [95%CI 0.9,2.9%]). Despite decreasing CFR (relative -0.5%/year [95%CI -1.0, -0.1%]), sepsis accounted for an increasing proportion of all deaths (relative +3.9%/year [95%CI 2.9, 4.9%]). Medical record reviews demonstrated that the EHR-based definition more accurately identified sepsis than administrative definitions (AUC 0.91 vs 0.52-0.55, p < 0.001). CONCLUSIONS: An objective EHR-based surveillance definition demonstrated an increase in population-level standardized sepsis incidence and mortality in Hong Kong between 2009-2018 and was much more accurate than administrative definitions. These findings demonstrate the feasibility and advantages of an EHR-based approach for widescale sepsis surveillance.

An External Validation of Scoring Systems in Mortality Prediction in Veno-Venous Extracorporeal Membrane Oxygenation.

Veno-venous extracorporeal membrane oxygenation (VV ECMO) offers the last resort in the treatment of acute respiratory distress syndrome (ARDS). Various scoring systems have been established, yet external validation of these scoring systems in the Asian population remains scarce. We aim to identify factors associated with hospital mortality and to validate various scoring systems in the prediction of hospital mortality. A retrospective analysis of adults admitted to Pamela Youde Nethersole Eastern Hospital intensive care unit who received VV ECMO from January 1, 2010 to June 30, 2019 was performed. Demographics, ventilation strategies, rescue therapies, and clinical outcomes were compared. The primary outcome was hospital mortality and secondary outcomes were intensive care unit (ICU) mortality, ICU, and hospital length of stay. There were 122 VV ECMO performed for ARDS, of which 78 survived and 44 died. VV ECMO performed for viral pneumonitis was significantly associated with better survival (55.1% vs. 25%, p = 0.001) compared with other causes. As for prediction scores, the PREdiction of Survival on ECMO Therapy-Score had the highest area under receiver operator curve of 0.733 (95% confidence interval [CI]: 0.643-0.823), whereas that of PRedicting dEath for SEvere ARDS on VV ECMO score was 0.662 (95% CI: 0.561-0.764), Respiratory Extracorporeal Membrane Oxygenation Survival Prediction score was 0.657 (95% CI: 0.553-0.761), Sequential Organ Failure Assessment score was 0.652 (95% CI: 0.547-0.757), and VV ECMO mortality score was 0.637 (95% CI: 0.532-0.742). In our cohort, VV ECMO performed for viral pneumonitis was associated with a higher hospital survival. Prediction scores are helpful in our population and provide a useful reference to hospital mortality.

Effect of the underlying malignancy on critically ill septic patient's outcome.

BACKGROUND: Sepsis is an important cause of mortality and morbidity among critically ill patients with underlying malignancy. METHODS: Patients with sepsis admitted to the intensive care unit (ICU) of the Pamela Youde Nethersole Eastern Hospital from January 1, 2010 to April 30, 2019 were recruited. Demographics, laboratory parameter, and outcome were analyzed. Those with underlying malignancy were matched with those without malignancy based on their severity of organ failure (defined by the sequential organ failure assessment [SOFA] score) and septic source. RESULTS: Two hundred sixty-three patients with underlying active malignancy were matched with 259 patients without malignancy. Those with malignancy had higher APACHE IV score (89 vs. 83), lower albumin (22.1 vs. 24.4), neutrophil count (6.0 vs. 9.3), hemoglobin (8.0 vs. 9.8), platelet count (113 vs. 133), less use of mechanical ventilation (35.7% vs. 45.9%), renal replacement therapy (22.1% vs. 28.2%) and vasopressor (66.2% vs. 74.9%), higher 30-day (34.2% vs. 24.3%) ICU (22.4% vs. 18.9%), and 1-year (62.4% vs. 36.7%) mortality compared with those without malignancy. A higher APACHE IV score and pulmonary sepsis were predictors of 30-day mortality by Cox regression analysis. CONCLUSION: Disease severity and pulmonary sepsis, but not underlying malignancy, predicted short-term mortality among critically ill septic patients.

A Case of Lemierre's Syndrome in Intensive Care Unit.

We report a 21-year-old young male with Lemierre's syndrome presented as tonsillitis and Fusobacterium septicemia with respiratory failure and required intensive care. Lemierre's syndrome is the septic embolic complication of recent pharyngeal illness. Fusobacterium spp. accounts for the majority of cases. High index of suspicion is needed and prolonged antibiotic is advised. It is seldom seen in intensive care but should never be forgotten.