Long-range air dispersion of Candida auris in a cardiothoracic unit outbreak in Hong Kong.

BACKGROUND: Nosocomial outbreaks of Candida auris, a multidrug-resistant fungus, are increasingly reported worldwide; the mode of transmission has usually been reported to be via direct contact. Some studies previously suggested potential short-distance air dispersal during high-turbulence activities, but evidence on long-range air dispersal remains scarce. AIM: To describe a C. auris nosocomial outbreak involving two wards (H7, 5E) in two local hospitals. METHODS: Samples were taken from patients, ward surfaces (frequently touched items and non-reachable surfaces) while settle plates were used for passive air sampling to investigate possible contributions by direct contact and air dispersal. Epidemiological and phylogenetic analyses were also performed on the C. auris isolates from this outbreak. FINDINGS: Eighteen patients were confirmed to have asymptomatic C. auris skin colonization. C. auris was expectedly identified in samplings from frequently touched ward items but was also isolated in two samples from ceiling supply air grilles which were 2.4 m high and inaccessible by patients. Moreover, one sample from a corridor return air grille as far as 9.8 m away from the C. auris cohort area was also positive. Two passive air samplings were positive, including one from a cubicle with no confirmed cases for four days, suggesting possible air dispersal of C. auris. Whole-genome sequencing confirmed clonality of air, environment, and patients' isolates. CONCLUSION: This is the first study to demonstrate potential long-range air dispersal of C. auris in an open-cubicle ward setting. Ventilation precautions and decontamination of out-of-reach high-level surfaces should be considered in C. auris outbreak management.

Transcatheter aortic valve implantation: initial experience in Hong Kong.

INTRODUCTION: Aortic stenosis is one of the most common valvular heart diseases in the ageing population. Patients with symptomatic severe aortic stenosis are at high risk of sudden death. Surgical aortic-valve replacement is the gold standard of treatment but many patients do not receive surgery because of advanced age or co-morbidities. Recently, transcatheter aortic valve implantation has been developed as an option for these patients. This study aimed to assess efficacy and safety of this procedure in the Hong Kong Chinese population. METHODS: Data for baseline patient characteristics, procedure parameters, and clinical outcomes up to 1-year post-implantation in a regional hospital in Hong Kong were collected and analysed. RESULTS: A total of 56 patients with severe aortic stenosis underwent the procedure from December 2010 to September 2015. Their mean (± standard deviation) age was 81.9 ± 4.8 years; 64.3% of them were male. Their mean logistic EuroSCORE was 22.6% ± 13.4%. After implantation, the mean aortic valve area improved from 0.70 cm2 ± 0.19 cm2 to 1.94 cm2 ± 0.37 cm2. Of the patients, 92% were improved by at least one New York Heart Association functional class. Stroke and major vascular complications occurred in one (1.8%) and five (8.9%) patients, respectively. A permanent pacemaker was implanted in seven (12.5%) patients. Both hospital and 30-day mortalities were 1.8%. The 1-year all-cause and cardiovascular mortality rates were 12.5% and 7.1%, respectively. CONCLUSIONS: Transcatheter aortic valve implantation has been developed as an alternative treatment for patients with symptomatic severe aortic stenosis who are deemed inoperable or high risk for surgery. Our results are very promising and comparable with those of major clinical trials.

Hemofiltration during cardiopulmonary bypass for high risk adult cardiac surgery.

AIMS: The role of hemofiltration (HF) during cardiopulmonary bypass (CPB) in adult cardiac surgery is controversial. It may be beneficial during prolonged CPB in high-risk surgery. Accordingly, we sought to compare two groups of patients undergoing high-risk cardiac surgery with or without HF. METHODS: One hundred and eighteen patients who underwent complex cardiac surgical procedures during a 12-month period were divided into two groups. Group I (n=61) comprised patients who were treated with hemofiltration during CPB. Group II (n=57) were not filtered. Estimated risk of death, standard demographic, clinical and surgical features were obtained and predetermined outcomes were studied. Statistical comparisons were made. RESULTS: Age, procedure times and mortality rates were similar in both groups. The mean volume of fluid removed in group I was 3.4 L. The preoperative mean Parsonnet score was 24.8 in group I and 22.5 in group II (ns). Postoperative serum hemoglobin, hematocrit, platelet, and albumin levels were all significantly higher in group I patients (p=0.0015) indicating hemoconcentration. Post-operative chest drainage showed a trend toward decreased post-operative bleeding in group I (p=0.065). Postoperative pleural effusions requiring chest tube drainage were significantly less in group I (9.8% vs. 29.8% 6; p = 0.0062). The incidence of lung infection was also decreased from 26.3% to 13.1% (p=0.05). Operative mortality was similar in both groups (11.4% in group 1, 10.5% in group II, ns). CONCLUSION: Hemofiltration during CPB attenuates postoperative anemia, thrombocytopenia and hypoalbuminemia, may reduce post-operative bleeding and appears to decrease post-operative pulmonary complications.

Functional organization of the Harvey murine sarcoma virus genome.

The comparative infectivity of Harvey murine sarcoma virus (Ha-MuSV) DNA for NIH 3T3 cells was determined for supercoiled Ha-MuSV DNA molecularly cloned in lambda phage and pBR322 at its unique EcoRI site (which is located near the middle of the 6-kilobase pair [kbp] unintegrated linear viral DNA) and for two cloned subgenomic fragments: one was 3.8 kbp and lacked about 1 kbp from each side of the EcoRI site, and the second did not contain the 3 kbp of the unintegrated linear viral DNA located on the 3' side of the EcoRI site. Each subgenomic DNA induced foci of transformed cells, but with a lower relative efficiency then genomic DNA. Transfection with intact vector Ha-MuSV DNA yielded results similar to those obtained after separation of Ha-MuSV DNA from vector DNA. Cells lines were then derived from individual foci transformed with each type of viral DNA. Focus-forming virus was recovered from transformed cells after superinfection with a helper-independent virus, but the efficiency varied by several orders of magnitude. For several transformed lines, the efficiency of recovery of focus-forming virus was correlated with the structure of the Ha-MuSV DNA in the cells before superinfection. When 32P-labeled Ha-MuSV DNA probes specific for sequences on either the 3' or 5' side of the EcoRI site were used to analyze the viral RNA in the transformed cell lines, all lines were found to hybridize with the 5' probe, but some lines did not hybridize with the 3' probe. The transformed lines contained high levels of the Ha-MuSV-coded p21 or its associated GDP-binding activity. We conclude that the transforming region and the sequences that code for the viral p21 protein are both located within the 2 kilobases closest to the 5' end of the Ha-MuSV genome.