Risk Factors for Surgical Site Infection after Lower Limb Revascularisation Surgery: a Systematic Review and Meta-Analysis of Prognostic Studies.

OBJECTIVE: To systematically review and meta-analyse adjusted risk factors for surgical site infection (SSI) after lower limb revascularisation surgery. DATA SOURCES: MEDLINE, Embase, Evidence Based Medicine Reviews, and the Cochrane Central Register of Controlled Trials (inception to 28 April 2022). REVIEW METHODS: Systematic review and meta-analysis conducted according to PRISMA guidelines. After protocol registration, databases were searched. Studies reporting adjusted risk factors for SSI in adults who underwent lower limb revascularisation surgery for peripheral artery disease were included. Adjusted odds ratios (ORs) were pooled using random effects models. GRADE was used to assess certainty. RESULTS: Among 6 377 citations identified, 50 studies (n = 271 125 patients) were included. The cumulative incidence of SSI was 12 (95% confidence interval [CI] 10 - 13) per 100 patients. Studies reported 139 potential SSI risk factors adjusted for a median of 12 (range 1 - 69) potential confounding factors. Risk factors that increased the pooled adjusted odds of SSI included: female sex (pooled OR 1.41, 95% CI 1.20 - 1.64; high certainty); dependent functional status (pooled OR 1.18, 95% CI 1.03 - 1.35; low certainty); being overweight (pooled OR 1.82, 95% CI 1.29 - 2.56; moderate certainty), obese (pooled OR 2.20, 95% CI 1.44 - 3.36; high certainty), or morbidly obese (pooled OR 1.65, 95% CI 1.08 - 2.52; moderate certainty); chronic obstructive pulmonary disease (pooled OR 1.42, 95% CI 1.17 - 1.71; high certainty); chronic limb threatening ischaemia (pooled OR 1.67, 95% CI 1.22 - 2.29; moderate certainty); chronic kidney disease (pooled OR 2.13, 95% CI 1.18 - 3.83; moderate certainty); intra-operative (pooled OR 1.23, 95% CI 1.02 - 1.49), peri-operative (pooled OR 1.92, 95% CI 1.27 - 2.90), or post-operative (pooled OR 2.21, 95% CI 1.44 - 3.39) blood transfusion (moderate certainty for all); urgent or emergency surgery (pooled OR 2.12, 95% CI 1.22 - 3.70; moderate certainty); vein bypass and or patch instead of endarterectomy alone (pooled OR 1.86, 95% CI 1.33 - 2.59; moderate certainty); an operation lasting ≥ 3 hours (pooled OR 1.86, 95% CI 1.33 - 2.59; moderate certainty) or ≥ 5 hours (pooled OR 1.60, 95% CI 1.18 - 2.17; moderate certainty); and early or unplanned re-operation (pooled OR 4.50, 95% CI 2.18 - 9.32; low certainty). CONCLUSION: This systematic review identified evidence informed SSI risk factors following lower limb revascularisation surgery. These may be used to develop improved SSI risk prediction tools and to identify patients who may benefit from evidence informed SSI prevention strategies.

Electrogenic Staphylococcus epidermidis colonizes nasal cavities and alleviates IL-6 progression induced by the SARS2-CoV nucleocapsid protein.

AIM: Certain probiotic bacteria have been shown to possess an immunomodulatory effect and a protective effect on influenza infections. Using the Staphylococcus epidermidis K1 colonized mice model, we assessed the effect of nasal administration of glycerol or flavin mononucleotide (FMN) on the production of interleukin (IL)-6 mediated by the severe acute respiratory syndrome coronavirus 2 (SARS2-CoV) nucleocapsid protein (NPP). METHODS AND RESULTS: FMN, one of the key electron donors for the generation of electricity facilitated by S. epidermidis ATCC 12228, was detected in the glycerol fermentation medium. Compared to the S. epidermidis ATCC 12228, the S. epidermidis K1 isolate showed significant expression of the electron transfer genes, including pyruvate dehydrogenase (pdh), riboflavin kinase (rk), 1,4-dihydroxy-2-naphthoate octaprenyltransferase (menA), and type II NADH quinone oxidoreductase (ndh2). Institute of cancer research (ICR) mice were intranasally administered with S. epidermidis K1 with or without pretreatment with riboflavin kinase inhibitors, then nasally treated with glycerol or FMN before inoculating the NPP. Furthermore, J774A.1 macrophages were exposed to NPP serum and then treated with NPP of SARS2-CoV. The IL-6 levels in the bronchoalveolar lavage fluid (BALF) of mice and macrophages were quantified using a mouse IL-6 enzyme-linked immunosorbent assay kit. CONCLUSIONS: Here, we report that nasal administration of NPP strongly elevates IL-6 levels in both BALF and J774A.1 macrophages. It is worth noting that NPP-neutralizing antibodies can decrease IL-6 levels in macrophages. The nasal administration of glycerol or FMN to S. epidermidis K1-colonized mice results in a reduction of NPP-induced IL-6 production.

Structure-guided design of immunomodulatory RNAs specifically targeting the cytoplasmic viral RNA sensor RIG-I.

The cytoplasmic immune sensor RIG-I detects viral RNA and initiates an antiviral immune response upon activation. It has become a potential target for vaccination and immunotherapies. To develop the smallest but potent immunomodulatory RNA (immRNAs) species, we performed structure-guided RNA design and used biochemical, structural, and cell-based methods to select and characterize the immRNAs. We demonstrated that inserting guanosine at position 9 to the 10mer RNA hairpin (3p10LG9) activates RIG-I more robustly than the parental RNA. 3p10LG9 interacts strongly with the RIG-I helicase-CTD RNA sensing module and disrupts the auto-inhibitory interaction between the HEL2i and CARDs domains. We further showed that 3p10LA9 has a stronger cellular activity than 3p10LG9. Collectively, purine insertion at position 9 of the immRNA species triggered more robust activation of RIG-1.

Mycobacterium tuberculosis Drug Resistance and Transmission among Human Immunodeficiency Virus-Infected Patients in Ho Chi Minh City, Vietnam.

Vietnam has a high burden of tuberculosis (TB) and multidrug-resistant (MDR) TB, but drug resistance patterns and TB transmission dynamics among TB/human immunodeficiency virus (HIV) coinfected patients are not well described. We characterized 200 Mycobacterium tuberculosis isolates from TB/HIV coinfected patients diagnosed at the main TB referral hospital in Ho Chi Minh City, Vietnam. Phenotypic drug susceptibility testing (DST) for first-line drugs, spoligotyping, and 24-locus mycobacterial interspersed repetitive unit (MIRU-24) analysis was performed on all isolates. The 24-locus mycobacterial interspersed repetitive unit clusters and MDR isolates were subjected to whole genome sequencing (WGS). Most of the TB/HIV coinfected patients were young (162/174; 93.1% aged < 45 years) males (173; 86.5% male). Beijing (98; 49.0%) and Indo-Oceanic (70; 35.0%) lineage strains were most common. Phenotypic drug resistance was detected in 84 (42.0%) isolates, of which 17 (8.5%) were MDR; three additional MDR strains were identified on WGS. Strain clustering was reduced from 84.0% with spoligotyping to 20.0% with MIRU-24 typing and to 13.5% with WGS. Whole genome sequencing identified five additional clusters, or members of clusters, not recognized by MIRU-24. In total, 13 small (two to three member) WGS clusters were identified, with less clustering among drug susceptible (2/27; 7.4%) than among drug-resistant strains (25/27; 92.6%). On phylogenetic analysis, strains from TB/HIV coinfected patients were interspersed among strains from the general community; no major clusters indicating transmission among people living with HIV were detected. Tuberculosis/HIV coinfection in Vietnam was associated with high rates of drug resistance and limited genomic evidence of ongoing M. tuberculosis transmission among HIV-infected patients.

Point-of-Care Ultrasound Performed by a Medical Student Compared to Physical Examination by Vascular Surgeons in the Detection of Abdominal Aortic Aneurysms.

BACKGROUND: The use of point-of-care ultrasound (POCUS) has become increasingly prevalent in medical practice as a non-invasive tool for focused bedside diagnosis. Consequently, some medical schools have begun implementing POCUS training as a standard in their medical school curriculum. The feasability and value of introducing POCUS training at the medical student level to screen for abdominal aortic aneurysms (AAA) should be explored. Given this, the objective of our study was to determine the test characteristics of point-of-care ultrasonography performed by a medical student versus physical examination by vascular surgeons compared to a gold standard reference scan for the detection of AAAs. METHODS: We conducted a prospective, observer-blinded study recruiting patients from an outpatient vascular surgery clinic. Participants were screened for AAAs by standardized physical examination by a blinded vascular surgeon, followed by a POCUS examination by a blinded medical student. The student underwent prior training by a vascular sonographer and emergency physician on 60 patients (16 were supervised). Ultrasonography was used to visualize and measure the proximal, mid, and distal aortic diameters. The maximal aortic diameter was noted and compared with measurements obtained by the reference scan (computed tomography scan or vascular sonographer-performed ultrasound). Reference scans were completed within 3 months of the recruitment visit. RESULTS: A total of 57 patients were enrolled over a 5-month period between October 2015 and March 2016. Mean age of recruited patients was 71 years, and 61% were male. Mean body mass index was 27.9 ± 4.3, and mean waist-to-hip ratio was 0.96 ± 0.10. Sixteen AAAs were detected by the reference scan, with an average maximal aortic diameter of 44.9 mm. Physical examination by a vascular surgeon detected 11 of 16 AAAs with 2 false positives (sensitivity and specificity of 66.7% [95% confidence interval [CI], 38.4-88.2] and 94.4% [95% CI, 81.3-99.3], respectively). POCUS detected 15 of 16 AAAs (sensitivity and specificity of 93.3% [95% CI, 68.1-99.8] and 100% [95% CI, 88.4-100], respectively). Seven of the 64 POCUS scans were indeterminate (>1 cm of the aorta was not visualized). Average time to conduct the physical examination was 35 sec versus 4.0 min for point-of-care ultrasonography. There was a strong linear correlation (R2 = 0.95) between maximal aortic diameter measured by point-of-care ultrasonography versus reference scan with a mean absolute difference of 2.6 mm. CONCLUSION: Point-of-care ultrasonography performed by a medical student is highly accurate and more effective in detecting AAAs than physical examination by vascular surgeons. The introduction of POCUS training at the medical student level and its wide-scale implementation as an extension to physical examination may lead to improved detection of AAAs.

Preinjury ASA score as an independent predictor of readmission after major traumatic injury.

BACKGROUND: Patients with trauma have a high predisposition for readmission after discharge. Unplanned solicitation of medical services is a validated quality of care indicator and is associated with considerable economic costs. While the existing literature emphasizes the severity of the injury, there is heterogeneity in defining preinjury health status. We evaluate the validity of the American Society of Anesthesiologists (ASA) Physical Status score as an independent predictor of readmission and compare it to the Charlson Comorbidity Index (CCI). METHODS: This is a single center, retrospective cohort study based on adult patients (>18 years of age) with trauma admitted to the Ottawa Hospital from January 1, 2004 to November 1, 2014. A multivariate logistic regression model is used to control for confounding and assess individual predictors. Outcome is readmission to hospital within 30 days, 3 months and 6 months. RESULTS: A total of 4732 adult patients were included in this analysis. Readmission rates were 6.5%, 9.6% and 11.8% for 30 days, 3 months and 6 months, respectively. Higher preinjury ASA scores demonstrated significantly increased risk of readmission across all levels in a dose-dependent manner for all time frames. The effect of preinjury ASA scores on readmission is most striking at 30 days, with patients demonstrating a 2.81 (1.88-4.22, P<0.0001), 3.59 (2.43-5.32, P<0.0001) and 7.52 (4.72-11.99, P<0.0001) fold odds of readmission for ASA class 2, 3 and 4, respectively, as compared with healthy ASA class 1 patients. The ASA scores outperformed the CCI at 30 days and 3 months. CONCLUSIONS: The preinjury ASA score is a strong independent predictor of readmission after traumatic injury. In comparison to the CCI, the preinjury ASA score was a better predictor of readmission at 3 and 6 months after a major traumatic injury. LEVEL OF EVIDENCE: Prognostic and Epidemiological Study, Level III.

Respiratory virus laboratory pandemic planning and surveillance in central Viet Nam, 2008-2010.

INTRODUCTION: Laboratory capacity is needed in central Viet Nam to provide early warning to public health authorities of respiratory outbreaks of importance to human health, for example the outbreak of influenza A(H1N1) pandemic in 2009. Polymerase chain reaction (PCR) procedures established as part of a capacity-building process were used to conduct prospective respiratory surveillance in a region where few previous studies have been undertaken. METHODS: Between October 2008 and September 2010, nose and throat swabs from adults and children (approximately 20 per week) presenting with an acute respiratory illness to the Ninh Hoa General Hospital were collected. Same-day PCR testing and result reporting for 13 respiratory viruses were carried out by locally trained scientists. RESULTS: Of 2144 surveillance samples tested, 1235 (57.6%) were positive for at least one virus. The most common were influenza A strains (17.9%), with pandemic influenza A(H1N1) 2009 and seasonal H3N2 strain accounting for 52% and 43% of these, respectively. Other virus detections included: rhinovirus (12.4%), enterovirus (8.9%), influenza B (8.3%), adenovirus (5.3%), parainfluenza (4.7%), respiratory syncytial virus (RSV) (3.9%), human coronavirus (3.0%) and human metapneumovirus (0.3%). The detection rate was greatest in the 0-5 year age group. Viral co-infections were identified in 148 (6.9%) cases. DISCUSSION: The outbreak in 2009 of the influenza A(H1N1) pandemic strain provided a practical test of the laboratory's pandemic plan. This study shows that the availability of appropriate equipment and molecular-based testing can contribute to important individual and public health outcomes in geographical locations susceptible to emerging infections.