Time-varying Reproductive Rates for SARS-CoV-2 and its Implications as a Means of Disease Surveillance on Lockdown Restrictions.

OBJECTIVE: To quantify the time-varying reproductive rates for SARS-CoV-2 and its implication in Louisiana. SUMMARY OF BACKGROUND DATA: Basic reproductive number (R0) and effective reproductive number (Re or Rt) are 2 measures of the ability of an infectious agent to spread in the environment. They differ in that R0 assumes zero immunity in the population, while Re or Rt accounts for change over time. Reproductive number modeling is influenced by several factors, including serial interval, the time between the onset of symptoms in an infector, and a secondary case. Quantification of the ability of a pathogen to spread is essential in guiding policy. METHODS: Here, we construct epidemic curves and calculate daily Rt values for the state of Louisiana and each of its 9 regions. RESULTS: Our results demonstrated variation over both time and geography in calculated R0 and Rt values. Generally, as time has progressed, predicted R0 and Rt values have decreased. In Louisiana, mean Rt was calculated at 3.07 in March and 0.82 by May. A reproductive number less than one is important as it indicates infectious spread will decline with time. The most recent finding of mean Rt = 0.82 is important. It stands in stark contrast to the situation in April when New Orleans, Louisiana, had the highest per capita coronavirus mortality rate in the United States - twice that of New York City and 4 times the rate in Seattle. CONCLUSION: As locations around the world begin to lift restrictions, monitoring of infectious spread will be essential.

Meta-analysis on Serial Intervals and Reproductive Rates for SARS-CoV-2.

OBJECTIVE: The aim of this study was to systematically review and meta-analyze all literature reporting the basic reproductive number (R0), effective reproductive number (Re or Rt), and the serial interval (SI) values of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. SUMMARY BACKGROUND DATA: To assess the rate at which an infectious disease can spread in a population, the 2 measures, R0 and Re or Rt, are widely used. One of the parameters which influence the calculations is the SI, the period between symptom onset in an infector and an infectee. METHODS: Web of Science, PubMed, Scopus, and Science Direct searching up to May 10, 2020, was performed. A continuous random-effect model was applied using the DerSimonian-Laird (inverse variance) method. Heterogeneity and publication bias were assessed. RESULTS: A total of 39 articles met the eligibility criteria. Our results demonstrated the mean SI was 5.45 days, with the 95% confidence interval (CI) of 4.23 to 6.66. Pooled estimates for reproduction rates was 3.14 (95% CI: 2.69-3.59) for R0 and 3.18 (95% CI: 2.89-3.47) for Rt. Subgroup analysis by geographical region and date of publication revealed variations over both time and geography in calculated R0 and Rt values. As time has progressed, predicted R0 and Rt values had decreased globally. CONCLUSIONS: The study findings indicate that one SARS-CoV-2-infected person is likely to infect 3 persons, supporting that COVID-19 is a highly contagious disease. As an essential objective metrics implied in risk assessment for this emerging pandemic, monitoring R0 and Re is necessary to indicate the effectiveness or failures of mitigation efforts.

Prehospital Mortality Due to Hemorrhagic Shock Remains High and Unchanged: A Summary of Current Civilian EMS Practices and New Military Changes.

ABSTRACT: Mortality secondary to trauma-related hemorrhagic shock has not improved for several decades. Underlying the stall in progress is the conundrum of effective prehospital interventions for hemorrhage control. As we know, neither pressing hard on the gas nor "stay and play" has changed mortality over the last 20 years. For this reason, when dealing with effective changes that will improve severe hemorrhage mortality outcomes, there is a need for the creation of a hybrid prehospital model. Improvements in mortality outcomes for patients with severe hemorrhage based on evidence for common civilian prehospital procedures such as in-field intubation and immediate fluid resuscitation with crystalloid solution are weak at best. The use of tourniquets, once considered too risky to use, however, has risen dramatically in large part due to success seen during their use in the military. Their use in the civilian setting shows promising results. Recently updated military Advanced Resuscitative Care guidelines propose the use of prehospital whole blood transfusion as well as in-field use of Zone 1 Resuscitative Endovascular Balloon Occlusion of the Aorta. Several case studies from Europe suggest these strategies are feasible for use in the civilian population, but could they be implemented in the US?

Single Institution Trial Comparing Whole Blood vs Balanced Component Therapy: 50 Years Later.

BACKGROUND: Early close ratio transfusion with balanced component therapy (BCT) has been associated with improved outcomes in patients with severe hemorrhage; however, this modality is not comparable with whole blood (WB) constituents. We compared use of BCT vs WB to determine if one yielded superior outcomes in patients with severe hemorrhage. We hypothesized that WB would lead to reduced in-hospital mortality and blood product volume if given in the first 24 hours of admission. STUDY DESIGN: This was a 1-year, single institution, prospective, observational study comparing BCT with WB in adult (18+y) trauma patients with active hemorrhage who required blood transfusion upon arrival at the emergency department. Primary endpoint was in-hospital mortality. Secondary endpoints included 24-hour transfusion volumes, in-hospital clinical outcomes, and complications. RESULTS: A total of 253 patients were included; 71.1% received BCT and 29.9% WB. The WB cohort had significantly more penetrating trauma (64.4% vs 48.9%; p = 0.03) and higher Shock Index (1.12 vs 0.92; p = 0.04). WB patients received significantly fewer units of packed red blood cells (PRBCs) (p < 0.001) and fresh frozen plasma (FFP) (p = 0.04), with a lower incidence of ARDS (p = 0.03) and fewer ventilator days (p = 0.03). Kaplan Meier survival analysis revealed no difference in survival between the 2 transfusion strategies (p = 0.80). When adjusted for various markers of injury severity and critical illness in Cox regression analysis, WB remained unassociated with mortality (hazard ratio 1.25; 95% CI 0.60-2.58; p = 0.55). CONCLUSIONS: There was no difference in survival rates when comparing BCT with WB. In the WB group, the incidence of ARDS, duration of mechanical ventilation, massive transfusion protocol (MTP) activation, and transfusion volumes were significantly reduced. Further research should be directed at analyzing whether there is a true hemorrhage-related pathophysiologic benefit of WB when compared with BCT.

Firearm homicide mortality is influenced by structural racism in US metropolitan areas.

INTRODUCTION: Metropolitan cities in the United States suffer from higher rates of gun violence. However, the specific structural factors associated with increased gun violence are poorly defined. We hypothesized that firearm homicide in metropolitan cities would be impacted by Black-White segregation index. METHODS: This cross-sectional analysis evaluated 51 US metropolitan statistical areas (MSAs) using data from 2013 to 2017. Several measures of structural racism were examined, including the Brooking Institute's Black-White segregation index. Demographic data were derived from the US Census Bureau, US Department of Education, and US Department of Labor. Crime data and firearm homicide mortality rates were obtained from the Federal Bureau of Investigation and the Centers for Disease Control. Spearman ρ and linear regression were performed. RESULTS: Firearm mortality was associated with multiple measures of structural racism and racial disparity, including White-Black segregation index, unemployment rate, poverty rate, single parent household, percent Black population, and crime rates. In regression analysis, percentage Black population exhibited the strongest association with firearm homicide mortality (ß = 0.42, p < 0.001). Black-White segregation index (ß = 0.41, p = 0.001) and percent children living in single-parent households (ß = 0.41, p = 0.002) were also associated with higher firearm homicide mortality. Firearm legislation scores were associated with lower firearm homicide mortality (ß = -0.20 p = 0.02). High school and college graduation rates were not associated with firearm homicide mortality and were not included in the final model. CONCLUSION: Firearm homicide disproportionately impacts communities of color and is associated with measures of structural racism, such as White-Black segregation index. Public health interventions targeting gun violence must address these systemic inequities. Furthermore, given the association between firearm mortality and single-parent households, intervention programs for at-risk youth may be particularly effective. LEVEL OF EVIDENCE: Epidemiological level II.

Zero Preventable Deaths by 2020: Analysis of Prehospital and Emergency Department Deaths Following Penetrating Trauma Stratified by Anatomic Location.

INTRODUCTION: Preventable deaths following trauma are high and unchanged over the last two decades. The objective of this study was to describe the location of death in patients with penetrating trauma, stratified by anatomic location of injury, in order to better tailor our approach to reducing preventable deaths from trauma. METHODS: This retrospective analysis of a prospectively maintained trauma registry included consecutive adult trauma activations with penetrating trauma at a level 1 trauma center between 07/2012 and 03/2018. Injuries were categorized as extremity, junctional, and torso. Head and neck injuries were excluded. Patients injured in >1 defined location were categorized as "multiple." Location of death was defined as on-scene, emergency department (ED), or hospital. Two-sided χ2 tests were used to compare groups. Multivariate analysis was performed using logistic regression. RESULTS: A total of 1024 patients were included with an overall case fatality rate (CFR) of 7.8%. The CFR following extremity injury (3.0%) was significantly lower than all other injury sites (P = .02).There were no significant differences in CFR for junctional (10.4%), torso (8.3%), or multiple injuries (9.6%). Forty percent of fatalities following junctional injury occurred on-scene and an additional 20% occurred in the ED. DISCUSSION: To our knowledge, this is the first study to describe location of death stratified by anatomic location of injury. There was no difference in the CFRs of junctional and torso injuries, and a large proportion of deaths occurred prior to reaching the hospital or in the trauma bay. These findings support reevaluating the classical algorithms and care pathways for patients with proximal penetrating trauma.

Neutrophil-to-Lymphocyte Ratio and Outcomes in Louisiana COVID-19 Patients.

BACKGROUND: Due to the rapidly escalating number of cases and the low baseline of overall health in Louisiana, we sought to determine the prognostic value of the neutrophil-to-lymphocyte ratio (NLR) in hospitalized COVID patients in two major metropolitan areas with the highest prevalence of cases and exceedingly high rates of obesity and other comorbid conditions. We hypothesized that elevated NLR would be a prognostic indicator of mortality. METHODS: This was a review of a prospective registry of adult (18+ years) hospitalized Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) patients from two large urban safety net hospitals in Louisiana. Blood cell counts at days 2 and 5 were used to obtain NLR. Receiver operating characteristic curve analysis assessed predictive capacity of NLR on mortality. Kaplan-Meier survival analysis and Cox regression models examined the effect of NLR on survival. RESULTS: The study population of 125 patients was majority African American (88.6%) and female (54.8%) with a mean age and body mass index of 58.7 years and 34.2. Most (96.0%) had comorbidities of which hypertension (72.0%), obesity (66.7%), and diabetes (40.0%) were the most common. Mortality was 18.4%. NLR > 4.94 on day 1 predicted intubation (P = 0.02). NLR above established cutoff values on hospital days 2 and 5 each significantly predicted mortality (P < 0.001 and P = 0.002, respectively). CONCLUSIONS: NLR is a prognostic factor for endotracheal intubation upon hospital admission and independent predictor for risk of mortality in SARS-CoV-2 patients on subsequent hospital days. Clinical research efforts should examine effects of strategies such as arginase inhibition alone and/or inhaled nitric oxide to ameliorate the effects of elevated NLR.

Asthma in COVID-19 patients: An extra chain fitting around the neck?

INTRODUCTION: The novel coronavirus disease 2019 (COVID-19) has rapidly spread across the globe. Pre-existing comorbidities have been found to have a dramatic effect on the disease course. We sought to analyze the effect of asthma on the disease progression and outcomes of COVID-19 patients. METHODS: We conducted a multi-center retrospective study of positively confirmed COVID-19 patients. The primary outcome of interest was in-hospital mortality. Secondary outcomes were the Intensive Care Unit (ICU) admission, intubation, mechanical ventilation, and length of hospital stay. RESULTS: A total of 502 COVID-19 adult patients (72 asthma and 430 non-asthma cohorts) with mean age of 60.7 years were included in the study. The frequency of asthma in hospitalized cohorts was 14.3%. Univariate analysis revealed that asthma patients were more likely to be obese (75% versus 54.2%, p = 0.001), with a higher frequency of intubation (40.3% versus 27.8%, p = 0.036), and required a longer duration of hospitalization (15.1 ± 12.5 versus 11.5 ± 10.6, p = 0.015). After adjustment, multivariable analysis showed that asthmatic patients were not associated with higher risk of ICU admission (OR = 1.81, 95%CI = 0.98-3.09, p = 0.06), endotracheal intubation (OR = 1.77, 95%CI = 0.99-3.04, p = 0.06) or complications (OR = 1.37, 95%CI = 0.82-2.31, p = 0.23). Asthmatic patients were not associated with higher odds of prolonged hospital length of stay (OR = 1.48, 95%CI = 0.82-2.66, p = 0.20) or with ICU stay (OR = 0.76, 95%CI = 0.28-2.02, p = 0.58). Kaplan-Meier curve showed no significant difference in the overall survival of the two groups (p = 0.65). CONCLUSION: Despite the increased prevalence of hospitalization in elder asthmatic COVID-19 patients, after adjustment for other variables, it was neither associated with increased severity nor worse outcomes.