Do Markets Price CEOs Health Hazards? Evidence from the COVID-19 Pandemic

We find evidence that markets anticipate the potential loss of firm value in the event of the CEO falling sick and eventually dying of COVID-19 in a sample of almost 3000 listed firms from across 137 regions in 10 European countries. First, we use soccer games as "super-spreader"events. The instrumented number of infected cases per capita in the region where company headquarters are located predicts a significant drop in stock returns during March and April 2020 for firms managed by CEOs with a higher probability of dying from COVID-19. Second, we show that the stock price of these firms increases significantly the day on which positive news on the development of COVID-19 vaccines are released in the market. © 2022 World Scientific Publishing Company. Midwest Finance Association.

Detailed analysis of in-hospital transmission of SARS-CoV-2 using whole genome sequencing.

BACKGROUND: Hospital transmission of SARS-CoV-2 has proved difficult to control, with healthcare-associated infections troublesome throughout. AIM: To understand factors contributing to hospital transmission of infections, which is necessary for containing spread. METHODS: An outbreak of 56 staff and patient cases of COVID-19 over a 31-day period in a tertiary referral unit is presented, with at least a further 29 cases identified outside of the unit and the hospital by whole genome sequencing (WGS). FINDINGS: Transmission is documented from staff to staff, staff to patients, and patients to staff, showing disruption of a tertiary referral service, despite implementation of nationally recommended control measures, superior ventilation, and use of personal protective equipment. There was extensive spread from the index case, despite this patient spending only 10 h bed bound on the ward in strict cubicle isolation and with an initial single target low level (CT = 32) polymerase chain reaction test. CONCLUSION: This investigation highlights how effectively and rapidly SARS-CoV-2 can spread in certain circumstances. It raises questions about infection control measures in place at the time and calls into question the premise that transmissibility can be reliably detected by using lower sensitivity rapid antigen lateral flow tests. We also highlight the value of early intervention in reducing impact as well as the value of WGS in understanding outbreaks.

Contact tracing & super-spreaders in the branching-process model.

In recent years, it became clear that super-spreader events play an important role, particularly in the spread of airborne infections. We investigate a novel model for super-spreader events, not based on a heterogeneous contact graph but on a random contact rate: Many individuals become infected synchronously in single contact events. We use the branching-process approach for contact tracing to analyze the impact of super-spreader events on the effect of contact tracing. Here we neglect a tracing delay. Roughly speaking, we find that contact tracing is more efficient in the presence of super-spreaders if the fraction of symptomatics is small, the tracing probability is high, or the latency period is distinctively larger than the incubation period. In other cases, the effect of contact tracing can be decreased by super-spreaders. Numerical analysis with parameters suited for SARS-CoV-2 indicates that super-spreaders do not decrease the effect of contact tracing crucially in case of that infection.

Accounting for super-spreader events and algebraic decay in SIR models

A central feature of pandemics is the emergence and decay of localized infection waves. While traditional SIR models for infectious diseases can reproduce such waves, they fail to capture two key features. First, SIR models are unable to represent short-duration super-spreader events which often trigger infection waves in a community. Second, SIR models predict exponential decay to an asymptotic state after the infection wave peaks. In contrast, observations suggest a slower algebraic decay. In this paper, we develop models for the basic reproduction number R0 to capture these features. To generate quantitative estimates for R0 during super-spreader events, we reconcile the SIR framework with the Wells-Riley model for airborne disease transmission. We also show that algebraic decay emerges naturally if models are modified to account for the behavioral tendency towards relaxing precautions as the infected fraction decreases. This approach merges for the first time behavioral with physicochemical aspects.(c) 2022 Elsevier B.V. All rights reserved.

Aerosol measurement identifies SARS-CoV 2 PCR positive adults compared with healthy controls.

BACKGROUND: SARS-CoV-2 is spread primarily through droplets and aerosols. Exhaled aerosols are generated in the upper airways through shear stress and in the lung periphery by 'reopening of collapsed airways'. Aerosol measuring may detect highly contagious individuals ("super spreaders or super-emitters") and discriminate between SARS-CoV-2 infected and non-infected individuals. This is the first study comparing exhaled aerosols in SARS-CoV-2 infected individuals and healthy controls. DESIGN: A prospective observational cohort study in 288 adults, comprising 64 patients testing positive by SARS CoV-2 PCR before enrollment, and 224 healthy adults testing negative (matched control sample) at the University Hospital Frankfurt, Germany, from February to June 2021. Study objective was to evaluate the concentration of exhaled aerosols during physiologic breathing in SARS-CoV-2 PCR-positive and -negative subjects. Secondary outcome measures included correlation of aerosol concentration to SARS-CoV-2 PCR results, change in aerosol concentration due to confounders, and correlation between clinical symptoms and aerosol. RESULTS: There was a highly significant difference in respiratory aerosol concentrations between SARS-CoV-2 PCR-positive (median 1490.5/L) and -negative subjects (median 252.0/L; p < 0.0001). There were no significant differences due to age, sex, smoking status, or body mass index. ROC analysis showed an AUC of 0.8918. CONCLUSIONS: Measurements of respiratory aerosols were significantly elevated in SARS-CoV-2 positive individuals, which helps to understand the spread and course of respiratory viral infections, as well as the detection of highly infectious individuals.

Pandemic Simulation and Contact Tracing: Identifying Super Spreaders

In the context of infectious human borne diseases, super spreaders are people who can transmit diseases to a larger number of people than the average person. Medically, it is assumed that one in every five people can be a super spreader. Using graph theory and social network analysis, we have identified these super spreaders in Chennai, given a synthetic dataset with the location history of a particular individual. We have also predicted the spread of the disease. Network graphs have been used to visualise the spread. This aids visualization of the spread of the pandemic and reduces the ion that accompanies statistical data. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Advanced Genetic Methodologies in Tracking Evolution and Spread of SARS-CoV-2.

A newly emerged coronavirus, SARS-CoV-2, caused severe pneumonia outbreaks in China in December 2019 and has since spread to various countries around the world. Here, we describe genetic methods to trace the evolution route and probe the transmission dynamics of this virus.

Contact tracing-induced Allee effect in disease dynamics.

Contact tracing, case isolation, quarantine, social distancing, and other non-pharmaceutical interventions (NPIs) have been a cornerstone in managing the COVID-19 pandemic. However, their effects on disease dynamics are not fully understood. Saturation of contact tracing caused by the increase of infected individuals has been recognized as a crucial variable by healthcare systems worldwide. Here, we model this saturation process with a mechanistic and a phenomenological model and show that it induces an Allee effect which could determine an infection threshold between two alternative states-containment and outbreak. This transition was considered elsewhere as a response to the strength of NPIs, but here we show that they may be also determined by the number of infected individuals. As a consequence, timing of NPIs implementation and relaxation after containment is critical to their effectiveness. Containment strategies such as vaccination or mobility restriction may interact with contact tracing-induced Allee effect. Each strategy in isolation tends to show diminishing returns, with a less than proportional effect of the intervention on disease containment. However, when combined, their suppressing potential is enhanced. Relaxation of NPIs after disease containment--e.g. because vaccination--have to be performed in attention to avoid crossing the infection threshold required to a novel outbreak. The recognition of a contact tracing-induced Allee effect, its interaction with other NPIs and vaccination, and the existence of tipping points contributes to the understanding of several features of disease dynamics and its response to containment interventions. This knowledge may be of relevance for explaining the dynamics of diseases in different regions and, more importantly, as input for guiding the use of NPIs, vaccination campaigns, and its combination for the management of epidemic outbreaks.

SARS/CoV-2: Behavioral Host Manipulation.

INTRODUCTION: Though it has not been extensively studied, host manipulation has been documented for various pathogens. Examples of this phenomenon can be seen in cases of toxoplasmosis, rabies, and the influenza virus. An examination of the possible means by which SARS/CoV-2 alters the behavior of its host to spread among populations is elaborated. Indirect evidence that serves as indicators of this phenomenon is presented. METHODS: This is primarily a theoretical document. Many of the ideas raised are not amenable to direct testing due to ethical concerns. However, several indirect means by which to test the hypothesis are discussed. Primary data from cell phones regarding miles traveled, number of times leaving home, etc., are among the possible indirect measures. RESULTS: The rapid ability of the SARS/CoV-2 virus to spread through society suggests that it may cause behavioral changes of the host to increase its transmission. Numerous cases of super spreader events are noted that have provided meaningful measures of host manipulation. CONCLUSION: In the case of SARS/CoV-2, the largest advantage of the pathogen is likely that between 50% and 70% of those infected are asymptomatic (John's Hopkins Coronavirus Resource Center, John's Hopkins University Corona Virus Resource Center. Available at https://coronavirus.jhu.edu/map.html , 2020). This component is a threat to elderly individuals and those immunocompromised who are more likely to have severe complications from the virus and die. To spread within these groups, a seemingly healthy host is necessary to carry the virus to them. The goal of the virus is not to kill the host, but to survive and reproduce.

Clinical characteristics and outcomes of patients with haematologic malignancies and COVID-19 suggest that prolonged SARS-CoV-2 carriage is an important issue.

Specificities of COVID-19 disease course in patients with haematologic malignancies are still poorly studied. So, we aimed to compare patients with haematologic malignancies to patients without malignancies, matched by sex and age and hospitalised for COVID-19 at the same time and in the same centre. Among 25 patients with haematologic malignancies, we found that mortality (40% versus 4%, p < 0.01), number of days with RT-PCR positivity (21.2 ± 15.9 days [range, 3-57] versus 7.4 ± 5.6 days [range, 1-24], p < 0.01), maximal viral load (mean minimal Ct, 17.2 ± 5.2 [range, 10-30] versus 26.5 ± 5.1 [range, 15-33], p < 0.0001) and the delay between symptom onset and clinical worsening (mean time duration between symptom onset and first day of maximum requirement in inspired oxygen fraction, 14.3 ± 10.7 days versus 9.6 ± 3.7 days, p = 0.0485) were higher than in other patients. COVID-19 course in patients with haematologic malignancies has a delayed onset and is more severe with a higher mortality, and patients may be considered as super-spreaders. Clinicians and intensivists need to be trained to understand the specificity of COVID-19 courses in patients with haematological malignancies.

Estimating the consequences of a COVID-19 super spreader: A stochastic model of a night on the town.

A stochastic model estimated the consequences of a COVID-19 super spreader event occurring in the local municipality of Stavanger, Norway as a result of a night on the town. The model imposed different infection control regulations and compared these different scenarios. For Stavanger's 161 locations of service, secondary transmissions from a super spreader event was estimated to infect a median of 37, requiring the quarantining of 200 guests given no infection control regulations, 23 and 167 when imposing social distancing regulations and other hygienic infection control measures, 7 infected and 63 quarantined guests with restrictions placed on the guest capacity, and 4 infected and 57 quarantined guests with both forms of restriction in use.

First Reported Nosocomial Outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 in a Pediatric Dialysis Unit.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a life-threatening respiratory condition caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was initially detected in China in December 2019. Currently, in Germany >140 000 cases of COVID-19 are confirmed. Here we report a nosocomial outbreak of SARS-CoV-2 infections in the pediatric dialysis unit of the University Hospital Münster (UHM). METHODS: Single-step real-time reverse-transcription polymerase chain reaction (rRT-PCR) from nasopharyngeal swabs was used to diagnose the index patient and identify infected contacts. Epidemiological links were analyzed by patient interviews and medical record reviews. In addition, each contact was assessed for exposure to the index case and monitored for clinical symptoms. Cycle threshold (Ct) values of all positive test results were compared between symptomatic and asymptomatic cases. RESULTS: Forty-eight cases were involved in this nosocomial outbreak. Nine contact cases developed laboratory-confirmed COVID-19 infections. Two SARS-CoV-2-positive cases remained clinically asymptomatic. Eleven cases reported flulike symptoms without positive results. Ct values were significantly lower in cases presenting typical COVID-19 symptoms, suggesting high viral shedding (P = .007). CONCLUSIONS: Person-to-person transmission was at the heart of a hospital outbreak of SARS-CoV-2 between healthcare workers (HCWs) and patients in the pediatric dialysis unit at UHM. Semiquantitative rRT-PCR results suggest that individuals with high viral load pose a risk to spread SARS-CoV-2 in the hospital setting. Our epidemiological observation highlights the need to develop strategies to trace and monitor SARS-CoV-2-infected HCWs to prevent COVID-19 outbreaks in the hospital setting.

Global stability analysis of the role of multi-therapies and non-pharmaceutical treatment protocols for COVID-19 pandemic.

In this paper, we sought and presented an 8-Dimensional deterministic mathematical COVID-19 dynamic model that accounted for the global stability analysis of the role of dual-bilinear treatment protocols of COVID-19 infection. The model, which is characterized by human-to-human transmission mode was investigated using dual non-pharmaceutical (face-masking and social distancing) and dual pharmaceutical (hydroxylchloroquine and azithromycin) as control functions following the interplay of susceptible population and varying infectious population. First, we investigated the model state-space and then established and computed the system reproduction number for both off-treatment ℜ 0 ( 1 ) = 10.94 and for onset-treatment ℜ 0 ( 2 ) = 3.224 . We considered the model for off-treatment and thereafter by incorporating the theory of LaSalle's invariant principle into the classical method of Lyapunov functions, we presented an approach for global stability analysis of COVID-19 dynamics. Numerical verification of system theoretical predictions was computed using in-built Runge-Kutta of order of precision 4 in a Mathcad surface. The set approach produces highly significant results in the main text. For example, while rapid population extinction was observed by the susceptible under off-treatment scenario in the first t f ≤ 18 days, the application of non-pharmaceuticals at early stage of infection proved very effective strategy in curtailing the spread of the virus. Moreso, the implementation of dual pharmacotherapies in conjunction with non-pharmaceuticals yields tremendous rejuvenation of susceptible population ( 0.5 ≤ S p ( t ) ≤ 3.143 c e l l s / m l 3 ) with maximal reduction in the rates of isolation, super spreaders and hospitalization of the infectives. Thus, experimental results of investigation affirm the suitability of proposed model for the control and treatment of the deadly disease provided individuals adheres to treatment protocols.

A super-spreader of SARS-CoV-2 in incubation period among health-care workers.

Since the coronavirus disease 2019 (COVID-19) identified in Wuhan, Hubei, China in December 2019, it has been characterized as a pandemic by World Health Organization (WHO). It was reported that asymptomatic persons are potential sources of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We present an outbreak among health-care workers incited by a doctor who cared a patient with COVID-19 in a Hospital in Wuhan, Hubei, China, which indicates existence of super-spreader even during incubation period.

Drawing transmission graphs for COVID-19 in the perspective of network science.

When we consider a probability distribution about how many COVID-19-infected people will transmit the disease, two points become important. First, there could be super-spreaders in these distributions/networks and second, the Pareto principle could be valid in these distributions/networks regarding estimation that 20% of cases were responsible for 80% of local transmission. When we accept that these two points are valid, the distribution of transmission becomes a discrete Pareto distribution, which is a kind of power law. Having such a transmission distribution, then we can simulate COVID-19 networks and find super-spreaders using the centricity measurements in these networks. In this research, in the first we transformed a transmission distribution of statistics and epidemiology into a transmission network of network science and second we try to determine who the super-spreaders are by using this network and eigenvalue centrality measure. We underline that determination of transmission probability distribution is a very important point in the analysis of the epidemic and determining the precautions to be taken.

Initial Viral Load of a COVID-19-Infected Case Indicated by its Cycle Threshold Value of Polymerase Chain Reaction Could be used as a Predictor of its Transmissibility - An Experience from Gujarat, India.

BACKGROUND: Transmission dynamics of the infectious disease Corona Virus Disease - 19 (COVID-19) is yet to be understood fully. The study aimed at exploring whether quantitative viral load of COVID-19-infected case indicated by cycle threshold (Ct) value of real-time reverse transcription polymerase chain reaction could predict about transmission pattern in the community. MATERIALS AND METHODS: An observational study was conducted involving 1976 individuals, suspected to be suffering from COVID-19 and contacts, of laboratory confirmed cases from selected districts of Gujarat, India. A total of 138 persons were detected to be positive. Weekly positivity showed an overall increasing trend during the studied weeks. It was observed that only 7% had high, 9% as moderate and rest, 84% had low viral load based on Ct values of real-time RT-PCR. RESULTS: Most secondary cases clustered around index cases with high viral load whereas fewer secondary cases clustered around index cases with low viral load. Each index high viral load case transmitted an average of 6.25 secondary cases whereas the same of low viral load transmitted an average of 0.8 case. CONCLUSION: If cases with higher viral load are selectively isolated on detection from the rest of the community along with contact tracing of all individuals, who came in contact with them during the previous 5 days, the quantum of transmission will reduce subsequently. Moreover, health-care workers often get infected while working, probably due to the fact that they often handle cases with higher viral load. The Ct value of all may be provided along with test report to safeguard everybody's health including health-care workers.

Epidemiology and clinical characteristics of 43 COVID-19 patients in Weifang, China.

BACKGROUND: To investigate the epidemiology and clinical characteristics of patients infected with coronavirus disease 2019 (COVID-19) in Weifang, China. METHODS: The demographic data of 43 COVID-19 patients identified in Weifang were used to investigate whether they had traveled to epidemic areas and whether they had close contact with confirmed cases. On admission, patients' symptoms and results of laboratory tests and imaging were analyzed. RESULTS: Among the 43 COVID-19 patients. including 9 third generation infected cases, 16 (37.2%) were imported, who infected the rest. Most cases were middle-aged with approximate sex ratio. A "super spreader", Mr. Zhang made it necessary to quarantine 69 medical personnel. Mr. Zhang directly infected six individuals who, in turn, infected another six individuals. Another patient, Mr. Wang, spread the infection to his five family members at a family gathering. Subsequently, the daughter infected her husband. The most common COVID-19 symptoms were fever, weakness, dry cough, and cough sputum. In most patients, white blood cell counts were not elevated and lymphocyte counts were decreased. Elevated C-reactive protein and serum amyloid A protein (SAA) levels were commonly observed. There was no death among the patients or infection among the medical staff. CONCLUSIONS: The infection by the COVID-19 in Weifang was mostly the result of close contact with imported cases. These circumstances underscore the need to comprehensively strengthen the management for patients to prevent and control the spread of the virus.

Genetic cluster analysis of SARS-CoV-2 and the identification of those responsible for the major outbreaks in various countries.

A newly emerged coronavirus, SARS-CoV-2, caused severe pneumonia outbreaks in China in December 2019 and has since spread to various countries around the world. To trace the evolution route and probe the transmission dynamics of this virus, we performed phylodynamic analysis of 247 high quality genomic sequences available in the GISAID platform as of 5 March 2020. Among them, four genetic clusters, defined as super-spreaders (SSs), could be identified and were found to be responsible for the major outbreaks that subsequently occurred in various countries. SS1 was widely disseminated in Asia and the US, and mainly responsible for outbreaks in the states of Washington and California as well as South Korea, whereas SS4 contributed to the pandemic in Europe. Using the signature mutations of each SS as markers, we further analysed 1539 genome sequences reported after 29 February 2020 and found that 90% of these genomes belonged to SSs, with SS4 being the most dominant. The relative degree of contribution of each SS to the pandemic in different continents was also depicted. Identification of these super-spreaders greatly facilitates development of new strategies to control the transmission of SARS-CoV-2.

Significance of super spreader events in COVID-19.

The number of secondary cases from each primary case determines how fast an epidemic grows. It is known that all cases do not spread the infection equally; super spreaders play an important role as they contribute disproportionately to a much larger number of cases including in the ongoing COVID-19 pandemic. Super spreaders have been reported for more than a century, but limited information is available in scientific literature. An epidemic containment strategy needs to include early identification of super spreaders to limit an explosive growth. Super spreaders tend to get stigmatized, resulting in late reporting and hiding of cases. It is important for program managers to be sensitive to the manner in which related information is shared with media and general public.