Estimation of the percentages of asymptomatic patients and undiagnosed patients of the novel coronavirus (SARS-CoV-2) infection in Hokkaido, Japan by using birth-death process with recursive full tracing

Abstract Background The novel Coronavirus SARS CoV-2 (COVID-19) outbreak was complicated by the lack of diagnostic testing kits. In early March 2020, leadership at Beaumont Hospital, Royal Oak Michigan (Beaumont) identified the need to develop high capacity testing modalities with appropriate sensitivity and specificity and rapid turnaround time. We describe the molecular diagnostic testing experience since initial rollout on March 16, 2020 at Beaumont, and results of repeat testing during the peak of the COVID-19 pandemic in MI. Methods Beaumont is an 1100 bed hospital in Southeast MI. In March, testing was initially performed with the EUA Luminex NxTAG CoV Extended Panel until March 28, 2020 when testing was converted to the EUA Cepheid Xpert Xpress SARS-CoV-2 for quicker turnaround times. Each assay was validated with a combination of patient samples and contrived specimens. Results During the initial week of testing there was > 20 % specimen positivity. As the prevalence grew the positivity rate reached 68% by the end of March (Figure 1). Many state and hospital initiatives were implemented during the outbreak, including social distancing and screening of asymptomatic patients to increase case-finding and prevent transmission. We also adopted a process for clinical review of symptomatic patients who initially tested negative for SARS-CoV-2 by a group of infectious disease physicians (Figure 2). This process was expanded to include other trained clinicians who were redeployed from other departments in the hospital. Repeat testing was performed to allow consideration of discontinuation of isolation precautions. During the surge of community cases from March 16 to April 30, 2020, we identified patients with negative PCR tests who subsequently had repeat testing based on clinical evaluation, with 7.1% (39/551) returning positive for SARS- CoV2. Of the patients who expired due to COVID-19 during this period, 4.3% (9/206) initially tested negative before ultimately testing positive. Figure 1 BH RO testing Epicurve Figure 2: Screening tool for repeat COVID19 testing and precautions Conclusion Many state and hospital initiatives helped us flatten the curve for COVID-19. Our hospital testing experience indicate that repeat testing may be warranted for those patients with clinical features suggestive of COVID-19. We will further analyze these cases and clinical features that prompted repeat testing. Disclosures All Authors: No reported disclosures

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Approximating Quasistationary Distributions of Birth–Death Processes

Journal of Applied Probability ◽

10.1239/jap/1354716656 ◽

2012 ◽

Vol 49 (4) ◽

pp. 1036-1051 ◽

Cited By ~ 7

Author(s):

Damian Clancy

Keyword(s):

State Space ◽

Population Biology ◽

Sufficient Conditions ◽

Convergence Result ◽

The State ◽

Death Process ◽

Sis Model ◽

Finite State ◽

Quasistationary Distributions ◽

Birth Death

For a sequence of finite state space birth–death processes, each having a single absorbing state, we show that, under certain conditions, as the size of the state space tends to infinity, the quasistationary distributions converge to the stationary distribution of a limiting infinite state space birth–death process. This generalizes a result of Keilson and Ramaswamy by allowing birth and death rates to depend upon the size of the state space. We give sufficient conditions under which the convergence result of Keilson and Ramaswamy remains valid. The generalization allows us to apply our convergence result to examples from population biology: a Pearl–Verhulst logistic population growth model and the susceptible-infective-susceptible (SIS) model for infectious spread. The limit distributions obtained suggest new finite-population approximations to the quasistationary distributions of these models, obtained by the method of cumulant closure. The new approximations are found to be both simple in form and accurate.

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Hypogeusia as the initial presenting symptom of COVID-19

BMJ Case Reports ◽

10.1136/bcr-2020-236080 ◽

2020 ◽

Vol 13 (5) ◽

pp. e236080 ◽

Cited By ~ 8

Author(s):

Lauren E Melley ◽

Eli Bress ◽

Erik Polan

Keyword(s):

Cardiopulmonary Arrest ◽

General Medicine ◽

Initial Symptom ◽

The Novel ◽

Severe Respiratory Distress ◽

Upper Respiratory Infection ◽

Respiratory Involvement ◽

Asymptomatic Patients ◽

Flavour Perception ◽

Novel Coronavirus

COVID-19 is the disease caused by the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which first arose in Wuhan, China, in December 2019 and has since been declared a pandemic. The clinical sequelae vary from mild, self-limiting upper respiratory infection symptoms to severe respiratory distress, acute cardiopulmonary arrest and death. Otolaryngologists around the globe have reported a significant number of mild or otherwise asymptomatic patients with COVID-19 presenting with olfactory dysfunction. We present a case of COVID-19 resulting in intensive care unit (ICU) admission, presenting with the initial symptom of disrupted taste and flavour perception prior to respiratory involvement. After 4 days in the ICU and 6 days on the general medicine floor, our patient regained a majority of her sense of smell and was discharged with only lingering dysgeusia. In this paper, we review existing literature and the clinical course of SARS-CoV-2 in relation to the reported symptoms of hyposmia, hypogeusia and dysgeusia.

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The Impact of COVID-19 Crisis upon the Consumer Buying Behavior of Fresh Vegetables Directly from Local Producers. Case Study: The Quarantined Area of Suceava County, Romania

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17155485 ◽

2020 ◽

Vol 17 (15) ◽

pp. 5485 ◽

Cited By ~ 6

Author(s):

Alina Butu ◽

Ioan Sebastian Brumă ◽

Lucian Tanasă ◽

Steliana Rodino ◽

Codrin Dinu Vasiliu ◽

...

Keyword(s):

Sociodemographic Factors ◽

The State ◽

Buying Behavior ◽

State Of Emergency ◽

Purchasing Intention ◽

Starting Point ◽

Fresh Vegetables ◽

Before And After ◽

The Impact ◽

Consumer Buying Behavior

The present paper intends to address the impact of COVID-19 crisis upon the consumer buying behavior of fresh vegetables directly from local producers as observed 30 days later, after enforcing the state of emergency in Romania within a well-defined area, namely, the quarantined area of Suceava. The study relies on the interpretation of answers received from the quarantined area (N = 257) to a questionnaire applied online nationwide. The starting point of this paper is the analysis of the sociodemographic factors on the purchasing decision of fresh vegetables directly from local producers before declaring the state of emergency in Romania (16 March 2020). Further research has been conducted by interpreting the changes triggered by the COVID-19 crisis on the purchasing intention of such products before and after the end of the respective crisis. The aim of this scientific investigation relies on identifying the methods by which these behavioral changes can influence the digital transformation of short food supply chains.

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Evaluation of the decay parameter for some specialized birth-death processes

Journal of Applied Probability ◽

10.2307/3214712 ◽

1992 ◽

Vol 29 (4) ◽

pp. 781-791 ◽

Cited By ~ 19

Author(s):

Masaaki Kijima

Keyword(s):

State Space ◽

Stationary Distribution ◽

The State ◽

Death Process ◽

Decay Parameter ◽

Speed Of Convergence ◽

Tridiagonal Matrices ◽

Decay Parameters ◽

Quasi Stationary Distribution ◽

Birth Death

Let N(t) be an exponentially ergodic birth-death process on the state space {0, 1, 2, ···} governed by the parameters {λn, μn}, where µ0 = 0, such that λn = λ and μn = μ for all n ≧ N, N ≧ 1, with λ < μ. In this paper, we develop an algorithm to determine the decay parameter of such a specialized exponentially ergodic birth-death process, based on van Doorn's representation (1987) of eigenvalues of sign-symmetric tridiagonal matrices. The decay parameter is important since it is indicative of the speed of convergence to ergodicity. Some comparability results for the decay parameters are given, followed by the discussion for the decay parameter of a birth-death process governed by the parameters such that limn→∞λn = λ and limn→∞µn = μ. The algorithm is also shown to be a useful tool to determine the quasi-stationary distribution, i.e. the limiting distribution conditioned to stay in {1, 2, ···}, of such specialized birth-death processes.

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Approximating Quasistationary Distributions of Birth–Death Processes

Journal of Applied Probability ◽

10.1017/s0021900200012869 ◽

2012 ◽

Vol 49 (04) ◽

pp. 1036-1051

Author(s):

Damian Clancy

Keyword(s):

State Space ◽

Population Biology ◽

Sufficient Conditions ◽

Convergence Result ◽

The State ◽

Death Process ◽

Sis Model ◽

Finite State ◽

Quasistationary Distributions ◽

Birth Death

For a sequence of finite state space birth–death processes, each having a single absorbing state, we show that, under certain conditions, as the size of the state space tends to infinity, the quasistationary distributions converge to the stationary distribution of a limiting infinite state space birth–death process. This generalizes a result of Keilson and Ramaswamy by allowing birth and death rates to depend upon the size of the state space. We give sufficient conditions under which the convergence result of Keilson and Ramaswamy remains valid. The generalization allows us to apply our convergence result to examples from population biology: a Pearl–Verhulst logistic population growth model and the susceptible-infective-susceptible (SIS) model for infectious spread. The limit distributions obtained suggest new finite-population approximations to the quasistationary distributions of these models, obtained by the method of cumulant closure. The new approximations are found to be both simple in form and accurate.

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COVID-19, mobility and self-isolation. Experiences of the Serbia’s citizens in the times of global pandemic

Sociologija ◽

10.2298/soc2004467p ◽

2020 ◽

Vol 62 (4) ◽

pp. 467-485

Author(s):

Jelena Pesic

Keyword(s):

Online Survey ◽

The State ◽

Sociological Research ◽

State Of Emergency ◽

Health Crisis ◽

Global Pandemic ◽

Public Media ◽

Before And After ◽

The Times ◽

The Given

The COVID-19 pandemic caused by the SARS-Cov-2 virus and closing the state borders across the world led to the mass return of the citizens of Serbia immediately before and after the declaration of the state of emergency in March 2020. The measure of placing under health supervision and the obligation of self-isolation, were the key means of mobility management in the situation of the health crisis in Serbia. How were the given measures implemented? How did they affect the citizens who returned to the country? What resources did they have at their disposal and in what way did they meet their basic needs during self-isolation? How was their experience of self-isolation shaped by public media perceptions of diaspora by representatives of the authorities and by their own social environment during the state of emergency? The aim of this paper is to answer these questions relying on the results of the online survey of 305 returnees, conducted during April and May 2020 by the researchers from the Institute for Sociological Research of the Faculty of Philosophy in Belgrade.

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The Life of a Simulation Center in the Era of the Novel Coronavirus Infection Pandemic

Virtual Technologies in Medicine ◽

10.46594/2687-0037_2021_3_1326 ◽

2021 ◽

Vol 1 (3) ◽

pp. 128-129

Author(s):

S. V. Khodus ◽

V. S. Oleksik

Keyword(s):

Simulation Training ◽

The Novel ◽

Test Task ◽

Before And After ◽

Simulation Scenario ◽

Coronavirus Infection ◽

Novel Coronavirus ◽

Simulation Center

A study was carried out among 76 students who took part in the Olympiad contests in practical medical skills in an innovative distance format. The data obtained testify to the effectiveness of distance simulation training, the assessment of which was carried out by students answering test questions before and after passing the test task, as well as by assessing the students' actions during the remote passage of the simulation scenario by experts.

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