scholarly journals Impacts of social distancing on the spread of infectious diseases with asymptomatic infection: A mathematical model

2021 ◽  
Vol 398 ◽  
pp. 125983
Author(s):  
He Huang ◽  
Yahong Chen ◽  
Zhijun Yan
Keyword(s):  
Mathematical Model ◽  
Infectious Diseases ◽  
Asymptomatic Infection ◽  
Social Distancing

scholarly journals Quantifying the contribution of asymptomatic infection to the cumulative incidence

2017 ◽  
Vol 145 (6) ◽  
pp. 1256-1258 ◽  
Author(s):  
D. CHAMPREDON ◽  
S. M. MOGHADAS
Keyword(s):  
Mathematical Model ◽  
Infectious Diseases ◽  
Cumulative Incidence ◽  
Analytical Formula ◽  
Asymptomatic Infection ◽  
Simple Analytical Formula

SUMMARYMany infectious diseases in humans may manifest with no or mild symptoms. While numerous studies have estimated the proportion of infectious individuals in whom symptoms are absent during the entire course of infection, the contribution of asymptomatic cases to the overall cumulative incidence is difficult to untangle. Here, with a mathematical model, we provide a simple analytical formula to quantify this contribution and highlight the potential for large errors that can arise when naively estimating it.

scholarly journals Addressing the COVID-19 transmission in inner Brazil by a mathematical model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. B. Almeida ◽  
T. N. Vilches ◽  
C. P. Ferreira ◽  
C. M. C. B. Fortaleza
Keyword(s):  
Mathematical Model ◽  
Disease Transmission ◽  
Abiotic Factors ◽  
Severe Pneumonia ◽  
Mitigation Strategies ◽  
Social Distancing ◽  
Control Disease ◽  
Set Up ◽  
Novel Coronavirus ◽  
Public Health Strategies

AbstractIn 2020, the world experienced its very first pandemic of the globalized era. A novel coronavirus, SARS-CoV-2, is the causative agent of severe pneumonia and has rapidly spread through many nations, crashing health systems and leading a large number of people to death. In Brazil, the emergence of local epidemics in major metropolitan areas has always been a concern. In a vast and heterogeneous country, with regional disparities and climate diversity, several factors can modulate the dynamics of COVID-19. What should be the scenario for inner Brazil, and what can we do to control infection transmission in each of these locations? Here, a mathematical model is proposed to simulate disease transmission among individuals in several scenarios, differing by abiotic factors, social-economic factors, and effectiveness of mitigation strategies. The disease control relies on keeping all individuals’ social distancing and detecting, followed by isolating, infected ones. The model reinforces social distancing as the most efficient method to control disease transmission. Moreover, it also shows that improving the detection and isolation of infected individuals can loosen this mitigation strategy. Finally, the effectiveness of control may be different across the country, and understanding it can help set up public health strategies.

scholarly journals Impact of early detection and vaccination strategy in COVID-19 eradication program in Jakarta, Indonesia

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dipo Aldila ◽  
Brenda M. Samiadji ◽  
Gracia M. Simorangkir ◽  
Sarbaz H. A. Khosnaw ◽  
Muhammad Shahzad
Keyword(s):  
Mathematical Model ◽  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Vaccination Strategy ◽  
Vaccination Rate ◽  
Rapid Testing ◽  
Social Distancing ◽  
Rapid Spread ◽  
Vaccine Potential ◽  
The Basic Reproduction Number

Abstract Objective Several essential factors have played a crucial role in the spreading mechanism of COVID-19 (Coronavirus disease 2019) in the human population. These factors include undetected cases, asymptomatic cases, and several non-pharmaceutical interventions. Because of the rapid spread of COVID-19 worldwide, understanding the significance of these factors is crucial in determining whether COVID-19 will be eradicated or persist in the population. Hence, in this study, we establish a new mathematical model to predict the spread of COVID-19 considering mentioned factors. Results Infection detection and vaccination have the potential to eradicate COVID-19 from Jakarta. From the sensitivity analysis, we find that rapid testing is crucial in reducing the basic reproduction number when COVID-19 is endemic in the population rather than contact trace. Furthermore, our results indicate that a vaccination strategy has the potential to relax social distancing rules, while maintaining the basic reproduction number at the minimum possible, and also eradicate COVID-19 from the population with a higher vaccination rate. In conclusion, our model proposed a mathematical model that can be used by Jakarta’s government to relax social distancing policy by relying on future COVID-19 vaccine potential.

The Basics of Microbiology

2021 ◽  
Author(s):  
Werner Solbach
Keyword(s):  
Infectious Diseases ◽  
Defense Mechanisms ◽  
Wide Spectrum ◽  
Severe Disease ◽  
Laboratory Diagnosis ◽  
Asymptomatic Infection ◽  
The Body ◽  
Sufficient Evidence ◽  
Effective Measure ◽  
Hygiene Measures

Microorganisms constitute 70 percent of the biomass on Planet Earth. Comparatively few species are adapted to colonize human surfaces and form a complex Meta-Organism with manyfold mutual benefits. Occasionally, microorganisms may overcome the barriers of the skin and mucosal surfaces and may multiply locally or in multiple sites inside the body. This process is called infection. Infections can be caused by bacteria, viruses, parasites, helminths, and fungi. Immediately after infection, numerous defense mechanisms of the immune system are activated to combat replication of the microbes. There is a balance between microorganism and human defense mechanisms, which may lead to either asymptomatic infection or result in a wide spectrum of symptoms from mild to severe disease and even death. The most important factors in the diagnosis of infectious diseases are a careful history, physical examination and the appropriate collection of body fluids and tissues. Laboratory diagnosis requires between 2 and 72 hours. Wherever possible, antibiotics should only be used when sufficient evidence of efficacy is available. Then, however, they should be used as early as possible and in high doses. In addition to everyday hygiene measures, vaccination is the most effective measure to prevent infectious diseases.

scholarly journals Evaluating the effectiveness of social distancing interventions against COVID-19

2020 ◽  
Author(s):  
Laura Matrajt ◽  
Tiffany Leung
Keyword(s):  
Mathematical Model ◽  
Contact Tracing ◽  
Old Adults ◽  
Social Distancing ◽  
The Us

AbstractSARS-CoV-2 has infected over 140,000 people as of March 14, 2020. We use a mathematical model to investigate the effectiveness of social distancing interventions lasting six weeks in a middle-sized city in the US. We explore four social distancing strategies by reducing the contacts of adults over 60 years old, adults over 60 years old and children, all adults (25, 75 or 95% compliance), and everyone in the population. Our results suggest that social distancing interventions can avert cases by 20% and hospitalizations and deaths by 90% even with modest compliance within adults as long as the intervention is kept in place, but the epidemic is set to rebound once the intervention is lifted. Our models suggest that social distancing interventions will buy crucial time but need to occur in conjunction with testing and contact tracing of all suspected cases to mitigate transmission of SARS-CoV-2.

scholarly journals Quantifying the impact of social groups and vaccination on inequalities in infectious diseases using a mathematical model

BMC Medicine ◽  
2018 ◽  
Vol 16 (1) ◽  
Author(s):  
James D. Munday ◽  
Albert Jan van Hoek ◽  
W. John Edmunds ◽  
Katherine E. Atkins
Keyword(s):  
Mathematical Model ◽  
Infectious Diseases ◽  
Social Groups ◽  
The Impact

Contagion

2020 ◽  
pp. 72-95
Author(s):  
Mark Davis ◽  
Davina Lohm
Keyword(s):  
Infectious Diseases ◽  
Social Distance ◽  
The Self ◽  
The Other ◽  
Social Distancing ◽  
Research Participants ◽  
The Social

Contagion is an age-old method of signifying infectious diseases like influenza and is a rich metaphor with strong biopolitical connotations for understandings of social distance, that is, the self as distinct from the other in the sense of space and identity. Contagion is therefore an important metaphor for the social distancing approaches recommended by experts during a pandemic, as was the case in 2009. This chapter, therefore, examines how research participants enacted social distancing as a method for reducing risk. It reflects on how these narratives reflected the meanings of contagion linked with distance, in particular, the notion that threat emerges elsewhere and in the figure of the other.

scholarly journals Evaluating the Effectiveness of COVID-19 Bluetooth-Based Smartphone Contact Tracing Applications

2020 ◽  
Vol 10 (20) ◽  
pp. 7113 ◽  
Author(s):  
Enrique Hernández-Orallo ◽  
Carlos T. Calafate ◽  
Juan-Carlos Cano ◽  
Pietro Manzoni
Keyword(s):  
Infectious Diseases ◽  
Epidemic Model ◽  
Contact Tracing ◽  
Reproductive Number ◽  
Smartphone Applications ◽  
Social Distancing ◽  
Implementation Model ◽  
Decentralized Model ◽  
Centralized Model

One of the strategies to control the spread of infectious diseases is based on the use of specialized applications for smartphones. These apps offer the possibility, once individuals are detected to be infected, to trace their previous contacts in order to test and detect new possibly-infected individuals. This paper evaluates the effectiveness of recently developed contact tracing smartphone applications for COVID-19 that rely on Bluetooth to detect contacts. We study how these applications work in order to model the main aspects that can affect their performance: precision, utilization, tracing speed and implementation model (centralized vs. decentralized). Then, we propose an epidemic model to evaluate their efficiency in terms of controlling future outbreaks and the effort required (e.g., individuals quarantined). Our results show that smartphone contact tracing can only be effective when combined with other mild measures that can slightly reduce the reproductive number R0 (for example, social distancing). Furthermore, we have found that a centralized model is much more effective, requiring an application utilization percentage of about 50% to control an outbreak. On the contrary, a decentralized model would require a higher utilization to be effective.

Dynamics between infectious diseases with two susceptibility conditions: A mathematical model.

2019 ◽  
Vol 309 ◽  
pp. 66-77 ◽  
Author(s):  
J.P. Gutiérrez-Jara ◽  
F.D. Córdova-Lepe ◽  
M.T. Muñoz-Quezada
Keyword(s):  
Mathematical Model ◽  
Infectious Diseases

INFLUENCE OF ASYMPTOMATIC PEOPLE ON MALARIA TRANSMISSION: A MATHEMATICAL MODEL FOR A LOW-TRANSMISSION AREA CASE

2020 ◽  
Vol 28 (01) ◽  
pp. 167-182
Author(s):  
IULIA MARTINA BULAI ◽  
STÉPHANIE DEPICKÈRE ◽  
VITOR HIRATA SANCHES
Keyword(s):  
Mathematical Model ◽  
Mortality Rate ◽  
Malaria Transmission ◽  
Equilibrium Points ◽  
Asymptomatic Infection ◽  
Human Populations ◽  
High Morbidity ◽  
Low Transmission ◽  
Transmission Area ◽  
Using Data

Malaria remains a primary parasitic disease in the tropical world, generating high morbidity and mortality in human populations. Recently, community surveys showed a high proportion of asymptomatic cases, which are characterized by a low parasitemia and a lack of malaria symptoms. Until now, the asymptomatic population is not treated for malaria and thus remains infective for a long time. In this paper, we introduce a four-dimensional mathematical model to study the influence of asymptomatic people on malaria transmission in low-transmission areas, specifically using data from Brazil. The equilibrium points of the system are calculated, and their stability is analyzed. Via numerical simulations, more in-depth analyzes of the space of some crucial parameters on the asymptomatic population are done, such as the per capita recovery rates of symptomatic and asymptomatic people, the ratio of the density of mosquitoes to that of humans, the mortality rate of mosquitoes and the probability of undergoing asymptomatic infection upon an infectious mosquito bite. Our results indicate that the disease-free equilibrium is inside the stability region if asymptomatic people are treated and/or the ratio of the density of mosquitoes to that of humans is decreased and/or the mortality rate of mosquitoes is increased.

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