MODELING CHOLERA TRANSMISSION UNDER DISEASE CONTROL MEASURES

2020 ◽  
pp. 1-26
Author(s):  
MARGARET BROWN ◽  
MIKO JIANG ◽  
CHAYU YANG ◽  
JIN WANG
Keyword(s):  
Disease Control ◽  
Disease Transmission ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Threshold Dynamics ◽  
Education Programs ◽  
Multiple Control ◽  
Indirect Transmission ◽  
Transmission Pathways ◽  
The Impact

We present a new mathematical model to investigate the transmission dynamics of cholera under disease control measures that include education programs and water sanitation. The model incorporates the impact of education programs into the disease transmission rates and that of water sanitation into the environmental pathogen dynamics. We conduct a detailed analysis to the autonomous system of the model and establish the local and global stabilities of its equilibria that characterize the threshold dynamics of cholera. We then perform an optimal control study on the general model with time-dependent controls and explore effective approaches to implement the education programs and water sanitation while balancing their costs. Our analysis and simulation highlight the complex interaction among the direct and indirect transmission pathways of the disease, the intrinsic growth of the environmental pathogen and the impact of multiple control measures, and their roles in collectively shaping the transmission dynamics of cholera.

scholarly journals Mathematical Modeling of Yellow Fever Transmission Dynamics with Multiple Control Measures

2019 ◽  
pp. 1-15 ◽  
Author(s):  
Tunde T. Yusuf ◽  
David O. Daniel
Keyword(s):  
Yellow Fever ◽  
Disease Transmission ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Equilibrium Solutions ◽  
Multiple Control ◽  
Mosquito Net ◽  
Vector Population ◽  
The World ◽  
Existence And Stability

Yellow-fever disease remains endemic in some parts of the world despite the availability of a potent vaccine and effective treatment for the disease. This necessitates continuous research to possibly eradicate the spread of the disease and its attendant burden. Consequently, a deterministicmodel for Yellow-fever disease transmission dynamics within the human and vector population is considered. The model equilibrium solutions are obtained while the criteria for their existence and stability are investigated. The model is solved numerically using the forth order Runge- Kunta scheme and the results are simulated for different scenarios of interest. Findings from the simulations show that the disease will continue to be prevalent in our society (no matter how small) as long as the immunity conferred by the available vaccine is not lifelong and the Yellowfever infected mosquitoes continue to have unhindered access to humans. Thus, justifying the wisdom behind the practice of continuous vaccination and the use of mosquito net in areas of high Yellow-fever endemicity. However, it was equally found that the magnitude of the Yellowfever outbreak can be remarkably reduced to a negligible level with the adoption of chemical or biological control measures which ensure that only mosquitoes with minimal biting tendency thrive in the environment.

scholarly journals Community Transmission via Indirect Media-To-Person Route: A Missing Link in the Rapid Spread of COVID-19

2021 ◽  
Vol 9 ◽  
Author(s):  
Qunfang Hu ◽  
Lei He ◽  
Ying Zhang
Keyword(s):  
Residential Environment ◽  
Control Measures ◽  
Transmission Route ◽  
Healthcare Facilities ◽  
Indirect Transmission ◽  
Rapid Spread ◽  
Community Transmission ◽  
Transmission Pathways ◽  
The Impact ◽  
Limit Capacity

To prevent the spread of coronavirus disease 2019 (COVID-19), stringent quarantine measures have been implemented so that healthy people and virus carriers have isolated themselves in the same community owing to the limit capacity of healthcare facilities. With the exponential growth of the infected population, the residential environment is contaminated by fomites from the infected residents and consequently threating the health of susceptible residents. Till now, little has been acknowledged on this indirect transmission route and its role on community transmission. Here we address the impact of self-isolated virus carriers on the residential environment and elucidate the potential transmission pathways via contaminated environment in communities. We urge further investigation on the superspreading cases in communities and hope to arouse the attention to evaluate the potential risk of indirect transmission route as well as the corresponding control measures.

scholarly journals The impact of contact structure on infectious disease control: influenza and antiviral agents

2007 ◽  
Vol 135 (7) ◽  
pp. 1124-1132 ◽  
Author(s):  
H.-P. DUERR ◽  
M. SCHWEHM ◽  
C. C. LEARY ◽  
S. J. De Vlas ◽  
M. EICHNER
Keyword(s):  
Disease Control ◽  
Contact Structure ◽  
Influenza Pandemic ◽  
Antiviral Treatment ◽  
Antiviral Agents ◽  
Emerging Infectious Diseases ◽  
Control Measures ◽  
Variable Degree ◽  
Contact Patterns ◽  
The Impact

SUMMARYPlanning adequate public health responses against emerging infectious diseases requires predictive tools to evaluate the impact of candidate intervention strategies. With current interest in pandemic influenza very high, modelling approaches have suggested antiviral treatment combined with targeted prophylaxis as an effective first-line intervention against an emerging influenza pandemic. To investigate how the effectiveness of such interventions depends on contact structure, we simulate the effects in networks with variable degree distributions. The infection attack rate can increase if the number of contacts per person is heterogeneous, implying the existence of high-degree individuals who are potential super-spreaders. The effectiveness of a socially targeted intervention suffers from heterogeneous contact patterns and depends on whether infection is predominantly transmitted to close or casual contacts. Our findings imply that the various contact networks' degree distributions as well as the allocation of contagiousness between close and casual contacts should be examined to identify appropriate strategies of disease control measures.

scholarly journals Serological detection of infection with canine distemper virus, canine parvovirus and canine adenovirus in communal dogs from Zimbabwe

2014 ◽  
Vol 85 (1) ◽  
Author(s):  
Anna McRee ◽  
Rebecca P. Wilkes ◽  
Jessica Dawson ◽  
Roger Parry ◽  
Chris Foggin ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Canine Distemper Virus ◽  
Wildlife Conservation ◽  
Canine Parvovirus ◽  
Control Measures ◽  
Domestic Dogs ◽  
Sub Saharan Africa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Canine Distemper ◽  
The Impact

Domestic dogs are common amongst communities in sub-Saharan Africa and may serve as important reservoirs for infectious agents that may cause diseases in wildlife. Two agents of concern are canine parvovirus (CPV) and canine distemper virus (CDV), which may infect and cause disease in large carnivore species such as African wild dogs and African lions, respectively. The impact of domestic dogs and their diseases on wildlife conservation is increasing in Zimbabwe, necessitating thorough assessment and implementation of control measures. In this study, domestic dogs in north-western Zimbabwe were evaluated for antibodies to CDV, CPV, and canine adenovirus (CAV). These dogs were communal and had no vaccination history. Two hundred and twenty-five blood samples were collected and tested using a commercial enzyme-linked immunosorbent assay (ELISA) for antibodies to CPV, CDV, and CAV. Of these dogs, 75 (34%) had detectable antibodies to CDV, whilst 191 (84%) had antibodies to CPV. Antibodies to canine adenovirus were present in 28 (13%) dogs. Canine parvovirus had high prevalence in all six geographic areas tested. These results indicate that CPV is circulating widely amongst domestic dogs in the region. In addition, CDV is present at high levels. Both pathogens can infect wildlife species. Efforts for conservation of large carnivores in Zimbabwe must address the role of domestic dogs in disease transmission.

scholarly journals The African swine fever control zone in South Africa and its current relevance

2016 ◽  
Vol 83 (1) ◽  
Author(s):  
Noluvuyo R. Magadla ◽  
Wilna Vosloo ◽  
Livio Heath ◽  
Bruce Gummow
Keyword(s):  
South Africa ◽  
Disease Control ◽  
African Swine Fever ◽  
Control Measures ◽  
Maximum Temperature ◽  
Boundary Line ◽  
Control Line ◽  
Control Zone ◽  
Ornithodoros Moubata ◽  
The Impact

African swine fever (ASF) has been reported in South Africa since the early 20th century. The disease has been controlled and confined to northern South Africa over the past 80 years by means of a well-defined boundary line, with strict control measures and movement restrictions north of this line. In 2012, the first outbreak of ASF outside the ASF control zone since 1996 occurred. The objective of this study was to evaluate the current relevance of the ASF control line as a demarcation line between endemic ASF (north) areas and ASF-free (south) area and to determine whether there was a need to realign its trajectory, given the recent outbreaks of ASF, global climate changes and urban development since the line’s inception. A study of ASF determinants was conducted in an area 20 km north and 20 km south of the ASF control line, in Limpopo, Mpumalanga, North West and Gauteng provinces between May 2008 and September 2012. The study confirmed that warthogs, warthog burrows and the soft tick reservoir, Ornithodoros moubata, are present south of the ASF control line, but no virus or viral DNA was detected in these ticks. There appears to be an increasing trend in the diurnal maximum temperature and a decrease in humidity along the line, but the impact of these changes is uncertain. No discernible changes in minimum temperatures and average rainfall along the disease control line were observed between 1992 and 2014. Even though the reservoirs were found south of the ASF boundary line, the study concluded that there was no need to realign the trajectory of the ASF disease control line, with the exception of Limpopo Province. However, the provincial surveillance programmes for the reservoir, vector and ASF virus south of this line needs to be maintained and intensified as changing farming practices may favour the spread of ASF virus beyond the control line.Keywords: African swine fever; warthog burrow; Ornithodoros moubata;control line

scholarly journals Individually Optimal Choices can be Collectively Disastrous in COVID-19 Disease Control

2021 ◽  
Author(s):  
Madison Stoddard ◽  
Debra Van Egeren ◽  
Kaitlyn Johnson ◽  
Smriti Rao ◽  
Josh Furgeson ◽  
...  
Keyword(s):  
Public Health ◽  
Disease Control ◽  
Control Measures ◽  
Disease Spread ◽  
Complete Suppression ◽  
Natural Immunity ◽  
Endemic Disease ◽  
Health Measures ◽  
The Impact

Abstract Background: The word ‘pandemic’ conjures dystopian images of bodies stacked in the streets and societies on the brink of collapse. Despite this frightening picture, denialism and noncompliance with public health measures are common in the historical record, for example during the 1918 Influenza pandemic or the 2015 Ebola epidemic. The unique characteristics of SARS-CoV-2—its high basic reproduction number (R0), time-limited natural immunity and considerable potential for asymptomatic spread—exacerbate the public health repercussions of noncompliance with interventions (such as vaccines and masks) to limit disease transmission. Our work explores the rationality and impact of noncompliance with COVID-19 disease control measures. Methods: In this work, we used game theory to explore when noncompliance confers a perceived benefit to individuals. We then used epidemiological modeling to predict the impact of noncompliance on control of COVID-19, demonstrating that the presence of a noncompliant subpopulation prevents suppression of disease spread. Results: Our modeling demonstrating that noncompliance is a Nash equilibrium under a broad set of conditions, and that the existence of a noncompliant population can result in extensive endemic disease in the long-term after a return to pre-pandemic social and economic activity. Endemic disease poses a threat for both compliant and noncompliant individuals; all community members are protected if complete suppression is achieved, which is only possible with a high degree of compliance. For interventions that are highly effective at preventing disease spread, however, the consequences of noncompliance are borne disproportionately by noncompliant individuals. Conclusions: In sum, our work demonstrates the limits of free-market approaches to compliance with disease control measures during a pandemic. The act of noncompliance with disease intervention measures creates a negative externality, rendering COVID-19 disease control ineffective in the short term and making complete suppression impossible in the long term. Our work underscores the importance of developing effective strategies for prophylaxis through public health measures aimed at complete suppression and the need to focus on compliance at a population level.

Tracking industry responsiveness to COVID-19 – what has happened and what lies ahead

2021 ◽  
Vol 61 (2) ◽  
pp. 442
Author(s):  
Joelle Mitchell ◽  
Derrick O'Keeffe
Keyword(s):  
Disease Transmission ◽  
Management Strategies ◽  
Petroleum Industry ◽  
Initial Response ◽  
Control Measures ◽  
Supply Chain Disruptions ◽  
Infection Control Measures ◽  
Risk Management Strategies ◽  
The Impact ◽  
Offshore Petroleum

This study will provide a longitudinal account of how the Australian offshore petroleum industry has responded to the COVID-19 pandemic, and how the response has evolved over time, and will provide a regulatory perspective on the future challenges arising from the changes that have occurred during the industry in response to the pandemic. Since March 2020, the National Offshore Safety and Environmental Management Authority has been actively collecting information about the approach taken by the offshore petroleum industry to respond to the COVID-19 pandemic. The initial response focused on infectious disease control measures, identifying strategies to prevent disease transmission on offshore facilities and to respond should an outbreak occur offshore. The next phase considered the potential consequences of the infection control measures on facility safety and integrity, including the impact of reduced personnel on board on safety critical maintenance activities and emergency response capability, assurance of competence profile requirements being sustained on facilities, the long-term consequences of delayed routine maintenance, supply chain disruptions and access to specialist workforce. It became apparent that a rapid recovery to pre-COVID-19 conditions was unlikely, and the impacts would likely continue for some time; and psychosocial and fatigue risk management strategies were explored. Data collection methods included: surveys of operators, workplace inspections, review of documents and records, interviews with members of the workforce and participation in industry working groups.

A SATURATED TREATMENT MODEL FOR THE TRANSMISSION DYNAMICS OF RABIES

2019 ◽  
Vol 4 (1) ◽  
pp. 201
Author(s):  
A A Ayoade ◽  
O J Peter ◽  
T A Ayoola ◽  
S Amadiegwu ◽  
A A Victor
Keyword(s):  
Incidence Rate ◽  
Nonlinear Differential Equations ◽  
Viral Disease ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Infectious Agents ◽  
Multiple Control ◽  
Saturated Incidence Rate ◽  
Saturated Incidence ◽  
Saturated Treatment

Rabies is a viral disease that claims about 59 000 lives globally every year. The ignorance of the fact that man can be a carrier of the disease makes every practical and theoretical approach towards the study of the disease a good development. In this work, a mathematical model is designed to incorporate a saturated incidence rate such that the incidence rate is saturated around the infectious agents. The model is studied qualitatively via stability theory of nonlinear differential equations to assess the effects of general awareness, constant vaccination and the saturated treatment on the transmission dynamics of rabies disease. The effective reproduction number is derived and the numerical simulation is carried out to verify the analytical results. It is discovered that while general awareness plays pivotal roles in averting rabies death, multiple control measures have the tendency of driving rabies to extinction.

TRANSMISSION DYNAMICS AND OPTIMAL CONTROL OF AN INFLUENZA MODEL WITH QUARANTINE AND TREATMENT

2012 ◽  
Vol 05 (03) ◽  
pp. 1260011 ◽  
Author(s):  
WEI-WEI SHI ◽  
YUAN-SHUN TAN
Keyword(s):  
Optimal Control ◽  
Disease Transmission ◽  
Reproduction Number ◽  
Influenza Pandemic ◽  
Control Measures ◽  
Globally Asymptotically Stable ◽  
Number Formula ◽  
Parameter Values ◽  
The Impact ◽  
Disease Free

We develop an influenza pandemic model with quarantine and treatment, and analyze the dynamics of the model. Analytical results of the model show that, if basic reproduction number [Formula: see text], the disease-free equilibrium (DFE) is globally asymptotically stable, if [Formula: see text], the disease is uniformly persistent. The model is then extended to assess the impact of three anti-influenza control measures, precaution, quarantine and treatment, by re-formulating the model as an optimal control problem. We focus primarily on controlling disease with a possible minimal the systemic cost. Pontryagin's maximum principle is used to characterize the optimal levels of the three controls. Numerical simulations of the optimality system, using a set of reasonable parameter values, indicate that the precaution measure is more effective in reducing disease transmission than the other two control measures. The precaution measure should be emphasized.

scholarly journals Measles in developing countries. Part II. The predicted impact of mass vaccination

1988 ◽  
Vol 100 (3) ◽  
pp. 419-442 ◽  
Author(s):  
A. R. Mclean ◽  
R. M. Anderson
Keyword(s):  
Developing Countries ◽  
Measles Virus ◽  
Age Distribution ◽  
Case Fatality ◽  
Mass Vaccination ◽  
Control Measures ◽  
Transmission Dynamics ◽  
Practical Significance ◽  
Epidemic Period ◽  
The Impact

SummaryA mathematical model is developed to mimic the transmission dynamics of the measles virus in communities in the developing world with high population growth rates and high case fatality rates. The model is used to compare the impacts of different mass vaccination programmes upon morbidity and mortality arising from infection by measles virus. Analyses identify three conclusions of practical significance to the design of optimal vaccination programmes. First, there is no single optimum age at which to vaccinate children for all urban and rural communities in developing countries. For a given community the best age at which to vaccinate depends critically on the age distribution of cases of infection prior to the introduction of control measures. Second, numerical studies predict that the introduction of mass vaccination will induce a temporary phase of very low incidence of infection before the system settles to a new pattern of recurrent epidemics. Mass vaccination acts to lengthen the inter-epidemic period in the postvaccination period when compared with that prevailing prior to control. Third, numerical simulations suggest that two-phase and two-stage vaccination programmes are of less benefit than one-stage programmes (achieving comparable coverage) aimed at young children. The paper ends with a discussion of the needs for: improved programmes of data collection; monitoring of the impact of current vaccination programmes; and the development of models that take account of viral transmission dynamics, host demography and economic factors.

Sign in / Sign up

Export Citation Format

Share Document