scholarly journals Optimal Strategies for Dengue Prevention and Control during Daily Commuting between Two Residential Areas

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 197 ◽  
Author(s):  
Daniel Lasluisa ◽  
Edwin Barrios ◽  
Olga Vasilieva
Keyword(s):  
Optimal Strategies ◽  
Control Measures ◽  
Transmission Model ◽  
Human Populations ◽  
Personal Protection ◽  
Residential Areas ◽  
Protection Measures ◽  
Infected People ◽  
Mosquito Nets ◽  
Dengue Prevention

: In this paper, we report an application for the mathematical theory of dynamic optimization for design of optimal strategies that account for daily commuting of human residents, aiming to reduce vector-borne infections (dengue) among human populations. Our analysis is based on a two-patch dengue transmission model amended with control variables that represent personal protection measures aimed at reduction of the number of contacts between mosquitoes and human hosts (e.g., the use of repellents, mosquito nets, or insecticide-treated clothing). As a result, we have proposed and numerically solved an optimal control problem to minimize the costs associated with the application of control measures, while also minimizing the total number of dengue-infected people in both residential areas. Our principal goal was to identify an optimal strategy for personal protection that renders the maximal number of averted human infections per unit of invested cost, and this goal has been accomplished on the grounds of cost-effectiveness analysis.

scholarly journals Risk estimation and prediction by modeling the transmission of the novel coronavirus (COVID-19) in mainland China excluding Hubei province

2020 ◽  
Author(s):  
Hui Wan ◽  
Jing-an Cui ◽  
Guo-jing Yang
Keyword(s):  
Mainland China ◽  
Hubei Province ◽  
Control Measures ◽  
Contact Tracing ◽  
Published Data ◽  
Chinese Government ◽  
Personal Protection ◽  
Protection Measures ◽  
Reproduction Ratio ◽  
Self Protection

AbstractBackgroundIn December 2019, an outbreak of coronavirus disease (COVID-19) was identified in Wuhan, China and, later on, detected in other parts of China. Our aim is to evaluate the effectiveness of the evolution of interventions and self-protection measures, estimate the risk of partial lifting control measures and predict the epidemic trend of the virus in mainland China excluding Hubei province based on the published data and a novel mathematical model.MethodsA novel COVID-19 transmission dynamic model incorporating the intervention measures implemented in China is proposed. COVID-19 daily data of mainland China excluding Hubei province, including the cumulative confirmed cases, the cumulative deaths, newly confirmed cases and the cumulative recovered cases for the period January 20th-March 3rd, 2020, were archived from the National Health Commission of China (NHCC). We parameterize the model by using the Markov Chain Monte Carlo (MCMC) method and estimate the control reproduction number Rc, as well as the effective daily reproduction ratio Re(t), of the disease transmission in mainland China excluding Hubei province.ResultsThe estimation outcomes indicate that Rc is 3.36 (95% CI 3.20-3.64) and Re(t) has dropped below 1 since January 31st, 2020, which implies that the containment strategies implemented by the Chinese government in mainland China excluding Hubei province are indeed effective and magnificently suppressed COVID-19 transmission. Moreover, our results show that relieving personal protection too early may lead to the spread of disease for a longer time and more people would be infected, and may even cause epidemic or outbreak again. By calculating the effective reproduction ratio, we prove that the contact rate should be kept at least less than 30% of the normal level by April, 2020.ConclusionsTo ensure the epidemic ending rapidly, it is necessary to maintain the current integrated restrict interventions and self-protection measures, including travel restriction, quarantine of entry, contact tracing followed by quarantine and isolation and reduction of contact, like wearing masks, etc. People should be fully aware of the real-time epidemic situation and keep sufficient personal protection until April. If all the above conditions are met, the outbreak is expected to be ended by April in mainland China apart from Hubei province.

scholarly journals The Transmission Dynamic of the COVID 19 Outbreak: A Predictive Dashboard

2021 ◽  
Vol 50 (11) ◽  
pp. 3439-3453
Author(s):  
Muhammad Fahmi Bin Ahmad Zuber ◽  
Norhayati Rosli ◽  
Noryanti Muhammad
Keyword(s):  
Standard Operating Procedure ◽  
Control Measures ◽  
World Health ◽  
Transmission Model ◽  
Health Economy ◽  
Economic Point ◽  
Social Distancing ◽  
Infected People ◽  
Infected Case ◽  
The World

COVID 19 outbreak gives a great impact worldwide. The disaster of this pandemic has resulted in a large number of human lives being lost. As all countries implemented quarantine and social distancing, the great lockdown all over the world lead to multiple crises including health, economy, financial, and collapse in industrial and educational activities. Movement Control Order (MCO) and social distancing which have been implemented as control measures in Malaysia also affected many sectors. The landscape now has successfully reduced the number of infected people. However, from the economic point of view, the Retail Group Malaysia (RGM) has projected the country’s retail industry suffers a negative growth rate for the first time in 22 years. If the epidemic continues, society will reach an impasse, a time when the lockdown will become more than some of them can tolerate. As recognized by the World Health Organization (WHO), modelling the outbreak based on the prior input data is more appropriate than the ‘risk of bias’ for decision-makers. Thus, this research is conducted to model the outbreak of the disease using the susceptible-infected-recovery-death (SIRD) compartmental model accompanying with the varying infection rate due to changes in MCO measures. The model assumes under the unavailability of the vaccine, recovered people can be reinfected. The epidemic parameters and reproduction numbers are estimated and fitted from the transmission model to the actual data using the Monte Carlo Markov Chain (MCMC) of Metropolis-Hasting. The model is solved using a numerical algorithm of the Runge-Kutta method. The predictive dashboard of a graphical user interface (GUI) is developed, hence monitoring and predicting the outbreak under the control measures of the two different types of MCO scenarios (which are called constant and alternate scenarios) can be performed. GUI for the dynamic transmission of the COVID 19 provides insight for the future outbreak, hence may help the respective stakeholders to propose the best policy of a new norm for all sectors. From the GUI, we can see that, when no or loose MCO is implemented or compliance of the public to the COVID 19 standard operating procedure (SOP), the infected case will increase rapidly up to 7.5 million. With strict MCO regulation or public obedient to the SOP, the infected case will decrease rapidly, but even after a long period of strict regulation, once the quarantine is stopped, the infected case will rise again. An alternative MCO scenario is suggested where a cyclic pattern of strict and loose MCO regulation is upheld, and it shows to flatten the curve while allow periods of less restricted lifestyle. This can be one of the alternatives to balance the life and livelihood.

Knowledge and Awareness of Dengue Fever

2018 ◽  
pp. 219-222
Author(s):  
Y. Arockia Suganthi ◽  
Chitra K. ◽  
J. Magelin Mary
Keyword(s):  
Dengue Fever ◽  
Prevention And Control ◽  
Control Measures ◽  
Infection Transmission ◽  
Standard Guideline ◽  
The World ◽  
Different Types ◽  
Prevention And Control Measures ◽  
Dengue Prevention ◽  
And Control

Dengue fever is a painful mosquito-borne infection caused by different types of virus in various localities of the world. There is no particular medicine or vaccine to treat person suffering from dengue fever. Dengue viruses are transmitted by the bite of female Aedes (Ae) mosquitoes. Dengue fever viruses are mainly transmitted by Aedes which can be active in tropical or subtropical climates. Aedes Aegypti is the key step to avoid infection transmission to save millions of people in all over the world. This paper provides a standard guideline in the planning of dengue prevention and control measures. At the same time gives the priorities including clinical management and hospitalized dengue patients have to address essentially.

Eye in COVID-19: A Brief Review

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Muhammad Mohsin Ali ◽  
Qudsia Anwar Dar ◽  
Zahid Kamal ◽  
Alishba Khan
Keyword(s):  
Infection Control ◽  
Respiratory Symptoms ◽  
Literature Search ◽  
Control Measures ◽  
Transmission Route ◽  
Ocular Manifestation ◽  
Personal Protection ◽  
Personal Protection Equipment ◽  
Ocular Manifestations ◽  
Infection Control Measures

This is a brief review covering the currently available literature on ocular manifestations of COVID-19, andprevention strategies for ophthalmologists. A literature search was carried out of Pubmed, Google Scholar andWHO database of publications on COVID. Keywords used in the search were eye, ocular manifestations,ophthalmology, COVID-19, nCoV-2019, and coronavirus disease. All available articles were reviewed and thosepertinent to the study topic were included. Considering the dearth of information available, ophthalmology journals were also searched separately for relevant articles. Major ocular manifestation of COVID reported in literature is red eye, which usually presents before the onset of respiratory symptoms. Since the eye can be a possible transmission route for SARS-CoV-2, infection control measures should be undertaken by ophthalmologists, including use of personal protection equipment and eye/face covering. A framework for structuring ophthalmological services during the COVID pandemic is also presented in this review.

scholarly journals High COVID-19 transmission potential associated with re-opening universities can be mitigated with layered interventions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ellen Brooks-Pollock ◽  
Hannah Christensen ◽  
Adam Trickey ◽  
Gibran Hemani ◽  
Emily Nixon ◽  
...  
Keyword(s):  
Prediction Interval ◽  
Mitigation Strategies ◽  
Control Measures ◽  
Transmission Model ◽  
Model Parameters ◽  
Infection Rates ◽  
First Year Students ◽  
Transmission Potential ◽  
Plausible Model ◽  
Effective Option

AbstractControlling COVID-19 transmission in universities poses challenges due to the complex social networks and potential for asymptomatic spread. We developed a stochastic transmission model based on realistic mixing patterns and evaluated alternative mitigation strategies. We predict, for plausible model parameters, that if asymptomatic cases are half as infectious as symptomatic cases, then 15% (98% Prediction Interval: 6–35%) of students could be infected during the first term without additional control measures. First year students are the main drivers of transmission with the highest infection rates, largely due to communal residences. In isolation, reducing face-to-face teaching is the most effective intervention considered, however layering multiple interventions could reduce infection rates by 75%. Fortnightly or more frequent mass testing is required to impact transmission and was not the most effective option considered. Our findings suggest that additional outbreak control measures should be considered for university settings.

scholarly journals Sources of SARS-CoV-2 and Other Microorganisms in Dental Aerosols

2021 ◽  
pp. 002203452110159
Author(s):  
A.P. Meethil ◽  
S. Saraswat ◽  
P.P. Chaudhary ◽  
S.M. Dabdoub ◽  
P.S. Kumar
Keyword(s):  
Infection Control ◽  
Dental Treatment ◽  
Quantitative Polymerase Chain Reaction ◽  
The United States ◽  
Control Measures ◽  
Personal Protection ◽  
Personal Protection Equipment ◽  
Linear Discriminant ◽  
16S Sequencing ◽  
Asymptomatic Patients

On March 16, 2020, 198,000 dentists in the United States closed their doors to patients, fueled by concerns that aerosols generated during dental procedures are potential vehicles for transmission of respiratory pathogens through saliva. Our knowledge of these aerosol constituents is sparse and gleaned from case reports and poorly controlled studies. Therefore, we tracked the origins of microbiota in aerosols generated during ultrasonic scaling, implant osteotomy, and restorative procedures by combining reverse transcriptase quantitative polymerase chain reaction (to identify and quantify SARS-CoV-2) and 16S sequencing (to characterize the entire microbiome) with fine-scale enumeration and source tracking. Linear discriminant analysis of Bray-Curtis dissimilarity distances revealed significant class separation between the salivary microbiome and aerosol microbiota deposited on the operator, patient, assistant, or the environment ( P < 0.01, analysis of similarities). We also discovered that 78% of the microbiota in condensate could be traced to the dental irrigant, while saliva contributed to a median of 0% of aerosol microbiota. We also identified low copy numbers of SARS-CoV-2 virus in the saliva of several asymptomatic patients but none in aerosols generated from these patients. Together, the bacterial and viral data encourage us to conclude that when infection control measures are used, such as preoperative mouth rinses and intraoral high-volume evacuation, dental treatment is not a factor in increasing the risk for transmission of SARS-CoV-2 in asymptomatic patients and that standard infection control practices are sufficiently capable of protecting personnel and patients from exposure to potential pathogens. This information is of immediate urgency, not only for safe resumption of dental treatment during the ongoing COVID-19 pandemic, but also to inform evidence-based selection of personal protection equipment and infection control practices at a time when resources are stretched and personal protection equipment needs to be prioritized.

scholarly journals Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England

Science ◽  
2021 ◽  
Vol 372 (6538) ◽  
pp. eabg3055 ◽  
Author(s):  
Nicholas G. Davies ◽  
Sam Abbott ◽  
Rosanna C. Barnard ◽  
Christopher I. Jarvis ◽  
Adam J. Kucharski ◽  
...  
Keyword(s):  
United States ◽  
Severe Acute Respiratory Syndrome ◽  
Reproduction Number ◽  
The United States ◽  
Control Measures ◽  
Transmission Model ◽  
Educational Institutions ◽  
Stringent Control ◽  
Dynamic Transmission Model ◽  
Credible Intervals

A severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, VOC 202012/01 (lineage B.1.1.7), emerged in southeast England in September 2020 and is rapidly spreading toward fixation. Using a variety of statistical and dynamic modeling approaches, we estimate that this variant has a 43 to 90% (range of 95% credible intervals, 38 to 130%) higher reproduction number than preexisting variants. A fitted two-strain dynamic transmission model shows that VOC 202012/01 will lead to large resurgences of COVID-19 cases. Without stringent control measures, including limited closure of educational institutions and a greatly accelerated vaccine rollout, COVID-19 hospitalizations and deaths across England in the first 6 months of 2021 were projected to exceed those in 2020. VOC 202012/01 has spread globally and exhibits a similar transmission increase (59 to 74%) in Denmark, Switzerland, and the United States.

scholarly journals Screening of Highly Expressed Mycobacterial Genes Identifies Rv3615c as a Useful Differential Diagnostic Antigen for the Mycobacterium tuberculosis Complex

2008 ◽  
Vol 76 (9) ◽  
pp. 3932-3939 ◽  
Author(s):  
Ben Sidders ◽  
Chris Pirson ◽  
Philip J. Hogarth ◽  
R. Glyn Hewinson ◽  
Neil G. Stoker ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Significant Proportion ◽  
Growth Conditions ◽  
Control Measures ◽  
Human Populations ◽  
Infected Cattle ◽  
Ifn Γ ◽  
Mycobacterial Antigens ◽  
And Control ◽  
Differential Antigens

ABSTRACT Tuberculous infections caused by mycobacteria, especially tuberculosis of humans and cattle, are important both clinically and economically. Human populations can be vaccinated with Mycobacterium bovis bacille Calmette-Guérin (BCG), and control measures for cattle involving vaccination are now being actively considered. However, diagnostic tests based on tuberculin cannot distinguish between genuine infection and vaccination with BCG. Therefore, identification of differential diagnostic antigens capable of making this distinction is required, and until now sequence-based approaches have been predominant. Here we explored the link between antigenicity and mRNA expression level, as well as the possibility that we may be able to detect differential antigens by analyzing quantified global transcriptional profiles. We generated a list of 14 candidate antigens that are highly expressed in Mycobacterium tuberculosis and M. bovis under a variety of growth conditions. These candidates were screened in M. bovis-infected and naïve cattle for the ability to stimulate a gamma interferon (IFN-γ) response. We identified one antigen, Rv3615c, which stimulated IFN-γ responses in a significant proportion of M. bovis-infected cattle (11 of 30 cattle [37%] [P < 0.01]) but not in naïve or BCG-vaccinated animals. Importantly, the same antigen stimulated IFN-γ responses in a significant proportion of infected cattle that did not respond to the well-characterized mycobacterial antigens ESAT-6 and CFP-10. Therefore, use of the Rv3615c epitope in combination with previously described differential tests based on ESAT-6 and CFP-10 has the potential to significantly increase diagnostic sensitivity without reducing specificity in BCG-vaccinated populations.

Sign in / Sign up

Export Citation Format

Share Document