scholarly journals Impacts of vaccination and asymptomatic testing on SARS-CoV-2 transmission dynamics in a university setting

2021 ◽  
Author(s):  
Emily J Nixon ◽  
Amy C Thomas ◽  
Daniel A Stocks ◽  
Antoine M. G. Barreaux ◽  
Gibran Hemani ◽  
...  
Keyword(s):  
Cumulative Incidence ◽  
Compartmental Model ◽  
Student Population ◽  
University Student ◽  
Vaccine Uptake ◽  
Transmission Dynamics ◽  
Testing Uptake ◽  
University Settings ◽  
The Impact ◽  
University Setting

We investigate the impact of vaccination and asymptomatic testing uptake on SARS-CoV-2 transmission in a university student population using a stochastic compartmental model. We find that the magnitude and timing of outbreaks is highly variable under different vaccine uptake levels. With low level interventions (no asymptomatic testing, 30% vaccinated), 53-71% of students become infected during the first term; with high interventions (90% using asymptomatic testing, 90% vaccinated) cumulative incidence is 7-9%, with around 80% of these cases estimated to be asymptomatic. Asymptomatic testing is most useful when vaccine uptake is low: when 30% of students are vaccinated, 90% uptake of asymptomatic testing leads to almost half the case numbers. Under high levels of vaccine uptake (70-90%), case numbers in the student population are largely driven by community importation. Our findings suggest that vaccination is critical for controlling SARS-CoV-2 transmission in university settings with asymptomatic testing being a useful supporting measure.

Pertussis in England and Wales: an investigation of transmission dynamics and control by mass vaccination

1989 ◽  
Vol 236 (1284) ◽  
pp. 213-252 ◽  
Keyword(s):  
Mathematical Models ◽  
Vaccine Efficacy ◽  
Case Reports ◽  
Mass Vaccination ◽  
Vaccine Uptake ◽  
Transmission Dynamics ◽  
England And Wales ◽  
Epidemic Period ◽  
The Impact ◽  
Induced Immunity

The epidemiology of pertussis and its prospects for control by mass vaccination in England and Wales are investigated by analyses of longitudinal records on incidence and vaccine uptake, and horizontal data on age-stratified case reports. Mathematical models of the transmission dynamics of the infection that incorporate loss of natural and vaccine-induced immunity plus variable vaccine efficacy are developed, and their predictions compared with observed trends. Analyses of case reports reveal that the individual force of infection is age dependent, with peak transmission in the 5- to 10-year-old age class. A model incorporating this age dependency, along with partial vaccine efficacy and loss of vaccine-induced immunity, generates predicted patterns that best mirror observed trends since mass vaccination was inaugurated in 1957 in England and Wales. Model projections accurately mirror the failure of mass vaccination to increase the inter-epidemic period of the infection (three years) over that pertaining before control. The analysis suggests that this is due to the impact of partial vaccine efficacy. Projected trends to not accurately reflect the low levels of pertussis incidence reported between epidemics in the periods of high vaccine uptake. This is thought to arise from a combination of factors, including loss of natural and vaccine induced immunity, biases in case reporting (where reporting efficiency is positively associated with the incidence of pertussis), and seasonal variations in transmission. Model predictions suggest that the vaccination of 88% of each birth cohort before the age of 1 year will eliminate bacterial transmission, provided the vaccine confers lifelong protection against infection. If vaccine-induced immunity is significantly less than lifelong (or if vaccination fails to protect all its recipients) repeated cohort immunization is predicted to be necessary to eliminate transmission. Future research needs are discussed, and emphasis is placed on the need for more refined data on vaccine efficacy, the duration of natural and vaccine-induced immunity and the incidence of clinical pertussis and subclinical infections (perhaps by the development of reliable serological tests). Future mathematical models will need especially to incorporate seasonality in transmission.

Negotiating networks of communication in a superdiverse environment: Urban multilingualism in the City of Southampton

Multilingua ◽  
2014 ◽  
Vol 33 (5-6) ◽  
Author(s):  
Linda Cadier ◽  
Clare Mar-Molinero
Keyword(s):  
Student Population ◽  
University Student ◽  
First Century ◽  
Port City ◽  
Social Hierarchies ◽  
Public And Private ◽  
International University ◽  
Linguistic Practices ◽  
The Impact ◽  
The City

AbstractThis article explores the impact of superdiversity on linguistic practices in Southampton, UK. Our focus seeks to identify what these practices are in an environment that we describe as superdiverse, and what is influencing, determining, shaping and contributing to these practices. Southampton is characterised by twenty-first century social mobilities typical of a port city, with a workforce that consists both of those who have settled here for decades, as well as others who are part of the European “new” migration, or who belong to the large international university student population. Our findings arise from a series of linked studies exploring social and linguistic cohesion in Southampton. These provide us with data on the negotiations implicit in the networks that structure urban multilingualism, and allow us to focus above all on examining the impact of our research on the language sensitisation of these communities. We explore the workplaces in a range of sites (public and private, large and small), comprising many nationalities, ethnicities and languages, and representing microcosms of complex, social hierarchies. Our approach is a grassroots, participatory one, seeking to involve our informants with our findings and sharing our analyses and recommendations.

scholarly journals A New Extension of State-Space SIR Model to Account for Underreporting- An Application to the COVID-19 transmission in California and Florida

2020 ◽  
Author(s):  
Vishal Deo ◽  
Gurprit Grover
Keyword(s):  
State Space ◽  
Gibbs Sampling ◽  
Compartmental Model ◽  
State Space Model ◽  
Case Fatality ◽  
Sampling Procedure ◽  
Transmission Dynamics ◽  
List Type ◽  
Space Formulation ◽  
The Impact

AbstractIn the absence of sufficient testing capacity for COVID-19, a substantial number of infecteds are expected to remain undetected. Since the undetected cases are not quarantined, they are expected to transmit the infection at a much higher rate than their quarantined counterparts. That is, under the lack of extensive random testing, the actual prevalence and incidence of the SARS-CoV-2 infection may be entirely different from that being reported. Thus, it is imperative that the information on the percentage of undetected (or unreported) cases be considered while estimating the parameters and forecasting the transmission dynamics of the epidemic.In this paper, we have developed a new version of the basic susceptible-infected-removed (SIR) compartmental model, called the susceptible-infected (quarantined/ free) -recovered-deceased [SI(Q/F)RD] model, to incorporate the impact of undetected cases on the transmission dynamics of the epidemic. Further, we have presented a Dirichlet-Beta state-space formulation of the SI(Q/F)RD model for the estimation of its parameters using posterior realizations from Gibbs sampling procedure. As a demonstration, the proposed methodology is implemented to forecast the COVID-19 transmission in California and Florida.HighlightsData calibrated for underreporting using excess deaths and case fatality rate.A new extension of SIR compartmental model, called SI(Q/F)RD, is introduced.A Dirichlet-Beta state-space formulation of the SI(Q/F)RD model is developed.Gibbs sampling used to estimate the Bayesian hierarchical state-space model.Proposed methodology is applied on the COVID-19 data of California and Florida.

scholarly journals Importation of SARS-CoV-2 following the "semaine de relâche" and Québec's (Canada) COVID-19 burden - a mathematical modeling study

2020 ◽  
Author(s):  
Arnaud Godin ◽  
Yiqing Xia ◽  
David L Buckeridge ◽  
Sharmistha Mishra ◽  
Dirk Douwes-Schultz ◽  
...  
Keyword(s):  
Public Health ◽  
Mathematical Modeling ◽  
Compartmental Model ◽  
Credible Interval ◽  
Transmission Dynamics ◽  
Cumulative Number ◽  
Imported Cases ◽  
The Impact ◽  
Very High

Background: The Canadian epidemics of COVID-19 exhibit distinct early trajectories, with Québec bearing a very high initial burden. The semaine de relâche, or March break, took place two weeks earlier in Québec as compared to the rest of Canada. This event may have played a role in the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We aimed to examine the role of case importation in the early transmission dynamics of SARS-CoV-2 in Québec. Methods: Using detailed surveillance data, we developed and calibrated a deterministic SEIR-type compartmental model of SARS-CoV-2 transmission. We explored the impact of altering the number of imported cases on hospitalizations. Specifically, we investigated scenarios without case importation after March break, and as scenarios where cases were imported with the same frequency/timing as neighboring Ontario. Results: A total of 1,544 and 1,150 returning travelers were laboratory-confirmed in Québec and Ontario, respectively (with symptoms onset before 2020-03-25). The cumulative number of hospitalizations could have been reduced by 55% (95% credible interval [95%CrI]: 51-59%) had no cases been imported after Québec's March break. However, had Québec experienced Ontario's number of imported cases, cumulative hospitalizations would have only been reduced by 12% (95%CrI: 8-16%). Interpretation: Our results suggest that case importation played an important role in the early spread of COVID-19 in Québec. Yet, heavy importation of SARS-CoV-2 in early March could be insufficient to resolve interprovincial heterogeneities in cumulative hospitalizations. The importance of other factors -public health preparedness, responses, and capacity- should be investigated.

Evaluation of the Impact of Migraine and Episodic Tension‐type Headache on the Quality of Life and Performance of a University Student Population

2001 ◽  
Vol 41 (7) ◽  
pp. 710-719 ◽  
Author(s):  
Marcelo Eduardo Bigal ◽  
Janaína Maciel Bigal ◽  
Michelle Betti ◽  
Carlos Alberto Bordini ◽  
José Geraldo Speciali
Keyword(s):  
Quality Of Life ◽  
Tension Type Headache ◽  
Student Population ◽  
University Student ◽  
And Performance ◽  
Type Headache ◽  
The Impact

scholarly journals INFEKTA—An agent-based model for transmission of infectious diseases: The COVID-19 case in Bogotá, Colombia

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0245787
Author(s):  
Jonatan Gomez ◽  
Jeisson Prieto ◽  
Elizabeth Leon ◽  
Arles Rodríguez
Keyword(s):  
Infectious Diseases ◽  
Disease Transmission ◽  
Computational Models ◽  
Compartmental Model ◽  
Transmission Dynamics ◽  
Agent Based Model ◽  
Agent Based ◽  
Social Distancing ◽  
The Impact ◽  
The Town

The transmission dynamics of the coronavirus—COVID-19—have challenged humankind at almost every level. Currently, research groups around the globe are trying to figure out such transmission dynamics under special conditions such as separation policies enforced by governments. Mathematical and computational models, like the compartmental model or the agent-based model, are being used for this purpose. This paper proposes an agent-based model, called INFEKTA, for simulating the transmission of infectious diseases, not only the COVID-19, under social distancing policies. INFEKTA combines the transmission dynamic of a specific disease, (according to parameters found in the literature) with demographic information (population density, age, and genre of individuals) of geopolitical regions of the real town or city under study. Agents (virtual persons) can move, according to its mobility routines and the enforced social distancing policy, on a complex network of accessible places defined over an Euclidean space representing the town or city. The transmission dynamics of the COVID-19 under different social distancing policies in Bogotá city, the capital of Colombia, is simulated using INFEKTA with one million virtual persons. A sensitivity analysis of the impact of social distancing policies indicates that it is possible to establish a ‘medium’ (i.e., close 40% of the places) social distancing policy to achieve a significant reduction in the disease transmission.

scholarly journals Modelling the transmission dynamics of Theileria annulata: model structure and validation for the Turkish context

Parasitology ◽  
2012 ◽  
Vol 139 (4) ◽  
pp. 441-453 ◽  
Author(s):  
A. J. SUTTON ◽  
T. KARAGENC ◽  
S. BAKIRCI ◽  
H. SARALI ◽  
G. PEKEL ◽  
...  
Keyword(s):  
Compartmental Model ◽  
Tick Infestation ◽  
Theileria Annulata ◽  
Transmission Dynamics ◽  
Tick Population ◽  
Temporal Separation ◽  
Intervention Measures ◽  
Tick Attachment ◽  
Using Data ◽  
The Impact

SUMMARYA mathematical model that describes the transmission dynamics of Theileria annulata is proposed that consists of 2 host components: the Hyalomma tick population and a compartmental model of T. annulata infection in the cattle population. The model was parameterized using data describing tick infestation and the infection status of cattle in Turkey from 2006 to 2008. The tick attachment rates are highly seasonal and because of the temporal separation of infectious and susceptible ticks virtually all ticks are infected by carrier cattle, so that annual peaks of disease in cattle do not impact on infection in the Hyalomma tick population. The impact of intervention measures that target the tick population both on the host and in the environment and their impact on the transmission of T. annulata were investigated. Interventions that have a limited ‘one-off’ impact and interventions that have a more permanent impact were both considered. The results from the model show the importance of targeting ticks during the period when they have left their first host as nymphs but have yet to feed on their second host.

scholarly journals Modelling SARS-CoV-2 transmission in a UK university setting

2020 ◽  
Author(s):  
Edward M Hill ◽  
Benjamin D Atkins ◽  
Matt J Keeling ◽  
Michael Tildesley ◽  
Louise Dyson
Keyword(s):  
Student Population ◽  
Contact Tracing ◽  
Community Members ◽  
Expected Time ◽  
Effective Contact ◽  
Single Room ◽  
The Uk ◽  
Nonpharmaceutical Interventions ◽  
The Impact ◽  
University Setting

Background: Around 40% of school leavers in the UK attend university and individual universities generally host thousands of students each academic year. Bringing together these student communities during the COVID-19 pandemic may require strong interventions to control transmission. Prior modelling analysis of SARS-CoV-2 transmission within universities that use compartmental modelling approaches suggest that outbreaks are almost inevitable. Methods: We constructed a network-based model to capture the interactions of a student population in different settings (housing, social and study). For a single academic term of a representative campus-based university, we ran a susceptible-latent-infectious-recovered type epidemic process, parameterised according to available estimates for SARS-CoV-2. We investigated the impact of: adherence to (or effectiveness of) isolation and test and trace measures; single-room isolation of cases; supplementary mass testing. Results: Incorporating uncertainty in the asymptomatic fraction of cases and their associated infectivity, in the absence of interventions our model estimated that 69% (55% - 75%) of the student population could be infected during the autumn term. With full adherence to test, trace and isolate measures, we found lower cumulative infection estimates of 19% (5% - 39%). Irrespective of the adherence to isolation measures, on average a higher proportion of students resident on-campus became infected than off-campus. Room isolation generated minimal benefits. A one-off instance of mass testing would not drastically reduce the term-long case load, though if performed a couple of weeks before the end-of-term it could reduce the expected end-of-term prevalence. Regular testing, together with high adherence to isolation, test and trace measures, could reduce the proportion infected during the term by more than 50% compared to having no mass testing. Conclusions: Our findings suggest SARS-CoV-2 may readily transmit in a university setting if there is limited adherence to nonpharmaceutical interventions and/or there are delays in receiving test results. Following isolation guidance and effective contact tracing curbed transmission and reduced the expected time an adhering student would spend in isolation. Additionally, widespread adherence throughout the term suppresses the amount of unwitting asymptomatic transmission to family and community members in the students' domicile regions after term ends.

Communication Recovery Groups for Persons with Aphasia: A Replicable Program for Medical and University Settings

2014 ◽  
Vol 24 (3) ◽  
pp. 106-113 ◽  
Author(s):  
Candace Vickers ◽  
Darla Hagge
Keyword(s):  
Medical Setting ◽  
Group Program ◽  
Intake Process ◽  
Student Volunteers ◽  
Group Members ◽  
University Settings ◽  
University Setting ◽  
Recovery Groups

This article describes Communication Recovery Groups (CRG), an aphasia group program that is sponsored by a medical setting and more recently a university setting. CRG's history and approach and its model of service in light of current healthcare challenges are summarized. The article also provides a detailed discussion regarding the logistics of offering conversation groups to persons with aphasia which are sponsored by medical and/or university settings, the intake process for new group members, and the training of student volunteers to help lead conversation groups.

scholarly journals Post-transplant cyclophosphamide containing regimens after matched sibling, matched unrelated and haploidentical donor transplants in patients with acute lymphoblastic leukemia in first complete remission, a comparative study of the ALWP of the EBMT

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jaime Sanz ◽  
Jacques-Emmanuel Galimard ◽  
Myriam Labopin ◽  
Boris Afanasyev ◽  
Moiseev Ivan Sergeevich ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Cumulative Incidence ◽  
Lymphoblastic Leukemia ◽  
Hematopoietic Stem ◽  
Free Survival ◽  
Post Transplant ◽  
Gvhd Prophylaxis ◽  
Donor Type ◽  
Matched Sibling ◽  
The Impact

Abstract Background There is no information on the impact of donor type in allogeneic hematopoietic stem cell transplantation (HCT) using homogeneous graft-versus-host (GVHD) prophylaxis with post-transplant cyclophosphamide (PTCy) in acute lymphoblastic leukemia (ALL). Methods We retrospectively analyzed outcomes of adult patients with ALL in CR1 that had received HCT with PTCy as GVHD prophylaxis from HLA-matched sibling (MSD) (n = 78), matched unrelated (MUD) (n = 94) and haploidentical family (Haplo) (n = 297) donors registered in the EBMT database between 2010 and 2018. The median follow-up period of the entire cohort was 2.2 years. Results Median age of patients was 38 years (range 18–76). Compared to MSD and MUD, Haplo patients received peripheral blood less frequently. For Haplo, MUD, and MSD, the cumulative incidence of 100-day acute GVHD grade II–IV and III–IV, and 2-year chronic and extensive chronic GVHD were 32%, 41%, and 34% (p = 0.4); 13%, 15%, and 15% (p = 0.8); 35%, 50%, and 42% (p = 0.01); and 11%, 17%, and 21% (p = 0.2), respectively. At 2 years, the cumulative incidence of relapse and non-relapse mortality was 20%, 20%, and 28% (p = 0.8); and 21%, 18%, and 21% (p = 0.8) for Haplo, MUD, and MSD, respectively. The leukemia-free survival, overall survival and GVHD-free, relapse-free survival for Haplo, MUD, and MSD was 59%, 62%, and 51% (p = 0.8); 66%, 69%, and 62% (p = 0.8); and 46%, 44%, and 35% (p = 0.9), respectively. On multivariable analysis, transplant outcomes did not differ significantly between donor types. TBI-based conditioning was associated with better LFS. Conclusions Donor type did not significantly affect transplant outcome in patient with ALL receiving SCT with PTCy.

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