scholarly journals Impact of Prior Infection on Protection and Transmission of SARS-CoV-2 in Golden Hamsters

2021 ◽  
Author(s):  
Cheng Zhang ◽  
Zhendong Guo ◽  
Nan Li ◽  
Huan Cui ◽  
Keyin Meng ◽  
...  
Keyword(s):  
Public Health ◽  
Direct Contact ◽  
Protective Immunity ◽  
Herd Immunity ◽  
Transmission Experiment ◽  
Indirect Contact ◽  
Golden Hamsters ◽  
Short Period ◽  
The Impact ◽  
Prior Infection

AbstractThe severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused over 100 million confirmed human infections, and 2 million more deaths globally since its emergence in the end of 2019. Several studies have shown that prior infection provided protective immunity against SARS-CoV-2 in non-human primate models. However, the effect of prior infection on blocking SARS-CoV-2 transmission is not clear. Here, we evaluated the impact of prior infection on protection and transmission of the SARS-CoV-2 virus in golden hamsters. Our results showed that prior infection provided protective immunity against SARS-CoV-2 re-challenge, but it was not sterizing immunity. The transmission experiment results showed that SARS-CoV-2 was efficiently transmitted from naive hamsters to prior infected hamsters by direct contact and airborne route, but not by indirect contact. Further, the virus was efficiently transmitted from prior infected hamsters to naive hamsters by direct contact, but not by airborne route and indirect contact. Surprisingly, the virus can be transmitted between prior infected hamsters by direct contact during a short period of early infection. Taken together, our study demonstrated that prior infected hamsters with good immunity can still be naturally re-infected, and the virus can be transmitted between prior infected hamsters and the naive through different transmission routes, implying the potential possibility of human re-infection and the risk of virus transmission between prior infected population and the healthy. Our study will help to calculate the herd immunity threshold more accurately, make more reasonable public health decisions, formulate an optimized population vaccination program, as well as aid the implementation of appropriate public health and social measures to control COVID-19.

scholarly journals Impact of Prior Infection on Severe Acute Respiratory Syndrome Coronavirus 2 Transmission in Syrian Hamsters

2021 ◽  
Vol 12 ◽  
Author(s):  
Cheng Zhang ◽  
Zhendong Guo ◽  
Nan Li ◽  
Huan Cui ◽  
Keyin Meng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Direct Contact ◽  
Herd Immunity ◽  
Healthy Population ◽  
Syrian Hamsters ◽  
Vaccination Coverage Rate ◽  
Contact Transmission ◽  
The Impact ◽  
Prior Infection ◽  
Sterilizing Immunity

Prior infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) provides protective immunity against reinfection. However, whether prior infection blocks SARS-CoV-2 transmission is not yet clear. Here, we evaluated the impact of prior infection on SARS-CoV-2 transmission in Syrian hamsters. Our results showed that prior infection significantly reduced SARS-CoV-2 replication in Syrian hamsters, but sterilizing immunity was not achieved. Prior infection blocked the airborne transmission of SARS-CoV-2 from previously infected Syrian hamsters to naïve Syrian hamsters and previously infected Syrian hamsters. Moreover, prior infection substantially reduced the efficiency of direct contact transmission between previously infected Syrian hamsters. However, prior infection had limited impact on SARS-CoV-2 transmission from previously infected Syrian hamsters to naïve Syrian hamsters via direct contact in the early course of infection. Human reinfection and SARS-CoV-2 transmission between a previously infected population and a healthy population would be likely, and a higher vaccination coverage rate was needed to reach herd immunity. Our work will aid the implementation of appropriate public health and social measures to control coronavirus infectious disease 2019 (COVID-19) pandemic.

scholarly journals Widespread Behavioral Responses by Mammals and Fish to Zoo Visitors Highlight Differences between Individual Animals

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2108
Author(s):  
Sarah A. Boyle ◽  
Nathan Berry ◽  
Jessica Cayton ◽  
Sarah Ferguson ◽  
Allesondra Gilgan ◽  
...  
Keyword(s):  
Direct Contact ◽  
Behavioral Responses ◽  
Valuable Insight ◽  
Mammal Species ◽  
Indirect Contact ◽  
The Public ◽  
Visitor Behavior ◽  
Zoo Animals ◽  
Behavioral Assessments ◽  
The Impact

The impact that humans have on zoo animals can vary based on the species of animal, exhibit design, and individual differences in behavioral responses. We independently analyzed data from 10 never-published studies that examined the impact of zoo visitors on zoo animal behavior. Of the 16 species studied, 90.9% of the mammal species and 60.0% of the fish species demonstrated a change in at least one behavior based on zoo visitor abundance or visitor behavior (e.g., noise, solicitation of interactions from zoo animals). In addition, behavioral changes associated with zoo visitors were present in animals housed in exhibits where there was direct contact with zoo visitors, as well as in exhibits where there was indirect contact and no direct contact. Individuals often varied in their behavioral responses, and some individuals appeared to seek out interactions with visitors. Our findings demonstrate that short-term research projects can provide valuable insight into individual animal-level and species-level responses to visitor abundance and visitor behavior in the zoo setting. We recommend that behavioral assessments focus on the analysis of behaviors of individual animals whenever possible, and we recommend that exhibits provide areas that allow for animals to retreat from the public view.

scholarly journals Different Modes of Transmission and Containment Strategies for COVID-19

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Sitaram Khadka ◽  
Hamid Saeed ◽  
Yogesh Bajgain ◽  
Janak Shahi ◽  
Tank Prasad Yadav ◽  
...  
Keyword(s):  
Direct Contact ◽  
Therapeutic Agent ◽  
Contact Tracing ◽  
Personal Hygiene ◽  
Infected Person ◽  
Safety Measures ◽  
Indirect Contact ◽  
Modes Of Transmission ◽  
Short Period ◽  
Environmental Decontamination

Coronavirus disease (COVID-19) is a respiratory infectious ailment caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The first outbreak of this disease occurred in China and declared a pandemic in a very short period of time. SARS-CoV-2 gets transmitted mainly through the respiratory tract by droplets or respiratory secretions and by direct contact with the infected person as well as indirect contact through touching the contaminated surface accompanied by poor hygiene practice. Until the vaccine, a therapeutic agent or any other treatment modality gets approved; contact tracing and management, social distancing, personal hygiene, respiratory etiquette, and environmental decontamination are the prime factors to be considered for transmission containment and hence for appropriate safety measures for COVID-19 which is possible with the support of social work from the community level.

scholarly journals Incidence of COVID-19 reinfection among Midwestern healthcare employees

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262164
Author(s):  
Anne Rivelli ◽  
Veronica Fitzpatrick ◽  
Christopher Blair ◽  
Kenneth Copeland ◽  
Jon Richards
Keyword(s):  
Incidence Rate ◽  
Protective Immunity ◽  
Healthcare Workers ◽  
Natural Infection ◽  
Herd Immunity ◽  
Primary Objective ◽  
Observational Cohort ◽  
Frequent Exposure ◽  
Prior Infection ◽  
Healthcare Employees

Given the overwhelming worldwide rate of infection and the disappointing pace of vaccination, addressing reinfection is critical. Understanding reinfection, including longevity after natural infection, will allow us to better know the prospect of herd immunity, which hinges on the assumption that natural infection generates sufficient, protective immunity. The primary objective of this observational cohort study is to establish the incidence of reinfection of COVID-19 among healthcare employees who experienced a prior COVID-19 infection over a 10-month period. Of 2,625 participants who experienced at least one COVID-19 infection during the 10-month study period, 156 (5.94%) experienced reinfection and 540 (20.57%) experienced recurrence after prior infection. Median days were 126.50 (105.50–171.00) to reinfection and 31.50 (10.00–72.00) to recurrence. Incidence rate of COVID-19 reinfection was 0.35 cases per 1,000 person-days, with participants working in COVID-clinical and clinical units experiencing 3.77 and 3.57 times, respectively, greater risk of reinfection relative to those working in non-clinical units. Incidence rate of COVID-19 recurrence was 1.47 cases per 1,000 person-days. This study supports the consensus that COVID-19 reinfection, defined as subsequent infection ≥ 90 days after prior infection, is rare, even among a sample of healthcare workers with frequent exposure.

scholarly journals Fighting Covid-19 Pandemic: Analysis of the Swedish Model vs. Lockdown Model

2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Turkistani Fatema ◽  
Sawad Aseel Bin
Keyword(s):  
Public Health ◽  
Manufacturing Industry ◽  
Herd Immunity ◽  
Economic Factors ◽  
Long Term Effects ◽  
Swedish Model ◽  
The Us ◽  
The Impact ◽  
Shed Light

Many countries resorted to the lockdown model that includes shutting down all non-essential activities to avoid the spread of COVID-19. Comparatively, Sweden applied the herd immunity model. The aim of this study is to analyze the Swedish model compared to the lockdown model based in other countries to understand the impact of these models on public health, health economics and overall economy of the respective countries. Based on the findings, the paper aims to shed light on which model proves to be more effective to cope with the pandemic and provide recommendations for other countries to follow accordingly. Our methodology was a narrative review that synthesizes current literature obtained from searches on various databases, authoritative texts, and hand searches. While it is too early to determine the long term effects of both models, it seems that Sweden’s herd immunity model is more effective considering aspects of overall public health, health economic factors, and the overall economy. The major cons of the Swedish model was a failure in controlling infection spread in elderly nursing homes, as half the death toll comprises individuals belonging to this community. While Sweden was able to soften the effect of COVID-19 impact on its economy without a lockdown, the manufacturing industry was impacted due to lack of availability of required parts to be supplied by other countries. Thus from our review , we found that Herd-immunity model is more effective, but it depends on other factors of the country such as population density, as it is not plausible for countries such as Spain, the US or Germany, which need to expose high numbers of people to COVID-19 to attain herd immunity.

Reducing transphobia: comparing the efficacy of direct and indirect contact

2019 ◽  
Vol 51 (7/8) ◽  
pp. 445-460
Author(s):  
Nitya Rani ◽  
Anand A. Samuel
Keyword(s):  
Direct Contact ◽  
Negative Impact ◽  
Relative Effectiveness ◽  
Post Intervention ◽  
Indirect Contact ◽  
Content Type ◽  
Post Test ◽  
Significant Negative Impact ◽  
The Impact

Purpose The transgender community faces prejudice and stigma and is one of the most ostracised groups in society. One of the ways to reduce prejudice is through intergroup contact. This may be achieved through direct or indirect contact. The purpose of this paper is to compare the impact of direct and indirect contact on reducing transphobia. Design/methodology/approach Direct contact was achieved through a transgender speaker panel and indirect contact involved a video presentation. In total, 159 students enroled in undergraduate courses at a prominent university in India were enlisted for this study. Perceptions regarding transgenders were measured using the genderism and transphobia scale. Perceptions were measured at three different time points – before the contact, immediately after the contact and one month post contact. Findings Results indicate that both direct and indirect contact cause a significant immediate decrease in transphobia at the post intervention stage. However, only direct contact caused significant reduction at the follow-up stage (one month after the intervention). Direct contact also effected a greater reduction in transphobia than indirect contact. Research limitations/implications This study extends previous research that shows that speaker panels involving sexual minority speakers can result in reducing stigma (e.g. Croteau and Kusek, 1992). The present study shows that such speaker panels can also be useful for reducing stigma against transgender individuals. Another important outcome of this study is the relative effectiveness of direct contact in reducing transphobia compared to indirect contact. Direct contact resulted in greater reduction in transphobia both at the post-test and follow-up stages compared to indirect contact. Practical implications The results of this study may benefit HR practitioners and policy makers in designing workplace initiatives and policies in creating an inclusive workplace. This study shows that meaningful interaction with transgenders would be a key step in reducing stigmatisation. Since direct contact is rarely expensive or time consuming, it can be a valuable tool to improve the integration of transgender individuals within society. Therefore, students and employees may be encouraged to interact with transgender individuals through panel discussions and workshops. Indirect contact may be used as a preliminary intervention in certain cases where direct contact may be difficult to organise. Social implications The stigma faced by transgender individuals has a significant negative impact on their quality of life (Grant et al., 2014; Reisner and Juntunen, 2015). It is, therefore, necessary to recognise and reduce prejudice against transgenders at both the college and school levels as well as in work organisations. Educators and managers have a significant role to play in this societal change. This study shows that stigma reduction can be achieved in a fairly simple way through contact theory. Originality/value This study is one of the first to investigate Indian students’ perceptions of transgenders. It improves on earlier studies using similar interventions in two main ways. First, this study includes a follow-up assessment, which was not performed in most studies. Second, random assignment of participants to one of two conditions improves the reliability of the findings.

scholarly journals Increasing but inadequate intention to receive Covid-19 vaccination over the first 50 days of impact of the more infectious variant and roll-out of vaccination in UK: indicators for public health messaging

2021 ◽  
Author(s):  
Patrik Bachtiger ◽  
Alexander Adamson ◽  
William A Maclean ◽  
Jennifer K Quint ◽  
Nicholas S Peters
Keyword(s):  
Public Health ◽  
Language Processing ◽  
Herd Immunity ◽  
Vaccine Hesitancy ◽  
Free Text ◽  
New Variant ◽  
The Impact ◽  
To Receive ◽  
Roll Out ◽  
Health Messaging

ABSTRACTObjectivesTo inform critical public health messaging by determining how changes in Covid-19 vaccine hesitancy, attitudes to the priorities for administration, the emergence of new variants and availability of vaccines may affect the trajectory and achievement of herd immunity.Methods>9,000 respondents in an ongoing cross-sectional participatory longitudinal epidemiology study (LoC-19, n=18,581) completed a questionnaire within their personal electronic health record in the week reporting first effective Covid-19 vaccines, and then again after widespread publicity of the increased transmissibility of a new variant (November 13th and December 31st 2020 respectively). Questions covered willingness to receive Covid-19 vaccination and attitudes to prioritisation. Descriptive statistics, unadjusted and adjusted odds ratios (ORs) and natural language processing of free-text responses are reported, and how changes over the first 50 days of both vaccination roll-out and new-variant impact modelling of anticipated transmission rates and the likelihood and time to herd immunity.FindingsCompared with the week reporting the first efficacious vaccine there was a 15% increase in acceptance of Covid-19 vaccination, attributable in one third to the impact of the new variant, with 75% of respondents “shielding” – staying at home and not leaving unless essential – regardless of health status or tier rules. 12.5% of respondents plan to change their behaviour two weeks after completing vaccination compared with 45% intending to do so only when cases have reduced to a low level. Despite the increase from 71% to 86% over this critical 50-day period, modelling of planned uptake of vaccination remains below that required for rapid effective herd immunity – now estimated to be 90 percent in the presence of a new variant escalating R0 to levels requiring further lockdowns. To inform the public messaging essential therefore to improve uptake, age and female gender were, respectively, strongly positively and negatively associated with wanting a vaccine. 22.7% disagreed with the prioritisation list, though 70.3% were against being able to expedite vaccination through payment. Teachers (988, 12.6%) and Black, Asian and Minority Ethnic (BAME) (837, 10.7%) groups were most cited by respondents for prioritisation.InterpretationIn this sample, the growing impact of personal choice among the increasingly informed public highlights a decrease in Covid-19 vaccine hesitancy over time, with news of a new variant motivating increased willingness for vaccination but at levels below what may be required for effective herd immunity. We identify public preferences for next-in-line priorities, headed by teachers and BAME groups, consideration of which will help build trust and community engagement critical for maximising compliance with not only the vaccination programme but also all other public health measures.

PUBLIC HEALTH

PEDIATRICS ◽  
1959 ◽  
Vol 24 (6) ◽  
pp. 1102-1107
Author(s):  
Andrew C. Fleck ◽  
Jerome O. Klein
Keyword(s):  
Public Health ◽  
Direct Contact ◽  
Present Knowledge ◽  
Causative Organism ◽  
Indirect Contact ◽  
Epidemiologic Evidence ◽  
Route Of Transmission ◽  
Probable Source ◽  
Asymptomatic Infant ◽  
Droplet Nuclei

On the basis of present knowledge, the various sources and accompanying pathways by which effective contacts between susceptible infants and the staphylococcus take place in the nursery outbreaks are as follows: 1) Direct contact with infective lesions; 2) direct and indirect contact spread from the asymptomatic infant carrier to the susceptible infant within the nursery, particularly under conditions of overcrowding and poor nursery technique. Personnel carriers, fomites and air-borne droplet nuclei and dust, as sources of outbreaks, do not command a body of convincing epidemiologic evidence at this time. The epidemiologic investigation of nursery-acquired disease requires that each infant at risk be followed for a minimum of 15 days. The most probable source and route of transmission of the causative organism can be identified. Control efforts should be based on the epidemiologic diagnosis.

scholarly journals Critical concepts for COVID-19 Mass Vaccination Site Operations

2021 ◽  
pp. 1-24
Author(s):  
Scott A. Goldberg ◽  
David Callaway ◽  
Daniel Resnick-Ault ◽  
Sujal Mandavia ◽  
Rodrigo Martinez ◽  
...  
Keyword(s):  
Public Health ◽  
Inventory Management ◽  
Communicable Disease ◽  
Vaccination Campaign ◽  
Herd Immunity ◽  
The United States ◽  
Mass Vaccination ◽  
Lessons Learned ◽  
Vaccination Site ◽  
The Impact

Abstract Mass vaccination campaigns have been used effectively to limit the impact of communicable disease on public health. However, the scale of the COVID19 vaccination campaign is unprecedented. Mass vaccination sites consolidate resources and experience into a single entity and are essential to achieving community (“herd”) immunity rapidly, efficiently, and equitably. Healthcare systems, local and regional public health entities, emergency medical services, and private organizations can rapidly come together to solve problems and achieve success. As medical directors at several mass vaccination site across the United States, we describe key mass vaccination site concepts including site selection, operational models, patient flow, inventory management, staffing, technology, reporting, medical oversight, communication, and equity. Lessons learned from experience operating a diverse group of mass vaccination sites will help to inform not only sites operating during the current pandemic but may serve as a blueprint for future outbreaks of highly infectious communicable disease.

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