scholarly journals Clustering and superspreading potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Hong Kong

2020 ◽  
Author(s):  
Dillon Adam ◽  
Peng Wu ◽  
Jessica Wong ◽  
Eric Lau ◽  
Tim Tsang ◽  
...  
Keyword(s):  
Public Health ◽  
Hong Kong ◽  
High Risk ◽  
Severe Acute Respiratory Syndrome ◽  
Contact Tracing ◽  
Social Environments ◽  
Health Authorities ◽  
Public Health Authorities ◽  
Local Transmission ◽  
Terminal Cluster

Abstract Superspreading events have characterised previous epidemics of severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) infections. Using contact tracing data, we identified and characterized SARS-CoV-2 clusters in Hong Kong. Given a superspreading threshold of 6-8 secondary cases, we identified 5-7 probable superspreading events and evidence of substantial overdispersion in transmissibility, and estimated that 20% of cases were responsible for 80% of local transmission. Among terminal cluster cases, 27% (45/167) ended in quarantine. Social exposures produced a greater number of secondary cases compared to family or work exposures (p<0.001) while delays between symptom onset and isolation did not reliably predict the number of individual secondary cases or resulting cluster sizes. Public health authorities should focus on rapid tracing and quarantine of contacts, along with physical distancing to prevent superspreading events in high-risk social environments.

scholarly journals Fueling the Covid-19 pandemic: summer school holidays and incidence rates in German districts

2021 ◽  
Author(s):  
Thomas Plümper ◽  
Eric Neumayer
Keyword(s):  
Public Health ◽  
Fixed Effects ◽  
Summer School ◽  
Incidence Rates ◽  
Contact Tracing ◽  
Robert Koch Institute ◽  
Cross Sectional ◽  
Holiday Period ◽  
Health Authorities ◽  
Public Health Authorities

AbstractBackgroundThe Robert-Koch-Institute reports that during the summer holiday period a foreign country is stated as the most likely place of infection for an average of 27 and a maximum of 49% of new SARS-CoV-2 infections in Germany.MethodsCross-sectional study on observational data. In Germany, summer school holidays are coordinated between states and spread out over 13 weeks. Employing a dynamic model with district fixed effects, we analyze the association between these holidays and weekly incidence rates across 401 German districts.ResultsWe find effects of the holiday period of around 45% of the average district incidence rates in Germany during their respective final week of holidays and the 2 weeks after holidays end. Western states tend to experience stronger effects than Eastern states. We also find statistically significant interaction effects of school holidays with per capita taxable income and the share of foreign residents in a district’s population.ConclusionsOur results suggest that changed behavior during the holiday season accelerated the pandemic and made it considerably more difficult for public health authorities to contain the spread of the virus by means of contact tracing. Germany’s public health authorities did not prepare adequately for this acceleration.

scholarly journals The Dutch COVID-19 Contact Tracing App (the CoronaMelder): Usability Study

10.2196/27882 ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. e27882
Author(s):  
Britt Elise Bente ◽  
Jan Willem Jaap Roderick van 't Klooster ◽  
Maud Annemarie Schreijer ◽  
Lea Berkemeier ◽  
Joris Elmar van Gend ◽  
...  
Keyword(s):  
Public Health ◽  
Older Adults ◽  
The Netherlands ◽  
Health Workers ◽  
Contact Tracing ◽  
Usability Tests ◽  
Health Authorities ◽  
Increased Risk ◽  
Public Health Authorities ◽  
Lower Education

Background Adoption and evaluation of contact tracing tools based on information and communications technology may expand the reach and efficacy of traditional contact tracing methods in fighting COVID-19. The Dutch Ministry of Health, Welfare and Sports initiated and developed CoronaMelder, a COVID-19 contact tracing app. This app is based on a Google/Apple Exposure Notification approach and aims to combat the spread of the coronavirus among individuals by notifying those who are at increased risk of infection due to proximity to someone who later tests positive for COVID-19. The app should support traditional contact tracing by faster tracing and greater reach compared to regular contact tracing procedures. Objective The main goal of this study is to investigate whether the CoronaMelder is able to support traditional contact tracing employed by public health authorities. To achieve this, usability tests were conducted to answer the following question: is the CoronaMelder user-friendly, understandable, reliable and credible, and inclusive? Methods Participants (N=44) of different backgrounds were recruited: youth with varying educational levels, youth with an intellectual disability, migrants, adults (aged 40-64 years), and older adults (aged >65 years) via convenience sampling in the region of Twente in the Netherlands. The app was evaluated with scenario-based, think-aloud usability tests and additional interviews. Findings were recorded via voice recordings, observation notes, and the Dutch User Experience Questionnaire, and some participants wore eye trackers to measure gaze behavior. Results Our results showed that the app is easy to use, although problems occurred with understandability and accessibility. Older adults and youth with a lower education level did not understand why or under what circumstances they would receive notifications, why they must share their key (ie, their assigned identifier), and what happens after sharing. In particular, youth in the lower-education category did not trust or understand Bluetooth signals, or comprehend timing and follow-up activities after a risk exposure notification. Older adults had difficulties multitasking (speaking with a public health worker and simultaneously sharing the key in the app). Public health authorities appeared to be unprepared to receive support from the app during traditional contact tracing because their telephone conversation protocol lacks guidance, explanation, and empathy. Conclusions The study indicated that the CoronaMelder app is easy to use, but participants experienced misunderstandings about its functioning. The perceived lack of clarity led to misconceptions about the app, mostly regarding its usefulness and privacy-preserving mechanisms. Tailored and targeted communication through, for example, public campaigns or social media, is necessary to provide correct information about the app to residents in the Netherlands. Additionally, the app should be presented as part of the national coronavirus measures instead of as a stand-alone app offered to the public. Public health workers should be trained to effectively and empathetically instruct users on how to use the CoronaMelder app.

scholarly journals On the Futility of Contact Tracing

2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Jay Bhattacharya ◽  
Mikko Packalen
Keyword(s):  
Public Health ◽  
Central Place ◽  
Contact Tracing ◽  
Health Authorities ◽  
Public Health Authorities

Throughout the COVID-19 epidemic, public health authorities have promoted contact tracing as a key tool to combat the spread of the SARS-CoV-2 virus. Jay Bhattacharya and Mikko Packalen argue that contact tracing does not deserve the central place it has received in the tool kit public health authorities use to control the virus, and that, in some cases, it may make an outbreak worse.

scholarly journals Imported chikungunya cases in an area newly colonised by Aedes albopictus: mathematical assessment of the best public health strategy

2016 ◽  
Vol 21 (18) ◽  
Author(s):  
Thomas Sochacki ◽  
Frédéric Jourdain ◽  
Yvon Perrin ◽  
Harold Noel ◽  
Marie-Claire Paty ◽  
...  
Keyword(s):  
Public Health ◽  
Surveillance System ◽  
Economic Cost ◽  
Public Health Strategy ◽  
Health Authorities ◽  
Laboratory Confirmation ◽  
Health Strategy ◽  
Imported Cases ◽  
Public Health Authorities ◽  
Local Transmission

We aimed to identify the optimal strategy that should be used by public health authorities against transmission of chikungunya virus in mainland France. The theoretical model we developed, which mimics the current surveillance system, predicted that without vector control (VC), the probability of local transmission after introduction of viraemic patients was around 2%, and the number of autochthonous cases between five and 15 persons per hectare, depending on the number of imported cases. Compared with this baseline, we considered different strategies (VC after clinical suspicion of a case or after laboratory confirmation, for imported or autochthonous cases): Awaiting laboratory confirmation for suspected imported cases to implement VC had no significant impact on the epidemiological outcomes analysed, mainly because of the delay before entering into the surveillance system. However, waiting for laboratory confirmation of autochthonous cases before implementing VC resulted in more frequent outbreaks. After analysing the economic cost of such strategies, our study suggested implementing VC immediately after the notification of a suspected autochthonous case as the most efficient strategy in settings where local transmission has been proven. Nevertheless, we identified that decreasing reporting time for imported cases should remain a priority.

A Brief Forewarning Intervention Overcomes Negative Effects of Salient Changes in COVID-19 Guidance

2021 ◽  
Author(s):  
Jeremy David Gretton ◽  
Ethan Andrew Meyers ◽  
Alexander C. Walker ◽  
Jonathan Albert Fugelsang ◽  
Derek J. Koehler
Keyword(s):  
Public Health ◽  
Health Behavior ◽  
Scientific Understanding ◽  
Contact Tracing ◽  
Negative Effects ◽  
Health Authorities ◽  
Public Health Authorities ◽  
Over Time ◽  
Health Messaging

During the COVID-19 pandemic, public health messaging, including guidance regarding protective health behavior (e.g., use of non-medical masks), changed over time. Although many revisions were a result of gains in scientific understanding, we nonetheless hypothesized that making changes in guidance salient would negatively impact evaluations of experts and health-protective intentions. In Study 1 (N = 300), we demonstrate that describing COVID-19 guidance in terms of inconsistency (versus consistency) leads people to perceive scientists and public health authorities less favorably (e.g., as less expert). Among a Canadian subsample, making guidance change salient also reduced intentions to download the COVID Alert contact tracing app. In Study 2 (N = 1399), we show that a brief forewarning intervention mitigates detrimental effects of changes in guidance. In the absence of forewarning, emphasizing inconsistency harmed judgments of public health authorities and reduced health-protective intentions, but forewarning eliminated this effect.

scholarly journals Virology, Epidemiology, Pathogenesis, and Control of COVID-19

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 372 ◽  
Author(s):  
Yuefei Jin ◽  
Haiyan Yang ◽  
Wangquan Ji ◽  
Weidong Wu ◽  
Shuaiyin Chen ◽  
...  
Keyword(s):  
Public Health ◽  
Severe Acute Respiratory Syndrome ◽  
World Health ◽  
Global Public Health ◽  
Current State ◽  
Health Authorities ◽  
Public Health Authorities ◽  
Health Organization ◽  
And Control ◽  
Present Understanding

The outbreak of emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease (COVID-19) in China has been brought to global attention and declared a pandemic by the World Health Organization (WHO) on March 11, 2020. Scientific advancements since the pandemic of severe acute respiratory syndrome (SARS) in 2002~2003 and Middle East respiratory syndrome (MERS) in 2012 have accelerated our understanding of the epidemiology and pathogenesis of SARS-CoV-2 and the development of therapeutics to treat viral infection. As no specific therapeutics and vaccines are available for disease control, the epidemic of COVID-19 is posing a great threat for global public health. To provide a comprehensive summary to public health authorities and potential readers worldwide, we detail the present understanding of COVID-19 and introduce the current state of development of measures in this review.

scholarly journals COVID-19 Vaccination during Pregnancy in Southeast Asia

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jia Ni Kwan ◽  
Hong Chuan Loh ◽  
Irene Looi
Keyword(s):  
Public Health ◽  
Severe Acute Respiratory Syndrome ◽  
Hand Hygiene ◽  
Southeast Asia ◽  
Pregnant Women ◽  
Effective Strategy ◽  
The Public ◽  
Health Authorities ◽  
Public Health Authorities ◽  
Vulnerable Population Groups

Southeast Asia is rapidly becoming the region hit hardest by coronavirus disease (COVID-19), as evidenced by the surging daily number of new confirmed cases and deaths. The COVID-19 crisis continues to worsen with the entry of the more transmissible variants of concern, primarily the Delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which was first identified in India. Pregnant women are among the vulnerable population groups at risk of suffering from severe COVID-19 and may experience poor pregnancy and neonatal outcomes due to the infection. Vaccination seems to be the most effective strategy to curb the pandemic and secondarily by social distancing, wearing face masks and practising hand hygiene. There has been limited yet reassuring evidence in support of vaccinating pregnant women against COVID-19. We sought to review the latest evidence regarding the safety, immunogenicity and reactogenicity of COVID-19 vaccines in pregnant women as well as the recommendations and guidance provided by the public health authorities in the countries in Southeast Asia.

scholarly journals Retarded Logistic Equation as a Universal Dynamic Model for the Spread of COVID-19

2020 ◽  
Author(s):  
B Shayak ◽  
Mohit M Sharma
Keyword(s):  
Public Health ◽  
Dynamic Model ◽  
Herd Immunity ◽  
Logistic Equation ◽  
Mitigation Measures ◽  
Contact Tracing ◽  
Health Measures ◽  
Health Authorities ◽  
City District ◽  
Public Health Authorities

ABSTRACTIn this work we propose the retarded logistic equation as a dynamic model for the spread of COVID-19 all over the world. This equation accounts for asymptomatic transmission, pre-symptomatic or latent transmission as well as contact tracing and isolation, and leads to a transparent definition of the instantaneous reproduction number R. For different parameter values, the model equation admits different classes of solutions. These solution classes correspond to, inter alia, containment of the outbreak via public health measures, exponential growth despite public health measures, containment despite reopening and second wave following reopening. We believe that the spread of COVID in every localized area such as a city, district or county can be accounted for by one of our solution classes. In regions where R > 1 initially despite aggressive epidemic management efforts, we find that if the mitigation measures are sustained, then it is still possible for R to dip below unity when far less than the region’s entire population is affected, and from that point onwards the outbreak can be driven to extinction in time. We call this phenomenon partial herd immunity. Our analysis indicates that COVID-19 is an extremely vicious and unpredictable disease which poses unique challenges for public health authorities, on account of which “case races” among various countries and states do not serve any purpose and present delusive appearances while ignoring significant determinants.

scholarly journals Massive SARS-CoV-2 RT-PCR Testing on Rural Communities in Manabi Province (Ecuador) Reveals Severe COVID-19 Outbreaks

2021 ◽  
Vol 104 (4) ◽  
pp. 1493-1494
Author(s):  
Esteban Ortiz-Prado ◽  
Aquiles R. Henriquez-Trujillo ◽  
Ismar A. Rivera-Olivero ◽  
Byron Freire-Paspuel ◽  
Alexander Paolo Vallejo-Janeta ◽  
...  
Keyword(s):  
Public Health ◽  
Rural Communities ◽  
Coastal Region ◽  
Contact Tracing ◽  
Rt Pcr ◽  
The Public ◽  
Health Infrastructure ◽  
Health Authorities ◽  
Public Health Authorities ◽  
The Impact

ABSTRACTRural communities from Latin America are particularly susceptible to develop serious outbreaks of infectious diseases. Inadequate diagnosis and poor health infrastructure jeopardize proper contact tracing and other actions to reduce the impact of COVID-19 in the region. We herein describe the preliminary data of our ongoing fieldwork of massive testing among nonhospitalized rural population in Manabi Province of the coastal region of Ecuador. A total of 1,479 people from six different rural communities were tested for SARS-CoV-2 by RT-qPCR following the CDC protocol; 350 individuals tested positive, resulting in an overall attack rate of 23.7% for SARS-CoV-2 infection. This ultrahigh prevalence must urge to the public health authorities from Ecuador to take immediate actions to counteract this dramatic scenario in Manabi Province and to improve SARS-CoV-2 testing countrywide.

scholarly journals Contact tracing following measles exposure on three international flights, Germany, 2017

2019 ◽  
Vol 24 (19) ◽  
Author(s):  
Sebastian Thole ◽  
Daniela Kalhoefer ◽  
Maria an der Heiden ◽  
Doris Nordmann ◽  
Inka Daniels-Haardt ◽  
...  
Keyword(s):  
Public Health ◽  
Data Protection ◽  
Contact Tracing ◽  
Transport Sector ◽  
Post Exposure Prophylaxis ◽  
European Guidelines ◽  
Health Authorities ◽  
Public Health Authorities ◽  
Contact Data ◽  
Exposure Prophylaxis

When a person with contagious measles has travelled by aircraft, European guidelines recommend contact tracing of passengers and crew within 5 days of exposure for post-exposure prophylaxis (PEP), and within 12 days of exposure for informing passengers and crew, in order to prevent further transmissions. To be effective, contact tracing requires prompt diagnosis, immediate notification of public health authorities and rapid availability of passenger contact data. We report two events of contact tracing initiated in Germany after two individuals with measles travelled on three international flights. In one event, contact tracing was initiated late because laboratory confirmation of a clinically diagnosed measles case was awaited unnecessarily. Accessing passenger contact data was difficult in both events because of data protection issues with the airline which was not based in Germany. In both events, passengers were not reached in time to provide PEP, and one event resulted in at least two secondary measles cases. As all passengers were reached before the incubation period ended, tertiary cases were most probably prevented. Public health authorities and the transport sector must collaborate to resolve competing legal regulations for infection prevention and data protection, to simplify and accelerate identification of air travellers exposed to communicable diseases.

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