scholarly journals Threshold analyses on combinations of testing, population size, and vaccine coverage for COVID-19 control in a university setting

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255864
Author(s):  
Xinmeng Zhao ◽  
Hanisha Tatapudi ◽  
George Corey ◽  
Chaitra Gopalappa
Keyword(s):  
Population Size ◽  
Vaccine Coverage ◽  
Disease Outbreaks ◽  
Face Mask ◽  
The United States ◽  
Contact Rate ◽  
Transmission Rates ◽  
Contact Rates ◽  
Residential University ◽  
Full Population

We simulated epidemic projections of a potential COVID-19 outbreak in a residential university population in the United States under varying combinations of asymptomatic tests (5% to 33% per day), transmission rates (2.5% to 14%), and contact rates (1 to 25), to identify the contact rate threshold that, if exceeded, would lead to exponential growth in infections. Using this, we extracted contact rate thresholds among non-essential workers, population size thresholds in the absence of vaccines, and vaccine coverage thresholds. We further stream-lined our analyses to transmission rates of 5 to 8%, to correspond to the reported levels of face-mask-use/physical-distancing during the 2020 pandemic. Our results suggest that, in the absence of vaccines, testing alone without reducing population size would not be sufficient to control an outbreak. If the population size is lowered to 34% (or 44%) of the actual population size to maintain contact rates at 4 (or 7) among non-essential workers, mass tests at 25% (or 33%) per day would help control an outbreak. With the availability of vaccines, the campus can be kept at full population provided at least 95% are vaccinated. If vaccines are partially available such that the coverage is lower than 95%, keeping at full population would require asymptomatic testing, either mass tests at 25% per day if vaccine coverage is at 63–79%, or mass tests at 33% per day if vaccine coverage is at 53–68%. If vaccine coverage is below 53%, to control an outbreak, in addition to mass tests at 33% per day, it would also require lowering the population size to 90%, 75%, and 60%, if vaccine coverage is at 38–53%, 23–38%, and below 23%, respectively. Threshold estimates from this study, interpolated over the range of transmission rates, can collectively help inform campus level preparedness plans for adoption of face mask/physical-distancing, testing, remote instructions, and personnel scheduling, during non-availability or partial-availability of vaccines, in the event of SARS-Cov2-type disease outbreaks.

scholarly journals Contact surveys reveal heterogeneities in age-group contributions to SARS-CoV-2 dynamics in the United States

2021 ◽  
Author(s):  
Taylor Chin ◽  
Dennis M. Feehan ◽  
Caroline O. Buckee ◽  
Ayesha S. Mahmud
Keyword(s):  
United States ◽  
Age Groups ◽  
The United States ◽  
Contact Rate ◽  
Age Group ◽  
Contact Rates ◽  
Contact Patterns ◽  
Age Structured ◽  
The Impact ◽  
Over Time

SARS-CoV-2 is spread primarily through person-to-person contacts. Quantifying population contact rates is important for understanding the impact of physical distancing policies and for modeling COVID-19, but contact patterns have changed substantially over time due to shifting policies and behaviors. There are surprisingly few empirical estimates of age-structured contact rates in the United States both before and throughout the COVID-19 pandemic that capture these changes. Here, we use data from six waves of the Berkeley Interpersonal Contact Survey (BICS), which collected detailed contact data between March 22, 2020 and February 15, 2021 across six metropolitan designated market areas (DMA) in the United States. Contact rates were low across all six DMAs at the start of the pandemic. We find steady increases in the mean and median number of contacts across these localities over time, as well as a greater proportion of respondents reporting a high number of contacts. We also find that young adults between ages 18 and 34 reported more contacts on average compared to other age groups. The 65 and older age group consistently reported low levels of contact throughout the study period. To understand the impact of these changing contact patterns, we simulate COVID-19 dynamics in each DMA using an age-structured mechanistic model. We compare results from models that use BICS contact rate estimates versus commonly used alternative contact rate sources. We find that simulations parameterized with BICS estimates give insight into time-varying changes in relative incidence by age group that are not captured in the absence of these frequently updated estimates. We also find that simulation results based on BICS estimates closely match observed data on the age distribution of cases, and changes in these distributions over time. Together these findings highlight the role of different age groups in driving and sustaining SARS-CoV-2 transmission in the U.S. We also show the utility of repeated contact surveys in revealing heterogeneities in the epidemiology of COVID-19 across localities in the United States.

scholarly journals Threshold analyses on rates of testing, transmission, and contact for COVID-19 control in a university setting

2020 ◽  
Author(s):  
Xinmeng Zhao ◽  
Hanisha Anand Tatapudi ◽  
George Corey ◽  
Chaitra Gopalappa
Keyword(s):  
Transmission Rate ◽  
Full Range ◽  
Face Mask ◽  
Contact Rate ◽  
Contact Rates ◽  
Time Of Infection ◽  
Four Levels ◽  
The Impact ◽  
Mass Test ◽  
Rate Threshold

We simulated epidemic projections of a potential COVID-19 outbreak in a university population of 38,000 persons, under varying combinations of mass test rate (0% to 10%), contact trace and test rate (0% to 50%), transmission rate (probability of transmission per contact per day), and contact rate (number of contacts per person per day). We simulated four levels of transmission rate, 14% (average baseline), 8% (average for face mask use), 5.4% (average for 3ft distancing), and 2.5% (average for 6ft distancing and face mask use), interpolating results to the full range to understand the impact of uncertainty in effectiveness, feasibility, and adherence of face mask use and physical distancing. We evaluated contact rates between 1 and 25, to identify the threshold that, if exceeded, could lead to several deaths. When transmission rate was 8%, for trace and test at 50%, the contact rate threshold was 8. However, any time delays in trace, test, and isolation quickly raised the number of deaths. Keeping contact rate to 3 or below was more robust to testing delays, keeping deaths below 1 up to a delay of 5 days from the time of infection to diagnosis and isolation. For a contact rate of 3, the number of trace and tests peaked to about 70 per day and relaxed to 25 with the addition of 10% mass test. When transmission rate was 5.4%, for trace and test at 50%, the contact rate threshold was 10. However, keeping contact rate to 4 or below was more robust to delays in testing, keeping deaths below 1 up to a delay of 6 days from the time of infection to diagnosis and isolation. For contact rate of 4, the number of trace and tests peaked at 50 per day and relaxed to 10 per day with the addition of 10% mass test. Threshold estimates can help develop on-campus scheduling and indoor-spacing plans in conjunction with plans for asymptomatic testing for COVID-19. Combination thresholds should be selected specific to the setting based on an assessment of the feasibility and resource 48 availability for testing and quarantine.

scholarly journals Transmission Potential of Zika Virus by Aedes aegypti (Diptera: Culicidae) and Ae. mediovittatus (Diptera: Culicidae) Populations From Puerto Rico

2021 ◽  
Author(s):  
Rebecca A Zimler ◽  
Donald A Yee ◽  
Barry W Alto
Keyword(s):  
Puerto Rico ◽  
Aedes Aegypti ◽  
Zika Virus ◽  
Mosquito Species ◽  
The United States ◽  
Infection Rates ◽  
Transmission Potential ◽  
Transmission Rates ◽  
Higher Doses ◽  
Local Transmission

Abstract Recurrence of local transmission of Zika virus in Puerto Rico is a major public health risk to the United States, where mosquitoes Aedes aegypti (Linnaeus) and Aedes mediovittatus (Coquillett) are abundant. To determine the extent to which Ae. mediovittatus are capable of transmitting Zika virus and the influence of viremia, we evaluated infection and transmission in Ae. mediovittatus and Ae. aegypti from Puerto Rico using serial dilutions of infectious blood. Higher doses of infectious blood resulted in greater infection rates in both mosquitoes. Aedes aegypti females were up to twice as susceptible to infection than Ae. mediovittatus, indicating a more effective midgut infection barrier in the latter mosquito species. Aedes aegypti exhibited higher disseminated infection (40–95%) than Ae. mediovittatus (<5%), suggesting a substantial midgut escape barrier in Ae. mediovittatus. For Ae. aegypti, transmission rates were low over a range of doses of Zika virus ingested, suggesting substantial salivary gland barriers.

scholarly journals The Arab region’s contribution to global COVID-19 research: Bibliometric and visualization analysis

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Sa’ed H. Zyoud
Keyword(s):  
Public Health ◽  
Saudi Arabia ◽  
Population Size ◽  
Low Income ◽  
Research Output ◽  
Arab World ◽  
The United States ◽  
Arab Countries ◽  
Public Health Issue ◽  
Global Research

Abstract Background At the global level and in the Arab world, particularly in low-income countries, COVID-19 remains a major public health issue. As demonstrated by an incredible number of COVID-19-related publications, the research science community responded rapidly. Therefore, this study was intended to assess the growing contribution of the Arab world to global research on COVID-19. Methods For the period between December 2019 and March 2021, the search for publications was conducted via the Scopus database using terms linked to COVID-19. VOSviewer 1.6.16 software was applied to generate a network map to assess hot topics in this area and determine the collaboration patterns between different countries. Furthermore, the research output of Arab countries was adjusted in relation to population size and gross domestic product (GDP). Results A total of 143,975 publications reflecting the global overall COVID-19 research output were retrieved. By restricting analysis to the publications published by the Arab countries, the research production was 6131 documents, representing 4.26% of the global research output regarding COVID-19. Of all these publications, 3990 (65.08%) were original journal articles, 980 (15.98%) were review articles, 514 (8.38%) were letters and 647 (10.55%) were others, such as editorials or notes. The highest number of COVID-19 publications was published by Saudi Arabia (n = 2186, 35.65%), followed by Egypt (n = 1281, 20.78%) and the United Arab Emirates (UAE), (n = 719, 11.73%). After standardization by population size and GDP, Saudi Arabia, UAE and Lebanon had the highest publication productivity. The collaborations were mostly with researchers from the United States (n = 968), followed by the United Kingdom (n = 661). The main research lines identified in COVID-19 from the Arab world are related to: public health and epidemiology; immunological and pharmaceutical research; signs, symptoms and clinical diagnosis; and virus detection. Conclusions A novel analysis of the latest Arab COVID-19-related studies is discussed in the current study and how these findings are connected to global production. Continuing and improving future collaboration between developing and developed countries will also help to facilitate the sharing of responsibilities for COVID-19 in research results and the implementation of policies for COVID-19.

scholarly journals Belonging in the Coronaverse: Will There Be Time?

2021 ◽  
Vol 1 (1) ◽  
pp. 100-115
Author(s):  
Kate Fischer ◽  
Malika Rakhmonova ◽  
Mike Tran
Keyword(s):  
College Experience ◽  
The United States ◽  
Limited Time ◽  
The Novel ◽  
Residential University ◽  
To Come ◽  
Novel Coronavirus ◽  
University Experience ◽  
The U.S ◽  
Older Siblings

Abstract Since the spring of 2020 SARS-CoV-2, the novel coronavirus, has upended lives and caused a rethinking of nearly all social behaviors in the United States. This paper examines the ways in which the pandemic, shutdown, and gradual move towards “normal” have laid bare and obfuscated societal pressures regarding running out of time as it pertains to the residential university experience. Promised by movies, television, and older siblings and friends as a limited-time offer, the “typical” college experience is baked into the U.S. imaginary, reinforcing a host of notions of who “belongs” on campus along lines of race, class, and age. Fed a vision of what their whole lives “should be”, students who enter a residential four-year college are already imbued with a nostalgia for what is yet to come, hailed, in Althusser’s (2006[1977]) sense, as university subjects even before their first class. The upheaval of that subjecthood during the pandemic has raised important questions about the purpose of the college experience as well as how to belong to a place that is no longer there.

A proposal to leverage high-quality veterinary diagnostic laboratory large data streams for animal health, public health, and One Health

2021 ◽  
pp. 104063872110030
Author(s):  
Craig N. Carter ◽  
Jacqueline L. Smith
Keyword(s):  
Public Health ◽  
Data Streams ◽  
One Health ◽  
Animal Health ◽  
Disease Outbreaks ◽  
Large Data ◽  
Health Impact ◽  
The United States ◽  
Zoonotic Diseases ◽  
Diagnostic Laboratory

Test data generated by ~60 accredited member laboratories of the American Association of Veterinary Laboratory Diagnosticians (AAVLD) is of exceptional quality. These data are captured by 1 of 13 laboratory information management systems (LIMSs) developed specifically for veterinary diagnostic laboratories (VDLs). Beginning ~2000, the National Animal Health Laboratory Network (NAHLN) developed an electronic messaging system for LIMS to automatically send standardized data streams for 14 select agents to a national repository. This messaging enables the U.S. Department of Agriculture to track and respond to high-consequence animal disease outbreaks such as highly pathogenic avian influenza. Because of the lack of standardized data collection in the LIMSs used at VDLs, there is, to date, no means of summarizing VDL large data streams for multi-state and national animal health studies or for providing near-real-time tracking for hundreds of other important animal diseases in the United States that are detected routinely by VDLs. Further, VDLs are the only state and federal resources that can provide early detection and identification of endemic and emerging zoonotic diseases. Zoonotic diseases are estimated to be responsible for 2.5 billion cases of human illness and 2.7 million deaths worldwide every year. The economic and health impact of the SARS-CoV-2 pandemic is self-evident. We review here the history and progress of data management in VDLs and discuss ways of seizing unexplored opportunities to advance data leveraging to better serve animal health, public health, and One Health.

scholarly journals A cross-sectional study measuring contact patterns using diaries in an urban and a rural community in South Africa, 2018

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jackie Kleynhans ◽  
Stefano Tempia ◽  
Meredith L. McMorrow ◽  
Anne von Gottberg ◽  
Neil A. Martinson ◽  
...  
Keyword(s):  
South Africa ◽  
Age Groups ◽  
Cross Sectional Study ◽  
Rural Site ◽  
Urban Site ◽  
Contact Rate ◽  
Sectional Study ◽  
Cross Sectional ◽  
Contact Rates ◽  
Contact Patterns

Abstract Background Describing contact patterns is crucial to understanding infectious disease transmission dynamics and guiding targeted transmission mitigation interventions. Data on contact patterns in Africa, especially South Africa, are limited. We measured and compared contact patterns in a rural and urban community, South Africa. We assessed participant and contact characteristics associated with differences in contact rates. Methods We conducted a cross-sectional study nested in a prospective household cohort study. We interviewed participants to collect information on persons in contact with for one day. We described self-reported contact rates as median number people contacted per day, assessed differences in contact rates based on participant characteristics using quantile regression, and used a Poisson model to assess differences in contact rates based on contact characteristics within age groups. We also calculated cumulative person hours in contact within age groups at different locations. Results We conducted 535 interviews (269 rural, 266 urban), with 17,252 contacts reported. The overall contact rate was 14 (interquartile range (IQR) 9–33) contacts per day. Those ≤18 years had higher contact rates at the rural site (coefficient 17, 95% confidence interval (95%CI) 10–23) compared to the urban site, for those aged 14–18 years (13, 95%CI 3–23) compared to < 7 years. No differences were observed for adults. There was a strong age-based mixing, with age groups interacting more with similar age groups, but also interaction of participants of all ages with adults. Children aged 14–18 years had the highest cumulative person hours in contact (116.3 rural and 76.4 urban). Conclusions Age played an important role in the number and duration of contact events, with children at the rural site having almost double the contact rate compared to the urban site. These contact rates can be utilized in mathematical models to assess transmission dynamics of infectious diseases in similar communities.

Food-Borne Disease Outbreaks in the United States, 1973

1975 ◽  
Vol 132 (2) ◽  
pp. 224-228 ◽  
Author(s):  
J. M. Hughes ◽  
M. H. Merson ◽  
R. A. Pollard
Keyword(s):  
United States ◽  
Disease Outbreaks ◽  
The United States ◽  
Food Borne

Eumops floridanus (Chiroptera: Molossidae)

2021 ◽  
Vol 53 (1009) ◽  
pp. 125-133
Author(s):  
Jessica M Vannatta ◽  
Jeffery A Gore ◽  
Verity L Mathis ◽  
Brian D Carver
Keyword(s):  
United States ◽  
Population Size ◽  
The United States ◽  
Small Population ◽  
Species Level ◽  
Small Population Size ◽  
Restricted Distribution ◽  
Dead Trees ◽  
Fish And Wildlife Service

Abstract Eumops floridanus (Allen, 1932) is a molossid commonly called the Florida bonneted bat or the Florida mastiff bat. Eumops floridanus is the largest species of bat in Florida and is one of 16 species in the genus Eumops. With one of the smallest distributions of any bat in the United States, it is endemic to southern peninsular Florida where it roosts in cavities of live and dead trees and man-made structures. Eumops floridanus was formerly classified as a subspecies of E. glaucinus but has been elevated to species level based on morphology. Due primarily to its restricted distribution, small population size, and the continued loss of habitat, E. floridanus is federally listed as “Endangered” (EN) by the United States Fish and Wildlife Service.

STAPHYLOCOCCAL DISEASE OUTBREAKS IN HOSPITAL NURSERIES IN THE UNITED STATES—DECEMBER 1971 THROUGH MARCH 1972

PEDIATRICS ◽  
1973 ◽  
Vol 51 (2) ◽  
pp. 413-417
Author(s):  
Richard E. Dixon ◽  
Richard A. Kaslow ◽  
George F. Mallison ◽  
John V. Bennett
Keyword(s):  
United States ◽  
Newborn Infants ◽  
Disease Outbreaks ◽  
The United States

Following the Food and Drug Administration's release of recommendations on limiting the use of products containing hexachlorophene (HCP) for bathing newborn infants, 142 hospitals spontaneously reported outbreaks of neonatal staphybococcal disease. Epidemiologic investigations were carried out in 73 of these hospitals; 66 had confirmed outbreaks of neonatal staphylococcal disease. In 60 of the 66, discontinuation of HCP bathing of newborn infants preceded the epidemic. Alterations in handwashing policies did not appear implicated in any outbreak investigated. These findings suggested that discontinuation of HCP bathing of newborn infants was associated with increased incidence of neonatal staphylococcal disease.

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