When Should Asymptomatic Persons Be Tested for COVID-19?

ABSTRACTOn 24 August 2020, the Centers for Disease Control and Prevention (CDC) updated its website to highlight that asymptomatic individuals, even those with exposure to a COVID-19-positive contact, do not necessarily need to be tested unless they have medical conditions associated with increased risk of severe illness from COVID-19. The CDC subsequently updated its guidance on 19 September 2020 to support testing of asymptomatic persons, including close contacts of persons with documented SARS-CoV-2 infection. In this editorial, the American Society for Microbiology Clinical and Public Health Microbiology Committee’s Subcommittee on Laboratory Practices comments on testing of asymptomatic individuals relative to current medical knowledge of the virus and mitigation measures. Specific points are provided concerning such testing when undertaking contact tracing and routine surveillance. Limitations to consider when testing asymptomatic persons are covered, including the need to prioritize testing of contacts of positive COVID-19 cases. We urge the CDC to consult with primary stakeholders of COVID-19 testing when making such impactful changes in testing guidance.

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Prevalence and risk factors for in-school transmission of SARS-CoV-2 in Massachusetts K-12 public schools, 2020-2021

10.1101/2021.09.22.21263900 ◽

2021 ◽

Author(s):

Sandra B Nelson ◽

Caitlin Dugdale ◽

Alyssa Bilinski ◽

Duru Cosar ◽

Nira L Pollock ◽

...

Keyword(s):

Public Schools ◽

Index Case ◽

Transmission Risk ◽

Mitigation Measures ◽

Contact Tracing ◽

Convenience Sample ◽

School Based ◽

Increased Risk ◽

K 12 ◽

Index Cases

Introduction The SARS-CoV-2 secondary attack rate (SAR) in schools is low when mitigation measures are adopted, Data on the relative impact of such strategies are limited. We evaluated the SARS-CoV-2 SAR in Massachusetts schools during 2020-21 and factors associated with transmission risk. Methods: In a convenience sample of 25 Massachusetts public K-12 school districts, de-identified information about SARS-CoV-2 cases and their school-based contacts was reported using a standardized contact-tracing tool. Index cases were included if they were in school while infectious. SAR was defined as the proportion of in-school contacts acquiring SARS-CoV-2 infection and designated as possible or probable in-school transmission by school-based teams. We compared exposure-specific SAR using unadjusted risk ratios (RR) with 95% confidence intervals (CI); p-values were calculated using Fishers exact tests. Results Eight districts (70 schools with >33,000 enrolled students) participated. There were 435 index cases and 1,771 school-based contacts (Table 1). Most contacts (1327/1771 [75%]) underwent SARS-CoV-2 testing and 39/1327 (2.9%) contacts tested positive. Of 39 positive contacts, 10 (25.6%) had clear out-of-school exposures and were deemed not in-school transmissions, so were excluded from further calculations. Twenty-nine (74.4%) contacts were deemed possible or probable in-school transmissions, resulting in an in-school SAR of 2.2%. Of the 29 in-school transmissions, 6 (20.7%) were staff-to-staff, 7 (24.1%) were staff-to-student, 3 (10.3%) were student-to-staff, and 13 (44.8%) were student-to-student; 6 (20.7%) occurred from index cases attending work/school while symptomatic. The unadjusted SAR (Table 2) was significantly higher if the index case was a staff member versus a student (RR 2.18, 95% CI 1.06-4.49; p=0.030), if the index case was identified via in-school contact tracing versus via school-based asymptomatic testing (RR 8.44, 95% CI 1.98-36.06; p=0.001), if the exposure occurred at lunch versus elsewhere (RR 5.74, 95% CI 2.11-15.63; p<0.001; all lunch transmissions were staff-to-staff), and if both parties were unmasked versus both masked (RR 6.98, 95% CI 3.09-15.77; p<0.001). For students, SAR did not differ by grade level. Conclusions Secondary attack rates for SARS-CoV-2 were low in public school settings with comprehensive mitigation measures in place before the emergence of the delta variant; lack of masking and staff-to-staff dining were associated with increased risk.

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ANOTHER LOOK AT HAND-WASHING BEHAVIOR

Social Behavior and Personality An International Journal ◽

10.2224/sbp.2005.33.7.629 ◽

2005 ◽

Vol 33 (7) ◽

pp. 629-634 ◽

Cited By ~ 13

Author(s):

Elizabeth Monk-Turner ◽

Donald Edwards ◽

Josh Broadstone ◽

Robert Hummel ◽

Selena Lewis ◽

...

Keyword(s):

Disease Control ◽

Hand Washing ◽

Data Support ◽

Regional University ◽

Control And Prevention ◽

Centers For Disease Control ◽

American Society ◽

American Society For Microbiology

Hand-washing behavior among students at a large regional university was observed. The authors noted how hand-washing behavior varied by race, gender, and having an observer present. Of the 410 subjects observed, most (221) were men and 232 were white. The authors expected that more women than men would wash their hands and that few subjects would wash their hands for the time (15 seconds or more) recommended by the American Society for Microbiology (ASM) and the Centers for Disease Control and Prevention (CDC). The data support both of these propositions.

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SARS-CoV-2 Seroprevalence Survey Among District Residents Presenting for Serologic Testing at Three Community-Based Test Sites — Washington, DC, July–August, 2020

10.1101/2021.02.15.21251764 ◽

2021 ◽

Author(s):

Adrienne Sherman ◽

Jacqueline Reuben ◽

Naomi David ◽

Delores P. Quasie-Woode ◽

Jayleen K. L. Gunn ◽

...

Keyword(s):

Mitigation Measures ◽

Severe Illness ◽

Sample Population ◽

Washington Dc ◽

Community Based ◽

Cross Sectional ◽

Convenience Sample ◽

Serologic Testing ◽

Increased Risk ◽

Prior Infection

ABSTRACTBackgroundThe District of Columbia (DC), a major metropolitan area, continues to see community transmission of SARS-CoV-2. While serologic testing does not indicate current SARS-CoV-2 infection, it can indicate prior infection and help inform local policy and health guidance. The DC Department of Health (DC Health) conducted a community-based survey to estimate DC’s SARS-CoV-2 seroprevalence and identify seropositivity-associated factors.MethodsA mixed-methods cross-sectional serology survey was conducted among a convenience sample of DC residents during July 27–August 21, 2020. Free serology testing was offered at three public test sites. Participants completed an electronic questionnaire on household and demographic characteristics, COVID-like illness (CLI) since January 1, 2020, comorbidities, and SARS-CoV-2 exposures. Univariate and bivariate analyses were conducted to describe the sample population and assess factors associated with seropositivity.ResultsAmong a sample of 671 participants, 51 individuals were seropositive, yielding an estimated seroprevalence of 7.6%. More than half (56.9%) of the seropositive participants reported no prior CLI; nearly half (47.1%) had no prior SARS-CoV-2 testing. Race/ethnicity, prior SARS-CoV-2 testing, prior CLI, employment status, and contact with confirmed COVID-19 cases were associated with seropositivity (P<0.05). Among those reporting prior CLI, loss of taste or smell, duration of CLI, fewer days between CLI and serology test, or prior viral test were associated with seropositivity (P≤0.006).ConclusionsThese findings indicate many seropositive individuals reported no symptoms consistent with CLI since January or any prior SARS-CoV-2 testing. This underscores the potential for cases to go undetected in the community and suggests wider-spread transmission than previously reported in DC.What is already known on this subject?Traditional case-based detection and syndromic surveillance efforts might not identify mildly symptomatic or asymptomatic SARS-CoV-2 infections. This is particularly true among people in the general population who do not have increased risk of severe illness or might not be tested otherwise. Consequently, the true population prevalence of prior SARS-CoV-2 infections might not be known.What this study adds?A community-based seroprevalence survey conducted in Washington, DC, during July 27–August 21, 2020 estimated that 7.6% of the convenience sample had antibodies to SARS-CoV-2, indicating prior infection. At the time of this survey, most of the participants reported that they had not been previously infected with or tested for SARS-CoV-2. These findings highlight both the value of serologic surveillance in complementing other surveillance methods, and the importance of continued prevention and mitigation measures, such as maintaining physical distances of at least 6 feet, avoiding crowds and poorly ventilated spaces, practicing frequent hand hygiene, and wearing face masks properly and consistently around people who do not live with you.

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A narrative review on current duodenoscope reprocessing techniques and novel developments

Antimicrobial Resistance and Infection Control ◽

10.1186/s13756-021-01037-z ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Maarten Heuvelmans ◽

Herman F. Wunderink ◽

Henny C. van der Mei ◽

Jan F. Monkelbaan

Keyword(s):

The United States ◽

Pathogen Transmission ◽

Clinical Implementation ◽

Sampling Protocol ◽

Strict Adherence ◽

United States Food ◽

Control And Prevention ◽

American Society ◽

High Level ◽

American Society For Microbiology

AbstractDuodenoscopy-associated infections occur worldwide despite strict adherence to reprocessing standards. The exact scope of the problem remains unknown because a standardized sampling protocol and uniform sampling techniques are lacking. The currently available multi-society protocol for microbial culturing by the Centers for Disease Control and Prevention, the United States Food and Drug Administration (FDA) and the American Society for Microbiology, published in 2018 is too laborious for broad clinical implementation. A more practical sampling protocol would result in increased accessibility and widespread implementation. This will aid to reduce the prevalence of duodenoscope contamination. To reduce the risk of duodenoscopy-associated pathogen transmission the FDA advised four supplemental reprocessing measures. These measures include double high-level disinfection, microbiological culturing and quarantine, ethylene oxide gas sterilization and liquid chemical sterilization. When the supplemental measures were advised in 2015 data evaluating their efficacy were sparse. Over the past five years data regarding the supplemental measures have become available that place the efficacy of the supplemental measures into context. As expected the advised supplemental measures have resulted in increased costs and reprocessing time. Unfortunately, it has also become clear that the efficacy of the supplemental measures falls short and that duodenoscope contamination remains a problem. There is a lot of research into new reprocessing methods and technical applications trying to solve the problem of duodenoscope contamination. Several promising developments such as single-use duodenoscopes, electrolyzed acidic water, and vaporized hydrogen peroxide plasma are already applied in a clinical setting.

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Implementing Building-Level SARS-CoV-2 Wastewater Surveillance on a University Campus

10.1101/2020.12.31.20248843 ◽

2021 ◽

Author(s):

Cynthia Gibas ◽

Kevin Lambirth ◽

Neha Mittal ◽

Md Ariful Islam Juel ◽

Visva Bharati Barua ◽

...

Keyword(s):

Monitoring Program ◽

Group Living ◽

Cost Effective ◽

Contact Tracing ◽

Weekly Schedule ◽

Term Care ◽

Increased Risk ◽

Asymptomatic Individuals ◽

The University ◽

Building Level

AbstractThe COVID-19 pandemic has been a source of ongoing challenges and presents an increased risk of illness in group environments, including jails, long term care facilities, schools, and, of course, residential college campuses. Early reports that the SARS-CoV-2 virus was detectable in wastewater in advance of confirmed cases sparked widespread interest in wastewater based epidemiology (WBE) as a tool for mitigation of COVID-19 outbreaks. One hypothesis was that wastewater surveillance might provide a cost-effective alternative to other more expensive approaches such as pooled and random testing of groups. In this paper, we report the outcomes of a wastewater surveillance pilot program at the University of North Carolina at Charlotte, a large urban university with a substantial population of students living in on-campus dormitories. Surveillance was conducted at the building level on a thrice-weekly schedule throughout the university’s fall residential semester. In multiple cases, wastewater surveillance enabled identification of asymptomatic COVID-19 cases that were not detected by other components of the campus monitoring program, which also included in-house contact tracing, symptomatic testing, scheduled testing of student athletes, and daily symptom reporting. In the context of all cluster events reported to the University community during the fall semester, wastewater-based testing events resulted in identification of smaller clusters than were reported in other types of cluster events. Wastewater surveillance was able to detect single asymptomatic individuals in dorms with total resident populations of 150-200. While the strategy described was developed for COVID-19, it is likely to be applicable to mitigation of future pandemics in universities and other group-living environments.

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