scholarly journals Higher viral load drives infrequent SARS-CoV-2 transmission between asymptomatic residence hall roommates

Author(s):  
Kristen K. Bjorkman ◽  
Tassa K. Saldi ◽  
Erika Lasda ◽  
Leisha Conners Bauer ◽  
Jennifer Kovarik ◽  
...  

ABSTRACTIn 2019-2020, the COVID-19 pandemic spread to over 200 countries in less than six months. To understand the basis of this aggressive spread, it is essential to determine the transmission rate and define the factors that increase the risk of transmission. One complication is the large fraction of asymptomatic cases, particularly in young populations: these individuals have viral loads indistinguishable from symptomatic people and do transmit the SARS-CoV-2 virus, but they often go undetected. As university students living in residence halls commonly share a small living space with roommates, some schools established regular, high density testing programs to mitigate on-campus spread. In this study, we analyzed longitudinal testing data of residence hall students at the University of Colorado Boulder. We observed that students in single rooms were infected at a lower rate than students in multiple occupancy rooms. However, this was not due to high rates of transmission between roommates, which only occurred approximately 20% of the time. Since these cases were usually asymptomatic at the time of diagnosis, this provides further evidence for asymptomatic transmission. Notably, individuals who likely transmitted to their roommates had an average viral load ∼6.5 times higher than individuals who did not. Although students were moved to separate isolation rooms after diagnosis, there was no difference in time to isolation between these cases with or without transmission. This analysis argues that inter-roommate transmission occurs in a minority of cases in university residence halls and provides strong correlative evidence that viral load can be proportional to the probability of transmission.

Facilities ◽  
2014 ◽  
Vol 32 (11/12) ◽  
pp. 709-722 ◽  
Author(s):  
Fatemeh Khozaei ◽  
Ahmad Sanusi Hassan ◽  
Kheir Al Kodmany ◽  
Yasser Aarab

Purpose – The aim of this paper is to identify the university student’s preferences for some important attributes of residence hall design. The study also attempts to highlight the differences and similarities in student’s preferences. Design/methodology/approach – The survey was distributed among students who were living in residence halls of a public university in Malaysia. A total of 752 students were recruited as participants. Data were collected using a self-administrated questionnaire. Students were asked to indicate their preferences rating a 4-point scale. The survey included questions concerning students’ preferences for residing in traditional and suite-style residence halls, single room and double room as well as rooms in which each student’s area is marked clearly. Collected data were analysed using PASW Statistics 17. Findings – The results indicated that, in total, students highly preferred residing in suite-style to traditional residence halls. Staying in a single room with shared bathroom was also preferred to double-sharing room. The results of study also indicated that living in a room in which each student ' s area is marked clearly is of great interest. The study proved significant differences in the students’ preferences based on their gender, nationality and study level. Practical implications – The outcome of this study can enhance the awareness of residence hall organizers and architects with regard to some of students’ priorities. Originality/value – The results give an important insight into student’s preferences towards their residence hall. The study provides statistic evidence unfavourably of traditional residence halls among the students of new generation. It also provides an insight into students ' greater needs and requirements for privacy.


2021 ◽  
Author(s):  
David W Eyre ◽  
Donald Taylor ◽  
Mark Purver ◽  
David Chapman ◽  
Tom Fowler ◽  
...  

Background Pre-Delta, vaccination reduced transmission of SARS-CoV-2 from individuals infected despite vaccination, potentially via reducing viral loads. While vaccination still lowers the risk of infection, similar viral loads in vaccinated and unvaccinated individuals infected with Delta question how much vaccination prevents onward transmission. Methods We performed a retrospective observational cohort study of contacts of SARS-CoV-2-infected index cases using contact testing data from England. We used multivariable logistic regression to investigate the impact of index case and contact vaccination on transmission, and how this varies with Alpha and Delta variants (classified using S-gene detection/calendar trends) and time since second vaccination. Results 51,798/139,164(37.2%) contacts tested were PCR-positive. Two doses of BNT162b2 or ChAdOx1 vaccines in Alpha variant index cases independently reduced PCR-positivity in contacts (aOR, adjusted odds ratio vs. unvaccinated=0.18[95%CI 0.12-0.29] and 0.37[0.22-0.63] respectively). The Delta variant attenuated vaccine-associated reductions in transmission: two BNT162b2 doses reduced Delta transmission (aOR=0.35[0.26-0.48]), more than ChAdOx1 (aOR=0.64[0.57-0.72]; heterogeneity p<0.001). Variation in viral load (Ct values) explained only a modest proportion of vaccine-associated transmission reductions. Transmission reductions declined over time since second vaccination, for Delta reaching similar levels to unvaccinated individuals by 12 weeks for ChAdOx1 and attenuating substantially for BNT162b2. Protection from vaccination in contacts also declined in the 3 months after second vaccination. Conclusions Vaccination reduces transmission of Delta, but by less than the Alpha variant. The impact of vaccination decreased over time. Factors other than PCR-measured viral load are important in vaccine-associated transmission reductions. Booster vaccinations may help control transmission together with preventing infections.


2021 ◽  
Author(s):  
Qing Yang ◽  
Tassa K Saldi ◽  
Erika Lasda ◽  
Carolyn J Decker ◽  
Camille L Paige ◽  
...  

We analyze data from the Fall 2020 pandemic response efforts at the University of Colorado Boulder (USA), where more than 72,500 saliva samples were tested for SARS-CoV-2 using quantitative RT-PCR. All samples were collected from individuals who reported no symptoms associated with COVID-19 on the day of collection. From these, 1,405 positive cases were identified. The distribution of viral loads within these asymptomatic individuals was indistinguishable from what has been previously reported in symptomatic individuals. Regardless of symptomatic status, approximately 50% of individuals who test positive for SARS-CoV-2 seem to be in non-infectious phases of the disease, based on having low viral loads in a range from which live virus has rarely been isolated. We find that, at any given time, just 2% of individuals carry 90% of the virions circulating within communities, serving as viral super-carriers and possibly also super-spreaders.


2021 ◽  
Vol 118 (21) ◽  
pp. e2104547118
Author(s):  
Qing Yang ◽  
Tassa K. Saldi ◽  
Patrick K. Gonzales ◽  
Erika Lasda ◽  
Carolyn J. Decker ◽  
...  

We analyze data from the fall 2020 pandemic response efforts at the University of Colorado Boulder, where more than 72,500 saliva samples were tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using qRT-PCR. All samples were collected from individuals who reported no symptoms associated with COVID-19 on the day of collection. From these, 1,405 positive cases were identified. The distribution of viral loads within these asymptomatic individuals was indistinguishable from what has been previously observed in symptomatic individuals. Regardless of symptomatic status, ∼50% of individuals who test positive for SARS-CoV-2 seem to be in noninfectious phases of the disease, based on having low viral loads in a range from which live virus has rarely been isolated. We find that, at any given time, just 2% of individuals carry 90% of the virions circulating within communities, serving as viral “supercarriers” and possibly also superspreaders.


Author(s):  
Mircea Fotino

A new 1-MeV transmission electron microscope (Model JEM-1000) was installed at the Department of Molecular, Cellular and Developmental Biology of the University of Colorado in Boulder during the summer and fall of 1972 under the sponsorship of the Division of Research Resources of the National Institutes of Health. The installation was completed in October, 1972. It is installed primarily for the study of biological materials without many of the limitations hitherto unavoidable in standard transmission electron microscopy. Only the technical characteristics of the installation are briefly reviewed here. A more detailed discussion of the experimental program under way is being published elsewhere.


Author(s):  
Joanna BOEHNERT

This workshop will create a space for discussion on environmental politics and its impact on design for sustainable transitions. It will help participants identify different sustainability discourses; create a space for reflection on how these discourses influence design practice; and consider the environmental and social implications of different discourses. The workshop will do this work by encouraging knowledge sharing, reflection and interpretative mapping in a participatory space where individuals will create their own discourse maps. This work is informed by my research “Mapping Climate Communication” conducted at the Centre for Science and Technology Policy Research (CSTPR) in the Cooperative Institute for Environmental Sciences (CIRES), the University of Colorado, Boulder. With this research project I developed a discourse mapping method based on the discourse analysis method of political scientists and sustainability scholars. Using my own work as an example, I will facilitate a process that will enable participants to create new discourse maps reflecting their own ideas and agendas.


2021 ◽  
Vol 20 ◽  
pp. 153303382110279
Author(s):  
Brooke E. Sanders ◽  
Lisa Ku ◽  
Paul Walker ◽  
Benjamin G. Bitler

The clinical use of molecular tumor profiling (MTP) is expanding and there is an increasing use of MTP data to manage patient care. At the University of Colorado, 18 patients were diagnosed with primary serous ovarian cancer between 9/2015 and 6/2019 and consented for banking and analysis of tumor, ascites and plasma. All 18 patients had tumor and plasma samples that were sent for MTP, and 13 of 18 patients additionally had ascites collected and sent for MTP. 50-gene panel testing and BRCA testing were performed on primary tumor. BRCA genetic variants were more likely to be identified in plasma as compared to ascites or tumor, though not statistically significant ( P = 0.17). Co-occurring genetic variants between plasma and ascites were less common in comparison to co-occurring variants between tumor and plasma or tumor and ascites, though not statistically significant ( P = 0.68). Variants in KDR (VEGFR2) and TP53 were most likely to be conserved across all 3 biocompartments. Mutant allele frequencies (MAF) of individual genetic variants varied across biocompartments, though tended to be highest in the tumor, followed by ascites.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S325-S326
Author(s):  
Lacy Simons ◽  
Ramon Lorenzo-Redondo ◽  
Hannah Nam ◽  
Scott C Roberts ◽  
Michael G Ison ◽  
...  

Abstract Background The rapid spread of SARS-CoV-2, the causative agent of Coronavirus disease 2019 (COVID-19), has been accompanied by the emergence of viral mutations, some of which may have distinct virological and clinical consequences. While whole genome sequencing efforts have worked to map this viral diversity at the population level, little is known about how SARS-CoV-2 may diversify within a host over time. This is particularly important for understanding the emergence of viral resistance to therapeutic interventions and immune pressure. The goal of this study was to assess the change in viral load and viral genome sequence within patients over time and determine if these changes correlate with clinical and/or demographic parameters. Methods Hospitalized patients admitted to Northwestern Memorial Hospital with a positive SARS-CoV-2 test were enrolled in a longitudinal study for the serial collection of nasopharyngeal specimens. Swabs were administered to patients by hospital staff every 4 ± 1 days for up to 32 days or until the patients were discharged. RNA was extracted from each specimen and viral loads were calculated by quantitative reverse transcriptase PCR (qRT-PCR). Specimens with qRT-PCR cycle threshold values less than or equal to 30 were subject to whole viral genome sequencing by reverse transcription, multiplex PCR, and deep sequencing. Variant populations sizes were estimated and subject to phylogenetic analysis relative to publicly available SARS-CoV-2 sequences. Sequence and viral load data were subsequently correlated to available demographic and clinical data. Results 60 patients were enrolled from March 26th to June 20th, 2020. We observed an overall decrease in nasopharyngeal viral load over time across all patients. However, the temporal dynamics of viral load differed on a patient-by-patient basis. Several mutations were also observed to have emerged within patients over time. Distribution of SARS-CoV-2 viral loads in serially collected nasopharyngeal swabs in hospitalized adults as determined by qRT-PCR. Samples were collected every 4 ± 1 days (T#1–8) and viral load is displayed by log(copy number). Conclusion These data indicate that SARS-CoV-2 viral loads in the nasopharynx decrease over time and that the virus can accumulate mutations during replication within individual patients. Future studies will examine if some of these mutations may provide fitness advantages in the presence of therapeutic and/or immune selective pressures. Disclosures Michael G. Ison, MD MS, AlloVir (Consultant)


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