Result for
Tag: transmission
February 3, 2021
Transmission of COVID-19 in 282 Clusters in Catalonia, Spain: A Cohort Study
The risk of transmission of COVID-19 was greater when the index case had a higher concentration of virus. A cohort study of 282 COVID-19 clusters (n=314 patients) in Spain conducted from March-April 2020 indicated that the risk of symptomatic COVID-19 was associated with the viral load of the index case. The secondary attack rate ranged…
SARS-CoV-2 Seropositivity among US Marine Recruits Attending Basic Training, United States, Spring–Fall 2020
A cross-sectional study of US Marine Recruits (n=3,249) conducted from Spring-Fall 2020 found a baseline IgG seroprevalence against SARS-Cov-2 of 9%. Participants were primarily males aged 18-20 from the Eastern US or states with large populations. Participants who identified as Hispanic or non-Hispanic Black had higher IgG prevalence (18%, OR=3.8 and 15%, OR=3.5, respectively) than…
February 2, 2021
Viral Sequencing Reveals US Healthcare Personnel Rarely Become Infected with SARS-CoV-2 through Patient Contact
[Pre-print, not peer reviewed] Patient to healthcare worker (HCW) transmission could be rare, according to viral sequencing of 32 SARS-CoV-2 infection clusters involving 96 HCWs in the Upper Midwest. Using 140 possible patient contacts, only 4% of HCW infections were clearly traced to a patient source. In comparison, 10% could be traced to a coworker,…
High Variability in Transmission of SARS-CoV-2 within Households and Implications for Control
[Pre-print, not peer reviewed] A probabilistic model based upon SARS-CoV-2 antibody and PCR test data from more than 9000 Utah households estimated a 35% household secondary attack rate. In contrast, the crude estimate for household attack rate unadjusted for serological test specificity was 15%. Given the high attack rate, the authors predict that the mean…
February 1, 2021
Mapping a Pandemic SARS-CoV-2 Seropositivity in the United States
[Pre-print, not peer-reviewed] Between May and July 2020, there were an estimated 4.8 undiagnosed cases of COVID-19 for every case diagnosed in the United States, and an estimated 16.8 million undiagnosed cases by mid-July, based on findings from a serostudy conducted among adults (n = 11,3182) who had not been diagnosed with COVID-19. Undiagnosed seropositivity…
January 29, 2021
Trends in Outbreak-Associated Cases of COVID-19 — Wisconsin, March–November 2020
COVID-19 cases linked to outbreaks on college campuses in Wisconsin increased rapidly in August 2020, and were followed by outbreaks at long-term care facilities, correctional facilities, and colleges/universities. From May 13–September 2, long-term care facilities (2,850 cases; 21%) and manufacturing or food processing facilities (2,672 cases; 20%) accounted for the largest number of outbreak-associated cases,…
January 28, 2021
Quantifying the Transmission Advantage Associated with N501Y Substitution of SARS-CoV-2 in the United Kingdom: An Early Data-Driven Analysis
Using publicly available SARS-CoV-2 sequencing data and COVID-19 surveillance data collected from August to December 2020 in the UK, Zhao et al. reconstructed the variant-specific instantaneous reproduction number, Rt, and estimated that the variant containing the N501Y mutation is 52% more transmissible than the wild-type virus. Zhao et al. (Jan 28, 2021). Quantifying the Transmission…
Resurgence of COVID-19 in Manaus, Brazil, despite High Seroprevalence
Despite a high SARS-CoV-2 seroprevalence of 76% among blood donors in Manaus, Brazil by October 2020, the area experienced a sudden rise in COVID-19 hospitalizations from 552 in December 2020 to 3,431 in January 2021. The authors suggest possible explanations for the resurgence in this setting where seroprevalence was higher than common estimates of the…
January 27, 2021
SARS-CoV-2 Infection and Mitigation Efforts among Office Workers, Washington, DC, USA
Two SARS-CoV-2 outbreaks in April, 2020 were identified among office workers in Washington, DC. The study identified two factors potentially associated with SARS-CoV-2 infection and transmission in the workplace: a significantly higher percentage of seropositive participants lived with someone who had a confirmed positive test result (13%) than those who were seronegative (1%), and more…
January 26, 2021
Implementation and Evolution of Mitigation Measures, Testing, and Contact Tracing in the National Football League, August 9–November 21, 2020
Investigation of a cluster of 41 SARS-CoV-2 infections that occurred within the National Football League in late September 2020 identified at least 7 cases of infection where transmission likely occurred during <15 minutes of cumulative interaction within 6 feet of an infected individual, as confirmed by wearable tracking devices. Interviews revealed that some of these…
Previous page Next page