Quote:

Chest CT Findings in Cases from the Cruise Ship Diamond Princess with Coronavirus Disease (COVID-19)
Radiol Cardiothorac Imaging. 2020 Apr; 2(2)


This retrospective study comprised 104 cases (mean age, 62 years ± 16 standard deviation, range, 25–93 years) with COVID-19 confirmed with reverse-transcription polymerase change reaction findings. CT images were reviewed, and the CT severity score was calculated for each lobe and the entire lung. CT findings were compared between asymptomatic and symptomatic cases.

Of 104 cases, 76 (73%) were asymptomatic, 41 (54%) of which had lung opacities on CT. Twenty-eight (27%) cases were symptomatic, 22 (79%) of which had abnormal CT findings.

BCSnob wrote:



An asymptomatic viral infection is still a viral infection which weakens the body, causes physiological changes the patient doesn't recognize (no outward symptoms), and likely makes one more susceptible to issues from underlying conditions.

Deb and Ed M wrote:



...... I'm no Doctor, but I can't help wondering if Covid had affected her sugar levels, resulting in her ultimate death... there's no way this lady's blood sugar could have gone this high, IMO

dturm wrote:

CDC MMWR

Risk for Newly Diagnosed Diabetes >30 Days After SARS-CoV-2 Infection Among Persons Aged <18 Years — United States, March 1, 2020–June 28, 2021

Sorry, didn't realize the CDC was going to release this in their weekly MMWR report dated tomorrow.

silversand wrote:

Any bleeding edge research (in preprint) on Omicron pathogenicity.... specifically, the contagious viral shedding period?

Quote:

Viral dynamics and duration of PCR positivity of the SARS-CoV-2 Omicron variant
MedRxiv preprint 14 Jan 2022

Background. The Omicron SARS-CoV-2 variant is responsible for a major wave of COVID-19, with record case counts reflecting high transmissibility and escape from prior immunity. Defining the time course of Omicron viral proliferation and clearance is crucial to inform isolation protocols aiming to minimize disease spread. Methods. We obtained longitudinal, quantitative RT-qPCR test results using combined anterior nares and oropharyngeal samples (n = 10,324) collected between July 5th, 2021 and January 10th, 2022 from the National Basketball Association's (NBA) occupational health program. We quantified the fraction of tests with PCR cycle threshold (Ct) values <30, chosen as a proxy for potential infectivity and antigen test positivity, on each day after first detection of suspected and confirmed Omicron infections, stratified by individuals detected under frequent testing protocols and those detected due to symptom onset or concern for contact with an infected individual. We quantified the duration of viral proliferation, clearance rate, and peak viral concentration for individuals with acute Omicron and Delta variant SARS-CoV-2 infections.

Results. A total of 97 infections were confirmed or suspected to be from the Omicron variant and 107 from the Delta variant. Of 27 Omicron-infected individuals testing positive =1 day after a previous negative or inconclusive test, 52.0% (13/25) were PCR positive with Ct values <30 at day 5, 25.0% (6/24) at day 6, and 13.0% (3/23) on day 7 post detection. Of 70 Omicron-infected individuals detected =2 days after a previous negative or inconclusive test, 39.1% (25/64) were PCR positive with Ct values <30 at day 5, 33.3% (21/63) at day 6, and 22.2% (14/63) on day 7 post detection. Overall, Omicron infections featured a mean duration of 9.87 days (95% CI 8.83-10.9) relative to 10.9 days (95% CI 9.41-12.4) for Delta infections. The peak viral RNA based on Ct values was lower for Omicron infections than for Delta infections (Ct 23.3, 95% CI 22.4-24.3 for Omicron; Ct 20.5, 95% CI 19.2-21.8 for Delta) and the clearance phase was shorter for Omicron infections (5.35 days, 95% CI 4.78-6.00 for Omicron; 6.23 days, 95% CI 5.43-7.17 for Delta), though the rate of clearance was similar (3.13 Ct/day, 95% CI 2.75-3.54 for Omicron; 3.15 Ct/day, 95% CI 2.69-3.64 for Delta).

Conclusions. While Omicron infections feature lower peak viral RNA and a shorter clearance phase than Delta infections on average, it is unclear to what extent these differences are attributable to more immunity in this largely vaccinated population or intrinsic characteristics of the Omicron variant. Further, these results suggest that Omicron's infectiousness may not be explained by higher viral load measured in the nose and mouth by RT-PCR. The substantial fraction of individuals with Ct values <30 at days 5 of infection, particularly in those detected due to symptom onset or concern for contact with an infected individual, underscores the heterogeneity of the infectious period, with implications for isolation policies.

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Infectious viral load in unvaccinated and vaccinated patients infected with SARS-CoV-2 WT, Delta and Omicron
MedRxiv preprint 11Jan2022

Background Viral load (VL) is one determinant of secondary transmission of SARS-CoV-2. Emergence of variants of concerns (VOC) Alpha and Delta was ascribed, at least partly, to higher VL. Furthermore, with parts of the population vaccinated, knowledge on VL in vaccine breakthrough infections is crucial. As RNA VL is only a weak proxy for infectiousness, studies on infectious virus presence by cell culture isolation are of importance.

Methods We assessed nasopharyngeal swabs of COVID-19 patients for quantitative infectious viral titres (IVT) by focus-forming assay and compared to overall virus isolation success and RNA genome copies. We assessed infectious viral titres during the first 5 symptomatic days in a total of 384 patients: unvaccinated individuals infected with pre-VOC SARS-CoV-2 (n= 118) or Delta (n= 127) and vaccine breakthrough infections with Delta (n= 121) or Omicron (n=18).

Findings Correlation between RNA copy number and IVT was low for all groups. No correlation between IVTs and age or sex was seen. We observed higher RNA genome copies in pre-VOC SARS-CoV-2 compared to Delta, but significantly higher IVTs in Delta infected individuals. In vaccinated vs. unvaccinated Delta infected individuals, RNA genome copies were comparable but vaccinated individuals have significantly lower IVTs, and cleared virus faster. Vaccinated individuals with Omicron infection had comparable IVTs to Delta breakthrough infections.

Interpretation Quantitative IVTs can give detailed insights into virus shedding kinetics. Vaccination was associated with lower infectious titres and faster clearance for Delta, showing that vaccination would also lower transmission risk. Omicron vaccine breakthrough infections did not show elevated IVTs compared to Delta, suggesting that other mechanisms than increase VL contribute to the high infectiousness of Omicron.

Quote:

The two key parameters when assessing VL are either RNA genome copies, often expressed in cycle threshold (Ct) values, or infectious virus that can only be assessed by virus isolation in cell culture. Although the process of human-to-human transmission is complex, VL can serve as a proxy, with higher VL posing a greater risk for onward transmission. In several epidemiological studies, higher viral load expressed as viral RNA was associated with an increased secondary transmission in household settings(3, 4). Shedding of infectious SARS-CoV-2 in the URT starts on average two days prior to the beginning of symptoms and gradually declines up to 8 days post onset of symptoms. Even though viral RNA could be detected afterwards, in most studies infectious virus was not detected in respiratory samples collected from immunocompetent individuals later than 8 days post onset of symptoms (5-9).