SARS-CoV-2 viral load assessment in respiratory samples

Kleiboeker, Steven B.; Cowden, Scott; Grantham, J. Aaron; Nutt, Jamie; Tyler, Aaron; Berg, Amy; Altrich, Michelle

doi:10.1016/j.jcv.2020.104439

Cited by 61 publications

(73 citation statements)

References 9 publications

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“…However, all the samples that failed to be positive for Viasure SARS-CoV-2 kit had viral loads over 2000 copies/mL of sample ( Matzkies et al, 2020 ). Considering the viral loads frequency distribution for SARS-CoV-2 ( Lavezzoet al, 2020 ; KleiboekerScott et al, 2020 ), this study would have a bias toward ultra low viral loads below 2000 copies/mL as less than 10% of SARS-CoV-2 positive patients are expected to have those loads ( Lavezzoet al, 2020 ; KleiboekerScott et al, 2020 ).…”

Section: Discussionmentioning

confidence: 99%

Analytical and clinical comparison of Viasure (CerTest Biotec) and 2019-nCoV CDC (IDT) RT-qPCR kits for SARS-CoV2 diagnosis.

et al. 2021

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Section: Discussionmentioning

confidence: 99%

Analytical and clinical comparison of Viasure (CerTest Biotec) and 2019-nCoV CDC (IDT) RT-qPCR kits for SARS-CoV2 diagnosis.

et al. 2021

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“…Another study from Switzerland compared 352 patients older than 16 years with 53 children under 16 years old and found a similar mean viral load between the two groups ( 21 ). Similarly, a study in the United States which included 4,428 patients with positive lab results found no variation in mean and median viral load values ( 22 ). Notably, other studies with smaller sample sizes had conflicting results regarding the relationship between SARS-CoV-2 viral load and age.…”

Section: Discussionmentioning

confidence: 97%

Association of Viral Load in SARS-CoV-2 Patients With Age and Gender

et al. 2021

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Background: The coronavirus disease 2019 (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), is a global public health emergency. Age and sex are two important factors associated with risks and outcomes of various diseases. COVID-19 morbidity also seems to be affected by patient age and sex. It has been found that older age groups have more severe COVID-19 symptoms and higher fatality rates while children tend to have lower prevalence and milder symptoms than adults.Methods: The study reviewed electronic medical records of COVID-19 patients from Madinah city, Saudi Arabia. The study included all cases who tested positive (n = 3,006) between March 20 and May 22, 2020. Data were obtained from the Health Electronic Surveillance Network (HESN) database.Results: Approximately 80% of the study sample were males and half were in the 30–40-year-old age group. The Ct value of the whole sample ranged from 15.08 to 35, with a mean of 27.44 (SD: 5.23; 95% C.I. = 27.25–27.66). The means of Ct values varied between age groups from 27.05 to 27.82. Analysis of the mean differences between age groups using one-way ANOVA indicated no statistically significant difference among the groups (F6,2999 = 1.63; p-value = 0.135). A comparison of mean Ct values of males (n = 2,422) and females (n = 584) revealed that males had a statistically significant higher mean Ct value (27.61 ± 5.20) than females (26.72 ± 5.31). The difference between the means of the two groups was −0.89 (95% C.I. = −1.36 to −0.42; t-test −3.71; df = 3,004; p-value < 0.001).Conclusion: The study found no statistically significant difference in viral loads between age groups. It showed that females had a higher SARS-CoV-2 viral load compared to males. The findings have implications for preventive strategies. Further studies are needed to correlate viral load with clinical symptoms and outcomes.

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“…repeated measurements on the same patient) to fit a compartmentalized viral load model. An example set of data and model fit (patient S14) from their work are shown in Figure 3(a) below: the model shows a very rapid increase of ~5 orders of magnitude over a few days to a peak viral load of order 10 7 copies/sample, a sharp drop of ~2 orders of magnitude over the next two days, and a somewhat slower decline 15 Using Figure 2 of Fears et al , the genome/PFU ratio is estimated to be ~20, ~1040, ~1140, ~189, and ~132 after 10, 30, 120, 240, and 960 minutes, respectively. [45] Buonanno et al appear use the "steady state" figure of 1.3 x 10 2 for c PFU (copies per PFU) in their analysis [22] .…”

Section: Skagitmentioning

confidence: 99%

Superspreading Events Without Superspreaders: Using High Attack Rate Events to Estimate N_º for Airborne Transmission of COVID-19

Prentiss¹,

Chu²,

Berggren³

2020

Preprint

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We study transmission of COVID-19 using five well-documented case studies : a Washington state church choir, a Korean call center, a Korean exercise class, and two different Chinese bus trips. In all cases the likely index patients were pre-symptomatic or mildly symptomatic, which is when infective patients are most likely to interact with large groups of people. An estimate of N 0 , the characteristic number of COVID-19 virions needed to induce infection in each case, is found using a simple physical model of airborne transmission. We find that the N 0 values are similar for five COVID-19 superspreading cases (~300-2,000 viral copies) and of the same order as influenza A. Consistent with the recent results of Goyal et al , these results suggest that viral loads relevant to infection from presymptomatic or mildly symptomatic individuals may fall into a narrow range, and that exceptionally high viral loads are not required to induce a superspreading event [1,2] . Rather, t he accumulation of infective aerosols exhaled by a typical pre-symptomatic or mildly symptomatic patient in a confined, crowdedspace (amplified by poor ventilation, particularly activity like exercise or singing, or lack of masks) for exposure times as short as one hour are sufficient. We calculate that talking and breathing release ~460 N 0 and ~10 N 0 (quanta)/hour, respectively, providing a basis to estimate the risks of everyday activities. Finally, we provide a calculation which motivates the observation that fomites appear to account for a smallpercentage of total COVID-19 infection events.

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SARS-CoV-2 viral load assessment in respiratory samples

Cited by 61 publications

References 9 publications

Analytical and clinical comparison of Viasure (CerTest Biotec) and 2019-nCoV CDC (IDT) RT-qPCR kits for SARS-CoV2 diagnosis.

Analytical and clinical comparison of Viasure (CerTest Biotec) and 2019-nCoV CDC (IDT) RT-qPCR kits for SARS-CoV2 diagnosis.

Association of Viral Load in SARS-CoV-2 Patients With Age and Gender

Superspreading Events Without Superspreaders: Using High Attack Rate Events to Estimate N_º for Airborne Transmission of COVID-19

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SARS-CoV-2 viral load assessment in respiratory samples

Cited by 61 publications

References 9 publications

Analytical and clinical comparison of Viasure (CerTest Biotec) and 2019-nCoV CDC (IDT) RT-qPCR kits for SARS-CoV2 diagnosis.

Analytical and clinical comparison of Viasure (CerTest Biotec) and 2019-nCoV CDC (IDT) RT-qPCR kits for SARS-CoV2 diagnosis.

Association of Viral Load in SARS-CoV-2 Patients With Age and Gender

Superspreading Events Without Superspreaders: Using High Attack Rate Events to Estimate Nº for Airborne Transmission of COVID-19

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Product

Resources

About

Superspreading Events Without Superspreaders: Using High Attack Rate Events to Estimate N_º for Airborne Transmission of COVID-19