scholarly journals Duration of viral shedding and culture positivity with post-vaccination breakthrough delta variant infections

2021 ◽  
Author(s):  
Mark J. Siedner ◽  
Julie Boucau ◽  
Rebecca Gilbert ◽  
Rockib Uddin ◽  
Jonathan Luu ◽  
...  
Keyword(s):  
Viral Load ◽  
Additional Data ◽  
Post Vaccination ◽  
Replication Competent Virus ◽  
Viral Shedding ◽  
Viral Culture ◽  
Culture Positivity ◽  
Nasal Swabs ◽  
Ambulatory Patients ◽  
Viral Load Quantification

Isolation guidelines for SARS-CoV-2 are largely derived from data collected prior to emergence of the delta variant. We followed a cohort of ambulatory patients with post-vaccination breakthrough SARS-CoV-2 infections with longitudinal collection of nasal swabs for SARS-CoV-2 viral load quantification, whole genome sequencing, and viral culture. All delta variant infections (8/8, 100%) in our cohort were symptomatic, compared with 64% (9/14) of non-delta variant infections. Delta variant breakthrough infections were characterized by higher initial viral load, longer duration of virologic shedding by PCR (median 13.5 vs 4 days, hazard ratio [HR] 0.45, 95%CI 0.17-1.17), greater likelihood of replication competent virus at early stages of infection (6/8 [75%] vs 3/14 [23%], P=0.03), and longer duration of culturable virus (median 7 vs 3 days, HR 0.38, 95%CI 0.14-1.02) compared to non-delta variants. Nonetheless, no individuals with delta variant infections had replication competent virus by day 10 after symptom onset or 24 hours after resolution of symptoms. These data support current US Center for Disease Control isolation guidelines and reinforce the importance of prompt testing and isolation among symptomatic individuals with delta variant breakthrough infections. Additional data are needed to evaluate these relationships among asymptomatic and more severe delta variant breakthrough infections.

scholarly journals Monoclonal antibody treatment drives rapid culture conversion in SARS-CoV-2 infection

2021 ◽  
Author(s):  
Julie Boucau ◽  
Kara W Chew ◽  
Manish Chandra Choudhary ◽  
Rinki Deo ◽  
James Regan ◽  
...  
Keyword(s):  
Viral Load ◽  
Disease Transmission ◽  
Treated Group ◽  
Antibody Treatment ◽  
Rapid Reduction ◽  
Viral Loads ◽  
Viral Culture ◽  
Nasal Swabs ◽  
Monoclonal Antibody Treatment ◽  
Viral Load Rebound

Monoclonal antibodies (mAbs) are the treatment of choice for high-risk ambulatory persons with mild to moderate COVID-19. We studied viral culture dynamics post-treatment in a subset of participants receiving the mAb bamlanivimab in the ACTIV-2 trial. Viral load by qPCR and viral culture were performed from anterior nasal swabs collected on study days 0 (day of treatment), 1, 2, 3, and 7. Treatment with mAb resulted in rapid clearance of culturable virus in participants without treatment-emergent resistance. One day after treatment, 0 of 28 (0%) participants receiving mAb and 16 of 39 (41%) receiving placebo still had culturable virus (p <0.0001); nasal viral loads were only modestly lower in the mAb-treated group at days 2 and 3. Recrudescence of culturable virus was detected in three participants with emerging mAb resistance and viral load rebound. The rapid reduction in shedding of viable SARS-CoV-2 after mAb treatment highlights the potential role of mAbs in preventing disease transmission.

scholarly journals Favorable outcome on viral load and culture viability using Ivermectin in early treatment of non-hospitalized patients with mild COVID-19, A double-blind, randomized placebo-controlled trial.

2021 ◽  
Author(s):  
Asaf Biber ◽  
Michal Mandelboim ◽  
Geva Harmelin ◽  
Dana Lev ◽  
Li Ram ◽  
...  
Keyword(s):  
Viral Load ◽  
Early Stage ◽  
Controlled Trial ◽  
Nasopharyngeal Swab ◽  
Multivariable Logistic Regression Model ◽  
Double Blind ◽  
Viral Shedding ◽  
Viral Culture ◽  
Culture Viability ◽  
Double Blinded

Background: Ivermectin, an antiparasitic agent, also has antiviral properties. Our aim was to assess whether ivermectin can shorten the viral shedding in patients at an early stage of COVID19 infection. Methods: The double blinded trial compared patients receiving ivermectin 0.2 mg/kg for 3 days vs. placebo in non-hospitalized COVID19 patients. RT-PCR from a nasopharyngeal swab was obtained at recruitment and then every two days. Primary endpoint was reduction of viral-load on the 6th day (third day after termination of treatment) as reflected by Ct level>30 (non-infectious level). The primary outcome was supported by determination of viral culture viability. Results: Eighty nine patients were eligible (47 in ivermectin and 42 in placebo arm). Their median age was 35 years. Females accounted for 21.6%, and 16.8% were asymptomatic at recruitment. Median time from symptom onset was 4 days. There were no statistical differences in these parameters between the two groups. On day 6, 34 out of 47 (72%) patients in the ivermectin arm reached the endpoint, compared to 21/ 42 (50%) in the placebo arm (OR 2.62; 95% CI: 1.09 to 6.31). In a multivariable logistic regression model, the odds of a negative test at day 6 was 2.62 time higher in the ivermectin group (95% CI: 1.06 to 6.45). Cultures at days 2 to 6 were positive in 3/23 (13.0%) of ivermectin samples vs. 14/29 (48.2%) in the placebo group (p=0.008). Conclusions: There were significantly lower viral loads and viable cultures in the ivermectin group, which could lead to shortening isolation time in these patients.

scholarly journals Duration of viral shedding and culture positivity with post-vaccination SARS-CoV-2 delta variant infections

JCI Insight ◽  
2021 ◽  
Author(s):  
Mark J. Siedner ◽  
Julie Boucau ◽  
Rebecca F. Gilbert ◽  
Rockib Uddin ◽  
Jonathan Luu ◽  
...  
Keyword(s):  
Post Vaccination ◽  
Viral Shedding ◽  
Culture Positivity

scholarly journals SARS-CoV-2 Antigen Tests Predict Infectivity Based on Viral Culture: Comparison of Antigen, PCR Viral Load, and Viral Culture Testing on a Large Sample Cohort

2021 ◽  
Author(s):  
James E Kirby ◽  
Stefan Riedel ◽  
Sanjucta Dutta ◽  
Ramy Arnaout ◽  
Annie Cheng ◽  
...  
Keyword(s):  
Viral Load ◽  
Diagnostic Testing ◽  
Lateral Flow ◽  
Nasopharyngeal Swab ◽  
Viral Culture ◽  
Culture Positivity ◽  
Antigen Tests ◽  
Relationship Of ◽  
The Relationship ◽  
Antigen Testing

The relationship of SARS-CoV-2 antigen testing results, viral load, and viral culture detection remains to be fully defined. Presumptively, viral culture can provide a surrogate measure for infectivity of sampled individuals, and thereby inform how and where to most appropriately deploy available diagnostic testing modalities. We therefore determined the relationship of antigen testing results from three lateral flow and one microfluidics assay to viral culture performed in parallel in 181 nasopharyngeal swab samples positive for SARS-CoV-2. Sample viral loads, determined by RT-qPCR, were distributed across the range of viral load values observed in our testing population. We found that antigen tests were predictive of viral culture positivity, with the LumiraDx method showing enhanced sensitivity (90%; 95% confidence interval (95% CI) 83-94%) compared with the BD Veritor (74%, 95% CI 65-81%), CareStart (74%, 95% CI 65-81%) and Oscar Corona (74%, 95% CI 65-82%) lateral flow antigen tests. Antigen and viral culture positivity were also highly correlated with sample viral load, with areas under the receiver?operator characteristic curves (ROCs) of 0.94-0.97 and 0.92, respectively. In particular, a viral load threshold of 100,000 copies/mL was 95% sensitive (95% CI, 90-98%) and 72% specific (95% CI, 60-81%) for predicting viral culture positivity. Taken together, the detection of SARS-CoV-2 antigen identified highly infectious individuals, some of whom may harbor 10,000-fold more virus in their samples than those with any detectable infectious virus. As such, our data support use of antigen testing in defining infectivity status at the time of sampling.

scholarly journals Transmission potential of vaccinated and unvaccinated persons infected with the SARS-CoV-2 Delta variant in a federal prison, July-August 2021

2021 ◽  
Author(s):  
Phillip P. Salvatore ◽  
Christine C. Lee ◽  
Sadia Sleweon ◽  
David W. McCormick ◽  
Lavinia Nicolae ◽  
...  
Keyword(s):  
Rt Pcr ◽  
Federal Prison ◽  
Transmission Potential ◽  
Vaccination Rates ◽  
Viral Shedding ◽  
Viral Culture ◽  
Culture Positivity ◽  
Health Practitioners ◽  
Polymerase Chain ◽  
Public Health Practitioners

Background The extent to which vaccinated persons who become infected with SARS-CoV-2 contribute to transmission is unclear. During a SARS-CoV-2 Delta variant outbreak among incarcerated persons with high vaccination rates in a federal prison, we assessed markers of viral shedding in vaccinated and unvaccinated persons. Methods Consenting incarcerated persons with confirmed SARS-CoV-2 infection provided mid-turbinate nasal specimens daily for 10 consecutive days and reported symptom data via questionnaire. Real-time reverse transcription-polymerase chain reaction (RT-PCR), viral whole genome sequencing, and viral culture was performed on these nasal specimens. Duration of RT-PCR positivity and viral culture positivity was assessed using survival analysis. Results A total of 978 specimens were provided by 95 participants, of whom 78 (82%) were fully vaccinated and 17 (18%) were not fully vaccinated. No significant differences were detected in duration of RT-PCR positivity among fully vaccinated participants (median: 13 days) versus those not fully vaccinated (median: 13 days; p=0.50), or in duration of culture positivity (medians: 5 days and 5 days; p=0.29). Among fully vaccinated participants, overall duration of culture positivity was shorter among Moderna vaccine recipients versus Pfizer (p=0.048) or Janssen (p=0.003) vaccine recipients. Conclusions As this field continues to develop, clinicians and public health practitioners should consider vaccinated persons who become infected with SARS-CoV-2 to be no less infectious than unvaccinated persons. These findings are critically important, especially in congregate settings where viral transmission can lead to large outbreaks.

scholarly journals Clinical and microbiological assessments of COVID-19 in healthcare workers: a prospective longitudinal study

2020 ◽  
Author(s):  
Antonin Bal ◽  
Karen Brengel-Pesce ◽  
Alexandre Gaymard ◽  
Grégory Quéromès ◽  
Nicolas Guibert ◽  
...  
Keyword(s):  
Viral Load ◽  
Longitudinal Study ◽  
Symptom Onset ◽  
Healthcare Workers ◽  
Respiratory Pathogen ◽  
Respiratory Pathogens ◽  
Prospective Longitudinal Study ◽  
Viral Shedding ◽  
Viral Culture ◽  
Prospective Longitudinal

BackgroundA comprehensive assessment of COVID-19 in healthcare workers (HCWs) including the investigation of viral shedding duration is critical.MethodsA longitudinal study including 319 HCWs was conducted. After SARS-CoV-2 screening with RT-PCR assay, other respiratory pathogens were tested with a multiplex molecular panel. For SARS-CoV-2 positive HCWs, the normalized viral load was determined weekly; viral culture and virus neutralization assays were also performed. For 190 HCWs tested negative, SARS-CoV-2 serological testing was performed one month after the inclusion.FindingsOf the 319 HCWs included, 67 (21.0%) were tested positive for SARS-CoV-2; two of them developed severe COVID-19. The proportion of smell and taste dysfunction was significantly higher in SARS-CoV-2 positive HCWs than in negative ones (38.8% vs 9.5% and 37.3% vs 10.7%, respectively, p<0.001). Of the 67 positive patients, 9.1% were tested positive for at least another respiratory pathogen (vs 19.5%, p=0.07). The proportion of HCWs with a viral load > 5.0 log10 cp/ml (Ct value <25) was less than 15% at 8 days after symptom onset; 12% of them were still positive after 40 days (Ct >37). More than 90% of culturable virus had a viral load > 4.5 log10 cp/ml (Ct < 26) and were collected within 10 days after symptom onset. From HCWs tested negative, 6/190 (3.2%) exhibited seroconversion for IgG antibodies.InterpretationOur data suggest that the determination of normalized viral load (or its estimation through Ct values) can be useful for discontinuing isolation of HCWs and facilitating their safe return to work. HCWs presenting mild COVID-19 are unlikely infectious 10 days after symptom onset.FundingFondation des Hospices Civils de Lyon. bioMérieux provided diagnostic kits.

scholarly journals Correlation of Pandemic (H1N1) 2009 Viral Load with Disease Severity and Prolonged Viral Shedding in Children

2010 ◽  
Vol 16 (8) ◽  
pp. 1265-1272 ◽  
Author(s):  
Chung-Chen Li ◽  
Lin Wang ◽  
Hock-Liew Eng ◽  
Huey-Ling You ◽  
Ling-Sai Chang ◽  
...  
Keyword(s):  
Viral Load ◽  
Disease Severity ◽  
Pandemic H1n1 ◽  
Viral Shedding ◽  
Pandemic H1n1 2009

scholarly journals SARS-CoV-2 Persistent Viral Shedding in the Context of Hydroxychloroquine-Azithromycin Treatment

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 890
Author(s):  
Michel Drancourt ◽  
Sébastien Cortaredona ◽  
Cléa Melenotte ◽  
Sophie Amrane ◽  
Carole Eldin ◽  
...  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Elderly Patients ◽  
Rare Event ◽  
Viral Shedding ◽  
Qrt Pcr ◽  
Viral Culture ◽  
D Dimer

SARS-CoV-2 nasopharyngeal shedding contributes to the spread of the COVID-19 epidemic. Among 3271 COVID-19 patients treated at the Hospital University Institute Méditerranée Infection, Marseille, France from 3 March to 27 April 2020, tested at least twice by qRT-PCR, the median SARS-CoV-2 nasopharyngeal shedding duration was 6 days (range 2–54 days). Compared with short shedders (qRT-PCR positivity < 10 days), 34 (1.04%) persistent shedders (qRT-PCR positivity ≥ 17 days; mean ± SD: 23.3 ± 3.8 days) were significantly older, with associated comorbidities, exhibiting lymphopenia, eosinopenia, increased D-dimer and increased troponin (p < 0.05), and were hospitalized in intensive care unit in 17.7% vs. 1.1% of cases (p < 0.0001). Viral culture was positive in six persistent shedders after day 10, including in one patient after day 17, and no viral co-pathogen was detected in 33 tested patients. Persistent shedders received azithromycin plus hydroxychloroquine ≥ 3 days in 26/34 (76.5%) patients, a figure significantly lower than in short shedders (86.6%) (p = 0.042). Accordingly, mortality was 14.7% vs. 0.5% (p < 0.0001). Persistent shedding was significantly associated with persistent dyspnea and anosmia/ageusia (p < 0.05). In the context of COVID-19 treatment, including treatment with azithromycin plus hydroxychloroquine, the persistence of SARS-CoV-2 nasopharyngeal shedding was a rare event, most frequently encountered in elderly patients with comorbidities and lacking azithromycin plus hydroxychloroquine treatment.

scholarly journals Infectivity of healthcare workers diagnosed with coronavirus disease 2019 (COVID-19) approximately 2 weeks after onset of symptoms: A cross-sectional study

2021 ◽  
pp. 1-3
Author(s):  
Yves Longtin ◽  
Hugues Charest ◽  
Caroline Quach ◽  
Patrice Savard ◽  
Mariana Baz ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Healthcare Workers ◽  
Positive Culture ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional ◽  
Viral Shedding ◽  
Viral Culture ◽  
Respiratory Coronavirus ◽  
Respiratory Specimens

Abstract We performed viral culture of respiratory specimens in 118 severe acute respiratory coronavirus virus 2 (SARS-CoV-2)–infected healthcare workers (HCWs), ∼2 weeks after symptom onset. Only 1 HCW (0.8%) had a positive culture. No factors for prolonged viral shedding were identified. Infectivity is resolved in nearly all HCWs ∼2 weeks after symptom onset.

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