scholarly journals A combined oro-nasopharyngeal swab is more sensitive than mouthwash in detecting SARS-CoV-2 by a high-throughput PCR assay

2020 ◽  
Author(s):  
Wiebke Michel ◽  
Jacqueline Farber ◽  
Milica Dilas ◽  
Ina Tammer ◽  
Jannik Baar ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Test Performance ◽  
Nasopharyngeal Swab ◽  
Virus Concentration ◽  
Upper Respiratory Tract ◽  
Sterile Water ◽  
Test Results ◽  
Pcr Assay ◽  
Previous Diagnosis ◽  
Upper Respiratory

Objectives: The optimal diagnostic specimen to detect SARS-CoV-2 by PCR in the upper respiratory tract is unclear. Mouthwash fluid has been reported as an alternative to nasopharyngeal and oropharyngeal swabs. We compared mouthwash fluid with a combined oro-nasopharyngeal swab regarding test performance. Methods: We tested asymptomatic persons with a previous diagnosis of COVID-19 and their household contacts. First, a mouthwash (gargling for at least 5 sec) with sterile water was performed. Then, with a single flocked swab the back of the throat and subsequently the nasopharynx were sampled. Samples were inactivated and analysed on a Roche cobas 6800 system with the Roche SARS-CoV-2 test. Results: Of 76 persons, 39 (51%) tested positive for SARS-CoV-2 by oro-nasopharyngeal swab. Mouthwash detected 13 (17%) of these infections but did not detect any additional infection. Samples that were positive in both tests, had lower cycle threshold (Ct)-values for oro-nasopharyngeal samples, indicating a higher virus concentration, compared to samples only positive in oro-nasopharyngeal swabs. Conclusions: Mouthwash is not as sensitive as combined oro-nasopharyngeal swab in detecting upper respiratory tract infection.

scholarly journals A combined oro-nasopharyngeal swab is more sensitive than mouthwash in detecting SARS-CoV-2 by a high-throughput PCR assay

Infection ◽  
2021 ◽  
Author(s):  
Wiebke Michel ◽  
Jacqueline Färber ◽  
Milica Dilas ◽  
Hans-Gert Heuft ◽  
Ina Tammer ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Test Performance ◽  
Nasopharyngeal Swab ◽  
Virus Concentration ◽  
Upper Respiratory Tract ◽  
Sterile Water ◽  
Pcr Assay ◽  
Upper Respiratory ◽  
Roche Cobas ◽  
Close Contacts

Abstract Objectives The optimal diagnostic specimen to detect SARS-CoV-2 by PCR in the upper respiratory tract is unclear. Mouthwash fluid has been reported as an alternative to nasopharyngeal and oropharyngeal swabs. We compared mouthwash fluid with a combined oro-nasopharyngeal swab regarding test performance. Methods In a large refugee facility, we retested individuals with a previous positive test for SARS-CoV-2 and their quarantined close contacts. All individuals were asymptomatic at the time of testing. First, a mouthwash (gargling for at least 5 s) with sterile water was performed. Then, with a single flocked swab the back of the throat and subsequently the nasopharynx were sampled. Samples were inactivated and analysed on a Roche cobas 6800® system with the Roche SARS-CoV-2 test. Results Of 76 individuals, 39 (51%) tested positive for SARS-CoV-2 by oro-nasopharyngeal swab. Mouthwash detected 13 of 76 (17%) infections, but did not detect any additional infection. Samples that were positive in both tests, had lower cycle threshold (Ct)-values for oro-nasopharyngeal samples, indicating a higher virus concentration, compared to samples only positive in oro-nasopharyngeal swabs. Conclusion Mouthwash is not as sensitive as combined oro-nasopharyngeal swab in detecting upper respiratory tract infection.

scholarly journals Comparison of two commercial molecular tests and a laboratory-developed modification of the CDC 2019-nCOV RT-PCR assay for the qualitative detection of SARS-CoV-2 from upper respiratory tract specimens

2020 ◽  
Author(s):  
Nicholas M. Moore ◽  
Haiying Li ◽  
Debra Schejbal ◽  
Jennifer Lindsley ◽  
Mary K. Hayden
Keyword(s):  
Respiratory Tract ◽  
Medical Record ◽  
Medical Record Review ◽  
Nasopharyngeal Swab ◽  
Upper Respiratory Tract ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Upper Respiratory ◽  
Record Review ◽  
Swab Specimen

ABSTRACTWe compared the ability of 2 commercial molecular amplification assays [RealTime SARS-CoV-2 on the m2000 (Abbott) and ID NOW™ COVID-19 (Abbott)] and a laboratory-developed test [modified CDC 2019-nCoV RT-PCR assay with RNA extraction by eMag® (bioMérieux) and amplification on QuantStudio™ 6 or ABI 7500 Real-Time PCR System (Life Technologies)] to detect SARS-CoV-2 RNA in upper respiratory tract specimens. Discrepant results were adjudicated by medical record review. 200 nasopharyngeal swab specimens in viral transport medium (VTM) were collected from symptomatic patients between March 27 and April 9, 2020. Results were concordant for 167 specimens (83.5% overall agreement), including 94 positive and 73 negative specimens. The RealTime SARS-CoV-2 assay on the m2000 yielded 33 additional positive results, 25 of which were also positive by the modified CDC assay but not by the ID NOW™ COVID-19 assay. In a follow-up evaluation, 97 patients for whom a dry nasal swab specimen yielded negative results by the ID NOW™ COVID-19 assay had a paired nasopharyngeal swab specimen collected in VTM and tested by the RealTime SARS-CoV-2 assay; SARS-CoV-2 RNA was detected in 13 (13.4%) of these specimens. Medical record review deemed all discrepant results to be true positives. The ID NOW™ COVID-19 test was the easiest to perform and provided a result in the shortest time: as soon as 5 minutes for positive and 13 minutes for negative result. The RealTime SARS-CoV-2 assay on the m2000 detected more cases of COVID-19 infection than the modified CDC assay or the ID NOW™ COVID-19 test.

scholarly journals Is it enough for COVID-19 screening test? Limitation of swab test and general characteristics of mild symptom patients

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Sungwoo Choi ◽  
Hyo Jeong Choi ◽  
Ho Jung Kim
Keyword(s):  
Screening Test ◽  
Community Treatment ◽  
Upper Respiratory Tract ◽  
Test Results ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Positive Rate ◽  
Upper Respiratory ◽  
Polymerase Chain ◽  
Discharge Criteria

The most common method for SARS-CoV-2 testing is throat or nasal swabbing by real-time reverse transcription polymerase chain reaction (RT-PCR) assay. In South Korea, drive-through swab test is used for screening system and community treatment centers (CTCs), which admit and treat confirmed COVID-19 patients with mild symptoms, are being used. This retrospective study was conducted on patients admitted to a CTC on March 6, 2020. A total of 313 patients were admitted. The nasal and throat swabs were collected from the upper respiratory tract, and a sputum test was performed to obtain lower respiratory samples. The positive rate of the first set of test, sputum test was higher than that of the swab test ( p = 0.011). In the second set of test, 1 week after the first ones, the rate of positive swab tests was relatively high ( p = 0.026). In the first set of test, 66 of 152 (43.4%) patients showed 24-h consecutive negative swab test results, when the sputum test results were considered together, that number fell to 29 patients (19.1%) ( p < 0.001). Also, in the second set of test, 63 of 164 (38.4%) patients met the discharge criteria only when the swab test was considered; that number fell to 30 (18.3%) when the sputum test results were also considered ( p < 0.001). Using the swab test alone is insufficient for screening test and discharge decision. Patients who may have positive result in the sputum test can be missed.

Conjunctivitis as a sign of persistent SARS-COV-2 infection? An observational study and report of late symptoms

2021 ◽  
pp. 112067212110565
Author(s):  
Jose Luis Vallejo-Garcia ◽  
L Balia ◽  
R Raimondi ◽  
G Rustioni ◽  
FI Camesasca ◽  
...  
Keyword(s):  
Foreign Body ◽  
Observational Study ◽  
Respiratory Tract ◽  
Recovery Phase ◽  
Nasopharyngeal Swab ◽  
Upper Respiratory Tract ◽  
End Points ◽  
Body Sensation ◽  
Upper Respiratory ◽  
Mean Time

Purpose To investigate if symptomatic conjunctivitis during the recovery phase of the disease could be associated to a persistent presence of SARS-CoV-2 in the upper respiratory tract. Secondary end points were to analyze the presence of SARS-CoV-2 in the conjunctiva of ocular symptomatic patients and to record the presence of ocular disturbances at this point of the disease. Methods An observational study including consecutive COVID19 patients treated at Humanitas Clinical and Research Hospital who were attending for nasopharyngeal swab to confirm the resolution of SARS-CoV-2 infection and end of isolation. We examined 129 consecutive patients from May to June 2020. The primary end point was to determine if symptomatic conjunctivitis at this point of the disease could be associated to a persistent presence of SARS-CoV-2 in the upper respiratory tract. Secondary end points were to analyze the presence of SARS-CoV-2 in the conjunctiva of ocular symptomatic patients and to record the presence of ocular disturbances at this point of the disease. Results One hundred twenty eight patients were included, 9.38% had conjunctivitis, none resulted positive to conjunctival PCR swab test, while two of them had positive nasopharyngeal result. Mean time elapsed since the first COVID-19 positive swab to the time of examination was 6 weeks (  ± 3). The only significant association was the presence of conjunctivitis with older age (65.3  ±  12.7 vs 56.7  +  13.5. p  =  0.046). Nasopharyngeal swab resulted positive in 22 patients (17.19%). While 88 patients (68.2%) did not have any ocular complain during their COVID19 disease. The 40 patients (31.8%) reporting ocular disturbances complained about: redness (25.43%), tearing (19.53%), burning (18.35%), foreign body sensation (17.18%), itching (15.62%), and discharge (12.5%). Conclusion This study showed that late conjunctivitis cannot be considered as a marker of persistent infection when patients are sent to confirm the resolution of SARS-CoV-2 infection.

scholarly journals Dry Eye and Dry Nose Caused by the Effect of Allergic Rhinitis on Tear and Nasal Secretion Osmolarity

2020 ◽  
pp. 014556132090848
Author(s):  
Alper Yenigun ◽  
Ahmet Elbay ◽  
Abdullah Ozdem ◽  
Havvanur Bayraktar ◽  
Omer Faruk Ozer ◽  
...  
Keyword(s):  
Allergic Rhinitis ◽  
Respiratory Tract ◽  
Respiratory Tract Infections ◽  
Nasal Secretion ◽  
Upper Respiratory Tract Infections ◽  
Upper Respiratory Tract ◽  
Test Results ◽  
Upper Respiratory ◽  
Tract Infections ◽  
Healthy Participants

Objective: Allergic rhinitis is a type 1 hypersensitivity reaction of immunoglobulin E in the rhino-ocular mucosa. This study was planned to demonstrate in patients with allergic rhinitis to evaluate changes in tear, nasal secretions, and blood osmolarity compared to healthy individuals. Method: Forty allergic rhinitis patients, 25 patients with acute upper respiratory tract infections, and 26 healthy participants were included in the study. Positive patients with allergic symptoms and skin prick test results were included in the allergic rhinitis group. Tear, nasal secretion, and blood osmolarity values were examined for the 3 groups. Result: In patients with allergic rhinitis, tear and nasal secretion osmolarity values were significantly higher in patients with acute upper respiratory tract infections and those of the healthy participants ( P = .001, P = .038). In blood osmolarity measurements, there was no statistical difference between the groups ( P = .489). In patients with allergic rhinitis, Schirmer test results were significantly shorter than patients who had acute upper respiratory tract infection and those of the healthy participants ( P = .001, P = .001). Patients with allergic rhinitis and acute upper respiratory tract infections had significantly shorter Schirmer test results than in healthy participants ( P = .001, P = .001). Conclusion: Tear osmolarity was increased in allergic rhinitis patients, and this was thought to lead to dry eye findings. In the presence of allergic rhinitis, nasal secretions were found more hyperosmolar than tears. Nasal secretion osmolarity was higher in allergic rhinitis patients than in patients with acute upper respiratory tract infections and control group.

scholarly journals SARS-CoV-2 Detection in Fecal Sample from a Patient with Typical Findings of COVID-19 Pneumonia on CT but Negative to Multiple SARS-CoV-2 RT-PCR Tests on Oropharyngeal and Nasopharyngeal Swab Samples

Medicina ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 290
Author(s):  
Barbara Brogna ◽  
Carlo Brogna ◽  
Mauro Petrillo ◽  
Adriana Modestina Conte ◽  
Giulio Benincasa ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Clinical Symptoms ◽  
Nasopharyngeal Swab ◽  
Upper Respiratory Tract ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Negative Results ◽  
Upper Respiratory ◽  
Polymerase Chain ◽  
Pcr Test

Reverse transcriptase polymerase chain reaction (RT-PCR) negative results in the upper respiratory tract represent a major concern for the clinical management of coronavirus disease 2019 (COVID-19) patients. Herein, we report the case of a 43-years-old man with a strong clinical suspicion of COVID-19, who resulted in being negative to multiple severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RT-PCR tests performed on different oropharyngeal and nasopharyngeal swabs, despite serology having confirmed the presence of SARS-CoV-2 IgM. The patient underwent a chest computed tomography (CT) that showed typical imaging findings of COVID-19 pneumonia. The presence of viral SARS-CoV-2 was confirmed only by performing a SARS-CoV-2 RT-PCR test on stool. Performing of SARS-CoV-2 RT-PCR test on fecal samples can be a rapid and useful approach to confirm COVID-19 diagnosis in cases where there is an apparent discrepancy between COVID-19 clinical symptoms coupled with chest CT and SARS-CoV-2 RT-PCR tests’ results on samples from the upper respiratory tract.

scholarly journals Aerosol Release by Healthy People during Speaking: Possible Contribution to the Transmission of SARS-CoV-2

2020 ◽  
Vol 17 (23) ◽  
pp. 9088
Author(s):  
Thomas Eiche ◽  
Martin Kuster
Keyword(s):  
Respiratory Tract ◽  
Potential Risk ◽  
Healthy People ◽  
Virus Concentration ◽  
Upper Respiratory Tract ◽  
Risk Of Infection ◽  
Data Set ◽  
Viral Particles ◽  
Infective Dose ◽  
Upper Respiratory

Our research aimed to review the potential risk of infection by SARS-CoV-2. We used an excerpt of a data set generated in May 2020 for reviewing the SARS-CoV-2 prevention concept of orchestras, singers and actors. People were sampled for droplet release for one-hour activities using a Grimm spectrometer covering a spectrum of 1 to 32 µm diameter. We estimated the number of “quanta” in the exhaled liquid from viral concentrations of 106 to 1011/mL, based on the Human Infective Dose 50 of 218 viral particles. We employed the Wells–Riley equation to estimate the risk of infection in typical meeting rooms for a one-hour meeting of 2, 4 and 6 people observing a 2 m distance. The four participating adults released a mean of 1.28 nLm3 while breathing, 1.68 nL/m3 while speaking normally, and two adults released a mean of 4.44 nL/m3 while talking with a raised voice. The combination of 50% breathing, 45% talking normally and 5% speaking with a raised voice increased the risk of infection above 5% for a one-hour meeting of two people. The result is based on 6 quanta released, corresponding to an initial virus concentration of 1000/nL (109/mL) in the fluid of the upper respiratory tract. Our data confirm the importance of using facemasks in combination with other measures to prevent transmission of SARS-CoV-2 at the workplace.

scholarly journals Shedding of infectious SARS-CoV-2 in symptomatic neonates, children and adolescents

2020 ◽  
Author(s):  
Arnaud G L’Huillier ◽  
G Torriani ◽  
F Pigny ◽  
L Kaiser ◽  
I Eckerle
Keyword(s):  
Respiratory Tract ◽  
Infectious Virus ◽  
Virus Isolation ◽  
Age Groups ◽  
Low Frequency ◽  
Nasopharyngeal Swab ◽  
Upper Respiratory Tract ◽  
Median Viral Load ◽  
Acute Respiratory Diseases ◽  
Upper Respiratory

AbstractChildren are underrepresented in COVID-19 case numbers, with most pediatric cases exhibiting limited severity, and do not seem to be major drivers of transmission, unlike for other respiratory viruses. That said, SARS-CoV-2 infects children across all age groups, and despite the high proportion of mild or asymptomatic infections, it would be naïve not to consider them as transmitters. To address this point we used cell culture to systematically assess the presence of cultivable SARS-CoV-2 in the upper respiratory tract in a cohort of our institution’s first 23 symptomatic neonates, children and teenagers with COVID-19 diagnosed by RT-PCR.Median age was 12.0 years (interquartile range [IQR 3.8–14.5], range 7 days-15.9 yrs). Most patients had an upper respiratory tract infection (n=13), followed by fever without source and pneumonia (each, n=2). Samples were collected at a median of 2 days (IQR 1–3) after symptom onset. Median viral load (VL) at time of diagnosis was 3.0×106 copies/ml (mean 4,4×108, IQR 6.9×103–4.4×108) from a nasopharyngeal swab (NPS).SARS-CoV-2 virus isolation was successful in 12/23 (52%) children after inoculating VeroE6 cells with a NPS specimen. SARS-CoV-2 isolation was determined by the presence of a typical cytopathic effect (CPE) and increased viral RNA in the supernatant. SARS-CoV-2 replication in all positive isolates (12/12) was confirmed by a second passage using new VeroE6 cells.Virus isolation was successful from NPS from all age groups, with a median initial VL of 1.7×108 copies/ml (mean 7.9×108, IQR 4.7×106–1.0×109) (Figure 1). The youngest patient that SARS-CoV-2 was isolated from was a 7-day old neonate. No correlation between disease presentation and success of virus isolation was observed.Our data show that initial VLs at diagnosis in symptomatic children is comparable to those in adults, and that symptomatic children of all ages shed infectious virus in early acute illness. Infectious virus isolation success was largely comparable to that of adults, although two specimens yielded an isolate at a lower VL (1.2×104 and 1.4×105 copies/ml) than what was observed in adults.SARS-CoV-2 shedding patterns of culture competent virus in symptomatic children resemble those observed in adults. Therefore, transmission of SARS-CoV-2 from children is plausible. Considering the relatively low frequency of infected children at this time, biological or other unknown factors could reduce transmission in this population. Both large serological investigations and systematic surveillance of acute respiratory diseases are needed to understand the role of children in this new pandemic.

Vinegar and Its Active Component Acetic Acid Inhibit SARS-CoV-2 Infection In Vitro and Ex Vivo

2020 ◽  
Author(s):  
Isabel Pagani ◽  
Silvia Ghezzi ◽  
Massimo Clementi ◽  
Guido Poli ◽  
Mario Bussi ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Antiviral Activity ◽  
Respiratory Tract ◽  
Active Component ◽  
Ex Vivo ◽  
Vero Cells ◽  
Nasopharyngeal Swab ◽  
Upper Respiratory Tract ◽  
Upper Respiratory

AbstractEffective and economical measures are needed to either prevent or inhibit the replication of SARS-CoV-2, the causative agent of COVID-19, in the upper respiratory tract. As fumigation of vinegar at low concentration (0.34%) ameliorated the symptoms of mild SARS-CoV-2 infection, we tested in vitro the potential antiviral activity of vinegar and of its active component, acetic acid. We here demonstrate that both vinegar and acetic acid indeed strongly inactivate SARS-CoV-2 infectivity in Vero cells. Furthermore, vinegar treatment caused a 90% inhibition of the infectious titer when directly applied to a nasopharyngeal swab transfer medium of a COVID-19 patient. These effects were potentiated if conduced at a temperature of 45 °C vs. 37 °C, a condition that is transiently generated in the upper respiratory tract during fumigation. Our findings are consistent and extend the results of studies performed in the early and mid-20th century on the disinfectant capacity of organic acids and can provide an affordable home-made aid to prevent or contain SARS-CoV-2 infection of the upper respiratory tract.

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