scholarly journals Detection of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) in outpatients: A multicenter comparison of self-collected saline gargle, oral swab, and combined oral–anterior nasal swab to a provider collected nasopharyngeal swab

Author(s):  
Christopher E. Kandel ◽  
Matthew Young ◽  
Mihaela Anca Serbanescu ◽  
Jeff E. Powis ◽  
David Bulir ◽  
...  

Abstract Background: Widespread testing for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) is necessary to curb the spread of coronavirus disease 2019 (COVID-19), but testing is undermined when the only option is a nasopharyngeal swab. Self-collected swab techniques can overcome many of the disadvantages of a nasopharyngeal swab, but they require evaluation. Methods: Three self-collected non-nasopharyngeal swab techniques (saline gargle, oral swab and combined oral-anterior nasal swab) were compared to a nasopharyngeal swab for SARS-CoV-2 detection at multiple COVID-19 assessment centers in Toronto, Canada. The performance characteristics of each test were assessed. Results: The adjusted sensitivity of the saline gargle was 0.90 (95% CI 0.86-0.94), the oral swab was 0.82 (95% CI, 0.72–0.89) and the combined oral–anterior nasal swab was 0.87 (95% CI, 0.77–0.93) compared to a nasopharyngeal swab, which demonstrated a sensitivity of ˜90% when all positive tests were the reference standard. The median cycle threshold values for the SARS-CoV-2 E-gene for concordant and discordant saline gargle specimens were 17 and 31 (P < .001), for the oral swabs these values were 17 and 28 (P < .001), and for oral–anterior nasal swabs these values were 18 and 31 (P = .007). Conclusions: Self-collected saline gargle and an oral–anterior nasal swab have a similar sensitivity to a nasopharyngeal swab for the detection of SARS-CoV-2. These alternative collection techniques are cheap and can eliminate barriers to testing, particularly in underserved populations.

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260184
Author(s):  
Dominik Kerimov ◽  
Pekka Tamminen ◽  
Hanna Viskari ◽  
Lauri Lehtimäki ◽  
Janne Aittoniemi

Background SARS-CoV-2 diagnosis relies on the performance of nasopharyngeal swabs. Alternative sample sites have been assessed but the heterogeneity of the studies have made comparing different sites difficult. Objectives Our aim was to compare the performance of four different sampling sites for SARS-CoV-2 samples with nasopharynx being the benchmark. Study design COVID-19 positive patients were recruited prospectively, and samples were collected and analysed for SARS-CoV-2 with RT-PCR from all four anatomical sites in 43 patients, who provided written informed consent. Results All anterior nasal and saliva samples were positive, while two oropharyngeal samples were negative. There was no significant difference in the cycle threshold values of nasopharyngeal and anterior nasal samples while saliva and oropharynx had higher cycle threshold values. Conclusions Anterior nasal swab performs as good as nasopharynx swab with saliva also finding all the positives but with higher cycle threshold values. Thus, we can conclude that anterior nasal swabs can be used for SARS-CoV-2 detection instead of nasopharyngeal swabs if the situation would require so.


2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Eva Kriegova ◽  
Regina Fillerova ◽  
Milan Raska ◽  
Jirina Manakova ◽  
Martin Dihel ◽  
...  

AbstractThe early identification of asymptomatic yet infectious cases is vital to curb the 2019 coronavirus (COVID-19) pandemic and to control the disease in the post-pandemic era. In this paper, we propose a fast, inexpensive and high-throughput approach using painless nasal-swab self-collection followed by direct RT-qPCR for the sensitive PCR detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This approach was validated in a large prospective cohort study of 1038 subjects, analysed simultaneously using (1) nasopharyngeal swabs obtained with the assistance of healthcare personnel and analysed by classic two-step RT-qPCR on RNA isolates and (2) nasal swabs obtained by self-collection and analysed with direct RT-qPCR. Of these subjects, 28.6% tested positive for SARS-CoV-2 using nasopharyngeal swab sampling. Our direct RT-qPCR approach for self-collected nasal swabs performed well with results similar to those of the two-step RT-qPCR on RNA isolates, achieving 0.99 positive and 0.98 negative predictive values (cycle threshold [Ct] < 37). Our research also reports on grey-zone viraemia, including samples with near-cut-off Ct values (Ct ≥ 37). In all investigated subjects (n = 20) with grey-zone viraemia, the ultra-small viral load disappeared within hours or days with no symptoms. Overall, this study underscores the importance of painless nasal-swab self-collection and direct RT-qPCR for mass testing during the SARS-CoV-2 pandemic and in the post-pandemic era.


Author(s):  
Carla Benea ◽  
Laura Rendon ◽  
Jesse Papenburg ◽  
Charles Frenette ◽  
Ahmed Imacoudene ◽  
...  

Abstract Objective: Evidence-based infection control strategies are needed for healthcare workers (HCWs) following high-risk exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2). In this study, we evaluated the negative predictive value (NPV) of a home-based 7-day infection control strategy. Methods: HCWs advised by their infection control or occupational health officer to self-isolate due to a high-risk SARS-CoV-2 exposure were enrolled between May and October 2020. The strategy consisted of symptom-triggered nasopharyngeal SARS-CoV-2 RNA testing from day 0 to day 7 after exposure and standardized home-based nasopharyngeal swab and saliva testing on day 7. The NPV of this strategy was calculated for (1) clinical coronavirus disease 2019 (COVID-19) diagnosis from day 8–14 after exposure, and for (2) asymptomatic SARS-CoV-2 detected by standardized nasopharyngeal swab and saliva specimens collected at days 9, 10, and 14 after exposure. Interim results are reported in the context of a second wave threatening this essential workforce. Results: Among 30 HCWs enrolled, the mean age was 31 years (SD, ±9), and 24 (80%) were female. Moreover, 3 were diagnosed with COVID-19 by day 14 after exposure (secondary attack rate, 10.0%), and all cases were detected using the 7-day infection control strategy: the NPV for subsequent clinical COVID-19 or asymptomatic SARS-CoV-2 detection by day 14 was 100.0% (95% CI, 93.1%–100.0%). Conclusions: Among HCWs with high-risk exposure to SARS-CoV-2, a home-based 7-day infection control strategy may have a high NPV for subsequent COVID-19 and asymptomatic SARS-CoV-2 detection. Ongoing data collection and data sharing are needed to improve the precision of the estimated NPV, and here we report interim results to inform infection control strategies in light of a second wave threatening this essential workforce.


Author(s):  
Fernanda de Paula Eduardo ◽  
Leticia Mello Bezinelli ◽  
Carlos Ariel Rodrigues de Araujo ◽  
João Vitor Vanderlan Moraes ◽  
Alexander Birbrair ◽  
...  

Author(s):  
Eric T. Beck ◽  
Wendy Paar ◽  
Lara Fojut ◽  
Jordan Serwe ◽  
Renee R. Jahnke

The Quidel Sofia SARS FIA test (SOFIA) is a rapid antigen immunoassay for detection of SARS-CoV-2 viral proteins from nasal or nasopharyngeal swab specimens. The purpose of this study was to compare the results of the SOFIA test to the Hologic Aptima SARS-CoV-2 TMA test (APTIMA TMA), a high-throughput molecular diagnostic test that uses transcription mediated amplification for detection of SARS-CoV-2 nucleic acid from upper respiratory specimens. Three hundred and 40-seven symptomatic patients, from an urgent care center in an area with a high prevalence of SARS-CoV-2 infections, were tested in parallel using nasal swabs on the SOFIA test and nasopharyngeal swabs on the APTIMA TMA test. The SOFIA test demonstrated an 82.0% positive percent agreement (PPA) compared to the APTIMA TMA test for symptomatic patients tested ≤ 5 days from symptom onset and a 54.5% PPA for symptomatic patients > 5 days from symptom onset. The Cepheid Xpert Xpress SARS-CoV-2 RT-PCR test was used to determine the cycle threshold (Ct) value from any specimens that were discrepant between the SOFIA and APTIMA TMA tests. Using a Ct value of ≤ 35 as a surrogate for SARS-CoV-2 culture positivity, we estimate that the SOFIA test detected 87.2% of symptomatic patients tested ≤ 5 days from symptom onset that were likely to be culture positive.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S654-S654
Author(s):  
Matthew Thompson ◽  
Monica L Zigman Suchsland ◽  
Victoria Lyon ◽  
Enos Kline ◽  
ShiChu Huang ◽  
...  

Abstract Background Seasonal influenza (flu) occurs annually, causing disease with substantial morbidity and mortality. Currently, flu is suspected from clinical features, but requires a laboratory test to confirm infection. No influenza tests in the United States are approved for use outside of clinical settings. We aimed to determine the accuracy of influenza self-testing using an at-home, app-guided, lateral flow assay compared with a molecular reference standard conducted at a laboratory among adults self-reporting influenza-like illness (ILI). Methods This is an observational study of individuals with self-reported ILI throughout the continental 48 United States recruited from the Flu Near You platform, online marketing, and clinics in the Seattle area. Recruitment took place from March 4 to April 26, 2019. Participants were directed to an iPhone App that determined eligibility, consent, and responses to symptom questions and risk factors. Individuals were mailed a commercially available CLIA-waived influenza lateral flow test to conduct at home, guided by the app, and returned the used test along with a second nasal swab collected in viral transport media to the research team. Influenza testing was performed by RT–PCR on the second nasal swab, as well as the residual fluid from the RDT. Accuracy of home test result (read by the participant), as well as image capture of the lateral flow test strip, were compared with the lab-based reference standard. Results To date, 1127 at-home flu tests were mailed to participants and 711 (63.1%) samples returned to the lab. There were 17 flu-positive results from the rapid diagnostic test for a flu positivity rate of 2.4%. Testing using the reference standard is currently in progress. We will share diagnostic accuracy results once testing of the reference standard is completed. Of the kits returned, 353 (49.7%)had an error recorded, which included errors in return packaging, reference standard, rapid test tube sample, or rapid test strip errors. Conclusion Overall, findings from this study will determine the accuracy of an at-home rapid diagnostic test, and inform more widely research design for evaluating smartphone-enhanced home tests for pathogens. Many samples returned to the lab had a recorded error, suggesting at-home testing requires additional feasibility testing and refinement of the current methods used. Disclosures All authors: No reported disclosures.


2020 ◽  
Vol 58 (6) ◽  
Author(s):  
Hélène Péré ◽  
Isabelle Podglajen ◽  
Maxime Wack ◽  
Edouard Flamarion ◽  
Tristan Mirault ◽  
...  

2015 ◽  
Vol 36 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Chang-Seop Lee ◽  
Bianca Montalmont ◽  
Jessica A. O’Hara ◽  
Alveena Syed ◽  
Charma Chaussard ◽  
...  

OBJECTIVENasal swab culture is the standard method for identifying methicillin-resistant Staphylococcus aureus (MRSA) carriers. However, this method is known to miss a substantial portion of those carrying MRSA elsewhere. We hypothesized that the additional use of a sponge to collect skin culture samples would significantly improve the sensitivity of MRSA detection.DESIGNHospitalized patients with recent MRSA infection were enrolled and underwent MRSA screening of the forehead, nostrils, pharynx, axilla, and groin with separate swabs and the forehead, axilla, and groin with separate sponges. Staphylococcal cassette chromosome mec (SCCmec) typing was conducted by polymerase chain reaction (PCR).PATIENTSA total of 105 MRSA patients were included in the study.RESULTSAt least 1 specimen from 56.2% of the patients grew MRSA. Among patients with at least 1 positive specimen, the detection sensitivities were 79.7% for the swabs and 64.4% for the sponges. Notably, 86.4% were detected by a combination of sponges and nasal swab, and 72.9% were detected by a combination of pharyngeal and nasal swabs, whereas only 50.9% were detected by nasal swab alone (P<0.0001 and P=0.0003, respectively). Most isolates had SCCmec type II (59.9%) and IV (35.7%). No correlation was observed between the SCCmec types and collection sites.CONCLUSIONScreening using a sponge significantly improves MRSA detection when used in addition to screening with the standard nasal swab.Infect Control Hosp Epidemiol 2014;36(1): 28–33


1970 ◽  
Vol 68 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Joyce McQuillin ◽  
P. S. Gardner ◽  
Patricia M. sturdy

SUMMARYThirty-five consecutive infants admitted into hospital in Newcastle upon Tyne with acute respiratory disease had cough/nasal swabs and nasopharyngeal secretions taken. Both types of specimens were examined the fluorescent antibody technique for respiratory syncytial virus; isolation techniques were also used. Twenty-eight specimens of nasopharyngeal secretion were positive, as were 26 of the corresponding cough/nasal swab preparations. Respiratory syncytial virus was isolated from all but one.Sixteen consecutive children who were only suitable for examination cough/nasal swab preparations were also investigated isolation and fluorescent antibody techniques for respiratory syncytial virus. Respiratory syncytial virus was isolated from eight, seven of whom were positive the fluorescent antibody technique. The use of cough/nasal swab preparations stained the fluorescent antibody technique, although not as efficient as nasopharyngeal secretions, may have a place in the rapid diagnosis of respiratory virus infection in older children and children in general practice. The importance of rapid diagnosis for respiratory virus infection in relationship to antiviral therapy was also discussed.


2010 ◽  
Vol 1 (1) ◽  
pp. 38 ◽  
Author(s):  
Dinar Adriaty ◽  
Ratna Wahyuni ◽  
Iswahyudi Iswahyudi ◽  
Indropo Agusni ◽  
Shinzo Izumi

East Java province still has some pocket of leprosy endemic areas. In order to solve the problem, molecular typing will make it feasible to study the transmission pattern of Mycobacterium leprae in leprosy endemic area. The present study is to analyze the presence of M.leprae DNA in the environment and to study variation number of TTC repeats and their distribution. Poteran Island is located in Madura, East Java and was chosen because this island has a high prevalence of leprosy and remains stable for the last five years. All samples were analyzed by PCR and the numbers of TTC repeats were confirmed by direct sequencing. Of all collected samples, 26.4% isolates of water resources (24); 61.9% nasal swabs (26); and 35.3% skin tissues (24) are positives. No statistically difference in the pattern distribution of TTC repeats between skin tissues of patients and nasal swab of households contact (p=0.594); also distribution of TTC repeats between skin tissues of leprosy patients and those of water resources (p=0.441); and distribution of TTC repeats between nasal swab of households contact with water resources (p=0.906). It means that the transmission of M.leprae in leprosy endemic area has closely related in 3 aspects: agent, host & environment.


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