Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
1.
Topics in Antiviral Medicine ; 31(2):214, 2023.
Article in English | EMBASE | ID: covidwho-2316884

ABSTRACT

Background: Zotatifin (eFT226) is a potent and selective inhibitor of eukaryotic initiation factor 4A (eIF4A), a host RNA helicase required for SARS-CoV-2 replication. In vitro, zotatifin demonstrates broad spectrum antiviral activity against all human coronaviruses tested. Zotatifin has physicochemical and pharmacokinetic (PK) properties suitable for convenient, single subcutaneous (sc) injection. This study assessed the safety, antiviral activity, and PK of zotatifin in non-hospitalized patients (pts) with mild/moderate COVID. Method(s): PROPEL is a randomized, placebo-controlled, double-blind study in non-hospitalized pts with mild/moderate COVID. At randomization, pts must have had a SARS-CoV-2 positive test within 7 days and at least 1 COVID symptom. Pts were randomized (3:1) to zotatifin or placebo sc in 3 cohorts of 12 pts each. Cohort 1, 2 and 3 received a single dose (SD) of zotatifin of 0.01. 0.02 and 0.035 mg/kg or matching placebo. Safety (adverse event (AE) and laboratory tests), antiviral activity (mid-turbinate nasal swabs and saliva), and plasma PK were collected over 30 days. The primary endpoint was safety;key secondary endpoints included SARS-CoV-2 viral load (VL) and PK. The study was not powered for statistical inferential testing. Result(s): 36 pts were enrolled across all three cohorts and completed a 30-day follow up. Data is currently available for pts in cohorts 1 and 2, 18 and 6 of whom received zotatifin and placebo, respectively. Baseline characteristics were comparable between groups. The most common AE was erythema at injection site in cohort 1 (44%) and cohort 2 (89%), vs. 0% in the zotatifin and pooled placebo groups, respectively. Other AE frequencies were comparable between zotatifin and placebo and no serious AEs were reported. The concentrationtime profile of zotatifin from cohorts 1 and 2 following sc administration was similar to that reported previously following IV administration, demonstrated a terminal elimination half-life (t1/2) of ~ 4 days, high steady-state volume of distribution (Vss) of 31 L/kg, and low plasma clearance (Cl) of 3.9 mL/min/kg. A faster time to viral RNA undetectability was observed with zotatifin vs. placebo (see Fig 1. Not statistically significant). Conclusion(s): Zotatifin was safe, well tolerated and demonstrated a trend in clinical antiviral activity in patients with mild to moderate COVID which supports further clinical development. Zotatifin sc route of administration supports a point of care treatment for COVID.

2.
J Virol Methods ; 316: 114713, 2023 06.
Article in English | MEDLINE | ID: covidwho-2255829

ABSTRACT

BACKGROUND: During the course of the COVID-19 pandemic, nasopharyngeal swabs, combined throat and nose swabs and saliva samples have been evaluated for SARS-CoV-2 detection using nucleic acid amplification tests (NAT). Literature on anterior nasal swabs is limited. We investigated a novel anterior nasal swab that has been designed to standardised self-collection, maximise sample uptake and improve user comfort. We used combined throat and nose swabs and neat saliva samples as the comparators. RESULTS: The overall positive percentage agreement between the Rhinoswab™ and the combined throat and nose swab was 95.2 % at day 2 post participant recruitment and 93.3 % on day 4 post participant recruitment. This was favourable to the positive percentage agreement with saliva at the same time points. CONCLUSION: In our study the Rhinoswab™ performed equally well in comparison to a combined throat and nose swab for the laboratory detection of SARS-CoV-2 using nucleic acid amplification techniques.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Nasopharynx , Pandemics , COVID-19 Testing , Saliva , Specimen Handling/methods
3.
Open Forum Infectious Diseases ; 9(Supplement 2):S633-S634, 2022.
Article in English | EMBASE | ID: covidwho-2189864

ABSTRACT

Background. The need for community surveillance of respiratory viruses in high-risk settings such as homeless shelters has been underscored by the COVID-19 pandemic. Here, we show that sampling high-touch surfaces is a low-cost, minimally intensive means of community respiratory virus surveillance. Methods. Environmental samples were collected weekly from adult and family homeless shelters in King County, WA from November 2019 - April 2020. At times when residents were present, a 10cm2 area of selected high-touch surfaces were swabbed and bioaerosol samples were collected in high-traffic areas. Surfaces included entrance and restroom doorknobs, counters, and surfaces unique to each shelter. Study staff collected mid-turbinate swabs from shelter resident participants aged > 3 months with symptoms of acute respiratory illness (ARI). All samples were tested by RT-PCR for 27 viruses. From January 1, 2020 onward, samples were also tested for SARS-CoV-2. Results. A total of 788 environmental swabs, 1509 nasal swabs, and 98 bioaerosol samples from 6 adult and 3 family shelters were tested. Adenovirus (109 positive swabs, 13.8% of tested swabs), rhinovirus (107, 13.6%) and human bocavirus (62, 7.9%) were the most frequently detected viruses in surface swabs. Rhinovirus (160, 10.6%), human coronaviruses (79, 5.24%) and influenza B (43, 2.85%) were the most detected in nasal swabs. All viruses detected in nasal swabs were found in surface swabs. Of 9 surfaces, exterior bathroom doorknobs were the physical location with the highest number of pathogens detected. SARS-CoV-2 was first detected in surface swabs on 3/20/20, and in nasal swabs on 3/10/20. Bioaerosol samples detected virus in a low percentage of samples relative to surface and nasal swabs. Table 1 Count and period prevalence of environmental viral detection by shelter type, November 18, 2019 - April 10, 2020. (Figure Presented) Conclusion. Respiratory viruses detected through environmental sampling in homeless shelters were similar to the viruses detected from ARI episodes in study participants. Environmental surface sampling presents a plausible, minimally invasive method of surveillance for both endemic and emerging respiratory pathogens, as evidenced by the detection of SARS-CoV-2 during the early stages of the pandemic. Further research could focus on sampling public locations for broader community surveillance and culturing viruses found on these surfaces.

4.
J Virol Methods ; 313: 114667, 2023 03.
Article in English | MEDLINE | ID: covidwho-2165658

ABSTRACT

PURPOSE: To investigate the performance of a combined nasal midturbinate- and oropharyngeal (NAOP) self-swab compared to a deep oropharyngeal (OP) swab by health care workers (HCW) in detecting SARS-CoV-2 in a real-life setting. METHODS: Paired swabs from 1119 participants were included. RT-PCR were used to detect SARS-CoV-2 in both swab samples. RESULTS: 330 participants tested positive. The sensitivity of the combined self-swab and OP swab was 96.9 % and 95.4 % respectively, whereas the Ct-values for self-swabs were significantly lower compared to OP swabs. CONCLUSION: The combined NAOP self-swab outperformed the OP swab and thus, the NAOP self-swab may be an alternative sampling method under the given circumstances.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/diagnosis , Nasopharynx , Oropharynx , Specimen Handling/methods
5.
Topics in Antiviral Medicine ; 30(1 SUPPL):17-18, 2022.
Article in English | EMBASE | ID: covidwho-1880403

ABSTRACT

Background: There have been few estimates of SARS-CoV-2 seroprevalence in rigorously sampled and geographically broad populations that include children, who have accounted for fewer diagnosed COVID-19 cases compared to adults. The COMPASS study assessed cross-sectional, population-based SARS-CoV-2 seroprevalence and PCR positivity among adults and children in 15 US communities. Methods: Time-location sampling was used to recruit adults and children >2 months of age from randomly selected venues in communities near participating research sites. Demographics, history of COVID-19 and willingness (likely, very likely or already received) to receive an approved COVID-19 vaccine were captured via an interviewer-administered questionnaire. Serologic analysis was performed using a SARS-CoV-2 IgG nucleocapsid antibody (Ab) assay (Abbott Diagnostics, Abbott Park, IL). PCR testing was performed on a mid-turbinate swab using an assay approved by the HPTN Laboratory Center. Prevalence estimates were constructed, overall and by age group (<18 y, 18-39 y, 40-59 y, 60+ y), for each community using survey weights that accounted for the sampling design. Results: A total of 22,732 persons were enrolled (median per community 1,246, range 511 to 2,925) from Jan 2021 to Aug 2021;of these, 2,151 (9.5%) were <18 y. Overall, SARS-CoV-2 seroprevalence (Ab+) ranged from 3.8 to 17.3% (median 12.5%) and SARS-CoV-2 PCR positivity ranged from 0 to 1.9% (median 0.7%). About half of Ab+ and half of PCR+ persons reported no prior or recent (within 14 days) COVID-19 symptoms, respectively [median by community 49.7% (IQR 45.8, 63.9) and 53.6% (IQR 44.3, 58.3)]. Most adults (18+ y) (median 77.3% [69.6 to 92.7%]) reported willingness to get a COVID-19 vaccination;willingness was higher among persons aged 60 y+ [median 88.1%, IQR 83.5, 90.6] compared to those aged 18-39 [median 72.5%, IQR 64.1, 79.8] and 40-59 [median 75.6%, IQR 72.5, 78.4]. The combined prevalence of prior (Ab+) or active (PCR+) SARS-CoV-2 infection across all communities ranged from 4.4 to 17.6% (median 12.7%), and was similar for children (median 12.7%, range 4.4 to 19.7%) and adults (median 12.5%, range 4.4% to 17.8%) among communities enrolling > 25 children (Figure). Conclusion: In this population-based survey, evidence of prior and active SARS-CoV-2 infection varied widely by community but, contrasting with earlier reports, not by age. These findings suggest that acquisition of SARS-CoV-2 is similar across all ages.

6.
J Clin Virol ; 152: 105170, 2022 07.
Article in English | MEDLINE | ID: covidwho-1814679

ABSTRACT

BACKGROUND: The Omicron variant of concern is characterised by more than 50 distinct mutations, most in the spike protein. The implications of these for disease transmission, tissue tropism and diagnostic testing needs study. OBJECTIVES: We evaluated the performance of RT-PCR on saliva (SA) swabs and antigen testing on mid-turbinate MT samples relative to RT-PCR on MT swabs. Patients (n = 453) presenting for outpatient testing at the Groote Schuur Hospital COVID-19 testing centre in Cape Town South Africa were recruited. Participants were recruited during the Delta (n = 304) and Omicron (n = 149) waves. RESULTS: In 30 confirmed Delta infections, positive percent agreement (PPA) of RT-PCR on saliva was only 73% compared to a composite standard of either MT or SA RT-PCR positivity, with rapid decay by day 3 after symptom onset. In contrast, in the 70 Omicron infections, SA performed as well as, or better than, MT samples up to day 5, with an overall PPA of SA swabs of 96% and MT of 93%. A change in antigen test performance was noted, with PPA of 93% in Delta, but only 68% for Omicron. CONCLUSIONS: Altered shedding kinetics appear to be present in Omicron-infected patients with more viral RNA detectable in saliva. Saliva swabs are a promising alternative to nasal samples, especially early in infection when sampling of both sites could improve detection. Lower sensitivity of antigen tests in Omicron is a concern and requires further study.


Subject(s)
COVID-19 Testing , COVID-19 , Humans , SARS-CoV-2 , Sensitivity and Specificity , South Africa , Tropism
7.
Microbiol Spectr ; 10(2): e0012822, 2022 04 27.
Article in English | MEDLINE | ID: covidwho-1752767

ABSTRACT

Saliva is an attractive sample for detecting SARS-CoV-2. However, contradictory reports exist concerning the sensitivity of saliva versus nasal swabs. We followed close contacts of COVID-19 cases for up to 14 days from the last exposure and collected self-reported symptoms, midturbinate swabs (MTS), and saliva every 2 or 3 days. Ct values, viral load, and frequency of viral detection by MTS and saliva were compared. Fifty-eight contacts provided 200 saliva-MTS pairs, and 14 contacts (13 with symptoms) had one or more positive samples. Saliva and MTS had similar rates of viral detection (P = 0.78) and substantial agreement (κ = 0.83). However, sensitivity varied significantly with time since symptom onset. Early on (days -3 to 2), saliva had 12 times (95% CI: 1.2, 130) greater likelihood of viral detection and 3.2 times (95% CI: 2.8, 3.8) higher RNA copy numbers compared to MTS. After day 2 of symptoms, there was a nonsignificant trend toward greater sensitivity using MTS. Saliva and MTS demonstrated high agreement making saliva a suitable alternative to MTS for SARS-CoV-2 detection. Saliva was more sensitive early in the infection when the transmission was most likely to occur, suggesting that it may be a superior and cost-effective screening tool for COVID-19. IMPORTANCE The findings of this manuscript are increasingly important with new variants that appear to have shorter incubation periods emerging, which may be more prone to detection in saliva before detection in nasal swabs. Therefore, there is an urgent need to provide the science to support the use of a detection method that is highly sensitive and widely acceptable to the public to improve screening rates and early detection. The manuscript presents the first evidence that saliva-based RT-PCR is more sensitive than MTS-based RT-PCR in detecting SARS-CoV-2 during the presymptomatic period - the critical period for unwitting onward transmission. Considering other advantages of saliva samples, including the lower cost, greater acceptability within the general population, and less risk to health care workers, our findings further supported the use of saliva to identify presymptomatic infection and prevent transmission of the virus.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , Humans , Nasopharynx , SARS-CoV-2/genetics , Saliva , Specimen Handling/methods
8.
Indian Journal of Medical Microbiology ; 39:S70, 2021.
Article in English | EMBASE | ID: covidwho-1734507

ABSTRACT

Background:The recent emergence of SARS CoV2 pandemic has posed formidable challenges for the clinical laboratories seeking diagnostic confirmation. The clinical and epidemiologic management of the SARS-CoV-2 pandemic is critically dependent on molecular assays with short turn-around time. To face the current COVID 19 pandemic, the need for the automated rapid diagnostic tool is essential. Early diagnosis with XPERT Xpress SARS -CoV2 can aid in therapeutic man- agement and outbreak control Methods:A retrospective study was performed on a total of 373 samples (nasopharyngeal, oropharyngeal, nasal or mid turbinate swabs/aspirate) from clinically suspected cases of SARS CoV 2 infection from March 30, 2020, to November 15, 2020, in the department of microbiology of our institute. The specimens were collected, placed in VTM and run on the Gene Xpert Dx according to manufacturer’s protocol. Results: Out of 373 samples tested 46 (12.3%) were positive, 319 (85.5%) were negative, 1 (0.26%) was presumptive positive and 7 (1.8%) samples were excluded due to Xpert error. Travel history was present in 79.2% of positive cases and 73.2% of the positive cases had flu-like symptoms (fever, dry cough, headache, myalgias, arthralgias and sore throat). The total tested patients had various emergency conditions: 109(29.2%) had RTA, 116(31.09%) had surgical emergencies, 64(17.1%) patients admitted with head injury and 84(22.5%) were delivery patients. Conclusions:Xpert Xpress SARS CoV2 is one step confirmatory test with a quick turnaround time and is ideal in cases of emergency conditions of patients. It can be utilized in multiple settings where actionable test results are needed to make informed treatment decisions quickly

9.
Diagnostics (Basel) ; 11(12)2021 Nov 27.
Article in English | MEDLINE | ID: covidwho-1542451

ABSTRACT

Due to their ease-of-use, lateral flow assay SARS-CoV-2 antigen-detecting rapid diagnostic tests could be suitable candidates for antigen-detecting rapid diagnostic self-test (Ag-RDST). We evaluated the practicability of the Ag-RDST BIOSYNEX Antigen Self-Test COVID-19 Ag+ (Biosynex Swiss SA, Freiburg, Switzerland), using self-collected nasal secretions from the turbinate medium (NMT), in 106 prospectively included adult volunteers living in Paris, France. The majority of the participants correctly understood the instructions for use (94.4%; 95% confidence interval (CI): 88.3-97.4), showing a great ability to perform the entire self-test procedure to obtain a valid and interpretable result (100%; 95% CI: 96.5-100), and demonstrated the ability to correctly interpret test results (96.2%; 95% CI: 94.2-97.5) with a high level of general satisfaction. About one in eight participants (# 15%) needed verbal help to perform or interpret the test, and only 3.8% of test results were misinterpreted. By reference to multiplex real-time RT-PCR, the Ag-RDST showed 90.9% and 100% sensitivity and specificity, respectively, and high agreement (98.1%), reliability (0.94), and accuracy (90.9%) to detect SARS-CoV-2 antigen. Taken together, our study demonstrates the high usability and accuracy of BIOSYNEX Antigen Self-Test COVID-19 Ag+ for supervised self-collected NMT sampling in an unselected adult population living in France.

10.
Diagnostics (Basel) ; 11(7)2021 Jul 14.
Article in English | MEDLINE | ID: covidwho-1526809

ABSTRACT

Millions of people are tested for COVID-19 daily during the pandemic, and a lack of evidence to guide optimal nasal swab testing can increase the risk of false-negative test results. This study aimed to determine the optimal insertion depth for nasal mid-turbinate and nasopharyngeal swabs. The measurements were made with a flexible endoscope during the collection of clinical specimens with a nasopharyngeal swab at a public COVID-19 test center in Copenhagen, Denmark. Participants were volunteer adults undergoing a nasopharyngeal SARS-CoV-2 rapid antigen test. All 109 participants (100%) completed the endoscopic measurements; 52 (48%) women; 103 (94%) white; mean age 34.39 (SD, 13.2) years; and mean height 176.7 (SD, 9.29) cm. The mean swab length to the posterior nasopharyngeal wall was 9.40 (SD, 0.64) cm. The mean endoscopic distance to the anterior and posterior end of the inferior turbinate was 1.95 (SD, 0.61) cm and 6.39 (SD, 0.62) cm, respectively. The mean depth to nasal mid-turbinate was calculated as 4.17 (SD, 0.48) cm. The optimal depths of insertion for nasal mid-turbinate swabs are underestimated in current guidelines compared with our findings. This study provides clinical evidence to guide the performance of anatomically correct nasal and nasopharyngeal swab specimen collection for virus testing.

11.
Am J Infect Control ; 49(10): 1242-1246, 2021 10.
Article in English | MEDLINE | ID: covidwho-1384855

ABSTRACT

BACKGROUND: Universal admission screening for SARS-CoV-2 in children and their caregivers (CG) is critical to prevent hospital outbreaks. We evaluated pooled SARS-CoV-2 antigen tests (AG) to identify infectious individuals while waiting for polymerase chain reaction (PCR) test results. METHODS: This single-center study was performed from November 5, 2020 to March 1, 2021. Nasal mid-turbinate and oropharyngeal swabbing for AG and PCR testing was performed in children with 2 individual swabs that were simultaneously inserted. Nasopharyngeal swabs were obtained from their CG. AG swabs were pooled in a single extraction buffer tube and PCR swabs in a single viral medium. Results from an adult population were used for comparison, as no pooled testing was performed. RESULTS: During the study period, 710 asymptomatic children and their CG were admitted. Pooled AG sensitivity and specificity was 75% and 99.4% respectively for detection of infectious individuals. Four false negatives were observed, though 3 out of 4 false negative child-CG pairs were not considered infectious at admission. Unpooled AG testing in an adult population showed a comparable sensitivity and specificity of 50% and 99.7%. AG performed significantly better in samples with lower Ct values in the corresponding PCR (32.3 vs 21, P-value < .001). CONCLUSIONS: Pooled SARS-CoV-2 AGs are an effective method to identify potentially contagious individuals prior admission, without adding additional strain to the child.


Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Caregivers , Emergency Service, Hospital , Humans , Sensitivity and Specificity
12.
Infect Dis (Lond) ; 53(12): 947-952, 2021.
Article in English | MEDLINE | ID: covidwho-1373618

ABSTRACT

INTRODUCTION: Most SARS-CoV-2 antigen-detecting rapid diagnostic tests require nasopharyngeal sampling, which is frequently perceived as uncomfortable and requires healthcare professionals, thus limiting scale-up. Nasal sampling could enable self-sampling and increase acceptability. The term nasal sampling is often not used uniformly and sampling protocols differ. METHODS: This manufacturer-independent, prospective diagnostic accuracy study, compared professional anterior nasal and nasal mid-turbinate sampling for a WHO-listed SARS-CoV-2 antigen-detecting rapid diagnostic test. The second group of participants collected a nasal mid-turbinate sample themselves and underwent a professional nasopharyngeal swab for comparison. The reference standard was real-time polymerase chain reaction (RT-PCR) using combined oro-/nasopharyngeal sampling. Individuals with high suspicion of SARS-CoV-2 infection were tested. Sensitivity, specificity, and percent agreement were calculated. Self-sampling was observed without intervention. Feasibility was evaluated by observer and participant questionnaires. RESULTS: Among 132 symptomatic adults, both professional anterior nasal and nasal mid-turbinate sampling yielded a sensitivity of 86.1% (31/36 RT-PCR positives detected; 95%CI: 71.3-93.9) and a specificity of 100.0% (95%CI: 95.7-100). The positive percent agreement was 100% (95%CI: 89.0-100). Among 96 additional adults, self nasal mid-turbinate and professional nasopharyngeal sampling yielded an identical sensitivity of 91.2% (31/34; 95%CI 77.0-97.0). Specificity was 98.4% (95%CI: 91.4-99.9) with nasal mid-turbinate and 100.0% (95%CI: 94.2-100) with nasopharyngeal sampling. The positive percent agreement was 96.8% (95%CI: 83.8-99.8). Most participants (85.3%) considered self-sampling as easy to perform. CONCLUSION: Professional anterior nasal and nasal mid-turbinate sampling are of equivalent accuracy for an antigen-detecting rapid diagnostic test in ambulatory symptomatic adults. Participants were able to reliably perform nasal mid-turbinate sampling themselves, following written and illustrated instructions. Nasal self-sampling will facilitate scaling of SARS-CoV-2 antigen testing.


Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Humans , Prospective Studies , Sensitivity and Specificity , Turbinates
13.
Emerg Infect Dis ; 27(11): 2887-2891, 2021 11.
Article in English | MEDLINE | ID: covidwho-1369635

ABSTRACT

Among symptomatic outpatients, subgenomic RNA of severe acute respiratory syndrome coronavirus 2 in nasal midturbinate swab specimens was concordant with antigen detection but remained detectable in 13 (82.1%) of 16 nasopharyngeal swab specimens from antigen-negative persons. Subgenomic RNA in midturbinate swab specimens might be useful for routine diagnostics to identify active virus replication.


Subject(s)
COVID-19 , SARS-CoV-2 , Diagnostic Tests, Routine , Humans , Nasopharynx , RNA
14.
J Clin Microbiol ; 59(9): e0084821, 2021 08 18.
Article in English | MEDLINE | ID: covidwho-1365128

ABSTRACT

Rapid and accurate diagnostic testing is essential to bring the ongoing COVID-19 pandemic to an end. As the demand for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing continues to increase amid supply shortages, many laboratories have investigated the use of sources other than nasopharyngeal (NP) swabs. Saliva and midturbinate (MT) nasal swabs are attractive alternatives, as they allow for self-collection and are well accepted by patients. Saliva also requires limited consumables. We compared the performance of health care provider-collected NP swabs, patient-collected MT swabs, and patient-collected saliva specimens for SARS-CoV-2 detection using a laboratory-developed PCR assay that had received Emergency Use Authorization by the FDA. Of 281 total evaluable samples, 33 (11.7%) NP swabs, 33 (11.7%) MT swabs, and 32 (11.4%) saliva specimens were positive for SARS-CoV-2 following resolution of discordant results. Compared to NP swabs, saliva exhibited a sensitivity of 90.9% (30/33) and specificity of 99.2% (246/248), while patient-collected MT swabs exhibited a sensitivity of 93.9% (31/33) and specificity of 99.2% (246/248). When comparing to the consensus standard, the sensitivity was found to be 100% (31/31) for both NP and MT swabs and 96.8% (30/31) for saliva specimens, while specificity was the same in both NP swabs and saliva specimens (98.8% [247/250]) and 99.2% (248/250) for MT swabs. Pretreatment of saliva with proteinase K and heating for 15 min prior to extraction reduced the invalid rate from 26.7% (52/195) to 0% (0/195). These data show that midturbinate nasal swabs and saliva are suitable sources for self-collection in individuals who require routine monitoring for SARS-CoV-2 infection.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Nasopharynx , Pandemics , RNA, Viral , Saliva , Specimen Handling
15.
Virol J ; 18(1): 95, 2021 05 04.
Article in English | MEDLINE | ID: covidwho-1216907

ABSTRACT

The 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.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , COVID-19/prevention & control , Mass Screening/methods , Self-Examination/methods , Clinical Laboratory Techniques/methods , Diagnostic Tests, Routine/methods , Humans , Real-Time Polymerase Chain Reaction , SARS-CoV-2/genetics , Sensitivity and Specificity , Specimen Handling/methods , Surveys and Questionnaires , Viral Load/methods
16.
Clin Infect Dis ; 72(7): 1253-1255, 2021 04 08.
Article in English | MEDLINE | ID: covidwho-1174887

ABSTRACT

Testing of paired midturbinate (MT) nasal and nasopharyngeal (NP) swabs, collected by trained personnel from 40 patients with coronavirus disease 2019 (COVID-19), showed that more NP (76/95 [80%]) than MT swabs tested positive (61/95 [64%]) (P = .02). Among samples collected a week after study enrollment, fewer MT than NP samples were positive (45% vs 76%; P = .001).


Subject(s)
COVID-19 , SARS-CoV-2 , Diagnostic Tests, Routine , Humans , Nasopharynx , Specimen Handling
SELECTION OF CITATIONS
SEARCH DETAIL