S568 Pre-Operative SARS-CoV2 Screening With TMA Nasopharyngeal Swab in Asymptomatic Patients Undergoing Non-Urgent Outpatient Procedures

Background/aimsTo explore if retinal findings are associated with COVID-19 infection.MethodsIn this prospective cross-sectional study, we recruited participants positive for COVID-19 by nasopharyngeal swab, with no medical history. Subjects underwent retinal imaging with an automated imaging device (3D OCT-1 Maestro, Topcon, Tokyo, Japan) to obtain colour fundus photographs (CFP) and optical coherence tomographic (OCT) scans of the macula. Data on personal biodata, medical history and vital signs were collected from electronic medical records.Results108 patients were recruited. Mean age was 36.0±5.4 years. 41 (38.0%) had symptoms of acute respiratory infection (ARI) at presentation. Of 216 eyes, 25 (11.6%) had retinal signs—eight (3.7%) with microhaemorrhages, six (2.8%) with retinal vascular tortuosity and two (0.93%) with cotton wool spots (CWS). 11 eyes (5.1%) had hyper-reflective plaques in the ganglion cell-inner plexiform layer layer on OCT, of which two also had retinal signs visible on CFP (CWS and microhaemorrhage, respectively). There was no significant difference in the prevalence of retinal signs in symptomatic versus asymptomatic patients (12 (15.0%) vs 13 (9.6%), p=0.227). Patients with retinal signs were significantly more likely to have transiently elevated blood pressure than those without (p=0.03).ConclusionOne in nine had retinal microvascular signs on ocular imaging. These signs were observed even in asymptomatic patients with normal vital signs. These retinal microvascular signs may be related to underlying cardiovascular and thrombotic alternations associated with COVID-19 infection.

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Comparison of saliva with healthcare workers- and patient-collected swabs in the diagnosis of COVID-19 in a large cohort

BMC Infectious Diseases ◽

10.1186/s12879-021-06343-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Mitnala Sasikala ◽

Yelamanchili Sadhana ◽

Ketavarapu Vijayasarathy ◽

Anand Gupta ◽

Sarala Kumari Daram ◽

...

Keyword(s):

Healthcare Workers ◽

Early Stage ◽

Cost Effective ◽

Hospitalized Patients ◽

Detection Sensitivity ◽

Nasopharyngeal Swab ◽

Predictive Values ◽

Qrt Pcr ◽

Asymptomatic Patients ◽

Sensitivity Specificity

Abstract Background A considerable amount of evidence demonstrates the potential of saliva in the diagnosis of COVID-19. Our aim was to determine the sensitivity of saliva versus swabs collected by healthcare workers (HCWs) and patients themselves to assess whether saliva detection can be offered as a cost-effective, risk-free method of SARS-CoV-2 detection. Methods This study was conducted in a hospital involving outpatients and hospitalized patients. A total of 3018 outpatients were tested. Of these, 200 qRT-PCR-confirmed SARS-CoV-2-positive patients were recruited for further study. In addition, 101 SARS-CoV-2-positive hospitalized patients with symptoms were also enrolled in the study. From outpatients, HCWs collected nasopharyngeal swabs (NPS), saliva were obtained. From inpatients, HCWs collected swabs, patient-collected swabs, and saliva were obtained. qRT-PCR was performed to detect SARS-CoV-2 by TAQPATH assay to determine the sensitivity of saliva detection. Sensitivity, specificity and positive/negative predictive values (PPV, NPV) of detecting SARS-CoV-2 were calculated using MedCalc. Results Of 3018 outpatients (asymptomatic: 2683, symptomatic: 335) tested by qRT-PCR, 200 were positive (males: 140, females: 60; aged 37.9 ± 12.8 years; (81 asymptomatic, 119 symptomatic). Of these, saliva was positive in 128 (64%); 39 of 81 asymptomatic (47%),89 of 119 symptomatic patients (74.8%). Sensitivity of detection was 60.9% (55.4–66.3%, CI 95%), with a negative predictive value of 36%(32.9–39.2%, CI 95%).Among 101 hospitalized patients (males:65, females: 36; aged 53.48 ± 15.6 years), with HCW collected NPS as comparator, sensitivity of saliva was 56.1% (47.5–64.5, CI 95%), specificity 63.5%(50.4–75.3, CI95%) with PPV of 77.2% and NPV of 39.6% and that of self-swab was 52.3%(44–60.5%, CI95%), specificity 56.6% (42.3–70.2%, CI95%) with PPV 77.2% and NPV29.7%. Comparison of positivity with the onset of symptoms revealed highest detection in saliva on day 3 after onset of symptoms. Additionally, only saliva was positive in 13 (12.8%) hospitalized patients. Conclusion Saliva which is easier to collect than nasopharyngeal swab is a viable alternate to detect SARS-COV-2 in symptomatic patients in the early stage of onset of symptoms. Although saliva is currently not recommended for screening asymptomatic patients, optimization of collection and uniform timing of sampling might improve the sensitivity enabling its use as a screening tool at community level.

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SARS-CoV-2 in peritoneal swabs from asymptomatic patients undergoing emergency abdominal surgery

Journal of Surgical Case Reports ◽

10.1093/jscr/rjab116 ◽

2021 ◽

Vol 2021 (4) ◽

Author(s):

Jasim AlAradi ◽

Rawan A Rahman AlHarmi ◽

Mariam AlKooheji ◽

Sayed Ali Almahari ◽

Mohamed Abdulla Isa ◽

...

Keyword(s):

Peritoneal Fluid ◽

Case Series ◽

Rapid Test ◽

Nasopharyngeal Swab ◽

Rt Pcr ◽

Protective Measures ◽

The Public ◽

Asymptomatic Patients ◽

Number Of Patients ◽

Viral Transfer

Abstract This is a case series of five patients with acute abdomen requiring surgery who tested positive for coronavirus disease 2019 (COVID-19) and were asymptomatic, with the purpose of detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in peritoneal fluid. Nasopharyngeal swab was done as a prerequisite for admission or prior to admission as part of random testing. Two methods of viral testing were employed: Xpert® Xpress SARS-CoV-2 (rapid test) and real-time reverse transcription polymerase chain reaction (RT-PCR). Either or both tests were done, with the former performed for patients requiring surgery immediately. Surgery was performed within 24–36 h from admission. Peritoneal fluid swabs were obtained for the detection of SARS-CoV-2 using RT-PCR test. Swabs were immediately placed in viral transfer media and delivered to the public health laboratory in an ice bag. SARS-CoV-2 was not detected in peritoneal swabs. Due to the limited number of patients, further studies are required; yet, protective measures should still be taken by surgeons when dealing with COVID-19 cases.

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Transmission dynamics of the delta variant of SARS-CoV-2 infections in Daejeon, South Korea

10.21203/rs.3.rs-934350/v1 ◽

2021 ◽

Author(s):

Hari Hwang ◽

Jun-Sik Lim ◽

Sun-Ah Song ◽

Chiara Achangwa ◽

Woobeom Sim ◽

...

Keyword(s):

South Korea ◽

Symptom Onset ◽

Credible Interval ◽

Transmission Dynamics ◽

Contact Tracing ◽

Nasopharyngeal Swab ◽

Strict Adherence ◽

Virus Shedding ◽

Viral Shedding ◽

Asymptomatic Patients

Abstract Background The delta variant of SARS-CoV-2 is now the predominant variant worldwide. However, its transmission dynamics remain unclear. Methods We analyzed all case patients in local clusters and temporal patterns of viral shedding using contact tracing data from 405 cases associated with the delta variant of SARS-CoV-2 between 22 June and 31 July 2021 in Daejeon, South Korea. Results Overall, half of the cases were aged under 19 years, and 20% were asymptomatic at the time of epidemiological investigation. We estimated the mean serial interval as 3.26 days (95% credible interval 2.92, 3.60), and 12% of the transmission occurred before symptom onset of the infector. We identified six clustered outbreaks, and all were associated with indoor facilities. In 23 household contacts, the secondary attack rate was 63% (52/82). We estimated that 15% (95% confidence interval, 13–18%) of cases seeded 80% of all local transmission. Analysis of the nasopharyngeal swab samples identified virus shedding from asymptomatic patients, and the highest viral load was observed two days after symptom onset. The temporal pattern of viral shedding did not differ between children and adults (P = 0.48). Conclusions Our findings suggest that the delta variant is highly transmissible in indoor settings and households. Rapid contact tracing, isolation of the asymptomatic contacts, and strict adherence to public health measures are needed to mitigate the community transmission of the delta variant.

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SARS-CoV-2 Infection in Asymptomatic Patients Hospitalized for Cardiac Emergencies: Implications for Patient Management

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2020.599299 ◽

2020 ◽

Vol 7 ◽

Author(s):

Thorsten Kessler ◽

Jens Wiebe ◽

Tobias Graf ◽

Heribert Schunkert ◽

Adnan Kastrati ◽

...

Keyword(s):

Patient Management ◽

Nasopharyngeal Swab ◽

Protective Equipment ◽

Optimal Care ◽

Emergency Admissions ◽

Emergency Procedures ◽

Asymptomatic Patients ◽

Cardiology Department ◽

Cardiac Emergencies ◽

Cardiac Emergency

Background: The coronavirus disease (COVID-19) pandemic imposed diverse challenges on the health care system. Morbidity and mortality of non-COVID-19 emergencies might also have changed because hospitals may not be able to provide optimal care due to restructured resources and uncertainties how to deal with potentially infected patients. It has been recommended to stratify treatment of cardiovascular emergencies according to cardiovascular risk. However, data on the prevalence of asymptomatic SARS-CoV-2 infection in patients presenting with cardiac emergencies remain scarce.Methods: We retrospectively analyzed patients' data from a tertiary cardiology department between April 15 and May 31, 2020. All patients were screened on admission for COVID-19 symptoms using a questionnaire and body temperature measurements. All hospitalized patients were routinely screened using nasopharyngeal swab testing.Results: In total, we counted 710 urgent and emergency admissions. Nasopharyngeal swab tests were available in 689 (97%) patients, 409 and 280 of which presented as urgent and emergency admissions, respectively. Among 280 emergency admissions, none tested positive for SARS-CoV-2.Conclusion: In cardiac emergency patients which were screened negative for COVID-19 symptoms, the prevalence of SARS-CoV-2 infection in regions with a modest overall prevalence is low. This finding might be helpful to better determine timing of emergency procedures and reasonable usage of protective equipment during the COVID-19 crisis and the future.

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SARS-CoV-2 show no infectivity at later stages in a prolonged COVID-19 patient despite positivity in RNA testing

10.1101/2021.03.18.21253228 ◽

2021 ◽

Author(s):

Xiu-Feng Wan ◽

Cynthia Y Tang ◽

Detlef Ritter ◽

Yang Wang ◽

Tao Li ◽

...

Keyword(s):

Large Scale ◽

Disease Onset ◽

Nasopharyngeal Swab ◽

Rt Pcr ◽

Virus Growth ◽

Chain Reactions ◽

Polymerase Chain Reactions ◽

Asymptomatic Patients ◽

Hospitalization Period ◽

Polymerase Chain

Inpatient COVID-19 cases present enormous costs to patients and health systems. Many hospitalized patients may still test COVID-19 positive, even after resolution of symptoms. Thus, a pressing concern for clinicians is the safety of discharging these asymptomatic patients if they have any remaining infectivity. This case report explores the viral viability in a patient with persistent COVID-19 over the course of a two-month hospitalization. Positive nasopharyngeal swab samples, analyzed by quantitative reverse transcription polymerase chain reactions (qRT-PCR), were collected and isolated in the laboratory, and infectious doses were analyzed throughout the hospitalization period. The patient experienced waning symptoms by hospital day 40 and had no viable virus growth in the laboratory by hospital day 41, suggesting no risk of infectivity, despite positive RT-PCR results, which prolonged his hospital stay. Notably, this case showed infectivity for at least 24 days from disease onset, which is longer than the discontinuation of transmission-based precautions recommendation by CDC. Thus, our findings suggest that the timeline for discontinuing transmission-based precautions may need to be extended for patients with prolonged illness. Additional large-scale studies are needed to draw definitive conclusions on the appropriate clinical management for these patients.

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Prospective comparison of saliva and nasopharyngeal swab sampling for mass screening for COVID-19

10.1101/2020.09.23.20150961 ◽

2020 ◽

Cited By ~ 2

Author(s):

◽

mathieu nacher ◽

magalie demar

Keyword(s):

Mass Screening ◽

Saliva Sample ◽

Field Testing ◽

Contact Tracing ◽

Nasopharyngeal Swab ◽

Rt Pcr ◽

Prospective Comparison ◽

Asymptomatic Patients ◽

Patient Groups ◽

Trained Staff

Current testing for COVID-19 relies on quantitative reverse-transcriptase polymerase chain reaction from a nasopharyngeal swab specimen. Saliva samples have advantages regarding ease and painlessness of collection, which does not require trained staff and may allow self-sampling. We enrolled 776 persons at various field-testing sites and collected nasopharyngeal and pooled saliva samples. 162 had a positive COVID-19 RT-PCR, 61% were mildly symptomatic and 39% asymptomatic. The sensitivity of RT-PCR on saliva samples versus nasopharygeal swabs varied depending on the patient groups considered or on Ct thresholds. There were 10 (6.2%) patients with a positive saliva sample and a negative nasopharyngeal swab, all of whom had Ct values<25. For symptomatic patients for whom the interval between symptoms onset and sampling was <10 days sensitivity was 77% but when excluding persons with isolated Ngen positivity (54/162), sensitivity was 90%. In asymptomatic patients, the sensitivity was only 24%. When we looked at patients with Cts <30, sensitivity was 83% or 88.9% when considering 2 genes. The relatively good performance for patients with low Cts suggests that Saliva testing could be a useful and acceptable tool to identify infectious persons in mass screening contexts, a strategically important task for contact tracing and isolation in the community.

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Coronavirus Disease 2019 Test Correlation Between Nasopharyngeal Swab and BAL in Asymptomatic Patients

CHEST Journal ◽

10.1016/j.chest.2020.11.006 ◽

2020 ◽

Author(s):

Jiwoon Chang ◽

Kai E. Swenson ◽

Arthur Sung ◽

Harmeet Bedi

Keyword(s):

Nasopharyngeal Swab ◽

Asymptomatic Patients ◽

Test Correlation

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Clinical Features of Asymptomatic SARS-CoV-2 Infection in Hemodialysis Patients

Kidney & Blood Pressure Research ◽

10.1159/000512535 ◽

2021 ◽

pp. 1-9

Author(s):

Maria Soledad Pizarro-Sánchez ◽

Alejandro Avello ◽

Sebastian Mas-Fontao ◽

Teresa Stock da Cunha ◽

Elena Goma-Garcés ◽

...

Keyword(s):

Risk Factor ◽

Observational Study ◽

Ace Inhibitors ◽

Troponin I ◽

Hemodialysis Patients ◽

Blood Analysis ◽

Clinical Spectrum ◽

Nasopharyngeal Swab ◽

Asymptomatic Patients ◽

Overall Mortality

Background: CKD is a risk factor for severe COVID-19. However, the clinical spectrum of COVID-19 in hemodialysis patients is still poorly characterized. Objective: To analyze the clinical spectrum of COVID-19 on hemodialysis patients. Method: A retrospective observational study was conducted on 66 hemodialysis patients. Nasopharyngeal swab PCR and serology for SARS-CoV-2, blood analysis, chest radiography, treatment, and outcomes were assessed. Results: COVID-19 was diagnosed in 50 patients: 38 (76%) were PCR-positive and 12 (24%) were PCR-negative but developed anti-SARS-CoV-2 antibodies. By contrast, 17% of PCR-positive patients failed to develop detectable antibodies against SARS-CoV-2. Among PCR-positive patients, 5/38 (13%) were asymptomatic, while among PCR-negative patients 7/12 (58%) were asymptomatic (p = 0.005) for a total of 12/50 (24%) asymptomatic patients. No other differences were found between PCR-positive and PCR-negative patients. No differences in potential predisposing factors were found between asymptomatic and symptomatic patients except for a lower use of ACE inhibitors among asymptomatic patients. Asymptomatic patients had laboratory evidence of milder disease such as higher lymphocyte counts and oxygen saturation and lower troponin I and interleukin-6 levels than symptomatic patients. Overall mortality was 7/50 (14%) and occurred only in symptomatic PCR-positive patients in whom mortality was 7/33 (21%). Conclusions: Asymptomatic SARS-CoV-2 infection is common in hemodialysis patients, especially among patients with initial negative PCR that later seroconvert. Thus COVID-19 mortality in hemodialysis patients may be lower than previously estimated based on PCR tests alone.

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Effectiveness of Face Masks in Blocking the Transmission of SARS-CoV-2: a Preliminary Evaluation of Masks Used by SARS-CoV-2-Infected Individuals

10.1101/2021.06.20.21259167 ◽

2021 ◽

Author(s):

Vinicius M Mello ◽

Cristiane M. Eller ◽

Andreza L. Salvio ◽

Felipe F. Nascimento ◽

Camila M. Figueiredo ◽

...

Keyword(s):

Nasopharyngeal Swab ◽

Preliminary Evaluation ◽

Chain Reaction ◽

Paired Samples ◽

Asymptomatic Patients ◽

Significant Difference ◽

Different Types ◽

Polymerase Chain ◽

Virus Blocking ◽

Inner Parts

In 2019, a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is trans-mitted via airborne route, caused a new pandemic namely, 'coronavirus disease 2019' (COVID-19). Although it is still debated whether the use of masks can prevent the transmission of SARS-CoV-2, no study has evaluated the virus-blocking efficacy of masks used by patients. We aimed to evaluate this efficacy of masks used by SARS-CoV-2-infected individuals. Data, masks used, and nasopharyngeal swab samples were obtained from these patients. Forty-five paired samples of nasopharyngeal swabs and masks were obtained and processed; the majority of masks were woven. Viral RNAs were amplified using quantitative reverse‐transcription polymerase chain reaction and detected only on the inner parts of masks. Median cycle threshold (CT) values of swabs and masks were 28.41 and 37.95, respectively. Statistically, there was a difference of ap-proximately 10 CT values between swabs and masks and no significant difference in CT values among different types of masks. There were statistically significant differences in CT values be-tween men and women and symptomatic and asymptomatic patients. Our findings suggest the blocking of the transmission of the virus by different types of masks and reinforce the use of masks by both infected and non-infected individuals.

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