Impact of Pool Testing in Detection of Asymptomatic Patients with COVID-19

Abstract Objective During the current pandemic, COVID-19 has been detected in patients using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) that confirms the presence of SARS-CoV-2 RNA. The demand for increased testing, particularly for asymptomatic individuals required alternative approaches to single-patient RT-PCR testing, such as pooling. Methods This study explored the impact of dilution on the detectability of SARS-CoV-2 in asymptomatic patients using RT-PCR and demonstrated that pooling can be effective in low prevalence populations. Results The RT-PCR results for the 3:1, 5:1, and 7:1 aliquot samples showed little differences in CT values, confirming detection capability at these dilutions. Conclusion Based on the results of the present study, a pooled approach with up to 5:1 sample aliquots and using the current RT-PCR methodology likely will detect SARS CoV2 RNA among asymptomatic patients.

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Symptoms COVID 19 Positive Vapers Compared to COVID 19 Positive Non-vapers

Journal of Primary Care & Community Health ◽

10.1177/21501319211062672 ◽

2022 ◽

Vol 13 ◽

pp. 215013192110626

Author(s):

David D. McFadden ◽

Shari L. Bornstein ◽

Robert Vassallo ◽

Bradley R. Salonen ◽

Mohammed Nadir Bhuiyan ◽

...

Keyword(s):

Nasopharyngeal Swab ◽

Symptom Experience ◽

Rt Pcr ◽

Chain Reaction ◽

Age And Gender ◽

Robust Variance ◽

Polymerase Chain ◽

And Gender ◽

Variance Estimates ◽

The Impact

Objectives: The purpose of the present study was to assess and describe the severity of symptoms reported by Covid-19 positive patients who vaped (smoked e-cigarettes) when compared to those who did not vape or smoke at the time of the diagnosis of Covid-19. Methods: Patients from this study are from a well-characterized patient cohort collected at Mayo Clinic between March 1, 2020 and February 28, 2021; with confirmed COVID-19 diagnosis defined as a positive result on reverse-transcriptase–polymerase-chain-reaction (RT-PCR) assays from nasopharyngeal swab specimens. Among the 1734 eligible patients, 289 patients reported current vaping. The cohort of vapers (N = 289) was age and gender matched to 1445 covid-19 positive patients who did not vape. The data analyzed included: date of birth, gender, ethnicity, race, marital status, as well as lifestyle history such as vaping and smoking and reported covid-19 symptoms experienced. Results: A logistic regression analysis was performed separately for each symptom using generalized estimating equations (GEE) with robust variance estimates in order to account for the 1:5 age, sex, and race matched set study design. Patients who vaped and developed Covid-19 infection were more likely to have chest pain or tightness (16% vs 10%, vapers vs non vapers, P = .005), chills (25% vs 19%, vapers vs non vapers, P = .0016), myalgia (39% vs 32%, vapers vs non vapers, P = .004), headaches (49% vs 41% vapers vs non vapers, P = .026), anosmia/dysgeusia (37% vs 30%, vapers vs non vapers, P = .009), nausea/vomiting/abdominal pain (16% vs 10%, vapers vs non vapers, P = .003), diarrhea (16% vs 10%, vapers vs non vapers, P = .004), and non-severe light-headedness (16% vs 9%, vapers vs non vapers, P < .001). Conclusion: Vapers experience higher frequency of covid-19 related symptoms when compared with age and gender matched non-vapers. Further work should examine the impact vaping has on post-covid symptom experience.

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Real-Time Polymerase chain reaction trends in COVID-19 patients

Pakistan Journal of Medical Sciences ◽

10.12669/pjms.37.1.3000 ◽

2020 ◽

Vol 37 (1) ◽

Author(s):

Dr Sana Abbas ◽

Aisha Rafique ◽

Dr Beenish Abbas ◽

Dr Rashid Iqbal

Keyword(s):

Polymerase Chain Reaction ◽

Real Time ◽

Tertiary Care ◽

False Negative ◽

Polymerase Chain Reaction Test ◽

Upper Respiratory Tract ◽

Rt Pcr ◽

Chain Reaction ◽

Asymptomatic Patients ◽

Polymerase Chain

Objective: To assess trends of real-time Polymerase Chain Reaction test in Coronavirus infected Patients. Methods: This cross-sectional analytical study was conducted at Tertiary Care Institute, Rawalpindi from March 2020 to June 2020. All patients confirmed COVID positive by real-time Polymerase Chain Reaction (PCR) with recent travel history, close contact with known diagnosed patients and had symptoms of fever or upper respiratory tract with body aches. Nasopharyngeal swabs were taken and results generated within 48 hours. Positive PCR was admission criteria follow up was carried out at 7th and 8th day, with negative PCR were discharged. However, those who had persistent positive PCR on the 8th day were tested again on 11th and 12th day. Those with persistent positive results beyond 12th day were shifted to specialized quarantine centres. Results: A total of three hundred and ninety-two patients with mild to moderate illness, PCR positive for COVID 19 were included study with age range 9 - 45 and mean 33.22±7.98 years. A total of 8 (2%) patients were females and 384(98%) males. The duration of the negative test result was Mean ± Std. Deviation 9.05±2.00 with 7 – 8 days 152(38.8%)in and 11 – 12 days in 160(40.8%). PCR results on Day 7 and 8 were negative in 144(36.7%) patients whereas positive in 248(63.3%). PCR results on Day 11 and 12 were negative in 312(79.6%) patients whereas positive in 80 (20.4%). Conclusion: To conclude Real-Time Polymerase Chain Reaction (rT-PCR) inclines to give false negative results additionally can stay positive in asymptomatic patients for moderately longer-term. Hence decision to discharge ought to be intricately adjusted between RT-PCR, clinical judgement, radiological examinations, and biochemical assays. doi: https://doi.org/10.12669/pjms.37.1.3000 How to cite this:Abbas S, Rafique A, Abbas B, Iqbal R. Real-Time Polymerase chain reaction trends in COVID-19 patients. Pak J Med Sci. 2021;37(1):180-184. doi: https://doi.org/10.12669/pjms.37.1.3000 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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A real-world experience of SARS-CoV-2 infection in a tertiary referral centre of Montréal: Unexpected low prevalence and low mortality

Canadian Liver Journal ◽

10.3138/canlivj-2021-0022 ◽

2021 ◽

pp. e20210022

Author(s):

Isaac Ruiz ◽

Geneviève Huard ◽

Claire Fournier ◽

Julien Bissonnette ◽

Hélène Castel ◽

...

Keyword(s):

Real World ◽

Rt Pcr ◽

Referral Centre ◽

Tertiary Referral ◽

Tertiary Referral Centre ◽

Health Care Centre ◽

Liver Unit ◽

Polymerase Chain ◽

Low Prevalence ◽

The Impact

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with chronic liver disease (CLD) and liver transplant (LT) recipients remains a concern. The aim of this study was to report the impact of coronavirus disease 2019 (COVID-19) infection among patients at the tertiary health care centre Centre hospitalier de l’Université de Montréal (CHUM) during the first wave of the SARS-CoV-2 pandemic. Methods: This real-world, retrospective cohort included all patients admitted to our liver unit and/or seen as an outpatient with CLD with or without cirrhosis and/or LT recipients who tested positive to SARS-CoV-2 infection. Cases were considered positive as defined by the detection of SARS-CoV-2 by reverse-transcription polymerase chain reaction (RT-PCR) on nasopharyngeal swabs. Results: Between April 1 and July 31, 2020, 5,637 were admitted to our liver unit and/or seen as outpatient. Among them, 42 were positive for SARS-CoV-2. Twenty-two patients had CLD without cirrhosis while 16 patients had cirrhosis at the time of the infection (13, 2, and 1 with Child–Pugh A, B, and C scores, respectively). Four were LT recipients. Overall, 15/42 patients (35.7%) were hospitalized; among them, 7/42 (16.7%) required respiratory support and 4/42 (9.5%) were transferred to the intensive care unit (ICU). Only 4/42 (9.5%) patients died: 2 with CLD without cirrhosis and 2 with CLD with cirrhosis. Overall survival was 90.5%. Conclusion: This real-world study demonstrates an unexpectedly low prevalence and low mortality in the context of SARS-CoV-2 infection among patients with CLD with or without cirrhosis and LT recipients.

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Evaluation of the Sensitivity of Reverse-Transcription Polymerase Chain Reaction to Detect Porcine Reproductive and Respiratory Syndrome Virus on Individual and Pooled Samples from Boars

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063870701900507 ◽

2007 ◽

Vol 19 (5) ◽

pp. 502-509 ◽

Cited By ~ 28

Author(s):

Albert Rovira ◽

Travis Clement ◽

Jane Christopher-Hennings ◽

Bob Thompson ◽

Mark Engle ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Reverse Transcription ◽

Biological Samples ◽

Acute Infection ◽

Respiratory Syndrome Virus ◽

Rt Pcr ◽

Chain Reaction ◽

Polymerase Chain ◽

The Impact ◽

Pooled Samples

Boar studs are continuously monitored for the presence of porcine reproductive and respiratory syndrome virus (PRRSV) by testing different biological samples by reverse-transcription polymerase chain reaction (RT-PCR). In most cases, samples are run in pools, even though the impact of pooling on the sensitivity of RT-PCR is unknown. The objective of this study was to evaluate the feasibility of using PCR on pooled samples through the estimation of the sensitivity of RT-PCR on different biological samples run individually, in pools of 3 and in pools of 5. Twenty-nine boars were inoculated with a low virulent PRRSV isolate. Serum, blood swab, and semen samples were obtained from each boar every 2 to 3 days for 2 weeks. Each sample was tested by RT-PCR undiluted or diluted 1:3 and 1:5 with negative samples. Eleven of the 29 boars did not appear to get infected from the inoculum, as evidenced by no seroconversion 15 days after inoculation. Data from the other 18 boars showed that serum was the best sample to detect PRRSV during acute infection, with the blood swab sample performing almost as well. Semen samples failed to detect PRRSV infection in most of the cases. Pooling samples at pool sizes of 3 and 5 resulted in a decrease in the sensitivity of RT-PCR. Sensitivity was reduced by 6% and 8%, respectively, when serum or blood swab samples were run in pools of 5. The impact of pooling on the sensitivity of PCR was higher in samples taken during the beginning of the viremic period.

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Assessment of Coronavirus in the Conjunctival Tears in Pediatric Patients with Asymptomatic COVID-19 Infection in Sohag Government, Egypt

The Open Ophthalmology Journal ◽

10.2174/1874364102115010083 ◽

2021 ◽

Vol 15 (1) ◽

pp. 83-88

Author(s):

Hany Mahmoud ◽

Ahmed Radwan ◽

Amr El Rashidy ◽

Hesham M. Hefny ◽

Amal H. Ali ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Pediatric Patients ◽

Nasopharyngeal Swab ◽

Rt Pcr ◽

Interventional Study ◽

Chain Reaction ◽

Intimate Contact ◽

Asymptomatic Patients ◽

Systemic Manifestations ◽

Polymerase Chain

Objective: The present study aims to evaluate coronavirus shedding in the tears of asymptomatic pediatric COVID-19 positive patients. Methods: A prospective interventional study that included a total of 145 pediatric asymptomatic COVID-19 patients hospitalized from 17th May 2020 to 16th July 2020 in Sohag Tropical Hospital. On admission, all of them were COVID-19 positive detected through nasopharyngeal swab. They were in intimate contact with positive symptomatic COVID-19 patients before testing and admission. Reverse Transcriptase Polymerase chain reaction (RT-PCR) was done for tears samples at an interval of 5 days after admission and twice before discharge. Results: Of the 145 asymptomatic pediatric COVID-19 positive patients, no one showed ocular or systemic manifestations. They were silent carriers. Ten were positive for tears sample on admission. They became negative for nasopharyngeal and tear samples before discharge. Conclusion: Pediatric positive COVID-19 patients can shed coronavirus through their tears. Even among asymptomatic patients, transmission through tears is possible.

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The development of GAMA Swab sampling chamber for walk-through sampling in patients with COVID-19 at Gadjah Mada Hospital

Journal of Community Empowerment for Health ◽

10.22146/jcoemph.57547 ◽

2020 ◽

Vol 3 (2) ◽

pp. 94

Author(s):

Hera Nirwati ◽

Dwi Aris Agung Nugrahaningsih ◽

Siswanto Siswanto ◽

Mahatma Sotya Bawono ◽

Titien Budhiaty ◽

...

Keyword(s):

Healthcare Worker ◽

Healthcare Workers ◽

Positive Pressure ◽

Protective Equipment ◽

Cross Contamination ◽

Rt Pcr ◽

Chain Reaction ◽

Aerosol Exposure ◽

Asymptomatic Patients ◽

Polymerase Chain

Collecting swab samples from the nasopharynx and oropharynx of patients with COVID-19 is essential in detecting SARS-CoV-2. This procedure potentially produces sufficient droplets. Since SARS-CoV-2 is transmitted through droplets, swab sampling has to be done carefully to prevent the risk of transmission to healthcare workers or the cross-contamination to the environment. The GAMA Swab Sampling Chamber (GSSC) is a positive-pressure chamber designed for collecting swab samples involving the healthcare worker positioned inside, while the patient is outside the chamber. The chamber is designed to minimize the risk of aerosol exposure to the healthcare worker due to leakage or when opening or closing the door. Accordingly, the healthcare worker does not need to use complete personal protective equipment (PPE) as they do when collecting swab samples without the chamber. After several tests to check the safety and the chamber’s function, the GSSC was used at Gadjah Mada Hospital. This chamber had been used to swab 51 asymptomatic patients, 72 suspected patients, and 284 voluntary persons for ten weeks. The results of reverse transcription-polymerase chain reaction (RT-PCR) examination of all samples from asymptomatic patients were negative, while 2 of 72 suspected patients (2.8%) and 4 of 284 voluntary persons (1.4%) had positive RT-PCR results. The use of GSSC can simplify the swab sampling, also reduces the need for PPE usage and a negative pressure isolation room which are limited in the current pandemic situation.

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Return to ART practices – The post-coronavirus disease era

10.25259/jrhm_49_2020 ◽

2021 ◽

Vol 2 ◽

pp. 2-6

Author(s):

Hrishikesh D. Pai ◽

Manisha Takhtani Kundnani ◽

Nandita Patil Palshetkar ◽

Rohan Palshetkar ◽

Pooja Mehta ◽

...

Keyword(s):

Infertility Treatment ◽

Rt Pcr ◽

National Guidelines ◽

Chain Reaction ◽

Assisted Reproduction Technology ◽

Asymptomatic Patients ◽

Art Practices ◽

Risk Patients ◽

Elective Procedure ◽

Polymerase Chain

Objectives: The objectives of the study were to analyze the prevalence of coronavirus disease (COVID) real-time polymerase chain reaction (RT-PCR) positivity among asymptomatic patients undergoing infertility treatment. Materials and Methods: This was an observational study done in five centers in five different cities in India, analyzing the prevalence of COVID RT-PCR-positive rates among asymptomatic patients willing to undergo infertility treatment. All patients underwent triage and COVID RT-PCR testing as per the national guidelines. Patients tested positive for COVID RT-PCR were advised to discontinue treatment. Results: The overall prevalence of COVID RT-PCR positivity in low-risk patients undergoing infertility treatment was found to be low. The incidence of COVID RT-PCR positivity in staff and doctors providing infertility care and not dealing directly with COVID-positive patients was observed to be 10.7%. Conclusion: The overall prevalence of the virus in asymptomatic people is low and elective procedure like assisted reproduction technology can be carried out with all precautions and sanitization protocols in place.

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Sensitivity of ID NOW and RT–PCR for detection of SARS-CoV-2 in an ambulatory population

eLife ◽

10.7554/elife.65726 ◽

2021 ◽

Vol 10 ◽

Author(s):

Yuan-Po Tu ◽

Jameel Iqbal ◽

Timothy O'Leary

Keyword(s):

Systematic Review ◽

Review Of Literature ◽

Rt Pcr ◽

Chain Reaction ◽

Pcr Assay ◽

Viral Loads ◽

Percent Agreement ◽

Asymptomatic Patients ◽

Polymerase Chain ◽

Low Sensitivity

Diagnosis of SARS-CoV-2 (COVID-19) requires confirmation by reverse transcription–polymerase chain reaction (RT–PCR). Abbott ID NOW provides fast results but has been criticized for low sensitivity. Here we determine the sensitivity of ID NOW in an ambulatory population presented for testing. The study enrolled 785 symptomatic patients, of whom 21 were positive by both ID NOW and RT–PCR, and 2 only by RT–PCR. All 189 asymptomatic patients tested negative. The positive percent agreement between the ID NOW assay and the RT–PCR assay was 91.3%, and negative percent agreement was 100%. The results from the current study were included into a larger systematic review of literature where at least 20 subjects were simultaneously tested using ID NOW and RT–PCR. The overall sensitivity for ID NOW assay was calculated at 84% (95% confidence interval 55–96%) and had the highest correlation to RT–PCR at viral loads most likely to be associated with transmissible infections.

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Flu Viral Multiplex Testing and its Implication for COVID-19 Testing

New Emirates Medical Journal ◽

10.2174/0250688201999200908150437 ◽

2020 ◽

Vol 01 ◽

Author(s):

Aaron Han ◽

Janet Hicban

Keyword(s):

Viral Agent ◽

Testing Strategy ◽

Rt Pcr ◽

Chain Reaction ◽

Parallel Testing ◽

Appropriate Treatment ◽

Simultaneous Testing ◽

Polymerase Chain ◽

The Impact ◽

Rule Out

Background: The diagnosis of viral causes for flu-like syndromes have been positively impacted by the availability of molecular assays. In recent years, syndromic multiplex panels have been able to give rapid turn-around-times and highly accurate results. We examine the use of this test during the first four months of 2020 during the COVID-19 pandemic. Methods: Retrospective review of 2145 patient results from multiplex syndromic flu panel using Biofire RP2 was performed. Cases in which parallel testing for COVID-19 by real-time polymerase chain reaction (RT-PCR) was compared. Results: 53% of the patients tested identified a viral agent. 13% of the positive cases were coinfection with more than a single virus. The most frequently detect virus(es) were rhinovirus/enterovirus, followed by coronaviruses (non-MERS, non COVID-19). One hundred patients had simultaneous testing for COVID-19. Seventeen (17%) had positive COVID-19 by RT-PCR. Three of these patients had coinfection with rhinovirus/enterovirus and COVID-19. The negative predictive value for COVID-19 based on a positive non-COVID agent was 95% in our sample. Conclusions: Viral syndromic panels are useful for rapid detection and appropriate treatment of patients. Our results suggest coinfection is infrequent, and we discuss the impact of COVID-19 on patient testing strategy. The use of multiplex panels is useful to provide accurate diagnosis and rule out important pathogens that have different treatment approaches.

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Interpretation of Diagnostic Tests for COVID-19 (SARS-COV-2)

BioMedica ◽

10.51441/biomedica//biomedica/5-392 ◽

2020 ◽

Vol 36 (2S) ◽

pp. 93-96

Author(s):

Sadaf Shafique ◽

Farheen Aslam ◽

Raheel Khan ◽

Asma Shaukat

Keyword(s):

Time Course ◽

Diagnostic Testing ◽

Enzyme Linked Immunosorbent Assay ◽

Rt Pcr ◽

Chain Reaction ◽

Ongoing Research ◽

Chemiluminescent Immunoassay ◽

Polymerase Chain ◽

Asymptomatic Individuals ◽

Day By Day

<p>The knowledge regarding diagnostic testing for SARS COV-2 is still at hit-and-trial phases, all over the world. Evolving day by day through ongoing research and extensive trials, use for SARS-COV-2 infectionsReverse Transcriptase-Polymerase Chain Reaction (RT-PCR) and IgM/ IgG serology by Enzyme Linked Immunosorbent Assay (ELISA) or Electro-Chemiluminescent Immunoassay remain the main stay of diagnosis. However, the time course for the PCR positivity and seroconversion seem to vary in children and adults both, which also includes a huge population of asymptomatic individuals who are potentially labelled negative hence posing a great threat to the surrounding community.</p>

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