SARS-CoV-2 RNA detection using pooling of self-collected samples: Simple protocol may foster asymptomatic surveillance

López-Lopes, Giselle Ibete Silva; Carmona, Rita de Cássia Compagnoli; Silva, Valeria Oliveira; Ahagon, Cintia Mayumi; Prado, Lincoln Spinazola do; Santos, Fábio dos; Silva, Daniela Bernardes Borges da; Santos, Katia Corrêa de Oliveira; Benega, Margarete Aparecida; Ribeiro, Willian Nery; Cilli, Audrey; Matsuda, Elaine Monteiro; Afonso, Ana Maria Sardinha; Timenetsky, María do Carmo Sampaio Tavares; Brígido, Luis Fernando de Macedo

doi:10.1101/2020.10.05.20205872

Cited by 7 publications

(5 citation statements)

References 16 publications

(19 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The cycle threshold value was considered as an indicator of amplification. Although, the cycle threshold value (Ct) <37 as positive and Ct >37 as negative was proposed by the manufacturer in product information leaflet but in pooling approach, the Ct value is found to be higher with pooled samples corresponding to deconvoluted samples (Lopez-Lopes et al, 2020;Sami et al, 2021). Sami et al found a mean difference of 0.96 in cycle threshold (Ct) of pooled and deconvoluted positive samples (Sami et al, 2021).…”

Section: Results Of Rt-pcrmentioning

confidence: 99%

A Pilot study screening bank currency in community circulation for potential carriage of SARS-CoV-2: how safe handling the currency is?

Shahid

Deifalla

Ismaeel

et al. 2022

AGJSR

View full text Add to dashboard Cite

Purpose: Currency seems to represent an important vehicle for transmission of pathogenic microorganisms, thus a potential in affecting the public health. Digital transactions are more common in developed countries; however, handling cash currency is still very common in many countries including Bahrain. A recent study from Australia reported that SARS-CoV-2 may survive for 28 days on smooth surfaces (including banknotes), however the study was purely experimental and done in controlled laboratory environment. There were worldwide speculations suggesting the possible transmission of SARS-CoV-2 infection through currency notes. A recent study from Bangladesh reported presence of SARS-CoV-2 in approximately 7% of currency samples collected from the community. No such study has been performed on Bahraini currency, so the present study was proposed to screen the cash currency in circulation in Bahrain for the possible presence of SARS-CoV-2. Method: We collected notes and coins of Bahraini currency and a few of Saudi riyals from different public sources of currency exchange. Two time points were selected for collection when percentage of tested positive cases was on its peak. All the samples were tested for the presence of SARS-CoV-2 antigen with rapid antigen detection kit and qRT-PCR method. For initial validation, 5 samples each of potential SARS-CoV-2 RNAs extracted from known positive cases and 5 samples of extracted RNA from known negative persons were tested by rapid antigen detection kit and qRT-PCR. The results of qRT-PCR were interpreted as per the interpretation chart provided by the supplier. Results: During the study period, a total of 250 currency samples were collected including different denominations of currency notes and coins. Majority of the currency samples were collected from grocery stores followed by food outlets. Following validation, the currency samples were tested, and all turned negative for SARS-CoV-2 by rapid antigen detection test as well as by RT-PCR. Conclusion: This study predicts on Bahraini currency posing no threat of SARS-CoV-2 transmission via currency exchange.

show abstract

Section: Results Of Rt-pcrmentioning

confidence: 99%

A Pilot study screening bank currency in community circulation for potential carriage of SARS-CoV-2: how safe handling the currency is?

Shahid

Deifalla

Ismaeel

et al. 2022

AGJSR

View full text Add to dashboard Cite

show abstract

“…Gargling a saline solution or filtered water can be carried out independently [38,39], saving the costs of support from clinical personnel and the accompanying personal protective equipment [39]. Moreover, gargle tests have been established as providing an effective approach to diagnosing respiratory infection among children [40], and they have been shown specifically to be effective in the diagnosis of SARS-CoV-2 infection [41]. The approach is particularly well-suited to a regular monitoring program, because samples from several participants can be tested together in a so-called pool testing procedure [41][42][43][44], with lower costs than individual testing [44].…”

Section: Testing Strategymentioning

confidence: 99%

“…Moreover, gargle tests have been established as providing an effective approach to diagnosing respiratory infection among children [40], and they have been shown specifically to be effective in the diagnosis of SARS-CoV-2 infection [41]. The approach is particularly well-suited to a regular monitoring program, because samples from several participants can be tested together in a so-called pool testing procedure [41][42][43][44], with lower costs than individual testing [44]. The possibility has been raised that pooling material prior to testing could potentially result in a reduced test sensitivity [44].…”

Section: Testing Strategymentioning

confidence: 99%

Pool Testing as a Strategy for Prevention of SARS-CoV-2 Outbreaks in Schools: Protocol for a Feasibility Study

Sweeney‐Reed¹,

Wolff²,

Niggel³

et al. 2021

JMIR Res Protoc

View full text Add to dashboard Cite

Background School closures are a widely implemented strategy for limiting infection spread in the current COVID-19 pandemic. The negative impact of school closures on children and young people is increasingly apparent, however. Objective We aim to evaluate the feasibility of an infection monitoring program in schools to enable targeted quarantining to replace school closures. The program is currently being implemented in two model schools in Magdeburg, Germany, within the framework of the Study of Coronavirus Outbreak Prevention in Magdeburg Schools (Studie zur Ausbruchsvermeidung von Corona an Magdeburger Schulen [STACAMA]). Methods Five pupils per class are pseudorandomly selected twice a week and asked to provide a gargle sample over a 16-week evaluation period. RNA is extracted from each sample individually in a laboratory and pooled according to school class for real-time reverse transcription polymerase chain reaction (rRT-PCR) analysis. Immediate individual sample testing will be carried out in the case of a positive pool test. Individual RNA extraction prior to pooling and application of rRT-PCR result in high test sensitivity. Testing will be performed in strict adherence to data protection standards. All participating pupils will receive a 16-digit study code, which they will be able to use to access their test Results When the study commenced on December 2, 2020, 520 (52%) pupils and their families or guardians had consented to study participation. The study was suspended after four test rounds due to renewed school closures resulting from rising regional infection incidence. Testing resumed when schools reopened on March 8, 2021, at which time consent to participation was provided for 54% of pupils. We will quantitatively and qualitatively evaluate the logistics and acceptability of the program. Conclusions The findings from this study should inform the design of infection surveillance programs in schools based on gargle samples and a PCR-based pool testing procedure, enabling the identification of aspects that may require adaptation before large-scale implementation. Our focus on each step of the logistics and on the experiences of families should enable a robust assessment of the feasibility of such an approach. International Registered Report Identifier (IRRID) DERR1-10.2196/28673

show abstract

“…Further, pooled testing reduces the effort for participants, making it easier to monitor over extended periods of time. Pooling has been reported for PCR tests detecting SARS-CoV-2 [ 13 , 14 , 15 , 16 ]. A recent report from a company suggests that pooled samples can successfully be analyzed by lateral flow point of care (PoC) test cassettes [ 17 ], but pooling has not become an established practice for rapid antigen tests.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Pooling on the Detection of the Nucleocapsid Protein of SARS-CoV-2 with Rapid Antigen Tests

et al. 2021

View full text Add to dashboard Cite

The COVID-19 pandemic puts significant stress on the viral testing capabilities of many countries. Rapid point-of-care (PoC) antigen tests are valuable tools but implementing frequent large scale testing is costly. We have developed an inexpensive device for pooling swabs, extracting specimens, and detecting viral antigens with a commercial lateral flow test for the nucleocapsid protein of SARS-CoV-2 as antigen. The holder of the device can be produced locally through 3D printing. The extraction and the elution can be performed with the entire set-up encapsulated in a transparent bag, minimizing the risk of infection for the operator. With 0.35 mL extraction buffer and six swabs, including a positive control swab, 43 ± 6% (n = 8) of the signal for an individual extraction of a positive control standard was obtained. Image analysis still showed a signal-to-noise ratio of approximately 2:1 at 32-fold dilution of the extract from a single positive control swab. The relative signal from the test line versus the control line was found to scale linearly upon dilution (R2 = 0.98), indicating that other pooling regimes are conceivable. A pilot project involving 14 participants and 18 pooled tests in a laboratory course at our university did not give any false positives, and an individual case study confirmed the ability to detect a SARS-CoV-2 infection with five-fold or six-fold pooling, including one swab from a PCR-confirmed COVID patient. These findings suggest that pooling can make frequent testing more affordable for schools, universities, and similar institutions, without decreasing sensitivity to an unacceptable level.

show abstract

SARS-CoV-2 RNA detection using pooling of self-collected samples: Simple protocol may foster asymptomatic surveillance

Cited by 7 publications

References 16 publications

A Pilot study screening bank currency in community circulation for potential carriage of SARS-CoV-2: how safe handling the currency is?

A Pilot study screening bank currency in community circulation for potential carriage of SARS-CoV-2: how safe handling the currency is?

Pool Testing as a Strategy for Prevention of SARS-CoV-2 Outbreaks in Schools: Protocol for a Feasibility Study

The Effect of Pooling on the Detection of the Nucleocapsid Protein of SARS-CoV-2 with Rapid Antigen Tests

Contact Info

Product

Resources

About