Ignite Creation Date:
2024-05-06 @ 3:25 PM
Last Modification Date:
2024-10-26 @ 1:49 PM
Study NCT ID:
NCT04629157
Status:
COMPLETED
Last Update Posted:
2021-08-03
First Post:
2020-11-04
Brief Title:
The LAVA Lateral Flow Antigen Validation and Applicability Study for COVID-19
Sponsor:
Alder Hey Childrens NHS Foundation Trust
Organization:
Alder Hey Childrens NHS Foundation Trust
Study Overview
Official Title:
The LAVA Lateral Flow Antigen Validation and Applicability Study for COVID-19
Status:
COMPLETED
Status Verified Date:
2020-11
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
LAVA
Brief Summary:
This is a pilot study which aims to assess the validity and applicability of lateral flow assays LFAs which can be used as a point of care test for COVID-19 The study will focus on children admitted to hospital or planned to have a procedure for which they require an anaesthetic RT-PCR is the current gold standard test for COVID-19 but it usually takes approximately 24-48 hours for a test result to be returned which can slow the clinical care given to a patient and can potentially increase the risk of healthcare worker HWC exposure to COVID-19 LFAs are a point of care test which can identify children who have a high viral load of COVID-19 and are performed using a more acceptable method of swabbing for children just inside the nostril Using LFA potentially enables the identification of infectious children with COVID-19 to aid with immediate care of patients and limiting HWC and other patients contact with the virus This study aims to assess the test failure rate and identify reasons for this which can be addressed It also aims to assess the discomfort of both tests for children provide a comparison between the time to LCA and RT-PCR result and provide data for a trial to adequately power a prospective trial comparing RT-PCR and LFA
Detailed Description:
During the ongoing COVID-19 pandemic testing of children for COVID-19 has become an area of substantial need and intense scrutiny The current gold-standard method for SARS-CoV-2 detection is the real time reverse transcriptase polymerase chain reaction RT-PCR performed on a sample from the respiratory system This diagnostic test identifies fragments of viral RNA which are specific to SARS-CoV-2 and amplifies them It can detect even relatively low levels of RNA in people who have contracted the virus but have not yet developed a high viral load or symptoms It can also detect RNA after the live virus has cleared but fragments of the virus RNA remain This test has a high analytical sensitivity and specificity However obtaining an adequate specimen is more difficult in children as the test is uncomfortable and not always well tolerated This means that the diagnostic sensitivity is approximately 801 Nevertheless RT-PCR currently remains the most accurate method of detection of SARS-CoV-2 However logistical issues around RT-PCR mean that the availability and usability of the test is reduced This is due to a combination of factors including testing site capacity processing capacity and the time taken to process and report the results by centralised laboratories The net result is that the high sensitivity and specificity of PCR is offset by the time lag for result reporting In acute hospitals these delays can lead to poor patient flow through clinical areas overuse of personal-protective equipment PPE or late recognition of nosocomial transmission Thus rapid testing is of particular importance in identifying highly infective individuals for example people who are about to undergo a high-risk aerosol generating procedure enter a crowded emergency room or in rapid investigation of localised outbreaks
Alternative methods and modalities of testing have therefore been explored in particular the use of anterior nasal swabs to detect the SARS-CoV-2 Salivary RT-PCR is also under investigation2 3 but is affected by some of the limitations of performing RT-PCR on any sample as described above An alternative method of detection of SARS-CoV-2 is the use of antigen testing using a lateral flow assay LFA4 Antigen-detection diagnostic test are designed to directly detect SARS-CoV-2 proteins produced by replicating virus in respiratory secretions Most antigen rapid diagnostic tests use a sandwich immunodetection method using a simple-to-use lateral flow test format similar to a pregnancy test Antigen detection tests have several advantages compared to RT-PCR 1 it can be performed on an anterior nasal swabs- a specimen which is much more acceptably obtained in children- 2 the results can be rapidly processed using a commercial kit at the bedside with a result being available within 30 minutes of the sample being taken and 3 it is less expensive to perform an antigen test compared to RT-PCR The trade-off for ease-of-use and rapid turnaround time of antigen tests is a decrease in sensitivity compared to RT-PCR particularly if the person has a low viral load eg they are early or late in the disease because the levels of antigens present in the upper respiratory tract might fall below the threshold for detection The analytical sensitivity appears to be approximately 50 overall but this increases during periods of anticipated infectivity when the viral load is 60000 RT-PCR cycle time threshold 27 to approximately 90 The specificity of antigen tests has consistently been reported to be very high 97 Thus if the antigen test is positive then it is very likely that it is a true result and the person does have COVID-19 Antigen-detection tests are therefore primarily being used to detect infectivity of an individual rather than being used as a clinical diagnostic test for COVID-19
The potential application of LFAs to defeat Covid-19 are evident with several clinical scenarios below demonstrating areas where comparing the performance of RT-PCR to LFA could improve the care of children and improve the safety of staff in hospital However evaluation of the use of these tests in clinical settings is essential before full implementation in routine clinical practice is advised
At present all children are tested for COVID-19 with RT-PCR when they are admitted to hospital regardless of their symptoms During the winter months when more children with respiratory symptoms will seek medical care current guidance recommends isolation or cohorting of these patients within hospital until their SARS-CoV-2 test is back5 However the majority of children are likely to have an alternative cause for their symptoms such as respiratory syncytial virus adenovirus or influenza Early identification of infectious children with COVID-19 using a point of care test would allow for more effective cohorting or isolation to occur and potentially reduce the spread of COVID-19 in hospital settings not just from children but their parents too who are likely to be infected as a household contact Besides early identification of children with COVID-19 using LFA will aid compliance with stringent use of PPE for healthcare workers caring for these children
Children being admitted for elective procedures are currently also routinely tested for COVID-19 with a nasopharyngeal swab prior to admission This is performed to reduce the chance of them harbouring SARS-CoV-2 at the time of having a high-risk aerosol generating procedure AGP where the risk of transmission of SARS-CoV-2 to staff is increased Generally these children are asymptomatic as the presence of ILI symptoms often precludes an anaesthetic being performed In this population LFAs could be used to identify children who were incubating SARS-CoV-2 at the time of swabbing but were not shedding the virus who have subsequently progress to start shedding the virus Table 1 Performing LFA potentially enables infectious children to be identified and can be used to guide decisions around proceeding with a procedure and the use of PPE in children when the procedure goes ahead
Finally LFAs could be used in high risk hospital areas particularly intensive care and high dependency units where high-risk AGPs are commonly performed and where children are more likely to have symptoms which are in-keeping with COVID-19 Surveillance of SARS-CoV-2 using RT-PCR is being performed routinely in some units but a 24-48 hour delay in the result has minimal impact on practice around AGPs LFAs may be utilised as a screening tool for infectious patients in these areas to support the use of appropriate PPE
Further use of these tests could also be considered within health care worker HCW screening for infectivity after known exposures to Covid-19 cases to limit the number of HCW absences due to potential exposure both outside and inside the hospital They could potentially also be used in the community in settings such as schools and sports clubs to identify infectious individuals Validation and usability in a controlled clinical setting is recommended prior to use in the wider community Mathematical analysis of LFAs shows that due to their high specificity the negative predictive value is good in times of both high and low prevalence even when the sensitivity of the test is low
Alternative methods and modalities of testing have therefore been explored in particular the use of anterior nasal swabs to detect the SARS-CoV-2 Salivary RT-PCR is also under investigation2 3 but is affected by some of the limitations of performing RT-PCR on any sample as described above An alternative method of detection of SARS-CoV-2 is the use of antigen testing using a lateral flow assay LFA4 Antigen-detection diagnostic test are designed to directly detect SARS-CoV-2 proteins produced by replicating virus in respiratory secretions Most antigen rapid diagnostic tests use a sandwich immunodetection method using a simple-to-use lateral flow test format similar to a pregnancy test Antigen detection tests have several advantages compared to RT-PCR 1 it can be performed on an anterior nasal swabs- a specimen which is much more acceptably obtained in children- 2 the results can be rapidly processed using a commercial kit at the bedside with a result being available within 30 minutes of the sample being taken and 3 it is less expensive to perform an antigen test compared to RT-PCR The trade-off for ease-of-use and rapid turnaround time of antigen tests is a decrease in sensitivity compared to RT-PCR particularly if the person has a low viral load eg they are early or late in the disease because the levels of antigens present in the upper respiratory tract might fall below the threshold for detection The analytical sensitivity appears to be approximately 50 overall but this increases during periods of anticipated infectivity when the viral load is 60000 RT-PCR cycle time threshold 27 to approximately 90 The specificity of antigen tests has consistently been reported to be very high 97 Thus if the antigen test is positive then it is very likely that it is a true result and the person does have COVID-19 Antigen-detection tests are therefore primarily being used to detect infectivity of an individual rather than being used as a clinical diagnostic test for COVID-19
The potential application of LFAs to defeat Covid-19 are evident with several clinical scenarios below demonstrating areas where comparing the performance of RT-PCR to LFA could improve the care of children and improve the safety of staff in hospital However evaluation of the use of these tests in clinical settings is essential before full implementation in routine clinical practice is advised
At present all children are tested for COVID-19 with RT-PCR when they are admitted to hospital regardless of their symptoms During the winter months when more children with respiratory symptoms will seek medical care current guidance recommends isolation or cohorting of these patients within hospital until their SARS-CoV-2 test is back5 However the majority of children are likely to have an alternative cause for their symptoms such as respiratory syncytial virus adenovirus or influenza Early identification of infectious children with COVID-19 using a point of care test would allow for more effective cohorting or isolation to occur and potentially reduce the spread of COVID-19 in hospital settings not just from children but their parents too who are likely to be infected as a household contact Besides early identification of children with COVID-19 using LFA will aid compliance with stringent use of PPE for healthcare workers caring for these children
Children being admitted for elective procedures are currently also routinely tested for COVID-19 with a nasopharyngeal swab prior to admission This is performed to reduce the chance of them harbouring SARS-CoV-2 at the time of having a high-risk aerosol generating procedure AGP where the risk of transmission of SARS-CoV-2 to staff is increased Generally these children are asymptomatic as the presence of ILI symptoms often precludes an anaesthetic being performed In this population LFAs could be used to identify children who were incubating SARS-CoV-2 at the time of swabbing but were not shedding the virus who have subsequently progress to start shedding the virus Table 1 Performing LFA potentially enables infectious children to be identified and can be used to guide decisions around proceeding with a procedure and the use of PPE in children when the procedure goes ahead
Finally LFAs could be used in high risk hospital areas particularly intensive care and high dependency units where high-risk AGPs are commonly performed and where children are more likely to have symptoms which are in-keeping with COVID-19 Surveillance of SARS-CoV-2 using RT-PCR is being performed routinely in some units but a 24-48 hour delay in the result has minimal impact on practice around AGPs LFAs may be utilised as a screening tool for infectious patients in these areas to support the use of appropriate PPE
Further use of these tests could also be considered within health care worker HCW screening for infectivity after known exposures to Covid-19 cases to limit the number of HCW absences due to potential exposure both outside and inside the hospital They could potentially also be used in the community in settings such as schools and sports clubs to identify infectious individuals Validation and usability in a controlled clinical setting is recommended prior to use in the wider community Mathematical analysis of LFAs shows that due to their high specificity the negative predictive value is good in times of both high and low prevalence even when the sensitivity of the test is low
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None