A new cost-effective saliva-based PCR test enables contractors to serial test for coronavirus infection.
HealthWatch, a company that has been working with the Construction Workers Health Trust since 2013 providing on-site health screening, has developed a fast-turnaround saliva-based serial Covid-19 test that can detect the presence of RNA from SARS Cov2, the virus that causes Covid 19. It also provides a quantitative measure of the amount of viral RNA. The ease of saliva sampling coupled with the fast turnaround (under 24 hours) and its affordability makes it an ideal test for screening large numbers of individuals on a frequent (eg weekly) basis.
Healthwatch PCR Screening
Serial PCR testing is recommended for essential construction sites, off-site facilities, or projects, where the cost of a shutdown due to a Covid-19 outbreak would be prohibitive. The test does not need to be administered by a medical professional and simply requires a designated person to oversee collecting of saliva samples and verify the chain of custody. The cost of the test is a fraction of the cost of other tests being offered on the market. PCR testing is also more sensitive and specific at detecting active infection in asymptomatic individuals than other methods, such as temperature monitoring, lamp testing, rapid antigen testing or anti-body testing.
In a CIF-hosted webinar, Professor Paul Moynagh, Professor of Immunology, Maynooth University, explained that PCR detects the RNA at the core of the virus. “This is achieved by amplifying the RNA in a sample, so the virus is more easily detected. If there are low levels of infection, say at the start or end of infection when a person may be asymptomatic, the test will amplify the RNA and easily detect infection.”
If an infected person arrives at a site before symptoms develop, PCR testing can detect the infection, and the person can isolate before symptoms develop. Importantly, this greatly increases the probability of preventing the seeding of infection on the site.
After a successful pilot programme on a CIF member site in December, the weekly serial saliva screening is being used on a number of construction, pharma and other essential businesses.
The high level of inquiries received following the CIF webinar indicates that a large number of contractors are increasing their defences against the virus, so they can protect their workers and their families, as well as take extra measures to protect against an onsite outbreak.
More recently it is being used on the New Children’s Hospital site by BAM Ireland.
What Is Serial Screening?
Serial screening has been identified as one of the major defences to control and prevent the transmission of SARS-CoV-2. This is used widely in some high-risk settings, essential services and elite/ professional sporting organisations. Regular screening greatly reduces the risk of seeding infection in group settings and is a critically important measure in keeping workplaces open and operational. The major challenges of frequent nasopharyngeal screening include turnaround times, costs and logistics, as well as the discomfort associated with taking the swabs. However, the HealthWatch saliva test does not have these challenges.
Healthwatch Screening Service
The HealthWatch Gold-Standard RT-qPCR for SARS-CoV-2 serial test service is designed to provide quality, affordable, and local screening. The test has been clinically validated.
For many, the nasopharyngeal swab collection of a sample is an intrusive, unpleasant experience, which can be difficult to tolerate. It requires, at the very least, a specialised nurse proficient in the procedure. In the past few months, there have been growing reports of false negatives due to inefficient swabbing techniques. Until now there has been no validated RT-qPCR for saliva testing in Ireland. Saliva allows for easy, non-invasive sample collection and, depending on when samples are received, can yield same-day or next-day results. No special swabs or qualified nursing staff are required to collect the sample.
Healthwatch’s saliva RT-qPCR test, carried out regularly, is ideally suited to screen for positive cases before infected individuals can transmit the infection to others. Serial screening works best when conducted frequently. “A negative result received a week ago gives you no information as to your infectiousness today,” says Jack Nolan, Managing Director, HealthWatch. “We recommend that serial screening is performed at a frequency of at least once per week to provide effective support for businesses to remain open and operational. “While the incubation period from initial infection to symptom presentation is typically around six days, many individuals can begin to transmit the virus for several days before becoming symptomatic while others may be infectious and remain asymptomatic.”
HealthWatch PCR Screening serial testing is provided on a nationwide basis and can be scaled up as demand grows.
To learn more about HealthWatch PCR Screening, the CIF webinar ‘Rapid, Affordable and Convenient Saliva Based RT qPCR Testing for COVID 19 13 11 2020’ can be viewed on the CIF Academy website www.ciftraining.ie. For more details, contact Lucinda Horwell, Commercial Director. HealthWatch by email at firstname.lastname@example.org
Gold Standard RT-qPCR-Saliva test for SARS-CoV-2 (COVID-19)
This test uses the quantitative method of RT-PCR to detect the presence of SARS-CoV2 RNA in Saliva samples.
Infectiousness depends on how much virus a person has. It is believed that the more virus you have in your respiratory system, the more likely you are to transmit to others.
RT-qPCR provides for high sensitivity and specificity and allows for detection of SARS CoV2 across the duration of infection and infectiousness.
The test ideally suited to screen for positive cases before the infected individual can transmit the infection to others.