After my report on Monday, you will be pleased with what I share with you today. (I skipped yesterday, since I needed to note the 72nd anniversary of Israel’s founding.)
It turns out saliva testing is far more reliable than nasopharyngeal tests for the presence of SARS-CoV-2 or COVID-19. More importantly, it means we can collect our own samples, further protecting health professionals from directly contacting those of us who might be infected.
Drs. Anne Wylie, Nathan Grubaugh, and Albert Ko of the Yale School of Public Health (along with 57 other Yale professionals) published a preprint in MedRxiv, “Saliva is more sensitive for Sars-CoV-2 detection in COVID-19 patients than nasopharyngeal swabs”.
As you know, collecting saliva requires no specialized swabs or tubes- but more importantly is tolerated by the subject more easily. And, this study employed saliva samples that were all collected by the subjects themselves- not the health care professionals. (The subjects were prohibited from ingesting food or water, as well as teeth brushing, until the sample was collected. Just like those tests your doctor requires once a year.)
These tests all had the subjects continually spit into a urine cup until it was 1/3 full. (That means about a 30 ml saliva sample was obtained.)
Each of the 98 healthcare professionals that was tested was of a moderate to high risk of SARS-CoV-2 exposure; the 44 patients were all COVID-19 patients. (Note that all subjects took both the saliva and the nasopharyngeal tests.)
Interestingly, SARS-CoV-2 detection in the saliva samples were more easily found and in a consistent fashion- regardless of the stage of the infection. (You do recall from Monday’s post that it was only after 3 weeks that the nasopharyngeal lateral flow analyses were routinely picking up the infection.) The saliva samples also detected that two of the healthcare workers that had been declared infection free were not! This implies that the saliva detection may be useful to detect those patients that are asymptomatic or with mild/subclinical infections.
(Another group had already suggested that saliva may be useful; this article had been published as a letter to the editor in the Journal of Clinical Microbiology. Drs. E. Williams, K. Bond, B. Zhang, M. Putland, and D. Williamson of the Royal Melbourne Hospital authored the study, Saliva as a non-invasive specimen for detection of SARS-CoV-2. This team employed 622 patients at their clinic; only 522 also had the saliva tests. )
So, we may finally have that simple and quick test procedure we need. Now, we just need folks to make millions of these kits, so we can end the quarantine.
Glad to hear it–I would much rather do a saliva swab than the stick up the nose!!!
That’s what enticed me, too, Marcia. And, the fact that it works better can’t hurt (pun intended), either!
yes!! i do prefer this one about which tests pass 🙂 and that light at the end of the tunnel is looking closer and larger now
vidya recently posted..Y is for Yugen
Touche, Vidya!
What a breakthrough for testing and so easy and painfree. Now if they could make enough tests for everyone maybe we could all breathe easier.
That has to be the big push, Martha!
Sounds like there is the possibility of a safe end to the quarantine. That would be a good thing, as opposed to, “We need to restart the economy, with or without the support of the medical community” type of attitude.
Alice Gerard recently posted..Life in these strange times: Xanadu
I’m with you on that, Alice.
I wonder for how long you have to abstain from water because if a person takes medication causing dry mouth I could see problems with filling that urine cup. But, apart from that, this is wonderful news. That initial swab test was awful. We need to know where we are both with positive cases and with antibody tests. My brother in law who was released from hospital earlier this week after three weeks battling COVID-19 was not given another test before release. They said he would “probably” test positive. We need something better.
Alana recently posted..Zig Zag Zoo #AtoZChallenge
It’s typically 6 to 8 hours- just like for the regular blood testing that we undertake for our annual physicals, Alana.
And, yes, we absolutely need better tests!