Hundreds of millions of RT-PCR tests have been performed this year in an attempt to control the coronavirus outbreak. Only in France, not less than 18 millions[1] people went through the unpleasant swab test between March and October 2020. It is time to take a detailed look at this instrument, which has established itself for ten years in the landscape of biological tests. Is it potentially dangerous ?
FILE PUBLISHED IN NEO SANTE n ° 106 DECEMBER 2020 The swab, it is a bit of the magic wand of the epidemics of positive cases experienced by many countries. Starting with France, record breaking. But the purpose of this investigation is not to revisit the reliability of the RT – PCR test which we have already discussed a lot in Neo Health[2]. We know that this test, when performed en masse on asymptomatic cases, has a very high chance of giving a false positive. This time, let's take a look at the swab, long mass detection weapon 18 centimeters, that we push to the bottom of the nasal cavity to collect viral material.
A decline of ten years
The "nasopharyngeal swab" was essential in the context of the H1N1 influenza epidemic of 2009, a pseudo-pandemic that caused a lot of ink to flow at the time, the public health scandal, the precursor of the one we are currently experiencing ... At the time, the swab and nasopharyngeal swab are not yet the gold standard. To be convinced, just look at the few rare studies published at the beginning of the years 2010 about this type of debit. Although not dating from yesterday, the nasopharyngeal test will take advantage of the health crisis to enter deeply into the official recommendations.
Here is what American researchers wrote in 2012, in the article "Comparison of nasal and nasopharyngeal swabs for detection of influenza in adults'[3]: "The pandemic of 2009 and increased resistance to antivirals type-specific increased the need for influenza testing specific, timely and well tolerated by patients. A variety of samples have been used for influenza screening, including nasopharyngeal swab (For example), the oropharyngeal swab, nasal washing and nasal aspiration. The nasal washing or aspiration is generally considered the "standard reference "for virus isolation, but it is difficult to achieve and unpleasant for patients. Swabs are easier and longer quick to collect and may be preferred by providers and patients. (…) Nowadays, no studies have compared nasal and nasopharyngeal swabs paired samples taken from adults ”.
In other words, we didn’t know much yet 10 years on the relevance of the different types of direct debits, both in terms of reliability of results and comfort for patients. But what we discover through these studies, it is the less invasive nature of a swab sample than by nasopharyngeal aspiration! The latter requires the presence of two people and is done using a much larger and much less comfortable cannula, we must admit it, especially for children[4]…
The nasopharyngeal sample becomes the benchmark
In 2020, 10 ans plus tard, the nasopharyngeal swab has become the gold standard, at least in France, a country particularly committed to the sampling of its population. En premier lieu, for seasonal influenza surveillance. « Plus de 1 300 general practitioners of the Sentinelles network provide clinical monitoring. Environ 300 of them, supported since 2015 par 116 pediatricians, carry out virological surveillance by taking nasopharyngeal samples which are analyzed at the National Reference Center for Respiratory Infections ”, explains the Institut Pasteur[5].
With the coronavirus pandemic, the swab confirmed its hegemony. Thus, in a decree published on 12 May 2020 in the Official Journal, co-signed by the Director General of Health, Jérôme Salomon, it is clearly indicates that "The preferred sample is a direct deep nasopharyngeal upper respiratory tract by swab or lower respiratory tract sampling (sputum or fluid brochoalveolar) »[6]. A decree that is in line with the recommendations of the Company French microbiology (SFM) of 6 April 2020. In a Focus published on 9 May 2020 by the national reference center (CNR) of the Institute Pastor, we can also read that "RT-PCR tests on samples nasopharyngeal are now considered the gold standard for respiratory viruses'. As to "Throat swabs", they have "A detection sensitivity lower than that of nasopharyngeal swabs " avec "Sometimes a high risk of false negative ".
Donc, if we are to believe the French health authorities who have, otherwise, less and less credibility in the eyes of the general public, to have a reliable test you MUST go through the nasopharyngeal swab and not a simple nasal swab (shallower) or in the throat (oro-pharyngé). But ... This is not the position of the WHO or other public health agencies. En effet, The World Health Organization recommends taking upper respiratory tract samples (nasopharyngeal and oropharyngeal swabs) and / or lower (expectoration) reserving endotracheal suction for patients with more severe respiratory symptoms.
No real benefit
As a matter of fact, the superiority of swab sampling is not the subject of scientific consensus. A simple saliva test performed at home or a few sputum sent to the lab are probably just as effective, and much less painful. The best synthesis of the state of knowledge has been produced by the Canadians of the National Institute of Excellence in Health and Social Services (INESSS). This document[7] compares the various international recommendations and twenty recent studies on swabs. I'll pass you the scientists' preferences for "flaked polyester swabs mounted on a plastic rod", let's focus on the real debate that relates to the site and the method of sampling to favor to detect SARS-CoV-2.
"The data in the literature are mixed, writes the Canadian institute. Some studies find higher positivity rates in sputum, suggesting that they should be used preferentially over nasal swabs [That 2020], nasopharyngés [Wu 2020] or throat [Lin 2020]. In other studies, sputum viral load is observed to be similar to throat swab [Pan 2020] and that the viral load of the throat swab is similar to that of the nasopharyngeal swab [Wolfel 2020], or the nasal swab [Zou et al., 2020] or nasopharyngeal [Becker 2020] has a viral load 8 greater than throat or saliva sampling. According to a Finnish study, the nasal swab would have a sensitivity comparable to nasopharyngeal aspiration [Waris et al., 2013]. ». Brief, that's kif-kif bourricot ...
The in-house self-test, equally valid !
"Two American studies [Which ones 2020, your 2020] have tested a different approach, either the self-debit, continues INESSS. They came to the conclusion that the positivity rate obtained from oral samples (saliva) and nasals performed by the patients themselves are similar to the positivity rates obtained from samples nasopharyngeal performed by healthcare professionals. More, review systematic [Khurshid 2020] and four primary studies [Iwasaki, Jamal, Pasomsub, Williams, 2020], including a canadian, have shown that saliva is an effective alternative, even more sensitive in certain circumstances than nasopharyngeal swabs, in addition to allowing the self-debit to home to detect SARS-CoV-2 on a large scale. An American protocol is currently being tested to demonstrate the feasibility of self-sampling of saliva in the context of COVID-19 [Sullivan, 2020] ».
For all these reasons, nothing obliges you to prefer the nasopharyngeal swab for reliability ! Besides, the possibility of having a less invasive sample remains open in many countries, even in France (insisting heavily ...) since the High Authority for Health (HAS) gave an opinion[8] favorable, the 20 septembre 2020 : «Saliva samples are an alternative but only for symptomatic patients. Today, the HAS validates the use of the oropharyngeal sample for RT-PCR tests of asymptomatic people in whom the nasopharyngeal sample is contraindicated ".
A painful or even painful test
“My wife had a headache accompanied by dots of color in front of his eyes during 2 days ", explains a Twitter user (where the swab has circulated well). "The nurse insisted / triturated so much that I really wanted to stick a loaf of him ", comments another on the same network. "One hour after the test, I still had a weird feeling deep in my nose. Not really painful either, but quite embarrassing. Especially since I took the test at period when I had strong allergies to pollens, it probably does not suit me help, I couldn't stop sneezing ", explains Nicolas[9]. "For my part I found it more unpleasant than painful, but i can't say it doesn't hurt all. Regarding my colleagues, I would say that 60 to 70% found it painful ", explains a nurse.
Depending on the sensitivity of the person tested and the dexterity of the practitioner the experiences are very personal. It is not in all case not a trivial medical act because there is a manipulation which must be well carried out. As the University Hospital of Angers explains in its video demonstration on Youtube (" Sample nasopharyngeal – COVID-19 »[10]), the first mistake to avoid is to introduce the swab parallel to the bridge of the nose. We come up against the "cribriform plate" which is a micro-perforated entry gate to the central nervous system, via the ramifications of the olfactory nerve.
And the blood-brain barrier?
Some articles online have claimed that the assholes could perforate the blood-brain barrier and that the tests could serve as a pretext to introduce nanoparticles into the brain. What about is he really ?
The blood-brain barrier, discovery in 1885, has the main function of isolating the central nervous system (SNC) blood circulation, by preventing foreign substances / potentially toxic molecules / pathogens from entering the brain and spinal cord. Après enquête, these articles ultimately turn out to disseminate unsubstantiated claims, which are not based on any study or proven fact. When the test is performed correctly, he does not touch the cribriform plate, but comes up against the oropharyngeal crossroads, between the back of the nose and the throat.
The swab cannot reach the blood-brain barrier or pierce this anatomical part, but on the other hand it can cause bleeding.
Many testimonies abounded in this direction, especially with a certain type of swab. An article[11] by medi-sphere.be (so in Belgium) report it 14 septembre 2020 what "New swabs delivered by the federal government to screening centers would cause one in two patients to bleed ». Dr Maxime Delvaulx, like others, denounce the suffering of patients: “We have been facing since 15 days to a swab problem. They are very sharp. Even rubbing it on the finger, it hurts. These swabs get caught in the hairs of the nose and they bleed one in two patients. In use, they are rigid and they break very quickly. » It leads doctors to make choices : «We no longer use them for children or adults on anticoagulants. »
Numerous contraindications
This is to say if this test is not trivial, especially for people who have a diverse medical history : heart problems (anticoagulant), O.R.L. problems, patients with psychiatric disorders, person with a nasal deviation, etc.. In fact the test is contraindicated in a fairly large number of cases. If it is not well spotted, a swab contraindication can turn into a nightmare : “Covid test caused cerebrospinal fluid to leak, rare complication in a weakened patient ”, title as well Sciences et Avenir the 2 last october: "An American patient consulted shortly after a Covid-19 nasal test for vomiting, headache, stiff neck, and cerebrospinal fluid leaking through the nose. The test, probably poorly administered (at the level of the cribriform plate, ed), had damaged the base of the skull, greatly weakened by an old puncture operation following intracranial hypertension ". “This case shows that healthcare professionals must follow protocols to the letter, indique Jarrett Walsh, author of this case study, published in the journal JAMA Otolaryngology–Head & Neck Surgery[12]. « Alternative methods to nasal screening should be considered in patients with known previous skull base defects, a history of sinus or base of the skull surgery, or conditions predisposing to the erosion of the base of the skull ".
Beware of contaminated swabs !
If the rumors of implantation of nanomaterials or DNA samples are not based on any credible source, on the other hand, contamination of the swabs can pose a real problem. Cases of contamination have been widely reported this year by the press (to see further). These swabs can infect the patient at the exact location of the respiratory viruses.. It is now known that some viruses can cross the nearby blood-brain barrier. Their main entry routes are either through the blood or through transport along neurons. "Regarding neurological disorders associated with respiratory viruses, we also know that it is the oropharyngeal sphere that is mainly affected, which is rather conducive to a brain infection ”, Explain France Culture, in a show[13] of 58 minutes dedicated to the "Blood-brain barrier : the last frontier ".
"Regarding SARS-CoV-2, 2 assumptions are raised to explain the neurological symptoms associated with the disease : the virus could reach the CNS through the blood (viral encephalitis), but the neurological disorders might also not be related to the virus itself and could be caused by the overreaction triggered in response to the virus (the cytokine storm) which would cause brain damage. This would therefore be an autoimmune encephalitis. Some make a 3rd hypothesis, that the nose could be the access route to the brain, since loss of smell is common to some patients with Covid-19 ". Hence the absolute necessity of having swabs sterile !
Suspicious imports or manufacturing
Or, very many articles relayed problems of contaminated batches. For example in Quebec, thousands of swabs imported from China have revealed[14] the presence of a fungus ! Other provinces in Canada have also been affected : Saskatchewan health officials reported receiving 7.000 contaminated swabs from the Public Health Agency of Canada. In British Columbia, There were 30.000. In manitoba, 8.800 screening tests from the National Microbiology Laboratory were contaminated, according to the Ministry of Health. New Brunswick also received 6.400 faulty Chinese test kits : "As soon as we received them, we found out that they were all contaminated with bacteria », explains Dr Richard Garceau, microbiologist-infectiologist at CHU Dumont who estimates that no less than 320.000 tests may have been contaminated. Contaminated in the sense that they are simply no longer sterile.
Also in Ontario, Premier Doug Ford has also confirmed that a delivery of 100.000 swabs from Asia arrived contaminated with mold earlier this month. When we know the number of Chinese swabs imported everywhere in countries in shortage, there is reason to wonder about the material that was used to test many Europeans.
The United States has had similar setbacks, But from their own manufacturers. Once due to "probable" contamination at the Centers for Disease Control and Prevention[15] which resulted in false positive results. Another time because of Randox laboratory[16] : 750 000 tests recalled for suspected contamination of the swab, in August 2020 ...
All these various facts show that the test equipment requires complex handling to benefit from complete sterility. Donc, find out where the test kits and swabs come from if you really have to get tested!
Your nose interests them ...
I couldn't finish this investigation without telling you about a discovery I made during my research on rumors of nanoparticles present in swabs. By consulting the site of PubMed reference, I smelled two interesting articles. The first, a study[17] indian dating 2010 : "Potential of the administration systems of nanoparticulate drugs by intranasal administration '. The authors explain that : "The brain benefits from intranasal administration because direct olfactory transport bypasses the blood-brain barrier and nanoparticles are absorbed and transported along the cellular processes of olfactory neurons through the plate screened to the synaptic junctions with the bulb neurons olfactory. "
This confirms the fact that your nose is not waterproof ... and that it could serve as a royal route for the absorption of new drugs, and in particular new nanoparticulate vaccines. Further studies followed in this meaning, as in 2019, this article[18] from Hungary : "Intranasal nanoparticulate systems such as alternative route of drug administration ". There is little almost the same as in the Indian study but with the following update : "According to studies reported on intranasal administration based on nanotechnology, potential attention has been focused on the brain targeting and vaccine delivery with results promising. Despite the significant research efforts in this area, the nanoparticle products for intranasal administration are not available. Thus, more efforts are needed to promote the introduction of intranasal nanoparticulate products that can meet regulatory affairs requirements with strong acceptance by patients. »
In conclusion, do you expect the next few years to see
enter the market for nasal vaccines composed of nanoparticles. A big
comfort of administration, their consequences could turn out to be much more
intrusive and definitive than the painful swab!
[1] « Covid : the number of PCR tests in clear acceleration in France ”. The echoes, 23 October 2020.
[2] See https://www.neosante.eu/4-raisons-de-detester-le-test/ and
«Tests you covid-19, watch out for false positives ! " on www.pryskaducoeurjoly.com
[3] « Comparison of Nasal and Nasopharyngeal Swabs for Influenza Detection in Adults ». Stephanie A. Irving et al. Clin Med Res. 2012 Nov
[4] « Comparing nose-throat swabs and nasopharyngeal aspirates collected from children with symptoms for respiratory virus identification using real-time polymerase chain reaction ». Stephen B Lambert et al. Pediatrics, sept. 2008.
[5] https://www.pasteur.fr/fr/comment-diagnostiquer-grippe
[6] " Screening of Covid-19 : one million swabs delivered by China await fire green to be used ', by Benoît Collombat, Cell investigation of Radio France, published on fanceinter.fr, Updated 16 mai 2020. https://www.franceinter.fr/depistage-du-covid-19-un-million-d-ecouvillons-livre-par-la-chine-attendent-le-feu-vert-pour-etre-utilises
[7] "COVID-19 and shortage of swabs ", 27 May 2020. https://www.inesss.qc.ca
[8] « COVID-19 : favorable opinion for oropharyngeal sampling in the event of contraindication to nasopharyngeal '
Press release from 25 sept. 2020 sure www.has-sante.fr
[9] « Covid-19 : is the PCR test painful ? »Maxime Poul, Yahoo News, 20 July 2020.
[10] https://youtu.be/fhShfC0Eczo
[11] https://www.medi-sphere.be/fr/actualites/de-nouveaux-ecouvillons-livres-par-le-federal-aux-centres-de-depistages-feraient-saigner-un-patient-sur-deux.html
[12] « Cerebrospinal Fluid Leak After Nasal Swab Testing for Coronavirus Disease 2019 », Christopher Blake Sullivan. October 1, 2020, JAMA Otolaryngol Head Neck Surg.
[13] The 25/05/2020. In the program "The scientific method", by Nicolas Martin. https://www.franceculture.fr/emissions/la-methode-scientifique/la-methode-scientifique-emission-du-lundi-25-mai-2020
[14] Radio Canada, published on 22 April 2020. https://ici.radio-canada.ca/nouvelle/1696091/test-depistage-ecouvillons-covid-19-contamines-chine-quebec
[15] « CDC coronavirus test kits were likely contaminated, federal review confirms ». 20 June 2020. www.washingtonpost.com
[16] « Tory-linked firm behind ‘contaminated’ Covid-19 tests keeps government contract », the 14 August 2020. www.mirror.co.uk
[17] Potential of nanoparticulate drug delivery systems by intranasal administration”, Javed Ali. Curr Pharm Des. 2010 May
[18] https://pubmed.ncbi.nlm.nih.gov/31453778/
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Keywords: coronavirus, swab, test PCR