Encouraging patients—even children—to be more directly involved in their own medical care may reduce the burden on healthcare workers and might even help those clinical laboratories struggling to hire enough phlebotomists to collect specimens
Researchers at Emory University School of Medicine have concluded a study which found that school-aged children can successfully use a nasal swab to obtain their own SARS-CoV-2 test specimens. This may come as a surprise to hospital and clinical laboratory personnel who have performed nasal swabbing for COVID-19 tests. Some people, adults included, find the procedure so uncomfortable it brings tears.
And yet, after being shown a 90-second how-to video and given a handout with written instructions and pictures, 197 Atlanta children who had COVID-19 symptoms between July and August of 2021 performed their own self-swabbing. A healthcare worker then collected a second swabbed sample. All samples were submitted to a clinical laboratory for PCR analysis.
The Emory study provides another example of how the healthcare system is engaging patients to be directly involved in their own medical care. Results of the study could positively impact clinical laboratories facing a shortage of personnel, as well as schools where children have to take repeated COVID-19 tests with the assistance of trained professionals.
In a study with 197 school-age children, researchers at Emory University School of Medicine found that children could self-swab themselves for COVID-19 testing after watching a 90-second instructional video. Clinical laboratory leaders who are short on personnel may find these results intriguing. (Photo copyright: Emory University.)
How Did the Children Do?
The self-collected swabs and those collected by a healthcare worker agreed 97.8% of the time for a positive result and 98.1% of the time for a negative result. The analysis showed that both collection methods identified the 44% of symptomatic kids who were positive for COVID-19.
“Seeing how closely the results line up between the children and trained healthcare workers is a strong indicator that these age groups are fully capable of swabbing themselves if given proper instruction,” said Jesse Waggoner, MD, an Assistant Professor of Infectious Diseases with the Emory University School of Medicine and one of the lead authors on the study, in an Emory University press release.
A higher percentage of children age eight and under needed assistance, such as more instruction before correctly completing self-collection—21.8% compared to 6.1% for children older—but SARS-CoV-2 detection among the two age groups did not differ.
Does FDA Approve of Self-Swabbing?
The US Food and Drug Administration (FDA) has not authorized COVID-19 tests that include self-swabbing by children under age 14. However, data from the Emory study, published in JAMA, is now available to test manufacturers seeking authorization for pediatric self-collection.
“Pediatric self-swabbing will support expanded testing access and should make it even easier to test school age populations with fewer resources,” said Tim Stenzel, MD, PhD, Director of the Office of In Vitro Diagnostics at the FDA, in the Emory statement. “This study furthers our knowledge of test accuracy with these types of samples and provides test manufacturers with data to support their EUA (Emergency Use Authorization) requests to the FDA.”
Self-swabbing versus Clinical Laboratory Worker
While it has been longstanding medical practice to have healthcare workers collect samples for respiratory tract infection testing, the Emory researchers suggest that allowing children to collect their own COVID-19 samples could be one way to reduce the burden of a shortage of healthcare workers.
The researchers also believe pediatric self-swabbing would expand access to diagnostic tests and make it easier to test school-age populations.
“Every minute of a healthcare worker’s time is at a premium,” said senior study author Wilbur Lam, MD, Professor of Pediatrics and Biomedical Engineering, Emory University and Georgia Tech, in a National Institutes of Health (NIH) press release. “Why not allow a kid to self-swab? It’s a win-win! They would rather do it themselves and it frees up the healthcare worker to do other things,” he added.
In 2020, a Stanford University School of Medicine study published in JAMA showed test samples collected by adults who swabbed their own nasal passages were as accurate as those collected by healthcare workers. This study involved 30 participants who had previously tested positive for COVID-19.
Though the Emory University and Stamford University studies were small, they agreed in their findings which is significant. Clinical laboratory executives and pathologists should expect this trend toward direct-to-consumer and other forms of self-testing to continue, even among young patients.
The technology uses an easy-to-administer low-cost patch that can be applied to the skin like an adhesive bandage. The patch is virtually painless because the microneedles are too small to reach nerve receptors. Another unique aspect to this innovative approach to collecting a specimen for diagnostic testing is that the Washington University in St. Louis (WashU) research team designed the microneedle patch to include plasmonic-fluor. These are ultrabright gold nanolabels that light up target protein biomarkers and can make the biomarkers up to 1,400 times brighter at low concentrations, compared to traditional fluorescent labels.
The patch, states a WashU news release, “… can be applied to the skin, capture a biomarker of interest and, thanks to its unprecedented sensitivity, allow clinicians to detect its presence.”
The technology is low cost, easy for clinicians or patients themselves to use, and could eliminate the need for a trip to patient service center where a phlebotomist would draw blood for clinical laboratory testing, the news release states.
“We used the microneedle patch in mice for minimally invasive evaluation of the efficiency of a cocaine vaccine, for longitudinal monitoring of the levels of inflammatory biomarkers, and for efficient sampling of the calvarial periosteum [a skull membrane]—a challenging site for biomarker detection—and the quantification of its levels of the matricellular protein periostin, which cannot be accurately inferred from blood or other systemic biofluids,” the researchers wrote. “Microneedle patches for the minimally invasive collection and analysis of biomarkers in interstitial fluid might facilitate point-of-care diagnostics and longitudinal monitoring.”
Mark Prausnitz, PhD, Regents’ Professor, J. Erskine Love Jr. Chair in Chemical and Biomolecular Engineering, and Director of the Center for Drug Design, Development, and Delivery at Georgia Tech, told WIRED, “Blood is a tiny fraction of the fluid in our body. Other fluids should have something useful—it’s just hard to get those fluids.”
“Previously, concentrations of a biomarker had to be on the order of a few micrograms per milliliter of fluid,” said Zheyu (Ryan) Wang, a PhD candidate in Srikanth Singamaneni’s lab at McKelvey School of Engineering and a lead author of the paper, in the WashU news release. By using plasmonic-fluor, researchers were able to detect biomarkers on the order of picograms per milliliter—one millionth of the concentration.
“That’s orders of magnitude more sensitive,” Wang said.
Can Microneedles Be Used as a Diagnostic Tool?
As reported in WIRED, the polystyrene patch developed by Srikanth Singamaneni’s lab at McKelvey School of Engineering removes interstitial fluid from the skin and turns the needles into “biomarker traps” by coating them with antibodies known to bind to specific proteins, such as Interleukin 6 (IL-6). Once the microneedles are mixed with plasmonic-fluor, the patch will glow if the IL-6 biomarkers are present.
The development of such a highly sensitive biomarker-detection method means skin becomes a potential pathway for using microneedles to diagnose conditions, such as myocardial infarction or to measure COVID-19 antibodies in vaccinated persons.
Because the WashU study is a proof-of-concept in mice, it may be many years before this technology finds its way to clinical application. Many skin biomarkers will need to be verified for direct links to disease before microneedle patches will be of practical use to clinicians for diagnostics. However, microneedle patch technology has already proven viable for the collection of blood.
In 2017, Massachusetts-based Seventh Sense Biosystems (7SBio) received 510(k) clearance for a new microneedle blood collection device. Called TAP, the device is placed on the upper arm and blood collection starts with a press of a button. The process takes two to three minutes.
Initially, the FDA clearance permitted only healthcare workers to use the device “to collect capillary blood for hemoglobin A1c (HbA1c) testing, which is routinely used to monitor blood sugar levels in diabetic or pre-diabetic patients,” a Flagship Pioneering news release noted.
Then, in 2019, the FDA extended its authorization “to include blood collection by laypersons. Regulators are also allowing the device to be used ‘at-home’ for wellness testing,” a 7SBio news release stated. This opened the door for a microneedle device to be used for home care blood collection.
“No one likes getting blood drawn, but blood is the single-most important source of medical information in healthcare today, with about 90% of all diagnostic information coming from blood and its components,” Howard Weisman, former CEO of 7SBio and current CEO of PaxMedica, a clinical-stage biopharmaceutical company, said in the Flagship Pioneering news release. “TAP has the potential to transform blood collection from an inconvenient, stressful, and painful experience to one people can do themselves anywhere, making health monitoring much easier for both healthcare professionals and patients.”
As microneedle technology continues to evolve, clinical laboratories should expect patches to be used in a growing number of drug delivery systems and diagnostic tests. But further research will be needed to determine whether interstitial fluid can provide an alternate pathway for diagnosing disease.