This is good news for clinical laboratories that already perform medical testing for telehealth providers and an opportunity for medical labs that do not, it is an opportunity to do so
Telemedicine visits have become commonplace since the arrival of COVID-19. Before the pandemic, telehealth was primarily used to give remote patients access to quality healthcare providers. But three years later both patients and physicians are becoming increasingly comfortable with virtual office visits, especially among Millennial and Gen Z patients and doctors.
Now, a recent study by the Perelman School of Medicine at the University of Pennsylvania (Penn Medicine) suggests that there could be a significant financial advantage for hospitals that conduct telemedicine. This would be a boon to clinical laboratories that perform medical testing for telemedicine providers.
According to Digital Health News, in July 2017 Penn Medicine launched a 24/7/365 copayment-free telemedicine program for its employees called Penn Medicine OnDemand. To engage with a telemedicine provider, patients must have a smartphone or tablet with a front-facing camera and updated operating system.
Telemedicine Visits Cost Less than In-Office Doctor Appointments
An analysis of the OnDemand program’s data collected from its inception through the end of 2019 found that the telemedicine appointment per-visit cost averaged around $380, whereas the cost of an in-person visit at an emergency department, primary care office, or urgent care clinic averaged around $493.
Typically, Penn Medicine’s employees used the telemedicine program for common, low risk health complaints. Healthcare conditions that many patients might otherwise not seek treatment for if an in-office visit was inconvenient.
“The data we analyzed pre-date the pandemic. It was a time when people were just putting a toe in the water and wondering, ‘Let me see if telemedicine could treat my needs,’” Krisda Chaiyachati MD, an internal medicine physician and Adjunct Assistant Professor at Penn Medicine, told Digital Health News. Chaiyachati lead the research team that conducted the telemedicine study.
“These days, people seem willing to jump in for an appropriate set of conditions,” he added. “The good news is that we made care easier while saving money, and we think the savings could be higher in the future.”
Chaiyachati and his colleagues found that telemedicine can save employers healthcare costs without sacrificing quality of care.
“The conditions most often handled by OnDemand are low acuity—non-urgent or semi-urgent issues like respiratory infections, sinus infections, and allergies—but incredibly common, so any kind of cost reduction can make a huge difference for controlling employee benefit costs,” Krisda Chaiyachati MD (above), a Penn Medicine physician and the study’s lead researcher, told Digital Health News. Clinical laboratories that already perform testing for telemedicine providers may see an increase in test orders once hospitals learn of the costs savings highlighted in the Penn Medicine study. (Photo copyright: Penn Medicine.)
Telemedicine on the Rise
The idea is not new. In late 2018, Planned Parenthood launched the Planned Parenthood Direct mobile app in New York State. The app provides New York patients with access to birth control, emergency contraception, and UTI treatment with no in-person visit required.
The program has since expanded across the country. Users of the app can connect with a physician to go over symptoms/needs, and the be sent a prescription within a business day to the pharmacy of their choice.
The concept is similar to Penn Medicine OnDemand, which gives patients 24/7 year around access to treatment for common and low-acuity medical issues in a convenient, virtual process.
Telemedicine was on the rise in other parts of the healthcare industry before the pandemic. According to “The State of Telehealth Before and After the COVID-19 Pandemic” published by Julia Shaver, MD, Kaiser Permanente, in the journal Primary Care: Clinics in Office Practice, 76% of US hospital systems had utilized some form of telemedicine by 2018. This rate grew exponentially while the healthcare system had to navigate a world with COVID-19 on the rise.
And, apparently, quality of care does not suffer when moved from in-person to virtual settings. Two studies conducted by The University of Rochester Medical Center (URMC) found telemedicine to be effective and that “common concerns about telemedicine don’t hold up to scrutiny,” according a news release.
In her New England Journal of Medicine (NEJM) paper on the studies, Kathleen Fear, PhD, URMC’s Director of Data Analytics, Health Lab, and her co-authors, wrote: “Three beliefs—that telemedicine will reduce access for the most vulnerable patients; that reimbursement parity will encourage overuse of telemedicine; and that telemedicine is an ineffective way to care for patients—have for years formed the backbone of opposition to the widespread adoption of telemedicine.”
However, URMC’s study found the opposite to be true. The NEJM authors wrote, “there is no support for these three common notions about telemedicine. At URMC, the most vulnerable patients had the highest uptake of telemedicine; not only did they complete a disproportionate share of telemedicine visits, but they also did so with lower no-show and cancellation rates. It is clear that … telemedicine makes medical care more accessible to patients who previously have experienced substantial barriers to care.
“Importantly, this access does not come at the expense of effectiveness. Providers do not order excessive amounts of additional testing to make up for the limitations of virtual visits. Patients do not end up in the ER or the hospital because their needs are not met during a telemedicine visit, and they also do not end up requiring additional in-person follow-up visits to supplement their telemedicine visit,” the NEJM authors concluded.
“Not only did our most vulnerable patients not get left behind—they were among those engaging the most with, and benefiting the most from, telemedicine services. We did not see worse outcomes or increased costs, or patients needing an increased amount of in-person follow up. Nor did we find evidence of overuse. This is good care, and it is equitable care for vulnerable populations,” Fear said in the news release.
“For patients, the message is clear and reassuring: Telemedicine is an effective and efficient way of receiving many kinds of healthcare,” she added.
Opportunities for Clinical Laboratories
Dark Daily has covered the fast growing world of telemedicine in many ebriefs over the years.
As telemedicine broadens its reach across the healthcare world, clinical laboratories and pathology groups would be wise to seek collaboration with health plans and providers of telemedicine to figure out where sample collection and testing fits into this new virtual healthcare space.
Research in the UK and US into how rapid WGS can prevent deaths and improve outcomes for kids with rare genetic diseases may lead to more genetic testing based in local clinical laboratories
Genetic scientists with the National Health Service (NHS) in England have embarked on an ambitious plan to offer rapid whole genome sequencing (rWGS) for children and babies with serious illnesses, as part of a larger initiative to embrace genomic medicine in the United Kingdom (UK).
The NHS estimates that the plan will benefit more than 1,000 children and babies each year, including newborns with rare diseases such as cancer, as well as kids placed in intensive care after being admitted to hospitals. Instead of waiting weeks for results from conventional tests, clinicians will be able to administer a simple blood test and get results within days, the NHS said in a press release.
The press release notes that about 75% of rare genetic diseases appear during childhood “and are responsible for almost a third of neonatal intensive care deaths.”
Here in the United States, pathologists and clinical laboratory managers should see this development as a progressive step toward expanding access to genetic tests and whole genome sequencing services. The UK is looking at this service as a nationwide service. By contrast, given the size of the population and geography of the United States, as this line of medical laboratory testing expands in the US, it will probably be centered in select regional centers of excellence.
“This strategy sets out how more people will be empowered to take preventative action following risk-based predictions, receive life-changing diagnoses, and get the support needed to live with genomically-informed diagnoses alongside improved access to cutting-edge precision [medicine] treatments. It also outlines how the NHS will accelerate future high-quality genomic innovation that can be adopted and spread across the country, leading to positive impacts for current and future generations,” the NHS wrote.
“This global first is an incredible moment for the NHS and will be revolutionary in helping us to rapidly diagnose the illnesses of thousands of seriously ill children and babies—saving countless lives in the years to come,” said NHS chief executive Amanda Pritchard (above) in a press release announcing the program. (Photo copyright: Hospital Times.)
New Rapid Whole Genome Sequencing Service
The NHS announced the plan following a series of trials last year. In one trial, a five-day old infant was admitted to a hospital in Cheltenham, Gloucester, with potentially deadly levels of ammonia in his blood. Whole genome sequencing revealed that changes in the CPS1 gene were preventing his body from breaking down nitrogen, which led to the spike in ammonia. He was given life-saving medication in advance of a liver transplant that doctors believed would cure the condition. Without the rapid genetic test, doctors likely would have performed an invasive liver biopsy.
Using a simple blood test, the new newborn genetic screening service in England is expected to benefit more than 1,000 critically ill infants each year, potentially saving their lives. “The rapid whole genome testing service will transform how rare genetic conditions are diagnosed,” explained Emma Baple, PhD, Professor of Genomic Medicine at University of Exeter Medical School and leader of the National Rapid Whole Genome Sequencing Service in the press release. “We know that with prompt and accurate diagnosis, conditions could be cured or better managed with the right clinical care, which would be life-altering—and potentially life-saving—for so many seriously unwell babies and children,” Precision Medicine Institute reported.
According to The Guardian, test results will be available in two to seven days.
Along with the new rWGS testing service, the NHS announced a five-year plan to implement genomic medicine more broadly. The provisions include establishment of an ethics advisory board, more training for NHS personnel, and an expansion of genomic testing within the existing NHS diagnostic infrastructure. The latter could include using NHS Community Diagnostics centers to collect blood samples from family members to test for inherited diseases.
UK’s Longtime Interest in Whole Genome Sequencing
The UK government has long been interested in the potential role of WGS for delivering better outcomes for patients with genetic diseases, The Guardian reported.
In 2013, the government launched the 100,000 Genomes Project to examine the usefulness of the technology. In November 2021, investigators with the project reported the results of a large pilot study in which they analyzed the genomes of 4,660 individuals with rare diseases. The study, published in the New England Journal of Medicine (NEJM) titled, “100,000 Genomes Pilot on Rare-Disease Diagnosis in Health Care—Preliminary Report,” found “a substantial increase in yield of genomic diagnoses made in patients with the use of genome sequencing across a broad spectrum of rare disease.”
The study’s findings suggest that use of WGS “could save the NHS millions of pounds,” The Guardian reported.
Whole Genome Sequencing System for Newborns in the US
“This NBS-rWGS [newborn screening by rapid whole genome sequencing] system is designed to complement the existing newborn screening process and has the potential to eliminate the diagnostic and therapeutic odyssey that many children and parents face,” Kingsmore said in a press release. “Currently, only 35 core genetic disorders are recommended for newborn screening in the United States, but there are more than 7,200 known genetic diseases. Outcomes remain poor for newborns with a genetic disease because of the limited number of recommended screenings. With NBS-rWGS, we can more quickly expand that number and therefore potentially improve outcomes through precision medicine.”
A more recent 2023 study which examined 112 infant deaths at Rady Children’s Hospital found that 40% of the babies had genetic diseases. In seven infants, genetic diseases were identified post-mortem, and in five of them “death might have been avoided had rapid, diagnostic WGS been performed at time of symptom onset or regional intensive care unit admission,” the authors wrote.
“Prior etiologic studies of infant mortality are generally retrospective, based on electronic health record and death certificate review, and without genome information, leading to underdiagnosis of genetic diseases,” said Christina Chambers, PhD, co-author of the study, in a press release. “In fact, prior studies show at least 30% of death certificates have inaccuracies. By implementing broad use of genome sequencing in newborns we might substantially reduce infant mortality.”
Pioneering work with whole genome sequencing for newborns, such as that being conducted by the clinical laboratory and genetic teams at Rady Children’s Hospital and the UK’s NHS, could allow doctors to make timely interventions for our most vulnerable patients.
Unlike most other CRISPR/Cas-9 therapies that are ex vivo treatments in which cells are modified outside the body, this study was successful with an in vivo treatment
Use of CRISPR-Cas9 gene editing technology for therapeutic purposes can be a boon for clinical laboratories. Not only is this application a step forward in the march toward precision medicine, but it can give clinical labs the essential role of sequencing a patient’s DNA to help the referring physician identify how CRISPR-Cas9 can be used to edit the patient’s DNA to treat specific health conditions.
Most pathologists and medical lab managers know that CRISPR-Cas9 gene editing technology has been touted as one of the most significant advances in the development of therapies for inherited genetic diseases and other conditions. Now, a pair of biotech companies have announced a milestone for CRISPR-Cas9 with early clinical data involving a treatment delivered intravenously (in vivo).
As with other therapies, determining which patients are suitable candidates for specific treatments is key to the therapy’s success. Therefore, clinical laboratories will play a critical role in identifying those patients who would most likely benefit from a CRISPR-delivered therapy.
Such is the goal of precision medicine. As methods are refined that can correct unwelcome genetic mutations in a patient, the need to do genetic testing to identify and diagnose whether a patient has a specific gene mutation associated with a specific disease will increase.
Cleveland Clinic describes ATTR amyloidosis as a “protein misfolding disorder” involving transthyretin (TTR), a protein made in the liver. The disease leads to deposits of the protein in the heart, nerves, or other organs.
According to Intellia and Regeneron, NTLA-2001 is designed to inactivate the gene that produces the protein.
The interim clinical trial data indicated that one 0.3 mg per kilogram dose of the therapy reduced serum TTR by an average of 87% at day 28. A smaller dose of 0.1 mg per kilogram reduced TTR by an average of 52%. The researchers reported “few adverse events” in the six study patients, “and those that did occur were mild in grade.”
Current treatments, the companies stated, must be administered regularly and typically reduce TTR by about 80%.
“These are the first ever clinical data suggesting that we can precisely edit target cells within the body to treat genetic disease with a single intravenous infusion of CRISPR,” said Intellia President and CEO John Leonard, MD, in a press release. “The interim results support our belief that NTLA-2001 has the potential to halt and reverse the devastating complications of ATTR amyloidosis with a single dose.”
He added that “solving the challenge of targeted delivery of CRISPR-Cas9 to the liver, as we have with NTLA-2001, also unlocks the door to treating a wide array of other genetic diseases with our modular platform, and we intend to move quickly to advance and expand our pipeline.”
In Part 2 of the Phase 1 trial, Intellia plans to evaluate the new therapy at higher doses. After the trial is complete, “the company plans to move to pivotal studies for both polyneuropathy and cardiomyopathy manifestations of ATTR amyloidosis,” the press release states.
Previous clinical trials reported results for ex vivo treatments in which cells were removed from the body, modified with CRISPR-Cas9 techniques, and then reinfused. “But to be able to edit genes directly in the body would open the door to treating a wider range of diseases,” Nature reported.
How CRISPR-Cas9 Works
On its website, CRISPR Therapeutics, a company co-founded by Emmanuelle Charpentier, PhD, a director at the Max Planck Institute for Infection Biology in Berlin, and inventor of CRISPR-Cas9 gene editing, explained that the technology “edits genes by precisely cutting DNA and then letting natural DNA repair processes take over.” It can remove fragments of DNA responsible for causing diseases, as well as repairing damaged genes or inserting new ones.
The therapies have two components: Cas9, an enzyme that cuts the DNA, and Guide RNA (gRNA), which specifies where the DNA should be cut.
Charpentier and biochemist Jennifer Doudna, PhD, Nobel Laureate, Professor of Chemistry, Professor of Biochemistry and Molecular Biology, and Li Ka Shing Chancellor’s Professor in Biomedical and Health at the University of California Berkeley, received the 2020 Nobel Prize in Chemistry for their work on CRISPR-Cas9, STAT reported.
It is important to pathologists and medical laboratory managers to understand that multiple technologies are being advanced and improved at a remarkable pace. That includes the technologies of next-generation sequencing, use of gene-editing tools like CRISPR-Cas9, and advances in artificial intelligence, machine learning, and neural networks.
At some future point, it can be expected that these technologies will be combined and integrated in a way that allows clinical laboratories to make very early and accurate diagnoses of many health conditions.
In the absence of a “gold standard,” researchers are finding a high frequency of false negatives among SARS-CoV-2 RT-PCR tests
Serology tests designed to detect antibodies to the SARS-CoV-2 coronavirus that causes the COVID-19 illness have been dogged by well-publicized questions about accuracy. However, researchers also are raising concerns about the accuracy of molecular diagnostics which claim to detect the actual presence of the coronavirus itself.
“Diagnostic tests, typically involving a nasopharyngeal swab, can be inaccurate in two ways,” said Steven Woloshin, MD, MS, in a news release announcing a new report that “examines challenges and implications of false-negative COVID-19 tests.” Woloshin is an internist, a professor at Dartmouth Institute, and co-director of the Geisel School of Medicine at Dartmouth.
“A false-positive result mistakenly labels a person infected, with consequences including unnecessary quarantine and contact tracing,” he stated in the news release. “False-negative results are far more consequential, because infected persons who might be asymptomatic may not be isolated and can infect others.”
Woloshin led a team of Dartmouth researchers who analyzed two studies from Wuhan, China, and a literature review by researchers in Europe and South America that indicated diagnostic tests for COVID-19 are frequently generating false negatives. The team published their results in the June 5 New England Journal of Medicine (NEJM).
For example, one research team in Wuhan collected samples from 213 hospitalized COVID-19 patients and found that an approved RT-PCR test produced false negatives in 11% of sputum samples, 27% of nasal samples, and 40% of throat samples. Their research was published on the medRxiv preprint server and has not been peer-reviewed.
The literature review Woloshin’s team studied was also published on medRxiv, titled, “False-Negative Results of Initial Rt-PCR Assays for COVID-19: A Systematic Review.” It indicated that the rate of false negatives could be as high as 29%. The authors of the review looked at five studies that had enrolled a total of 957 patients. “The collected evidence has several limitations, including risk of bias issues, high heterogeneity, and concerns about its applicability,” they wrote. “Nonetheless, our findings reinforce the need for repeated testing in patients with suspicion of SARS-Cov-2 infection.”
Another literature review, published in the Annals of Internal Medicine, titled, “Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction–Based SARS-CoV-2 Tests by Time Since Exposure,” estimated the probability of false negatives in RT-PCR tests at varying intervals from the time of exposure and symptom onset. For example, the authors found that the median false-negative rate was 38% if a test was performed on the day of symptom onset, versus 20% three days after onset. Their analysis was based on seven studies, five of which were peer-reviewed, with a total of 1330 test samples.
Doctors also are seeing anecdotal evidence of false negatives. For example, clinicians at UC San Diego Health medical center treated a patient with obvious symptoms of COVID-19, but two tests performed on throat samples were negative. However, a third test, using a sample from a bronchial wash, identified the virus, reported Medscape.
Sensitivity and Specificity of COVID-19 Clinical Laboratory Tests
The key measures of test accuracy are sensitivity, which refers to the ability to detect the presence of the virus, and specificity, the ability to determine that the targeted pathogen is not present. “So, a sensitive test is less likely to provide a false-negative result and a specific test is less likely to provide a false-positive result,” wrote Kirsten Meek, PhD, medical writer and editor, in an article for ARUP Laboratories.
“Analytic” sensitivity and specificity “represent the accuracy of a test under ideal conditions in which specimens have been collected from patients with either high viral loads or a complete absence of exposure,” she wrote. However, “sensitivity and specificity under real-world conditions, in which patients are more variable and specimen collection may not be ideal, can often be lower than reported numbers.”
In a statement defending its ID Now molecular point-of-care test, which came under scrutiny during a study of COVID-19 molecular tests by NYU Langone Health, Northwell Health, and Cleveland Clinic, according to MedTech Dive, Abbott Laboratories blamed improper sample collection and handling for highly-publicized false negatives produced by its rapid test. An FDA issued alert about the test on May 14 noted that Abbott had agreed to conduct post-market studies to identify the cause of the false negatives and suggest remedial actions.
Issues with Emergency Use Authorizations
In their NEJM analysis, Woloshin et al point to issues with the FDA’s process for issuing Emergency Use Authorizations (EUAs). For example, they noted variations in how manufacturers are conducting clinical evaluations to determine test performance. “The FDA prefers the use of ‘natural clinical specimens’ but has permitted the use of ‘contrived specimens’ produced by adding viral RNA or inactivated virus to leftover clinical material,” they wrote.
When evaluating clinical performance, manufacturers ordinarily conduct an index test of patients and compare the results with reference-standard test, according to the Dartmouth researchers. For people showing symptoms, the reference standard should be a clinical diagnosis performed by an independent adjudication panel. However, they wrote, “it is unclear whether the sensitivity of any FDA-authorized commercial test has been assessed in this way.” Additionally, a reference standard for determining sensitivity in asymptomatic people “is an unsolved problem that needs urgent attention to increase confidence in test results for contact-tracing or screening purposes.”
Continued adherence to current measures, such as physical distancing and surface disinfection.
Development of highly sensitive and specific tests or combinations of tests to minimize the risk of false-negative results and ongoing transmission based on a false sense of security.
Improved RT-PCR tests and serological assays.
Development and communication of clear risk-stratified protocols for management of negative COVID-19 test results.
“These protocols must evolve as diagnostic test, transmission, and outcome statistics become more available,” they wrote.
Meanwhile, clinical laboratories remain somewhat on their own at selecting which COVID-19 molecular and serology tests they want to purchase and run in their labs. Complicating such decisions is the fact that many of the nation’s most reputable in vitro diagnostics manufacturers cannot produce enough of their COVID-19 tests to meet demand.
Consequently, when looking to purchase tests for SARS-CoV-2, smaller medical laboratory organizations find themselves evaluating COVID-19 kits developed by little-known or even brand-new companies.
‘Aerosol and Surface Stability’ study shows that the virus can remain infectious in aerosol form for hours and on surfaces for days
By now, clinical laboratory workers, microbiologists, and phlebotomists should be fully aware of the potential for transmission on surfaces of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the novel coronavirus that causes Coronavirus disease 2019 (COVID-19). The CDC’s latest Morbidity and Mortality Weekly Report revealed that the coronavirus “was identified on a variety of surfaces in cabins of both symptomatic and asymptomatic infected passengers up to 17 days after cabins were vacated on the Diamond Princess, but before disinfection procedures had been conducted,” the New York Post reported. That means the virus can survive on surfaces significantly longer than CDC previously believed.
But did you know a recent study published in the New England Journal of Medicine (NEJM) found that SARS-CoV-2 can also survive in the air for many hours, potentially allowing aerosolized transmission of the virus as well?
The NEJM study also showed that the stability of SARS-CoV-2 to survive on surfaces and in aerosolized form mirrors the stability of the SARS coronavirus (SARS-CoV) that caused the severe acute respiratory syndrome (SARS) outbreak of 2003.
This is critically important information for clinical laboratory professionals in open-space laboratories, phlebotomists collecting medical laboratory specimens, and frontline healthcare workers who come in direct contact with potentially infected patients. They should be aware of every potential COVID-19 transmission pathway.
Hospital infection control teams will be particularly
interested in the possibility of airborne transmission, as they often visit
infected patients and are tasked with tracking both the source of the infection
as well as individuals who may be exposed to sick patients.
The NEJM study, titled “Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1” was conducted by scientists at the National Institute of Allergy and Infectious Diseases (NIAID), an agency of the US Department of Health and Human Services (HHS), the Centers for Disease Control and Prevention (CDC), Princeton University, and University of California, Los Angeles. The researchers concluded that SARS-CoV-2 remains in the air “up to three hours post aerosolization.”
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They also found the virus was detectable for up to four
hours on copper and up to 24 hours on cardboard. The scientists concluded SARS-CoV-2
can remain on plastic and stainless-steel surfaces for two to three days,
though the amount of the virus on surfaces decreases over time.
“Our results indicate that aerosol and fomite transmission of SARS-CoV-2 is plausible, since the virus can remain viable and infectious in aerosols for hours and on surfaces up to days,” the study states. “These findings echo those with SARS-CoV-1, in which these forms of transmission were associated with nosocomial spread and super-spreading events, and they provide information for pandemic mitigation efforts.”
But Can COVID-19 Be Caught Through Air?
However, as noted in Wired, the researchers did not clearly state that infected persons can spread COVID-19 to others in the same airspace. Some experts have pointed out that there is a difference between a virus that can exist as an aerosol—defined as a liquid or solid suspended in gas under only limited conditions—and the measles virus, for example, which the CDC estimates “can live for up two hours in an airspace where the infected person has coughed or sneezed.”
“While the researchers tested how long the virus can survive
in aerosols suspended in the air, they didn’t actually sample the air around
infected people,” Wired noted. “Instead, they put the virus into a
nebulizer and puffed it into a rotating drum to keep it airborne. Then, they
tested how long the virus could survive in the air inside the drum.”
Neeltje van Doremalen, PhD, a research fellow at National Institutes of Health (NIH) and researcher at the NIAID’s Rocky Mountain Laboratories in Hamilton, Montana, who coauthored the NEJM study, cautioned against an overreaction to this latest research. On Twitter she wrote, “Important: we experimentally generated [COVID-19] aerosols and kept them afloat in a drum. This is not evidence of aerosol transmission.”
Nonetheless, the World House Organization (WHO) took note of the study’s findings and on March 16, 2020, announced it was considering “airborne precautions” for healthcare workers, CNBC reported in its coverage of a virtual press conference on March 16, 2020, led by Maria Van Kerkhove, MS, PhD, Technical Lead for WHO’s Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Task Force.
Van Kerkhove emphasized that health officials were
monitoring results from other studies investigating how environmental
conditions such as humidity, temperature, and ultraviolet light affect
the disease and its ability to live on different surfaces.
To Be or Not to Be an Airborne Pathogen
Stanley Perlman, MD, PhD, Professor of Microbiology and Immunology at the University of Iowa, believes aerosol transmission ultimately will be found not to play a large role in COVID-19 transmission.
“I think the answer will be, aerosolization occurs rarely, but not never,” Perlman told STAT. “You have to distinguish between what’s possible and what’s actually happening.”
In an NEJM editorial, Perlman expanded on those thoughts. “Although specific anti-coronaviral therapies are still in development, we now know much more about how to control such infections in the community and hospitals, which should alleviate some of this fear,” he wrote. “Transmission of [SARS-CoV-2] probably occurs by means of large droplets and contact and less so by means of aerosols and fomites, on the basis of our experience with SARS-CoV and MERS-CoV. Public health measures, including quarantining in the community as well as timely diagnosis and strict adherence to universal precautions in healthcare settings, were critical in controlling SARS and MERS. Institution of similar measures will be important and, it is hoped, successful in reducing the transmission of [SARS-CoV-2].”
An NIH news release announcing the SARS-CoV-2 stability study highlighted two additional observations:
“If the viability of the two coronaviruses is
similar, why is SARS-CoV-2 resulting in more cases? Emerging evidence suggest
that people infected with SARS-CoV-2 might be spreading virus without
recognizing, or prior to recognizing, symptoms. That would make disease control
measures that were effective against SARS-CoV-1 less effective against its
successor.
In contrast to SARS-CoV-1, most secondary cases
of virus transmission of SARS-CoV-2 appear to be occurring in community
settings rather than healthcare settings. However, healthcare settings are also
vulnerable to the introduction and spread of SARS-CoV-2, and the stability of
SARS-CoV-2 in aerosols and on surfaces likely contributes to transmission of
the virus in healthcare settings.”
Clearly, the scientific community has not agreed on
aerosolization as a definite source of infection. Nevertheless, clinical
laboratory workers in settings where potential exposure to SARS-CoV-2 exists
should take precautions against airborne transmission until scientists can
definitively determine whether this latest coronavirus can be acquired through
the airborne transmission.