Thursday, July 23, 2020

Hospital Air Shows Heavy Presence of SARS-Cov-2

Co-written by: Dr. Robert L. Bard / Research & Edits by: Lennard M. Gettz

August 13, 2020 - Recent headlines show evidence of Coronavirus pathogens in hospital air supply and air passageways- creating a systemic hazard for the staff and patients under critical care. Substantial controversy about the role played by SARS-CoV-2 in aerosols in disease transmission, due in part to detections of viral RNA but failures to isolate viable virus from clinically generated aerosols[1]. 

Excerpt of active study Abstract (posted 8/4) held by Dr. John Lednicky and research team from the University of Florida: "Air samples were collected in the room of two COVID-19 patients, one of whom had an active respiratory infection with a nasopharyngeal (NP) swab positive for SARS-CoV-2 by RT-qPCR. By using VIVAS air samplers that operate on a gentle water-vapor condensation principle, material was collected from room air and subjected to RT-qPCR and virus culture. The genomes of the SARS-CoV-2 collected from the air and of virus isolated in cell culture from air sampling and from a NP swab from a newly admitted patient in the room were sequenced. Findings - Viable virus was isolated from air samples collected 2 to 4.8m away from the patients. ... Those with respiratory manifestations of COVID-19 produce aerosols in the absence of aerosol-generating procedures that contain viable SARS-CoV-2, and these aerosols may serve as a source of transmission of the virus".

Similar studies have been conducted in prior months to support this theory of airborne pathogens in urgent care centers, including one from February 19 through March 2, 2020 by the CDC. A study was performed in a small sample from regions with few confirmed cases (which might not reflect real conditions in outbreak regions where hospitals are operating at full capacity). In this study, CDC officials tested intensive care units (ICU) and a general COVID-19 wards (GW) at Huoshenshan Hospital in Wuhan, China.  "Air and Surface samples were tested to determine distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards. Contamination was greater in intensive care units than general wards. Virus was widely distributed on floors, computer mice, trash cans, and sickbed handrails and was detected in air ≈4 m from patients. [3]

As of March 30, 2020, approximately 750,000 cases of coronavirus disease (COVID-19) had been reported globally since December 2019 (1), severely burdening the healthcare system (2). The extremely fast transmission capability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has aroused concern about its various transmission routes. This study led to 3 conclusions. First, SARS-CoV-2 was widely distributed in the air and on object surfaces in both the ICU and GW, implying a potentially high infection risk for medical staff and other close contacts. Second, the environmental contamination was greater in the ICU than in the GW; thus, stricter protective measures should be taken by medical staff working in the ICU. Third, the SARS-CoV-2 aerosol distribution characteristics in the ICU indicate that the transmission distance of SARS-CoV-2 might be 4 m. [3]

Initiatives are in full swing from health departments and hospital safety leaders to advance sanitization measures and decontamination initiatives in hospitals. Agencies indicate that without adequate environmental controls, patients with airborne infectious disases will pose a risk to other patients and healthcare workers. Heating, Ventilation and Air Conditioning (HVAC)  expertise is essential for proper environmental management when planning control of airborne infectious disease outbreaks.   This may include frequent inspection and upgrades of air filtration systems- such as HEPA Filtering and proper discharging of air to the outside (by creating negative room pressure in patient rooms and airflow management). Other initiatives like stepping up hospital safety inspections and advancing disinfecting, and sanitizing measures to include more current technologies like UV-C light disinfection.




HEPA FILTERS (Source: EPA.gov)
HEPA is a type of pleated mechanical air filter. It is an acronym for "high efficiency particulate air [filter]" (as officially defined by the U.S. Dept. of Energy).  This type of air filter can theoretically remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns (µm). The diameter specification of 0.3 microns responds to the worst case; the most penetrating particle size (MPPS). Particles that are larger or smaller are trapped with even higher efficiency. Using the worst case particle size results in the worst case efficiency rating (i.e. 99.97% or better for all particle sizes).

MERV RATING
Minimum Efficiency Reporting Values, or MERVs, report a filter's ability to capture larger particles between 0.3 and 10 microns (µm).
  • This value is helpful in comparing the performance of different filters
  • The rating is derived from a test method developed by the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) [see www.ashrae.org].
  • The higher the MERV rating the better the filter is at trapping specific types of particles.
  • See complete rating chart from 1-16
Consider using portable air cleaners to supplement increased HVAC system ventilation and filtration. Directing the airflow so that it does not blow directly from one person to another reduces the potential spread of droplets that may contain infectious viruses. Air cleaning may be useful when used along with source control and ventilation, but it is not a substitute for either method. Source control involves removing or decreasing pollutants such as smoke, formaldehye or particles with viruses. The use of air cleaners alone cannot ensure adequate air quality, particularly where significant pollutant sources are present and ventilation is insufficient. See ASHRAE and CDC for more information on air cleaning and filtration and other important engineering controls. [6]


FROM THE MEDICAL FIELD
By: Megan Meller, MS, MPH

I can’t recommend a specific product but want to emphasize the importance of building HVAC systems and the number of air exchanges that take place in a room. Below I’ve included a table that summarizes guidelines from the CDC for air exchanges in various healthcare settings.


When COVID-19 made it’s presence known, we worked closely with our Facility Operations department to ensure that our exam rooms and hospital rooms were meeting these requirements. In some cases, adjusts were needed and were made. We do use HEPA filters throughout our organization which is a fairly standard technology in healthcare. We do use portable filters but only in select departments (e.g. Oncology) and have not added more for COVID-19. HEPA filters in theory are able to capture coronavirus particles but we don’t know how practical this is and I would not rely solely on this to prevent infection. Afterall, COVID-19 spread appears to be primarily occurring via droplets.   It is much easier to maintain centralized units than individual ones. In addition to shoring up our ventilation systems for COVID, we also implemented physical barriers to protect our patients and staff against COVID including: dedicated negative pressure hospital units, respirators, and organizational wide face masking requirements. The key that I want to stress here is the emphasis on ventilation rather than filtration as complementary to other measures such as social distancing and masking.


References: 
1) Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients
2) Study finds evidence of COVID-19 in air, on hospital surfaces
3) Aerosol and Surface Distribution of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospital Wards, Wuhan, China, 2020 https://wwwnc.cdc.gov/eid/article/26/7/20-0885_article
4) Minesotta Dept of Health (Airborne Infectious Disease Management): 








UV-C AIR SANITIZING INSTALLED IN HVAC SYSTEMS
In 2006, the U.S. Environmental Protection Agency approved a test plan for Biological Inactivation Efficiency by HVAC In-Duct Ultraviolet Light Air Cleaners. (1) The tests were conducted using three organisms, two bacteria (Bacillus atrophaeus and Serratia marcescens) and one bacterial virus (MS2).  These organisms were selected because their sizes, shapes and susceptibility to UV inactivation make them reasonable surrogates for biological warfare agents (BWAs). Generally, vegetative bacteria are readily killed and bacterial spores are more difficult. To model use in a VAC system, RTI used a test duct designed for testing filtration and inactivation efficiencies of aerosol, bioaerosol, and chemical challenges.  The bioaerosol inactivation efficiencies calculated for the three organisms were 9% for B. atrophaeus, 99.96% for S. marcescens and 75% for MS2. The irradiance was measured as 1190 W/cm2 at 161 cm(63 in.) upstream from the lamps with an airflow of 0.93 m3/sec (1970 cfm). The system had four lamps that were burned in for 100 hours prior to measurements.

Due to the recent pandemic, companies developing this technology are (now) on the fast track to advance UVC installations for a wide range of professional and commercial environments.  Specific testing is currently underway as to the efficacy against SARS-CoV-2 (the virus that causes COVID-19) but historically, systems like those developed by Fresh-Aire UV have been tested and proven effective against pathogens that require even greater UVC dosages.  "Every microorganism requires a specific UVC dosage for inactivation including the novel coronavirus. UV disinfection has been employed for decades in water treatment; these microwatt values have been used for reference to gauge UVC efficiency against a large cross-section of microorganisms. UV disinfection systems for room, surface & HVAC are (also) an ideal proactive measure to complement filtration", stated Aaron Engel, VP of Business Development at Fresh-Aire UV.

UV lamps have been used to inactivate airborne microorganisms for many years. Much of the early work was directed at the control of very infectious microorganisms (particularly Mycobacterium tuberculosis, the causative agent of tuberculosis), often in medical facilities. Wavelengths within the short wave, or C band of UV light (UVC), were found to be the most effective germicidal light wavelengths. UVC usually is generated by use of UVC fluorescent lamps. These lamps use electrical discharge through low-pressure mercury vapor enclosed in a glass tube that transmits UVC light (primarily at the mercury wavelength of 253.7 nm). Because this wavelength has been found to be about the optimum for killing microorganisms, UVC from mercury lamps also is referred to as UVG to indicate that it is germicidal. UVG has been shown to inactivate viruses, mycoplasma, bacteria, and fungi when used appropriately.


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HISTORY
Niels Ryberg Finsen (1860-1904) was the first to employ UV rays in treating disease. He was awarded the Nobel Prize for Medicine in 1903 for his invention of the Finsen curative lamp, which was used successfully through the 1950s. [01]  Updates in the technology for commercial use evolved as UV-C germicidal lamps in the 1930's and have been primarily used in healthcare facilities. UVGI is highly recognized for addressing airborne microbial disease prevention (including influenza and tuberculosis). UVC is proven to prevent airborne transmission by deactivating airborne pathogens, but public use has been curtailed due to its potential to cause cancers and cataracts upon direct contact. [02]

The history of UVGI air disinfection has been one of promise, disappointment, and rebirth. Investigations of the bactericidal effect of sunlight in the late 19th century planted the seed of air disinfection by UV radiation. First to nurture this seed was Richard L. Riley and his mentor William F. Wells, who both discovered the spread of airborne infection by droplet nuclei and demonstrated the ability of UVGI to prevent such spread. With the enduring research of Riley and others, and an increase in tuberculosis (TB) during the 1980s, interest in UVGI was revitalized. With modern concerns regarding multi- and extensive drug-resistant TB, bioterrorism, influenza pandemics, and severe acute respiratory syndrome, interest in UVGI continues to grow. Research is ongoing, and there is much evidence on the efficacy of UVGI and the proper way to use it, though the technology has yet to fully mature.  [3]

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Epilogue: Straight Answers from the CDC
In our commitment to publish helpful information about innovative solutions, we rely on top health  authorities to provide us with unbiased clarity and technical standards. We inquired about how UV-C Disinfecting technology truly ranked as the future solution to defeating viruses and transmitted diseases. Steve Martin, PhD, an engineer in NIOSH’s Respiratory Health Division provided us with these valuable statements:

Q: Does the CDC see UV-C Disinfecting as the next trend- evolving from chemical spray sanitizing?
A: No.  CDC understands that germicidal UV technologies, including patient room terminal cleaning devices (sometimes called UV robots), can provide enhanced surface disinfection over the use of chemical disinfectants alone. However, UV technologies, as they currently exist, will never replace manual chemical cleaning in healthcare spaces.  While UV can be very efficient at inactivating pathogens on surfaces, UV-C energy cannot substantially penetrate blood and other bodily fluids, or through other simple spills and splashes that occur in the course of patient care, even those that have dried and left residues. Thus, healthcare surfaces need to first be thoroughly cleaned to remove gross contamination before the UV energy can directly impact the surfaces and provide the most disinfection benefit. Then, UV systems that are properly applied can effectively inactivate many of the pathogens that manual cleaning may have left behind.

Q: From an original post on 2016, CDC warned about potential OZONE output from UV.  It has been evident that companies have since been addressing the testing, preventing and validating of ozone output.  Does CDC have enough data on this upgrade?
A: Concerns about UV lamps producing ozone have existed for decades and there have not been any significant “upgrades” since 2016.  There are some UV-C lamps designed specifically to produce ozone.  Ozone-producing lamps generally do not use an internal coating on the glass (or quartz) tube so UV energy at wavelengths below 200 nm (predominantly 185 nm) is emitted from the lamp. These wavelengths are responsible for ozone production.  There is a separate group of UV-C lamps designed specifically not to produce ozone.  This group is the low-pressure mercury vapor lamps used for germicidal ultraviolet (GUV) applications.  GUV lamps have interior coatings to block UV energy at wavelengths below 200 nm from escaping the tube, so ozone is not created. Unfortunately, ozone-producing lamps and GUV lamps of the same type and size can often be powered using the same electrical connectors and electronic drivers (ballasts).  So, it is critical for the end user to choose the proper lamp for their application.  If they choose a typical GUV lamp for a germicidal application, then ozone is not a concern.  If an end user unknowingly chooses an ozone-producing lamp that happens to fit properly into their GUV device, then ozone exposures will happen. CDC always recommends that end users communicate with the UV device manufacturer or a reputable UV system designer when purchasing replacement UV lamps.

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CONTRIBUTORS

ROBERT L. BARD, MD, PC, DABR, FASLMS
Advanced Imaging & Diagnostic Specialist
Dr. Bard received the 2020 nationally acclaimed Ellis Island Award for his lifetime achievement in advanced cancer diagnostic imaging. He co-founded the 9/11 CancerScan program to bring additional diagnostic support to all first responders from Ground Zero. His main practice in midtown, NYC (Bard Diagnostic Imaging- www.CancerScan.com) uses the latest in digital imaging technology and has been also used to help guide biopsies and in many cases, even replicate much of the same reports of a clinical invasive biopsy. Imaging solutions such as high-powered sonograms, Power Doppler Histogram, sonofluoroscopy, 3D/4D image reconstruction and the Power Doppler Histogram  are safe, noninvasive, and do not use ionizing radiation. 

MEGAN MELLER, MS, MPH is an Infection Preventionist with Gundersen Health System based in La Crosse, Wisconsin. From a young age, Megan has been passionate about science and the world of infectious diseases. Megan received her Master of Science in Microbiology at Indiana University-Bloomington where she studied alphavirus replication and her Master of Public Health (MPH) from the University of Wisconsin School of Medicine and Public Health. While working on her MPH, Megan worked closely with Infection Control departments and the communicable disease section at the Wisconsin Department of Health Services. In her current role, Megan is the lead Infection Preventionist for Gundersen’s outpatient departments and works closely with infection control partners located at regional hospitals. Megan is also a media consultant for the Infection Control and Infectious Disease departments and serves as an infection control consultant for numerous organizational groups.  


PIERRE KORY, M.D., M.P.A.
Dr. Kory is Board Certified in Internal Medicine, Critical Care, and Pulmonary Medicine. He served as the Medical Director of the Trauma and Life Support Center at the University of Wisconsin where he was an Associate Professor and the Chief of the Critical Care Service. He is considered a pioneer and national/international expert in the field of Critical Care Ultrasound and is the senior editor of the widely read textbook “Point-of-Care Ultrasound” (winner of the President’s Choice Award for Medical Textbooks from the British Medical Association in 2015).  Most recently, Dr. Kory joined the emergency volunteer team during the early COVID-19 pandemic in NYC at Mount Sinai Beth Israel Medical Center. He is also a founding member of the Front Line COVID-19 Critical Working Group (flccc.net) composed of 5 critical care experts that devised the COVID-19 treatment protocol called MATH+. (www.covid19criticalcare.com/)

AARON ENGEL
Mr Engel is Vice-President of Business Development for Fresh-Aire UV, a global leader in UV disinfection technologies. Aaron has 20 years experience in the design, manufacturing and marketing of UV disinfection systems for domestic and international applications including those for residential, commercial and healthcare. Aaron has worked on projects with various groups & associations including the definitive study on UV inactivation of airborne bioterrorism agents sponsored by RTI, the United States EPA & US National Homeland Security. Aaron is frequent guest speaker and lecturer and contributes to publications on IAQ technologies and UV disinfection. Aaron is a member on various ASHRAE committees including TC2.9 Ultraviolet Air and Surface Treatment and the Programs Chair for TC2.9.  www.freshaireuv.com



2) Disinfection and Sterilization Guideline for Disinfection and Sterilization in Healthcare Facilities (2008)
3) US National Library of Medicine National Institutes of Health: The History of Ultraviolet Germicidal Irradiation for Air Disinfection  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2789813/
4) Far-UVC light: A new tool to control the spread of airborne-mediated microbial diseases

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