National Nurses United Response To COVID-19

What is known: It is a coronavirus, which is a large family of viruses that can infect animals and/or humans. COVID-19 is similar to the viruses that cause SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome). 

What is known: Several published reports have established a basic picture of clinical symptoms and outcomes for those infected with COVID-19. These symptoms can include fever, cough, muscle soreness, weakness, diarrhea, headache, and other symptoms. While some symptoms appear to be common, there is also diversity in how COVID-19 manifests (Table 1).

Several additional reports underline the potential seriousness of a COVID-19 infection, including damage to lung tissue that has become characteristic to COVID-19. Shi et al. (Feb 24, 2020) describe this damage:

“COVID-19 pneumonia manifests with chest CT imaging abnormalities, even in asymptomatic patients, with rapid evolution from focal unilateral to diffuse bilateral ground-glass opacities that progressed or co-existed with consolidations within 1-3 weeks.”[4]

The Chinese Centers for Disease Control and Prevention (Chinese CDC) reported recently that approximately 20% of COVID-19 cases are classified as severe or critical.[5] COVID-19 infections may result in life-threatening conditions including acute respiratory distress syndrome, acute kidney injury, cardiac injury, and liver dysfunction (Table 2) and may require hospitalization, intensive care, intubation, or other significant life-saving interventions. In some cases COVID-19 may lead to death; the Chinese CDC reported that 2.3% of confirmed COVID-19 cases died.[6] The World Health Organization’s reports indicate that 3.4% of reported cases have died.[7] There is currently no cure, only supportive treatment, and no vaccine.

What is known: The virus is spread through human to human transmission. Asymptomatic cases are occurring and can be infectious. Two studies indicate that the most infectious period may actually be the first four days or so after exposure. Researchers found very high levels of the virus in upper respiratory tract samples before clinical symptoms occurred.[1,2]

What is unknown: All modes of transmission for COVID-19 have yet to be established.

However, current epidemiological evidence supports aerosol transmission of COVID-19. Aerosols, particles suspended in air, can be transmitted by an infected person through breathing, talking, coughing, and sneezing.[3] They can also be generated during medical procedures such as intubation and bronchoscopy. Particles vary in size; larger aerosol particles can remain suspended in the air for several minutes, while smaller or lighter ones can linger in the air for hours and travel through the room and ventilation systems. Perfume spray demonstrates the extent of aerosol distribution as it can be smelled from a distance for quite some time as the particles disperse throughout the room.

Similar to SARS (severe acute respiratory syndrome), researchers have found that SARS-CoV-2, the virus that causes COVID-19, can survive and stay infectious in aerosols for at least 3 hours.[4] SARS-CoV-2 can also survive on surfaces for an extended period of time. For example, genetic material from SARS-CoV-2 was detected on a number of surfaces in the Diamond Princess cruise cabins of both symptomatic and asymptomatic infected passengers 17 days after they vacated.[5] Asymptomatic virus shedding and viability in the air and on surfaces may explain the rapid person-to-person transmission. As such, all contact and airborne precautions must be maintained to protect healthcare workers.

[1] Woelfel, Roman et al. Clinical Presentation and Virological Assessment of Hospitalized Cases Of Coronavirus Disease 2019 In A Travel-Associated Transmission Cluster. MedRxiv, Cold Spring Harbor Laboratory Press, 2020. https://doi.org/10.1101/2020.03.05.20030502

[2] Nishiura, Hiroshi, et al. Serial Interval of Novel Coronavirus (COVID-19) Infections. International Journal of Infectious Diseases, Elsevier, 2020. https://doi.org/10.1016/j.ijid.2020.02.060

[3] Jones, R.M. and L.M. Brosseau, Aerosol transmission of infectious disease. Journal of Occupational and Environmental Medicine, 2015. 57(5): p. 501-8.

[4] N van Doremalen, et al. Aerosol and surface stability of HCoV-19 (SARS-CoV-2) compared to SARS-CoV-1. The New England Journal of Medicine, 2020. DOI: 10.1056/NEJMc2004973.

[5] Moriarty, et al. Public Health Responses to COVID-19 Outbreaks on Cruise Ships — Worldwide, February–March 2020. MMWR Morb Mortal Wkly Rep. DOI: http://dx.doi.org/10.15585/mmwr.mm6912e3

The situation is evolving rapidly. Please see the links below for the most up-to-date information.

World Health Organization (WHO)’s Dashboard
https://experience.arcgis.com/experience/685d0ace521648f8a5beeeee1b9125cd

Airborne precautions are needed for COVID-19.

Bourouiba, Lydia, “Turbulent Gas Clouds and Respiratory Pathogen Emissions: Potential Implications for Reducing Transmission of COVID-19,” JAMA, March 26, 2020, https://jamanetwork.com/journals/jama/fullarticle/2763852.

Summary:

• This paper reported on what is known about disease transmission via respiratory droplets created by human exhalations, sneezes, and coughs.

• Droplet transmission was originally defined in 1897, large and small droplets defined in 1930s. This model of infectious disease transmission hasn’t been updated since. And yet, the CDC and WHO maintain use of this paradigm despite more recent research.

• More recent research over the past few decades performed with instrumentation that better measures particle sizes and movement has determined that human exhalations, coughs, and sneezes (the things that supposedly create large droplets under old model) are actually made of multiphase turbulent gas clouds (a puff) that entrains ambient air and traps and carries clusters of particles of a wide range of sizes.

• This includes viral particles in people who are sick.

• Pathogen-carrying gas clouds emitted when people breath, cough, and sneeze can travel up to 23-27 feet.
   

Patients infected with SARS-CoV-2 produce viral particles that can be aerosolized when they breath, cough, sneeze, etc.

Wolfel, Roman, et al., “Virological assessment of hospitalized patients with COVID-2019,” Nature, April 1, 2020, published online at https://www.nature.com/articles/s41586-020-2196-x.

Summary:

• This study examined viral loads and isolates for patients hospitalized with COVID-19. The majority of patients in this study presented with upper respiratory tract symptoms. Viral loads from upper respiratory tract samples were extremely high (more than 1000 times higher than SARS). Live virus was isolated from upper respiratory tract tissues.

• Michael Osterholm, PhD, MPH, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, said, “The findings [of this study] confirm that COVID-19 is spread simply through breathing, even without coughing… They also challenge the idea that contact with contaminated surfaces is a primary means of spread,” (emphasis added). http://www.cidrap.umn.edu/news-perspective/2020/03/study-highlights-ease-spread-covid-19-viruses.
   

Leung, Nancy H. L. et al. “ Respiratory virus shedding in exhaled breath and efficacy of face masks,” Nature Medicine, April 3, 2020, https://www.nature.com/articles/s41591-020-0843-2

Summary:

• This study examined viral presence and load in exhaled breath of patients with lab-confirmed influenza, seasonal coronaviruses, or rhinovirus.

• Found viral presence in exhaled breath, even without cough, for all types of viruses in both droplet (>5 micron) and aerosol (<5 micron) particles.

SARS-CoV-2 virus can survive in the environment, including in the air.

Doremalen et al., “Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1,” New England Journal of Medicine, April 16, 2020, https://www.nejm.org/doi/full/10.1056/NEJMc2004973?query=featured_home.

Summary:

• This study examined how long SARS-CoV-2 can survive in aerosols suspended in the air and on surfaces of different types (metal, plastic, cardboard).

• They found that SARS-CoV-2 can survive up to three hours in aerosols, four hours on copper, 24 hours on cardboard, 2-3 days on plastic and stainless steel.

• The authors conclude, “Our results indicate that aerosol and fomite transmission of [SARs-CoV-2] is plausible, as the virus can remain viable in aerosols for multiple hours and on surfaces up to days.” This study was conducted by NIH and CDC scientists in addition to UCLA and Princeton.
   

Chin, Alex W H et al. “Stability of SARS-CoV-2 in different environmental conditions,” The Lancet Microbe, April 2, 2020, https://www.sciencedirect.com/science/article/pii/S2666524720300033?via%3Dihub.

Summary:

• This study examined the ability of SARS-CoV-2 to survive outside the human body in different environmental conditions.

• They found that SARS-CoV-2 can survive outside the human body for up to 14 days at 39 degrees Fahrenheit, 7 days at 72 degrees Fahrenheit and remains infectious in both situations.

• They found that SARS-CoV-2 can survive on different surfaces:

  • Printing and tissue papers- up to 3 hours

  • Wood and cloth- up to 2 days

  • Glass and banknote- up to 4 days

  • Stainless steel and plastic- up to 7 days

  • Surgical mask- detectable level of infectious virus found after 7 days on outer layer of mask

• They also tested the impact of different disinfectants, used at working concentrations, to successfully inactivate SARS-CoV-2:

  • Household bleach (1:49)

  • Household bleach (1:99)

  • Ethanol (70%)

  • Povidone-iodine (7.5%)

  • Chloroxylenol (0.05%)

  • Chlorhexidine (0.05%)

  • Benzalkonium chloride (0.1%)

Fears, Alyssa C. et al. “Comparative dynamic aerosol efficiencies of three emergent coronaviruses and the unusual persistence of SARS-CoV-2 in aerosol suspensions,” medxRiv, April 18, 2020, https://www.medrxiv.org/content/10.1101/2020.04.13.20063784v1

Summary:

• This study looked at the viability of SARS-CoV-2 in suspended aerosols and found that SARS-CoV-2 remained infectious after 16 hours suspended in aerosols. This further reinforces airborne/aerosol transmission of SARS-2.

• The authors state: “Our approach of quantitative measurement of infectivity of viral airborne efficiency complemented by qualitative assessment of virion morphology leads us to conclude that SARS-CoV-2 is viable as an airborne pathogen.”
   

Environmental contamination

Guo, Zhen-Dong et al., “Aerosol and Surface Distribution of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospital Wards, Wuhan, China, 2020,” Emerging Infectious Diseases, April 10, https://wwwnc.cdc.gov/eid/article/26/7/20-0885_article.

Summary:

• This study looked at environmental contamination in an ICU and a general ward in hospital in China where patients with COVID-19 were placed.

• They found SARS-CoV-2 on many surfaces in patient rooms and on units, including doorknobs, bedrails, patient masks, computer mouse, keyboards, etc.

• Many positive results on floors not just in patient room but throughout the unit. 50% of the samples from the soles of healthcare workers’ shoes were positive.

• They also measured SARS-CoV-2 in air samples and found several air samples positive in addition to finding that the samples from the air outlets were positive for virus.

• Underlines nurses’ need for PPE!
   

Santarpia, Joshua L et al., “Transmission Potential of SARS-CoV-2 in Viral Shedding Observed at the University of Nebraska Medical Center,” medRxiv (pre-print), March 26, 2020, https://www.medrxiv.org/content/10.1101/2020.03.23.20039446v2.

Summary:

• This study looked at the presence of virus in air samples taken in patient rooms in addition to environmental samples.

• SARS-CoV-2 was found in a majority of air samples taken at greater than 6 ft from patient.

• SARS-CoV-2 was found in a majority of hallway air samples.

• SARS-CoV-2 was found in the air samplers worn by sampling personnel even when the patients did not cough.
   

Chia, Po Ying et al. “ Detection of Air and Surface Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospital Rooms of Infected Patients” medRxiv April 9, 2020, https://www.medrxiv.org/content/10.1101/2020.03.29.20046557v1.full.pdf

Summary:

• This study examined surface and air contamination in airborne infection isolation rooms of patients with confirmed COVID-19 infections in Singapore.

• They found that 56.7% of the rooms had at least one environmental surface contaminated, with 18.5% of the toilet seats and toilet flush button being contaminated.

• High touch surface contamination was shown in ten (66.7%) out of 15 patients in the first week of illness, and three (20%) beyond the first week of illness (p = 0.010).

• Air sampling of two COVID-19 patients (both day 5 of symptoms) detected SARS-CoV-2 PCR positive particles of sizes >4 µm and 1-4 µm. In a single subject at day 9 of symptoms, no SARS-CoV-2 PCR-positive particles were detected.
   

Protective PPE, including at minimum N95 respirators, gowns/coveralls, eye protection, and gloves, is important to protect nurses and other healthcare workers from exposure to SARS-CoV-2.

Cheng, C.C. et al., (March 5, 2020), “Escalating infection control response to the rapidly evolving epidemiology of the Coronavirus disease 2019 (COVID-19) due to SARS-CoV-2 in Hong Kong.” Infection Control and Hospital Epidemiology, March 2020, p 1-24 https://www.cambridge.org/core/journals/infection-control-and-hospital-epidemiology/article/escalating-infection-control-response-to-the-rapidly-evolving-epidemiology-of-the-coronavirus-disease-2019-covid19-due-to-sarscov2-in-hong-kong/52513ACC56587859F9C601DC747EB6EC

Summary:

• Hong Kong has more effectively contained the outbreak of COVID-19 than many other countries. This study reports a description of infection control measures adopted during response to COVID-19 in Hong Kong.

• 42 of 1275 patients evaluated were identified as having COVID-19 in first 42 days of the outbreak.

• 11 of 413 (2.7%) healthcare workers caring for these patients had unprotected exposure requiring a 14-day quarantine.

• No healthcare workers were infected, no nosocomial transmission observed. Environmental surveillance of viral particles conducted- in breathing zone of patient, wipe samples from surfaces in patient rooms.

• Infection control measures implemented include:

  • 36 patients immediately isolated upon admission in AIIRs, 6 in non-AIIR

  • Standard, contact, droplets, and airborne precautions for suspected or confirmed cases

  • Stepped up use of PPE during aerosol generating procedures

  • Surgical masks worn by all HCWs, patients, and visitors in clinical areas implemented since day 5

  • Promotion of hand hygiene by HCWs and patients
     

Wang, Xinghuan et al. “Association between 2019-nCoV transmission and N95 respirator use” J Hospital Infection, March 3, 2020, https://www.journalofhospitalinfection.com/article/S0195-6701(20)30097-9/fulltext

Summary:

• This study examined the infection rate in two groups of departments.

  • Three departments were in the “mask group” because they utilized N95 respirators and also frequently performed hand hygiene (respiratory, ICU, and Infectious Disease).

  • Three departments were in the “non-mask group” because early in the outbreak they hadn’t implemented precautions- staff did not wear masks and disinfected and cleaned hands “occasionally.”

• There were significantly more confirmed or probable COVID-19 patients cared for in the departments in the “mask group,” meaning workers in those units had significantly more exposure than the “non-mask group.”

• “Mask group” reported statistically significantly fewer infections than the “non-mask group.”

  • 0 out of 278 staff in “mask group” were infected

  • 10 out of 213 staff in “no mask group” were infected

  • Difference was found to be statistically significant

• Found similar results in two other hospitals- staff wearing N95s and frequently conducting hand hygiene were not infected
   

Chen, Weiyun et al “ To Protect Healthcare Workers Better, To Save More Lives,” Anesthesia & Analgesia, March 30, 2020, https://journals.lww.com/anesthesia-analgesia/Abstract/publishahead/To_Protect_Healthcare_Workers_BetterTo_Save_More95724.aspx.

Summary:

• This study reported on healthcare worker protections implemented in China during three phases.

• First stage- this was an unknown disease and healthcare workers were not protected. At this time, the infection rate ranged from 3.5% to 29% among healthcare workers in different hospitals in the epicenter of Wuhan according to previous reports, when the initial source of the novel coronavirus still remained unknown.

• Second stage- inadequate protection for healthcare workers due to supply shortages. During this period of time, the number of confirmed cases in China was still increasing rapidly. By February 11, 2020, a total of 1,716 health care workers were confirmed with COVID-19, including five deaths.

• Third stage- disease severity acknowledged and full protection of healthcare workers. “The highest level of precaution, so called “full precaution,” is mandatory for high-risk exposure, a disposable surgical cap, test-fit N95 masks or respirators, gloves, goggles or face shield, gown and fluid-resistant shoe covers. We would like to point out that the key element of full precaution is the complete coverage of the head and facial skin…” No healthcare worker infections reported in this third period.

Feldman, Oren et al., “Exposure to a Surrogate Measure of Contamination From Simulated Patients by Emergency Department Personnel Wearing Personal Protective Equipment,” JAMA, April 27, 2020, https://jamanetwork.com/journals/jama/fullarticle/2765377

Summary:

• Experienced healthcare workers performed care tasks commonly required by patients with COVID (e.g., airway management and ventilatory support) in a simulation. A non-visible fluorescent compound was used as a marker of contamination- applied surfaces and secretion areas on the manikin-patient.

• Healthcare workers wore N95 respirators, eye protection, isolation gowns, and gloves.

• 7 of 8 participants had fluorescent markers (contamination) on their exposed skin, primarily neck.

• All participants had fluorescent markers (contamination) in their hair.

• Half had fluorescent markers (contamination) on their shoes.

• “The findings suggest that the current recommendations for personal protective equipment may not fully prevent exposures in emergency department settings. Clothing that covers all skin may further diminish exposure risk.”