COVID-19 Q&A with Dr. Shannon Magari

COVID-19 Q&A with Dr. Shannon Magari

As a follow up to her webinar “Mitigate the spread of COVID-19 in Office Settings,” Dr. Shannon Magari has answered questions from customers on how to run a workplace in the age of COVID-19.

Quill recognizes that each business and institution has different needs and challenges. The views expressed here belong solely to the presenter Dr. Magari of the Colden Corporation and are meant to provide you information in order to help you make the best decisions for your business. Please refer to the legal disclaimer at the end of this document for important limitations regarding this content.

How often should I clean common-area surfaces in my workplace?

  • High-touch surfaces in common areas should be cleaned at the start of the day and periodically throughout the day. The frequency will depend on the level of activity. It may be prudent to clean surfaces in high traffic areas every two hours or more frequently.
  • High-touch surfaces include doorknobs, light switches, railings, countertops, desktops, work surfaces, phones, copiers, printers, fax machines, refrigerators, microwaves and sinks.
  • Efforts should be made to minimize the number of shared items in the workplace. For workstations and other items that must be shared, they should be cleaned and disinfected between every shift and in between employee handoffs.

No matter how much you clean though, we cannot forget how important good consistent hand hygiene is. Washing and sanitizing your hands routinely throughout the day will help reduce your risk of contracting the virus.

Do I need to check our employee’s temperature when they arrive at work?

Temperature screening is not generally required when employees arrive at work (check your local authorities to be sure); however, it is an important screening tool that can be used to help keep sick employees out of the workplace. If you cannot conduct this screening safely on-site, you could ask employees to check their temperatures before they leave their house. A fever is generally considered to be at 100.4°F and above (check local guidance as some state and local authorities may have a lower temperature threshold).

Even though temperature screening is an important tool, it should not be the only control measure employed and are not a replacement for other COVID-19 protective measures, such as social distancing. Many people with COVID-19 are asymptomatic, so while keeping employees with above-normal temperatures at home will help, it will not guarantee that you will keep all workers with COVID-19 out of the office. Other COVID-19 transmission controls, such as completing a comprehensive symptom and contact questionnaire each morning, masks and social distancing measures should also be enacted.

The content of screening questions is integral to the effectiveness of the tool. The CDC provides general guidance on screening question considerations here (see “Should we be screening employees for COVID-19 symptoms…” FAQ item).

Are there certain types of masks that should be worn?

The following types of masks are the most effective according to recent studies:

  • N99 and N95 filtering facepiece respirators (FFRs) are capable of filtering out particles, including bacteria and viruses, and can reduce the transmission of COVID-19. However, these respirators should be reserved for healthcare providers. If an employer requires the use of an FFR, they must have an OSHA-compliant Respiratory Protection Program.
  • We find that disposable surgical masks made from nonwoven polypropylene have the highest filtering efficiencies and tend to be the most comfortable for the longest periods of time.
  • Hybrid homemade masks that combine two layers of 600-thread-count cotton with another material like silk or flannel are also very effective in filtering large and small particles.

When selecting a mask, do NOT choose masks that:

  • Are made of fabric that makes it hard to breathe such as vinyl.
  • Have exhalation values or vents, which allow virus particles to escape.

What do I need to do if an employee tests positive for COVID-19?

  • The employee who tested positive must be removed from the workplace and isolate themselves following the current CDC guidance for isolation. If the employee is at the workplace, arrangements should be made for their safe transport home or to a healthcare provider as appropriate (avoid use of public transportation, as that can increase spread of COVID-19).
  • The employee or employee’s supervisor should inform the designated in-house COVID-19 point person.
  • The employer should work with the local Department of Health to begin identifying any workers who may have come into close contact with (generally those within 6 feet for 15 minutes or more, check your local jurisdiction for the definition of close contact) the sick employee for up to 48 hours before they developed symptoms or tested positive.
  • Close contacts of the COVID-19 positive employee must go home to quarantine for 14 days, self-monitor for symptoms, and contact a designated employee immediately if they develop COVID-19-related symptoms.
  • There are some limited exceptions to the 14-day quarantine if the employee who had close contact with the case is identified as a critical infrastructure worker and they remain asymptomatic.

In general, the CDC recommends:

  • Close off any areas used by the infected person within 48 hours of symptom development (we believe that those with COVID-19 are infectious for 48 hours before they develop symptoms).
  • Wait 24 hours before cleaning and disinfecting to minimize potential for other employees being exposed to respiratory droplets. If waiting 24 hours is not feasible, wait as long as possible.
  • CDC guidance for cleaning and disinfecting your workspace when someone is sick can be found here.

In addition to checking with your state and local health departments, you can find more guidance from the CDC here.

If an employee tests positive, do I have to notify other employees?

The only employees who need to be notified of a positive case are those who have been identified to have had close contact (generally withing 6 feet for 15 minutes or more, check your local jurisdiction) with the infected individual.

The infected individual’s privacy must be protected, and you should consult with your legal and human resource departments for company-specific guidance.

Should our employees be tested regularly if they work on-site in the office?

In general, office settings for non-critical infrastructure employees, routine testing of asymptomatic employees without known contact with a case is probably not practical, nor is it recommended at this time. As the availability of testing increases, the turnaround times decrease and the costs come down, it should become feasible to test employees more routinely.

If employees are exhibiting symptoms of COVID-19, they should be removed from the office and referred to their healthcare professional for evaluation to determine if testing is needed. 

I keep hearing that ventilation is important—what steps should I take to check the ventilation of my office?

Since we have evidence that the virus can be spread within a room through the air, it is important that your ventilation systems be reviewed to ensure they are functioning as designed and that guidance from the American Society of Heating Refrigeration and Air Conditioning Engineers (ASHRAE) on preventing the spread of the virus is reviewed and where possible, alterations to the system are made.

In general, AHSRAE recommends the following in their paper titled “Position on Infectious Aerosols”:

  • Increase the percentage of fresh air introduced into a space, up to 100%, as indoor and outdoor conditions permit.
  • Increase total airflow supply to occupied spaces, if possible.
  • Disable demand-control ventilation (DCV) controls that reduce air supply based on temperature or occupancy.
  • Inspect filter housing and racks to ensure appropriate filter fit and check for ways to minimize filter bypass.
  • Improve central air and other HVAC filtration to minimum efficiency reporting value MERV-13 or the highest compatible with the filter rack, and seal edges of the filter to limit bypass.
  • Keep systems running longer hours (24/7 if possible).
  • When appropriately selected and deployed, single-space HEPA or high-MERV (>13) filtration units (either ceiling mounted or portable) can be highly effective in reducing/lowering concentrations of infectious aerosols in a single space. These units should have a Clean Air Delivery Rate >400, as determined by the Association of Home Appliance Manufacturers (AHAM) Verifide seal, for tobacco smoke (0.09 – 1 micron). For these units, we recommend that a procedure for safe removal and disposal of spent filters be followed.
  • Add duct- or air-handling-unit-mounted, upper room, and/or portable UVGI devices in connection to in-room fans in high-density spaces.
  • Bypass energy recovery ventilation systems that leak potentially contaminated exhaust air back into the outdoor air supply.

I have an open office layout. Is it still possible to have employees come into the office? What steps should I take to best protect them?

These layouts are more difficult to work within, but yes, employees can still come into an open office if proper precautions are taken. There are several layers of protection that should be considered to keep individuals working in an open office plan. They are outlined in the CDC’s “hierarchy of controls” and a solid health and safety plan, based on the elements of this rubric, will help ensure employees can work as safely as possible.

Examples of controls in each layer include:

  • Elimination/Substitution – screening; both temperature screening and symptom, close contact and travel questionnaires each morning to keep sick employees or those with exposure out of the workplace.
  • Engineering Controls – barriers like plexiglass, touchless surfaces and enhanced HVAC as previously discussed.
  • Administrative Controls – cleaning protocols, social distancing measures, reducing the work force, staggering shifts, prohibiting congregating in the office, hand hygiene, etc.
  • Personal Protective Equipment – a universal masking policy within an open plan space with breaks to eat only when socially distanced.

No one control will be completely effective at stopping the transmission of the virus but taken all together will help slow the spread.

If someone tests positive, how long should they isolate?

If someone tested positive but did not experience symptoms, they must isolate for 10 days after they tested positive, so long as they do not develop symptoms during that 10 days. If they develop symptoms during this 10-day period, they must meet additional criteria noted below to end their home isolation.

If someone tested positive and was symptomatic, they must isolate for 10 days since symptoms first appeared and 24 hours with no fever without the use of fever-reducing medications has passed and other symptoms of COVID-19 are improving.

Of note, loss of taste and smell may persist for weeks or months after recovery and need not delay the end of isolation​.

These recommendations are taken from the CDC site, which should be referenced for the most up-to-date information.

What should we do if an employee comes in close contact with someone who has tested positive? (.i.e. spouse, boyfriend/girlfriend, customer or client)

For COVID-19, the CDC defines a close contact as “any individual who was within 6 feet of an infected person for at least 15 minutes starting from two days before illness onset.” The 15 minutes is cumulative, meaning multiple interactions within 6 feet are added together to determine an individual’s exposure. Please check your local jurisdiction for the definition of close contact. Some states consider close contact as those within 6 feet for 10 minutes or more.

In most all jurisdictions, you are still considered a close contact even if you were wearing a mask while you were around someone with COVID-19.

Asymptomatic close contacts must self-quarantine for 14 days. There are some limited exceptions to the 14-day quarantine if the employee that had close contact with the case is identified as a critical infrastructure worker and they remain asymptomatic.

An infected person can spread COVID-19 starting 48 hours (or 2 days) before the person had any symptoms or tested positive for COVID-19. Therefore, facilities where the infected person worked should be closed off to other employees, cleaned, and disinfected.

More information is available from the CDC at

I am not a critical infrastructure worker and was identified as a close contact and my COVID-19 test came back negative. Do I still need to quarantine for 14 days after I was last exposed?

Yes. You must still self-quarantine for 14 days from your last day of exposure to the infected individual. It can take up to 14 days after exposure to the virus for a person to develop COVID-19 symptoms. A negative result before the end of the 14-day quarantine period does not rule out possible infection. There is currently no way to shorten a 14-day quarantine, with testing or other means. By self-quarantining for 14 days, you lower the chance of exposing others to COVID-19.

Viral testing looks for an active infection and provides a “snapshot in time.” It is not an indication of past or future infection and would need to be repeated routinely to successfully screen out infected employees from work.

Currently, we know that the amount of virus shed by an infected individual will vary over the course of the infection, making the timing of sample collection important. Ideally, samples should be collected near the time of symptom onset to achieve the highest test sensitivity (sensitivity is the ability of a test to correctly classify an individual as having the disease). Individuals may be actively infected but have a negative test result if the sample is collected too early in the infection cycle; this is considered a false-negative result.

False-negative results may occur in cases that are infectious but are not yet symptomatic or in those who are in recovery. Due to these testing limitations, an asymptomatic close contact must continue to meet the 14-day quarantine requirement even with a negative test result.

What do we do if an employee has traveled from a different state?

For domestic travel, follow state and local travel restrictions in your area. For up-to-date information and travel guidance, check the state or local health department where you are, along your route, and at your planned destination. For easy reference, AAA maintains a website that catalogs a number of travel advisories by state, which can be found here. The New York Times is also maintaining a list of each state’s travel restrictions here.

While you are traveling, it is possible a state or local government may put into place travel restrictions, such as stay-at-home or shelter-in-place orders, mandated quarantines upon arrival, or even state border closures. Plan to keep checking for updates as you travel.

Consult with your HR department for your company-specific travel guidance.


Dr. Shannon R. Magari holds a Doctor of Science in Environmental Health from Harvard University with a concentration in Occupational Epidemiology and Masters degrees in public health and engineering. As a Principal owner of Colden Corp., she serves as Vice President of Health Sciences and co-chair of the litigation support practice. Dr. Magari continues to perform air quality research through an academic appointment at the T.H. Chan Harvard School of Public Health. She currently serves at the President of the Northeast Biological Safety Association.

The views and opinions expressed in this document belong solely to the presenter Dr. Magari of the Colden Corporation, who is not speaking on behalf of Quill Lincolnshire Inc. or its affiliates (“Quill”). Quill does not necessarily endorse the views expressed herein or agree that the document establishes health and safety standards to which all employers must adhere. Quill makes no guarantee regarding the accuracy or reliability of the content. This document is for informational purposes only and should not be considered or relied upon as legal advice. Companies are encouraged to consult an attorney for legal advice regarding workplace safety.