Ebola and More – Responding to Pandemic Virus Infections

Ebola and More – Preparing and Responding to Pandemic Virus Infections

A Client Guide from Healthy Buildings

October 2014
Ebola was first reported in 1976 and outbreaks limited to a few hundred people have sporadically erupted in Sudan, Zaire (now Congo), Gabon, Uganda and most recently (and to a much greater extent), several countries in Western Africa. The disease has also occurred as a result of laboratory activity in several first world countries.

Pandemic Epidemic over a wide geographic area and affecting a large proportion of the population

This virus is by no means the only one to have the potential to create pandemics, and building managers should consider this larger picture in their response to the latest concerns over Ebola.

As an example, in 1918, near the end of World War One, the Spanish press began reporting widespread fevers, headaches, malaise, coughs and sore throats, quickly degrading to pneumonia, lung hemorrhage and rapid death. What became swiftly apparent however was that this phenomenon was not restricted to Spain – it was only wartime press censorship in most other developed countries that was limiting popular knowledge of these illnesses. What transpired in the coming year was one of the worst epidemics of influenza to strike the world’s human population, leaving approximately 40 million victims dead.

In both cases, these viruses have the potential to strike not just elderly or weak individuals, but those in the prime of their lives, those who are out in society in direct contact with each other in the workplace.

So how likely is it that we are to be victims of another pandemic virus outbreak? And what can building owners, managers and employers do to prepare for and mitigate the risks this challenge presents?

Viruses often circulate in animals, particularly birds and in some mammals, such as pigs and monkeys, before mutating into a form infectious to humans – and then mutating again to become highly transmissible between humans. Ebola may have followed this pattern with bats as its natural reservoir host.

Human Transmission

The World Health Organization states:

“The Ebola virus is transmitted among humans through close and direct physical contact with infected bodily fluids, the most infectious being blood, feces and vomit…The Ebola virus can also be transmitted indirectly, by contact with previously contaminated surfaces and objects. The risk of transmission from these surfaces is low and can be reduced even further by appropriate cleaning and disinfection procedures.

Ebola virus disease is not an airborne infection. Airborne spread among humans implies inhalation of an infectious dose of virus from a suspended cloud of small dried droplets.

This mode of transmission has not been observed during extensive studies of the Ebola virus over several decades.”

Nonetheless, some in the scientific community

[1] see the potential for aerosol transmission of this disease. However unlikely, should this virus escape into the North American population, our advice is consistent with what it has always been for the pandemic flu and other viral infections:

Hygiene Standards

Studies show that this virus may remain viable on hard surfaces for up to 24 hours, especially if associated with organic debris. A primary intervention that building managers and employers can take is to communicate and require strict adherence to personal hygiene etiquette. At a minimum, employers should ask staff to wash their hands regularly, cover their mouths when they sneeze, and dispose of used tissues carefully. Other specific measures will depend on what is learned about the transmissibility of a particular organism but housekeeping measures used to control viruses in general have included use of 1/10 bleach/water solution or other biocidal product, combined with appropriate use of personal protective equipment (such as eye goggles, rubber gloves, N95 respirators), to regularly clean the following surfaces:

a) All restroom surfaces, toilets, urinals, sinks, doors, floors and walls to a height of six feet from the floor. Be vigilant in disinfecting all handles, doorknobs, taps and levers likely to have been touched by hand. There is a viable theory that toilets create infectious aerosols when flushed.

b) All surfaces in break room, cafeterias or kitchens to a height of six feet.

c) All water fountains.

d) All surfaces in offices to a height of six feet, including walls, partitions, file cabinets, furniture.

e) All handrails of stairwells and doorknobs or push plates on doors in stairwells

f) Clean out all refrigerators, discard all opened food and drink containers. Wipe internals of refrigerators with the dilute bleach solution. Clean outside of refrigerator including door handles.

g) Finally, place plenty of hand sanitizer solution around the office spaces for everyone to use.


HVAC Operation and Maintenance


Over the past 34 years Healthy Buildings has preached the value of good HVAC operation and maintenance as an effective means to provide acceptable indoor air quality to building occupants. At this time there is no consensus that Ebola could be transmitted though ventilation systems but it is feasible that virus transmission can occur through droplet transmission under some circumstances. A sneeze will eject millions of viable virus particles inside droplets. The largest of these droplets, greater than 10 microns in diameter, will travel only about 3 to 6 feet, and if inhaled are paradoxically less infectious, because they are too large to reach the lower reaches of the lungs. The smaller droplets, less than 5 microns, can travel further on air currents and tend to be more infectious as they penetrate deeper in the respiratory systems.

So it stands to reason that the better ventilated a space, the greater the dilution. Higher dilution means better air exchange and lower infection rates. This common-sense reasoning has been confirmed, up to a point, by a 1991 study[2], along with an equation known as the Wells-Riley Equation, both of which found that lower than ASHRAE-recommended ventilation rates increase infection level potential, though ventilation rates greater than this tend to bring diminishing returns. So in general, a wise building engineer will verify the ventilation rate of the building to ensure that minimum ASHRAE Standards for ventilation are observed.


Viruses and Filters:
A study has shown that MERV 16 filters are capable of 76% efficiency for a type of influenza virus

Viruses in droplets will eventually desiccate and die, in a time frame of hours or days, and there is little evidence that HVAC return air systems help spread such agents.  Nevertheless, hospital HVAC designs for infectious patients are generally “once through” systems that do not recycle the air. In commercial buildings, filters are unlikely to check viruses unless their efficiencies are MERV 12 or above. Though these filter standards are increasingly found in Class A office space, this is uncommon in most buildings.   Even with good quality filters, the key is routine inspections and maintenance to ensure they are well installed with no air bypass gaps.

“Social Distancing”

Travel Restriction:
The WHO has estimated that a 99% restriction of travel into a country would be expected to delay spread of a virus by only about two months – as a result there has been little appetite to restrict travel to date.

There are medical and non-medical interventions that are in development for this current potential crisis. We should not count on a strain-specific vaccination available for Ebola, or other virus strains in general, until well after a pandemic has spread, if at all. Should a virus really break out into the population at large, we can expect governmental organizations to provide specific health monitoring and quarantine recommendations. For example, medical quarantine measures were the first line of defense in Dallas.

There are non-medical interventions that may be just as important, and some of these could fall at the feet of building managers and employers. When we examine past pandemics, we see some interesting commonalities. During the Spanish flu outbreak which struck worldwide, Western Samoa and Iceland avoided it completely by imposing travel restrictions. Later pandemics involved more careful disease tracking. During an influenza outbreak in 1957 a WHO panel discovered that there were jumps in infection rates immediately following public assemblies such as conferences and festivals, and in camps, army units and schools. Another study found that school closures saw a decrease in viral infections, and this pattern of a relationship between school attendance and spread of infection was seen again in a 1968 pandemic. This has developed into a proposed technique for controlling pandemics called “social distancing.” Travel restrictions can form part of this approach, but there is not much hope that this will be very successful as societies are much more mobile now then in the past. Air travel is likely to be a very effective infection vector.

However isolation has good potential – minimizing opportunities for mass gatherings. Advice to building owners and employers from cognizant authorities therefore spotlights stay-at-home measures, made easier by the advent of internet-based communications. Managers should be aware of the “second wave” phenomenon that has characterized some past pandemics – there have been a second wave of infections that followed the first.

Telecommuting has never grown to the extent that its proponents promised, because of the value of human interaction. This has been good for the commercial real estate industry, yet should social distancing be forced on the industry during a pandemic, it will be interesting to observe whether there will be a long term negative impact on office space demand, or whether demand will bounce back rapidly. Healthy Buildings is betting on the latter.

The short term consequences of social distancing will need to be carefully managed to limit the human and financial damage to a particular organization.

Documentation and Communication

The constant drumbeat of media attention paid to pandemics as they cycle though our population cannot be ignored by the building manager. Tenants, insurers, and other stakeholders in a commercial building benefit from routine documentation that verify the steps outlined above have been implemented in advance of a Pandemic. At Healthy Buildings we can provide our clients with a comprehensive documentation package that shows the adoption of a response plan. This package will be the core of a communication strategy that will position the building owner or employer as a perceptive, professional and prepared business.

Proactive IAQ Monitoring:
Proactive IAQ monitoring protects owners against liability. This is a major and tangible advantage of Healthy Buildings programs. It demonstrates that the owner has done due diligence to assure a healthy building or portfolio of buildings.

Building owners adopting Healthy Buildings indoor air quality inspection programs can rest assured that professional, high quality indoor environmental documentation will be on file for their building. Any buyer, litigant or regulator interested in IAQ will find the building management has practiced good due diligence, can comply with current standards of care and has inspected the various components of the mechanical systems just as current standards require.


As with nearly every other indoor environmental topic, steadily increasing levels of knowledge have helped to reduce the impact of disease, leading humans to longer, healthier lives. We have never known more about pandemic virus outbreaks than we know today, so there is some cause for optimism that catastrophe can be avoided, though this is by no means certain. The best that an employer and building manager can do is to research, prepare, document and communicate.

Other Resources

BOMA International Website has listed several valuable resources for further information.


This guide is one of a series of information sheets available to our clients covering topical indoor environmental concerns of the day. They are intended to help guide our clients towards contemporary Governmental and Industry recommended response measures and to present a context for the issue. The references in this guide may help our clients develop a response plan that meets their specific needs. However the guides we publish cannot and do not represent a comprehensive action plan for specific users to follow.

[1] http://www.cidrap.umn.edu/news-perspective/2014/09/commentary-health-workers-need-optimal-respiratory-protection-ebola

[2] Nardell EA, Keegan J, Cheney SA, Etkind SC Airborne infection. Theoretical limits of protection achievable by building ventilation. Am Rev Respir Dis. 1991 Aug;144(2):302-6.

© Healthy Buildings International, Inc.

By | 2019-04-05T14:27:40+00:00 October 15th, 2014|Blog, News & Announcements|Comments Off on Ebola and More – Responding to Pandemic Virus Infections

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