2019 Novel Coronavirus (COVID-19) Outbreak: A Review of the Current Literature and Built Environment (BE) Considerations to Reduce Transmission.
With the increasing spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that results in coronavirus disease 19 (COVID-19), corporate entities, federal, state, county and city governments, universities, school districts, health care facilities, assisted living organizations, daycares, homeowners, and other building owners and occupants have an opportunity to reduce the potential for transmission through built environment (BE) mediated pathways. Over the last decade, substantial research into the presence, abundance, diversity, function, and transmission of microbes in the BE has taken place and revealed common pathogen exchange pathways and mechanisms. In this paper, Scientists have synthesized this microbiology of the BE research and the known information about SARS-CoV-2 to provide actionable and achievable guidance to BE decision makers, building operators, and all indoor occupants attempting to minimize infectious disease transmission through environmentally mediated pathways.
2019 Novel Coronavirus (COVID-19) and Impact of BE transmission
In December 2019, a novel CoV (SARS-CoV-2) was identified in Wuhan, Hubei Province, a major transport hub of central China. In the months since the identification of the initial cases, COVID-19 has spread to 112 countries and territories and there are approximately 114,230 confirmed cases (as of March 9, 2020). The modes of transmission have been identified as host-to-human and human-to-human. There is preliminary evidence that environmentally mediated transmission may be possible; specifically, that COVID-19 patients could be acquiring the virus through contact with abiotic (BE) surfaces.
Since most humans spend >90% of their daily lives inside the BE . BEs serve as potential transmission vectors for the spread of COVID19 by forcing close interactions between individuals, by acting as fomites (objects or materials which are likely to carry infectious diseases), and through viral exchange and transfer through the air.
The knowledge of the transmission dynamics of COVID-19 is still currently developing, but based upon studies on SARS-, MERS-CoV, preliminary data on SARSCoV-2, and CDC recommendations, it seems likely that SARS-CoV-2 can potentially persist on fomites anywhere from a couple of hours up to 9 days. While transmission of coronavirus has only been documented through respiratory droplet spread and not through deposition on fomites, steps should still be taken to clean and disinfect all potential sources of SARS-nCoV-2 under the assumption that active virus may be transmitted through these abiotic surfaces.
Control and Mitigation Efforts in the BE
- The spread of COVID-19 is a rapidly developing situation, but there are steps that can be taken, inside and outside of the BE, to help prevent the spread of disease. On a personal level, proper handwashing is a critical component of controlling the spread of SARS-CoV-2, other coronaviruses, and many respiratory infections.
- Individuals should avoid contact and spatial proximity with infected persons and wash hands frequently for at least 20 seconds with soap and hot water.
- Personal hygiene is the key to prevent the spread of COVID-19.
- Building HVAC operational practices can also reduce the potential for spread of SARS-CoV-2.
Higher outside air fractions and higher air exchange rates in buildings may help to dilute the indoor contaminants from air that is breathed within the BE which is possible by increasing ventilation damper positions on air-handling units. However , not all air-handling systems have the capacity to substantially increase outside air ratios, and those that do may require a more frequent filter maintenance protocol. Increasing outside air fractions may come with increased energy consumption as well.
- Increasing evidence indicates that humidity can play a role in the survival of membrane-bound viruses, such as SARS-CoV-2.
Maintaining a relative humidity between 40%-60% within the BE may help to limit the spread and survival of SARS-CoV-2 within the BE, while minimizing the risk of mold growth, and maintaining hydrated and intact mucosal barriers of human occupants.
The number of individuals who have contracted COVID-19 or have been exposed to SARS-CoV-2 has been increasing dramatically. It is essential and high time to spread awareness and take care of our loved ones through any means possible.