Facility Infection Risk Estimator v2.1
A Module from
BranchPattern’s
happē tool
USER GUIDE. This module is compatible with all browsers except Microsoft Explorer 11. The information provided in this user guide is intended to supplement the instructions given in the information bubbles associated with module’s input and output.
BranchPattern’s Facility Infection Risk EstimatorTM module is intended to estimate a) the aerosol viral particle removal efficiency resulting from several different removal mechanisms and b) the associated probability of infection for adults and children, given a set of input conditions including space parameters, demographic factors, and time.
This module is one component of our Health and Productivity Performance Estimator (happēTM) tool. The initial version of the tool was developed in 2009 to estimate the impact various indoor environmental quality (IEQ) conditions have on productivity and health. Based on IEQ peer reviewed research, it provides both percentage impacts and dollar amounts using weighted average salary dollars.
BranchPattern uses happēTM as part of pre- and post-occupancy evaluations to assess the impacts that existing space conditions are having on occupants. It’s also used during retrocomissioning and design to assess the relative impacts of different energy conservation measures (ECMs) or system types on productivity and health. BranchPattern has also found that making life cycle cost analyses more comprehensive increases the likelihood for sustainable and health/wellness focused decision-making throughout the design/construction process.
Summary of Changes to v2.1 of the Facility Infection Risk EstimatorTM
- Mask selections have been updated to reflect ongoing changes to the types of mask technology available and new research/testing of effective mask efficiencies.
- Vaccination for SARS-CoV-2 is now included for adults.
New variants of SARS-CoV-2 continue to evolve and spread within our communities. Research regarding the degree of infectiousness, mortality risk and resistance to vaccines of these variants is ongoing. For the following variants, we recommend multiplying the probability of infection results by the factors indicated. As new information becomes available we will update this recommendation.
- UK Variant: Data indicates increased infectiousness from 1.4 to 1.7. We have been using 1.5.
- Delta Variant: Data indicates increased infectiousness from 2.0 to 3.0. We have been using 2.5.
- Omicron BA.1 Subvariant: This impacts both the degree of infectiousness and the effectiveness of the vaccine. Multiply the probability of infection results from the calculator by the following: (8-(3.84*% Boosted))/(1-(0.8*% Boosted))
- Omicron BA.2 subvariant: This impacts both the degree of infectiousness and the effectiveness of the vaccine. Multiply the probability of infection results from the calculator by the following: (10.4-(4.68*% Boosted))/(1-(0.8*% Boosted))
This module was initially peer reviewed by Josephine Lau, Ph.D., Associate Professor of Durham School of Architectural Engineering and Construction, University of Nebraska – Lincoln. Dr. Harmon has subsequently co-authored a peer reviewed paper with Dr. Lau on the tool, available here: https://doi.org/10.1177/1420326X211039544.
Tutorial Videos:
What’s New in Facility Infection Risk Estimator, Version 2
County Case Numbers – Risk Factors
Figuring Out Your CFM Numbers
Case Study: K-12
Case Study: Cafe Dining
Disclaimer
This module was developed by employees of BranchPattern and is being made available for public use. The studies and models used for this module (referenced below) are based primarily on a) Influenza (in general and Influenza A in particular) and b) what we know as of 09/01/2020 for SARS-CoV-2. Influenza output is therefore most relevant to Influenza A but general interpretations could be made relative to Influenza B. Interpretations of output for SARS-CoV-2 should be made with the recognition we still have much to learn about SARS-CoV-2 and the resulting COVID-19 illness.
Also note that the mathematical models used by this module represent a simplified version of reality. The Facility Infection Risk EstimatorTM is designed to act as a simple heuristic for comparing the relative impacts from a baseline and design set of conditions. It is important that the user be aware of these simplifications, and that actual removal efficiencies and probabilities of infection will vary from the results given in this module. The results are intended to supplement, not replace, the judgement of qualified individuals competent in the knowledge domains of mechanical engineering, industrial hygiene, indoor air quality, infection control, and particle/pathogen airborne transmission.
The module is provided ‘as is’ without any warranty of any kind, either express, implied, or statutory, including, but not limited to, any warranty that the module will conform to specifications, any implied warranties of merchantability, fitness for a particular purpose, and freedom from infringement, and any warranty that the documentation will conform to the module, or any warranty that the module will be error-free. In no event shall BranchPattern be liable for any damages, including, but not limited to, direct, indirect, special or consequential damages, arising out of, resulting from, or in any way connected with this module, whether or not based upon warranty, contract, tort, or otherwise, whether or not injury was sustained by persons or property or otherwise, and whether or not loss was sustained from, or arose out of the results of, or use of, the module provided hereunder.
For more information, or to discuss your output results, feel free to connect with us.