Potential demand for respirators and surgical masks during a hypothetical influenza pandemic in the United States

Abstract

Background: To inform planning for an influenza pandemic, we estimated US demand for N95 filtering facepiece respirators (respirators) by healthcare and emergency services personnel and need for surgical masks by pandemic patients seeking care.

Methods: We used a spreadsheet-based model to estimate demand for 3 scenarios of respirator use: base case (usage approximately follows epidemic curve), intermediate demand (usage rises to epidemic peak and then remains constant), and maximum demand (all healthcare workers use respirators from pandemic onset). We assumed that in the base case scenario, up to 16 respirators would be required per day per intensive care unit patient and 8 per day per general ward patient. Outpatient healthcare workers and emergency services personnel would require 4 respirators per day. Patients would require 1.2 surgical masks per day.

Results and conclusions: Assuming that 20% to 30% of the population would become ill, 1.7 to 3.5 billion respirators would be needed in the base case scenario, 2.6 to 4.3 billion in the intermediate demand scenario, and up to 7.3 billion in the maximum demand scenario (for all scenarios, between 0.1 and 0.4 billion surgical masks would be required for patients). For pandemics with a lower attack rate and fewer cases (eg, 2009-like pandemic), the number of respirators needed would be higher because the pandemic would have longer duration. Providing these numbers of respirators and surgical masks represents a logistic challenge for US public health agencies. Public health officials must urgently consider alternative use strategies for respirators and surgical masks during a pandemic that may vary from current practices.

Keywords: influenza pandemic; respiratory protective devices.

Figure 1.

Schematic of alternative structures to modeling total N95 filtering facepiece respirators (respirators) use. *Example of demand that follows the epidemic curve. **In the Base Case, demand for respirators among intensive care unit, general ward, and nursing home workers was assumed to follow the epidemic curve; demand for respirators among first responders and those working in outpatient settings was assumed to follow the Intermediate Demand model. ***All sectors assumed to follow the Intermediate Demand model.

Figure 2.

Demand for N95 filtering facepiece respirators (respirators) for different models and scenarios. For each scenario and distribution model, ranges result from variations in respirator use rates and epidemiologic and healthcare use parameters. Abbreviation: AR, attack rate.

Figure 3.

Surgical mask demand by pandemic scenario. For each scenario, ranges result from variations in surgical mask use rates and epidemiologic and healthcare use parameters. Surgical mask demand is the same for the base, intermediate, and maximum scenario, as it is meant for source control and the number of patients is proportional to the epidemic curve. Abbreviation: AR, attack rate.

Figure 4.

Variation of demand for N95 filtering facepiece respirators (respirators) with usage rates for different settings; for the base case (bars are centered around approximately 2.5B, the estimated demand for respirators for the 20% Attack Rate; high severity scenario; each bar shows the minimum and maximum demand obtained when varying the parameters in the interval featured on the left axis). Interpretation: if respirator use rate in the outpatient sector changes to 2/day/healthcare worker (50% reduction), total demand for respirators reduces to 1.7 billion). Abbreviations: ED, emergency department; EMS, emergency medical service; GW, general ward; ICU, intensive care unit.