Table 5.

Literature data used for calculation of the infection risk of influenza A.

Parameter	Influenza A	Remarks
c	1 × 105 TCID50a/mL	Geometric mean from seven patients (Murphy et al., 1973 [51])
Respiratory deposition and infectious dose	ID50 = 1.8TCID50r = 0.385b	Infectious dose for aerosol ≤3 μm, mean value of the range: 0.6–3.0; β = 0.6 (Alford et al., 1966 [53])
	ID50 = 223.5TCID50r = 0.0031	Upper respiratory tract infectious dose, for larger aerosol mean value of the range: 127–320 reported by Douglas (1975) [54]; β, total respiratory fraction reported by Hinds (1999) [48]
Viability of influenza virus	<20 °C and 60% RH approximately 20% remained viable at t = 0, f(t) = 0.0351e−0.261t	Extrapolated from Fig. 6 in Hemms et al.(1960) [55]
v(t)j	Assume final nucleus size represents 6% of the initial volume (Nicas et al., 2005 [42])	Calculation given by Sze To et al. (2008) [49]

^aTCID₅₀ refers to the mean tissue-culture infectious dose, a unit to describe the quantity of virus.

^br = 0.385 is used for calculation as the infectious dose is for aerosols of ≤3 μm (Fig. 4).