Table 2 Variables used to estimate R _A for TB infection in an Internet café

Number of people in enclosed airspace (N)

60^a

Volume of shared airspace (V) (m³)

1155^a

Total exposure time (t) (h)

10

Breathing rate (p) (m³/h)

0.3^b

Number of infectious people (I)

1

Air exchange rate per hour (A/h)

1, 3, 5

Number of days of exposure (n) (days)

1–150