Volume 3, Number 3—September 1997
Synopsis
Using a Mathematical Model to Evaluate the Efficacy of TB Control Measures
Table 1
Nosocomial TB outbreaks involving health-care workers who performed high-risk procedures
Pulmonary ventilation p(m3/min) | Room volume V(m3) | No. of susceptible persons S0 | No. of uninfected
persons ![]() |
Exposure time t (min) | Infection rate q (qpm) | Disinfection rate C (ACH) | |
---|---|---|---|---|---|---|---|
Bronchoscopy | 10-2 | 200 | 13 | 3 | 150 | 6 | 1.26 |
Abscess irrigation | 6 x 10-3a | 200b | 5 | 1 | 150b | 38 | 6b |
Autopsy | 10-2 | 200b | 4 | 0c | 150b | 94 | 11 |
Intubation | 6 x 10-3a | 3000 | 3 | 1 | 66 | 514 | 2.4d |
aSurgical masks were adopted.
bEstimated value; actual data are not available
cWe assumed S=0.001≈0.
dIn the emergency department where this outbreak developed, 60% of the air was recirculated without filtration; we assumed an airflow rate of 6 ACH, obtaining an effective disinfection rate equal to 40% of 6 ACH.