Tuberculosis transmission and the impact of intervention on the incidence of infection.
METHODS
England and Wales.


OBJECTIVE
To quantify the relative contribution of vaccination, chemotherapy and preventive therapy to the reduction in tuberculosis incidence in England and Wales between 1953 and 1990.


METHODS
A compartmental model of tuberculosis transmission was fitted to notification data between 1913 and 1939 to estimate pre-vaccination parameters. Best-fit estimates of the rates of chemotherapy and preventive therapy were derived by fitting the model to notification data between 1953 and 1990. Published vaccination rates were used.


METHODS
Number of cases of pulmonary tuberculosis averted.


RESULTS
The numbers of respiratory tuberculosis cases averted between 1953 and 1990 by the use of preventive therapy, vaccination and chemotherapy were 288318, 57085 and 206996, respectively.


CONCLUSIONS
Of those interventions considered, preventive therapy has the greatest impact on transmission. The duration of infectiousness is long, with an onset that is likely to pre-date sputum positivity.
Pitman
R
R
Division of Primary Care and Population Health Sciences, Imperial College School of Medicine at St. Mary's, London, United Kingdom. RPitman@phls.org.uk
Jarman
B
B
Coker
R
R
D019072:Antibiotic Prophylaxis; D000995:Antitubercular Agents / Q000627:therapeutic use*; D004739:England / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008962:Models, Theoretical; D011315:Preventive Medicine; D015397:Program Evaluation; D032581:Tuberculosis Vaccines / Q000627:therapeutic use*; D014397:Tuberculosis, Pulmonary / Q000517:prevention & control* / Q000635:transmission*; D014852:Wales / Q000453:epidemiology
D000995:Antitubercular Agents; D032581:Tuberculosis Vaccines