The annual risk of infection with Mycobacterium tuberculosis in England and Wales since 1901.
METHODS
England and Wales.


OBJECTIVE
To estimate the magnitude and trend in the annual risk of infection with Mycobacterium tuberculosis in England and Wales since 1901.


METHODS
Estimates for the prechemotherapy era are derived assuming that 1% of new infections among 0-4 year olds led to fatal tuberculosis meningitis, as found in the Netherlands. The estimates are validated against data from the 1949-1950 national tuberculin survey. We explore the trend thereafter using tuberculous meningitis notifications and data from the 1971-1973 national tuberculin survey, and discuss the utility of data collected under the national bacille Calmette-Guérin (BCG) vaccination scheme for estimating the annual risk of infection.


RESULTS
Tuberculosis meningitis mortality rates among 0-4 year olds declined at 4% per annum until 1950, and suggest that the annual risk of infection declined from 12% in 1901 to 1.9% in 1949. The decline in the annual risk of infection probably accelerated in 1950, although its magnitude cannot be determined accurately.


CONCLUSIONS
An accelerated decline in the annual risk of infection in England and Wales from 1950 probably resulted from the introduction of chemotherapy, which dramatically reduced the prevalence of sources of infection in the population. Data collected during the national BCG vaccination scheme were found to be unsuitable for estimating infection risks.
Vynnycky
E
E
Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine, UK.
Fine
P E
PE
D000293:Adolescent; D017677:Age Distribution; D001500:BCG Vaccine / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D003625:Data Collection; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D012307:Risk Factors; D017678:Sex Distribution; D015996:Survival Rate; D014373:Tuberculin; D014390:Tuberculosis, Meningeal / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*; D014852:Wales / Q000453:epidemiology
D001500:BCG Vaccine; D014373:Tuberculin