Recent transmission of tuberculosis in Madrid: application of capture-recapture analysis to conventional and molecular epidemiology.
BACKGROUND
Population-based studies using a combination of molecular techniques and conventional epidemiological methods have been used to study the dynamics of tuberculosis (TB) transmission but the relative utility of each technique has not yet been established.


METHODS
A prospective population-based molecular and epidemiological study of patients diagnosed with TB was conducted in three urban districts of Madrid (Spain) during 1997-1999. Analysis was performed using the capture-recapture method including covariates in which conventional epidemiological data and the information on clustered cases obtained by DNA fingerprinting were regarded as independent and complementary procedures.


RESULTS
The estimate obtained by molecular analysis alone, that 31.6% of TB cases were due to recent transmission, was revised to 44.8% (95% CI: 31.4-58.2) using the capture-recapture method. The estimated completeness of the combined databases for identification of recent transmission was 59.2%. Underestimation of the true prevalence of recent transmission was higher with conventional epidemiology than molecular analysis, particularly for patients <35 years old and those with a history of imprisonment.


CONCLUSIONS
In this study, use of the capture-recapture technique allowed us to combine epidemiological information obtained by conventional and molecular methods to quantify the number of cases of recently transmitted TB in the community and identify specific populations at high risk of disease. This information is clearly important because such groups are a prime target for improved TB control measures. In the long term, this combination of techniques may contribute significantly to control the spread of TB.
Iñigo
J
J
Dirección General de Salud Pública, Consejería de Sanidad de la Comunidad de Madrid, Aduana 29, 28013 Madrid, Spain. jesus.inigo@madrid.org
Arce
A
A
Martín-Moreno
J M
JM
Herruzo
R
R
Palenque
E
E
Chaves
F
F
D000328:Adult; D016000:Cluster Analysis; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000235:genetics*; D013030:Spain / Q000453:epidemiology; D014376:Tuberculosis / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission*; D014504:Urban Health / Q000706:statistics & numerical data
D004269:DNA, Bacterial