Risk factors for tuberculosis in contact investigations in Rotterdam, the Netherlands.
Contact investigations around tuberculosis patients enable early detection of infection and disease, and prevention of secondary tuberculosis cases. We aim to identify risk factors for M. tuberculosis transmission to contacts of tuberculosis patients, based on unique data from routine contact investigations by the Public Health Service in Rotterdam, the Netherlands, collected between 2001 and 2006. Through logistic regression analysis, we determined the effect of various risk factors on the chance of finding a latent tuberculosis (TB) infection or overt tuberculosis case among contacts. A total of 1165 index patients with active tuberculosis were registered and at least one contact was investigated in 731, resulting in 21,540 contacts overall. Altogether, the contact investigations led to 91 cases of active tuberculosis. Of the 12,698 contacts eligible for screening by tuberculin skin test, 1091 (9%) were diagnosed with latent tuberculosis infections. Risk factors were old age of the contact, old age of the index patient, and the relationship to the index. A larger fraction of infected close contacts was strongly associated with infections among more distant contacts. Our findings emphasize the importance of including these personal and interpersonal risk factors in decision making in contact investigations.
Department of Public Health, Erasmus MC, University Medical Center Rotterdam; ; Department of Infectious Disease Control, Municipal Public Health Service Rotterdam-Rijnmond, Rotterdam, The Netherlands.
Jesse Eduard
JE
Verdier
Department of Public Health, Erasmus MC, University Medical Center Rotterdam;
Sake
S
Jan de Vlas
Department of Infectious Disease Control, Municipal Public Health Service Rotterdam-Rijnmond, Rotterdam, The Netherlands.
Inge D
ID
Kidgell-Koppelaar
Department of Public Health, Erasmus MC, University Medical Center Rotterdam; ; Department of Infectious Disease Control, Municipal Public Health Service Rotterdam-Rijnmond, Rotterdam, The Netherlands.
Jan Hendrik
JH
Richardus
contact investigations; epidemiological risk factors; tuberculosis screening.; tuberculosis transmission