Transmission of tuberculosis from adults to children in a Paris suburb.

Tuberculosis in children is often acquired by contact with a family or household member. The aim of our study was to evaluate risk factors for latent infection and active disease in exposed children in a suburb of Paris. We examined medical records for the period 1997-2000 at six departmental centers for medical prevention in Val de Marne. Thirty-nine patients aged 18 years or more with M. tuberculosis-positive sputum samples, and living with children or adolescents, were identified. Ninety-one children, aged 3 months-17 years, were exposed to these index cases. All the children initially underwent a tuberculin skin test and chest radiography, and children with no criteria for latent infection or active disease at time of initial evaluation were asked to attend a second evaluation 3 months later. Overall, 20 of the 91 (22%) children were infected, including 4 children identified only at the second evaluation. Eight (40%) of the 20 infected children had active disease, including 2 of the 4 children identified at the second evaluation. The risk of infection was not influenced by the children's age, but was significantly associated with three characteristics of the adult cases, i.e., age younger than 40 years, presence of cavitary lesions, and smears with more than 100 bacilli per microscopic field. In conclusion, our results call for early examination of all exposed children, in order to prevent infection and progression to active disease, and for a routine second evaluation after the adult contact has ended. Copyright 2002 Wiley-Liss, Inc.