[Contacts of children with tuberculous patients].

One hundred and nine adults recently diagnosed of active pulmonary tuberculosis (all of them with smear positive sputum) were selected. Their household contacts under fifteen years of age were studied. 73.1 por 100 of the children were tuberculin-positive, and 33.1 por 100 of these "reactors" had developed a pulmonary tuberculosis themselves. The bacillary density in the sputum of the source case was correlated to percentage of infected and ill children among his contacts. Neonatal vaccination with BCG showed a protective effect against the illness in children under eight years of age.