[Investigation of some risk factors in tubercular infection in children].
A total of 2057 children, from a village with an isolated farm of tuberculous cattle have been classified in the following groups: A--1843 children from healthy families; B--140 children whose parents were working at the bovine farm; C--70 tb contacts, and D--4 children with parents working at the farm and relatives suffering with tuberculosis. All were skin tested simultaneously with 1 and 10 PPD units. Milk was brought home from the farm by those who worked there, that was used without boiling. A total of 14,5% of all the children had a reaction of more than 5 mm to one PPD unit. The percentages were of 8,4 in group A 52,1 in group B and 94,3 in group C (P less than 0,001). Incidence of more than 9 mm reactions was of 5% in group A, 45% in group B and 91,4% in group C (P less than 0,001). The mean diameter for one PPD unit was of 1,1 mm in group A, 7,58 mm in group B and 15,88 mm in group C (P less than 0,001). The major risk factor is represented by the tuberculous patients, but use of milk, or of milk derivatives from diseased cattle could also be incriminated. Synchronous neutralization of these two sources of contamination remains the primary action to be carried out for the prevention of the tuberculous infection dissemination.