1 The Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada
Gastric washings from 58 children with positive tuberculin tests measuring more than 10 mm of induration of 5 TU of Old Tuberculin, but no other evidences of tuberculous infection, were studied by mycobacterial cultures and guinea pig inoculation. Two children had positive cultures for M. tuberculosis hominis. In one child the source of infection was readily identifiable. In the other, no index case has been discovered. In a third child, whose tuberculin test was less than 10 mm of induration, a scotochromogen was found on gastric lavage cultures.
While it would be impractical to suggest that all children with positive tuberculin tests should have gastric lavage cultures, the possibility that such a child has the potential to infect others must he borne in mind. The routine use of isoniazid is recommended in all such tuberculin-positive children, not for "chemoprophylaxis" technically, but, more precisely, for specific treatment of the infection indicated by the tuberculin reaction itself.