Jw. Shands et al., TUBERCULIN TESTING IN A TERTIARY HOSPITAL - PRODUCT VARIABILITY, Infection control and hospital epidemiology, 15(12), 1994, pp. 758-760
Nine percent of 2,721 hospital employees, previously tuberculin negati
ve, were PPD positive when tested with 5 TU of PPD (Aplisol, Parke-Dav
is). Seventy percent of the positive reactions were found to be errone
ous on retesting with Tubersol (Connaught). The excessive potency of A
plisol led to excessive expenditures of time and money investigating a
nonexistent outbreak.