OBJECTIVE The proportion of tuberculin reactors in a population and the intensity of tuberculin reactions have been shown to increase with increasing exposure to mycobacterial infection, eg, repeated BCG immunization. These observations suggested that tuberculin reactivity would become uniformly high in individuals with a high mycobacterial load who did not have a known cause of anergy. Since t...

To the Editor: Several reports, including one by Shands et al (Infect Control Hosp Epidemiol 1994;15:758-760), indicate an apparent widespread high falsepositive rate associated with the use of Aplisol (Parke-Davis) tuberculin material.lj Numerous other reports indicate that this problem is not recent.2-5 To date, investigators have emphasized the cost and increased frequency of false-positive ...

A sensitive two-step simultaneous enzyme immunoassay (EIA) for human gamma interferon (IFN-gamma) has been developed and used as an in vitro test for human tuberculosis (TB) in comparison with tuberculin skin testing. The EIA was shown to be highly sensitive, detecting less than 0.5 IU of recombinant human IFN-gamma per ml within a linear detection range of 0.5 to 150 IU/ml. The assay was highl...

OBJECTIVE Recommendations that purified protein derivative (PPD) RT-23 tuberculin should not be kept and used more than 24 to 48 hours after opening are rarely complied with. The aim of this study was to determine whether using PPD RT-23 tuberculin from vials that had been open for a longer time could affect results of tuberculin tests and whether the solution could become contaminated. METHO...

mantoux test using 2 iu of tuberculin prepared in iran was performed on 6675 healthy persons randomly selected from an urban population (shiraz) of iran. in 3776 persons with no evidence of previous bcg vaccination the rate of positive reaction was less than 2% up to the age of 14, slightly more than 2% among those 15-19 years of age, but strikingly higher (45.5%) in older age groups (p<0.001)....