The predictive value of induration 24 hours after administration of purified protein derivative (PPD) was examined. Altogether 1082 healthy schoolchildren were tested using 5 tuberculin units of PPD. Induration was measured at 24, 48, and 72 hours. At 24 hours, induration of any size had a relatively low positive predictive value (63%), although indurations > 5 mm had a higher (86%) positive pr...

BACKGROUND Repeat tuberculin skin tests may be false positive due to boosting of waned immunity to past mycobacterial exposure. We evaluated whether an ELISPOT test could identify tuberculosis (TB) contacts with boosting of immunity to non-tuberculous mycobacterial exposure. METHODOLOGY/PRINCIPAL FINDINGS We conducted tuberculin and ELISPOT tests in 1665 TB contacts: 799 were tuberculin test ...

BACKGROUND This study explored the effect of screening and treatment of refugees for latent tuberculosis infection (LTBI) before entrance to the United States as a strategy for reducing active tuberculosis (TB). The purpose of this study was to estimate the costs and benefits of LTBI screening and treatment in United States bound refugees prior to arrival. METHODS Costs were included for fore...

541 animals from three dairy farms () were firstly screened for bovine tuberculosis by tuberculin skin testing, out of which 71 (13.12%) animals were found tuberculin reactors. The serum samples of 71 tuberculin positive104 tuberculin negative and 363 non tuberculin tested animals were then evaluated by Purified Protein Derivative (PPD)-ELISA. PPD-ELISA yielded 57.74%, 8.65% and 24.24% seroposi...

To evaluate the effect of BCG vaccination and T lymphocyte subpopulations on the reactivity to the tuberculin skin test, 113 asymptomatic HIV+ individuals were tuberculin tested by intradermal injection of 5TU of purified protein derivative and the levels of circulating lymphocyte (CD3, CD4 and CD8) subpopulations determined by indirect immunofluorescence. Ninety-two percent of the subjects inc...

tuberculosis (tb) is an important health problem in developing countries, with varying clinical presentations depending on the organs/systems involved. to study the spectrum of clinical and paraclinical aspects of extra pulmonary tb in children suffering from pulmonary tb. this study has been carried out on 65 children with tuberculosis, admitted in tb wards of national research institute of tu...

Monocytes isolated from the peripheral blood of tuberculin-positive and tuberculin-negative donors were exposed to PPD, extensively washed, and incubated with autologous or homologous lymphocytes. Lymphocyte transformation was measured morphologically and by incorporation of (14)C-labeled thymidine. Monocytes from tuberculin-positive subjects induced transformation of autologous lymphocytes in ...