Detection of Latent Tuberculosis Infection in Nursing Students by Combined TST and IGRA Serial Testing

Nursing students are Occupationally at risk group for tuberculosis. Tuberculosis can either be as Latent tuberculosis (LTBI) or as active tuberculosis infection (TBI). Lack of awareness and not taking appropriate self defence exposes this group to acquire tuberculosis. it is the prime responsibility of governments and the managements of hospitals must take care of the health care workers. There is no optimal or single specific test for detection of LTBI. Tuberculin skin test ( TST) is used for screening to detect LTBI. But TSThas many variations, modern immunological tests like detection of interferon gamma release assay are found to be more reliable. In TB high burden countries, persistently elevated interferon gamma level is found in some health care workers, constantly exposed to M.tuberculosis positive clinical samples. Serial testing of combined TST and Quantiferon gold helps in detecting nursing students with LTBI. Methodology ; 85 nursing students on admission were tested for detection of Latent TBI. In TST the induration size was increased to 15 mm. these tests . 25 first year medical students and fifteen microbiology techinicians were included as controls. Result : only one nursing student showed 15 mm induration and a very high Gamma interferon level, persistently positive gamma interferon was found in 5 technologists, combined test after three, six and twelve months overcame the false positives faced in single TST or IGRA. www.jmscr.igmpublication.org Impact Factcor-1.1147 ISSN (e)-2347-176x