tuberculin skin test results in health care workers of imam khomeini hospital (kermanshah 2004)

introduction :  working in hospital as a health care worker (hcw) predisposes the staffs to the risk of tuberculosis infection (tb). majority of hospitals around the world have developed protocols to prevent their personnel against tb. this study was carried out to determine the status of tb prevalence in the hcws using tuberculin skin test to establish an occupational health protection against tb in exposed hcws during their employment. materials and methods : all 437 hcw personnel of imam khomeini hospital of kermanshah were invited to take part in the study in 2004. tuberculin skin test performed and results were observed after three and six days. the subjects with tuberculin negative results, ppd induration less than 10mm, were tested again after 10 days and the results were observed after three days. x 2 and fisher exact test were used for data analysis. results :  318 (72.8%) hcw personnel, 130 (41%) women and 188 (59%) men, agreed to participate in the study. mean age was 37.4 ± 8.67 years old and mean employment duration in the hospital was 13.5±8.51 years. 163 (51.3%) of participants had positive ppd result, of whom 161 subjects developed ppd positive result within first test and only two subjects observed positive ppd result in the second test. there was no observation of delayed tuberculin hypersensitivity. the frequency of booster effect was 2.3%. the highest and the lowest rates of ppd positive were seen in laboratory and emergency units (66.7% and 28.6% respectively). there was a positive statistical relation between age and duration of employment and positive ppd result (p<0.001).  prevalence of positive ppd was significantly lower in women than men (p<0.004). there was no significant difference between subjects with and without history of b.c.g vaccination and ppd positive results even in ppd induration size more than 5 mm. conclusion : hcws employed at imam khomeini hospital of kermanshah are at substantially increased risk for tb, suggesting significant risks from infected patients’ transmission. control of hospital spread of tb in kermanshah which is an area that requires urgent attention, is necessary.  introducing health care profile and periodic ppd tests, which may help to earlier diagnosis of infected hcws with effective chemoprophylaxis to prevent them from tb, are highly recommended