2005. T-SPOT(®).TB Test for Latent Tuberculosis Infection Diagnosis and Treatment Guidance in Thai Healthcare Professionals

BACKGROUND: Data on efficacy of T-SPOT(®).TB Test (T-SPOT) in diagnosing latent tuberculosis infection (LTBI) and guiding isoniazid preventive therapy (IPT) among healthcare professionals (HCP) in tuberculosis (TB)-endemic settings are limited. METHODS: A prospective study was conducted among Thai HCP undergoing T-SPOT in June 2016 (initial screening) and June 2017 (follow-up). Nine-month isoniazid preventive therapy (IPT) was offered among the HCP with positive T-SPOT. The incidence of TB and the rates of conversion and reversion of T-SPOT were evaluated during the 1-year follow-up period (June 2016 to June 2017). RESULTS: A total of 140 HCP underwent initial T-SPOT; the median age was 27 years (IQR 25–31 years), 89% were female and 23 (16%) were T-SPOT-positive. Eighty-nine HCP (64%) had both initial and follow-up T-SPOTs. Among the 89 HCP, the initial and follow-up rates of T-SPOT positivity were 19% (N = 17) and 24% (N = 21), respectively. The conversion and reversion rates were 10% (N = 9) and 6% (N = 5), respectively. All of the nine HCP (100%) with T-SPOT conversion reported significant contacts with patients who had active pulmonary TB without using appropriate personal protection equipment. During the 1-year follow-up period, incidence of TB were significantly higher among HCP with T-SPOT conversion compared with HCP with persistent positive T-SPOT, HCP with T-SPOT reversion and HCP with persistent negative T-SPOT [22 vs. 8 vs. 0 vs. 0 cases/100 person-years; P < 0.001]. Of the 17 HCP with positive initial T-SPOT, 8 (47%) completed IPT. The incidence of TB was significantly lower and the T-SPOT reversion rate was significantly higher among HCP completing IPT compared with HCP declining or not completing IPT (0 vs. 11 cases/100 person-years; P < 0.001 and 63% vs. 0%; P = 0.009, respectively). CONCLUSION: T-SPOT could be used for diagnosing LTBI, guiding IPT and identifying HCP with subsequent risk for TB. The serial T-SPOT may be used for evaluating IPT efficacy. DISCLOSURES: All authors: No reported disclosures.