TITLE:
IGRA Testing in Suriname, an Intermediate Tuberculosis Incidence Country
AUTHORS:
Sheila Alexandra Regina Kort, Jayant Satishkumar Kalpoe, Fitzgerald Anoep Gopie
KEYWORDS:
QFT, TST, LTBI, NTM, BCG
JOURNAL NAME:
Journal of Tuberculosis Research,
Vol.12 No.4,
November
1,
2024
ABSTRACT: Background: Latent tuberculosis can progress to active TB. To diagnose LTBI the TST is used, which shows cross reactivity with NTM and BCG, giving way to overdiagnosis of LTBI. The sophisticated QFT is also used to diagnose LTBI and hardly has cross reactivity. Based on previous findings we assumed overdiagnosis of LTBI in Suriname because of false positive TST results due to NTM. Method: To evaluate our premise, we conducted a prospective study comparing the TST and QFT results of patients who had undergone both tests. Results: 64.1% of patients with a positive deemed TST had a negative QFT result, of which 64% were not prescribed TPT or did not complete TPT. At one year follow up no cases of active TB were encountered. Conclusion: False positive TST results lead to overestimation of LTBI incidence. Whenever an unexpected positive TST result is encountered it is advisable to perform a QFT for a more accurate diagnosis.