Determining the Need for Additional Testing With Quantiferon Tb Gold in Patients With Positive Tuberculin Skin Tests and a History of Bcg Vaccination

Authors

Antony J. Arumairaj, Internal Medicine, New York Medical College, Metropolitan Hospital Center, New York, USA.Follow
Hansang Park, Internal Medicine, New York Medical College, Metropolitan Hospital Center, New York, USA.
Fernando Quesada, Internal Medicine, New York Medical College, Metropolitan Hospital Center, New York, USA.
Brian Altonen, Biostatistics and Epidemiology, New York City Health and Hospitals Corporation, New York, USA.Follow
Shobhana Chaudhari, Internal Medicine, New York Medical College, Metropolitan Hospital Center, New York, USA.
Joseph Mattana, Internal Medicine, New York Medical College, Metropolitan Hospital Center, New York, USA.
Imnett Habtes, Internal Medicine, Division of Pulmonary and Critical Care, New York Medical College, Metropolitan Hospital Center, New York, USA.

Author Type(s)

Faculty

DOI

10.7759/cureus.39272

Journal Title

Cureus

First Page

e39272

Document Type

Article

Publication Date

5-1-2023

Department

Medicine

Abstract

OBJECTIVE: To determine if the QuantiFERON-TB Gold (QFT) testing can be obviated for the diagnosis of latent tuberculosis infection (LTBI) in patients with a positive tuberculin skin test (TST) and a history of Bacillus Calmette-Guerin (BCG) vaccination by identifying high-risk features in patients with positive TST and a history of BCG vaccination who are associated with positive QFT. METHODS: Retrospective chart review was done for 76 adult patients by dividing them into two groups. Group 1 consisted of true positive TST patients who had BCG vaccination and were positive for QFT. Group 2 consisted of false positive TST patients who had BCG vaccination but were negative for QFT. The two groups were compared to determine if the high-risk features of TST induration diameter of 15mm and more, TST induration of 20mm and more, recent immigration to the US, the advanced age of more than 65 years, country of origin with high TB burden, known exposure to active TB, and smoking history were more prevalent in Group 1 compared to Group 2. RESULTS: Group 1 had 23 patients and Group 2 had 53 patients. Group 1 had a higher prevalence of patients with PPD induration of more than 10mm than Group 2, which was statistically significant with a P value of 0.03. Other risk factors of advanced age, exposure to active TB and smoking did not show statistically significant differences between Groups 1 and 2. Conclusion: This study also confirms that if the TST induration is more than 10mm in patients with a history of BCG vaccination, the TST induration is likely because of LTBI and is less likely because of cross-reaction with BCG vaccination.

Recommended Citation

Arumairaj, A. J., Park, H., Quesada, F., Altonen, B., Chaudhari, S., Mattana, J., & Habtes, I. (2023). Determining the Need for Additional Testing With Quantiferon Tb Gold in Patients With Positive Tuberculin Skin Tests and a History of Bcg Vaccination. Cureus, 15 (5), e39272. https://doi.org/10.7759/cureus.39272