A quantitative characterization of tuberculin skin test indurations using hyperspectral imaging to enable automated latent tuberculosis screening
type: CreativeWork
description: An estimated two billion people globally are believed to harbour latent tuberculosis infection (LTBI), which is a precursor to active tuberculosis (TB). Immunocompromising conditions, such as human immunodeficiency virus (HIV) infection, diabetes, chronic renal failure, and chemotherapy, are associated with the risk of progression from LTBI to active TB. People with LTBI represent a major reservoir for new active TB cases. Thus, the detection and management of LTBI is key to the world health organisation (WHO) goal to reduce TB incidence globally by 90% by the year 2035. The tuberculin skin test (TST) is the most widely used test for LTBI in low- and middle-income countries (LMICs). It involves the injection of tuberculin into the forearm skin of a participant. An induration – a subdermal lump – forms at the injection site 48 – 72 hours after the test. Using the Mantoux reading method, diagnosis is obtained using a pen and a ruler to measure the induration diameter and comparing it with consensus thresholds. Mantoux readings are subject to inter- and intra-observer subjective variations in readings. The manual nature of this method precludes any repeat analysis or validation after the 72-hour expiry of an induration. Furthermore, the Mantoux method does not provide any significant insight on the pathophysiology of indurations which could improve current understanding of LTBI. Recent applications of hyperspectral imaging (HSI) in other dermatological applications provides evidence of its viability in addressing the shortcomings of the TST. Thus, the aim of this research was to develop and validate an HSI-based approach for quantitative characterisation of TST indurations that can aid the diagnosis of LTBI. This aim was achieved through three objectives. The first objective was to develop and validate an HSI protocol for reliable and reproducible acquisition of spectral signatures of TST injection sites. An enclosure was designed to implement and validate the develope…
abstract: An estimated two billion people globally are believed to harbour latent tuberculosis infection (LTBI), which is a precursor to active tuberculosis (TB). Immunocompromising conditions, such as human immunodeficiency virus (HIV) infection, diabetes, chronic renal failure, and chemotherapy, are associated with the risk of progression from LTBI to active TB. People with LTBI represent a major reservoir for new active TB cases. Thus, the detection and management of LTBI is key to the world health organisation (WHO) goal to reduce TB incidence globally by 90% by the year 2035. The tuberculin skin test (TST) is the most widely used test for LTBI in low- and middle-income countries (LMICs). It involves the injection of tuberculin into the forearm skin of a participant. An induration – a subdermal lump – forms at the injection site 48 – 72 hours after the test. Using the Mantoux reading method, diagnosis is obtained using a pen and a ruler to measure the induration diameter and comparing it with consensus thresholds. Mantoux readings are subject to inter- and intra-observer subjective variations in readings. The manual nature of this method precludes any repeat analysis or validation after the 72-hour expiry of an induration. Furthermore, the Mantoux method does not provide any significant insight on the pathophysiology of indurations which could improve current understanding of LTBI. Recent applications of hyperspectral imaging (HSI) in other dermatological applications provides evidence of its viability in addressing the shortcomings of the TST. Thus, the aim of this research was to develop and validate an HSI-based approach for quantitative characterisation of TST indurations that can aid the diagnosis of LTBI. This aim was achieved through three objectives. The first objective was to develop and validate an HSI protocol for reliable and reproducible acquisition of spectral signatures of TST injection sites. An enclosure was designed to implement and validate the develope…
author: Oladokun, Ajibola Samson
language: en
keywords: Skin, Tuberculosis
date published: 2025
date modified: 2026-07-22T22:22:52Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Human Biology

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/42630