# Tuberculosis Diagnostic Methods: Clinical Applicability, Implementation Challenges, and Integrated Testing Strategies

## TL;DR

This review evaluates TB diagnostic methods, focusing on their real-world use, challenges, and how to integrate them effectively in different healthcare settings.

## Contribution

The paper offers an implementation-focused analysis of TB diagnostics, addressing gaps in existing guidelines and emphasizing operational and contextual factors.

## Key findings

- Current TB diagnostic methods vary in effectiveness and feasibility depending on healthcare resources and infrastructure.
- Modern techniques like NAATs and LAMP offer advantages but face implementation barriers such as biosafety and workforce limitations.
- Integrated diagnostic strategies tailored to local conditions can improve TB detection and equity in testing.

## Abstract

Tuberculosis (TB) remains one of the leading causes of death from a single infectious agent worldwide, a burden further exacerbated by HIV co-infection and the increasing prevalence of drug-resistant strains. Although a wide range of laboratory diagnostic methods are currently available, their applicability, implementation, and clinical impact vary substantially across healthcare settings with different levels of complexity and resources. This review provides a comprehensive overview of the main laboratory diagnostic methods for active and latent TB, emphasizing their clinical applicability, implementation challenges, and role within integrated diagnostic strategies. Conventional approaches, such as smear microscopy and culture, are discussed alongside modern diagnostic technologies, including automated nucleic acid amplification tests (NAATs), loop-mediated isothermal amplification (LAMP), line probe assays (LPAs), next-generation sequencing (NGS), and lateral flow assays, highlighting their strengths and limitations in distinct epidemiological and operational contexts. Unlike existing WHO guidelines and prior reviews that predominantly focus on test performance and recommendation status, this review adopts an implementation-oriented perspective, critically examining diagnostic methods in light of real-world constraints, regional disparities, and evidence gaps. Particular attention is given to limitations related to laboratory infrastructure, biosafety, workforce capacity, and sustainability, as well as to under-addressed areas such as latent TB, metagenomic approaches, and the investigation of co-pathogens. By integrating WHO guidance with contextual and operational considerations, this review aims to support rational test selection and the development of flexible, integrated diagnostic workflows tailored to local health system capacity, patient populations, and clinical scenarios, thereby strengthening the effectiveness and equity of TB diagnostic strategies.