Tuberculosis (TB)

Early TB detection

TB detection and diagnosis


Mother and child, with a doctor at a TB facility, Nepal
WHO/SEARO

Too many people have undetected TB for too long; late detection of TB increases their risk of transmitting the disease to others, having poor health outcomes, or that they and their family will suffer distress and economic hardship. Progress in controlling TB and mitigating its consequences can be expedited through early diagnosis and treatment. WHO has summarised approaches, guidelines and tools for early detection of TB in Early detection of Tuberculosis: An overview of approaches, guidelines and tools.

There are two principal pathways to early TB case detection. The most important is the “patient-initiated pathway”, which starts with a person with TB actively seeking care when experiencing symptoms. This success in completing this pathway depends on: adequate knowledge in the population about when and where to seek care; equitable access to high quality health care services with minimal financial barriers; quality-assured diagnostic services; sufficient capacity to identify those who should be tested for TB; a well-functioning referral system; and mandatory notification for all health care providers (Figure 1).

The second pathway - the “screening pathway” - refers to the active identification of persons with suspected TB among people who do not actively seek care for symptoms or signs compatible with TB, as well as among people who start but do not follow through the patient- initiated pathway.

Figure 1. The patient-initiated pathway and the screening pathway

The patient-initiated pathway and the screening pathway.

Systematic screening for active TB

Systematic screening has the potential to detected TB in people who would otherwise go undiagnosed or would be diagnosed too late. If done in the right way and targeting the right people, systematic screening can reduce suffering and deaths. However, potential benefits need to balanced against the risks and costs of screening. Mass screening and screening in low-risk groups should be avoided since it risks wasting resources and causing more harm than good. The prioritization of high-risk groups for screening, as well as the choice of screening approach depend on the local TB epidemiology, the health-system context, and the resources available. Systematic screening should be considered as a complementary targeted approach after appropriate efforts have been made to address barriers along the “patient-initiated pathway.”

For more information see Systematic screening for active tuberculosis- Principles and recommendations and Operational guidance on systematic screening for active tuberculosis. An online tool- ScreenTB - to help prioritization of risk groups and chose appropriate screening and diagnostic algorithms has been developed.

TB diagnostics and laboratory strengthening

A high-quality laboratory system that uses modern diagnostics is a prerequisite for the early, rapid and accurate detection of TB and drug resistance. Uptake of TB diagnostic technologies requires appropriate laboratory infrastructure, sufficient human resources and adequate policy reform at country level to enable their effective use in TB screening and diagnostic algorithms.

Chest radiography in TB detection

Chest radiography is an essential tool for the early detection of TB, and therefore fundamental to achieve the targets set out in WHO’s End TB Strategy. It is useful both as a tool for systematic TB screening, as well as for triaging people with respiratory symptoms.

Public-Private Mix (PPM) for TB Care and Control

Public-Private Mix (PPM) for TB Care and Control represents a comprehensive approach for systematic involvement of all relevant health care providers in TB control. One of the key objectives of PPM is to ensure early detection and prompt notification of TB by all health care providers that manage TB.

Practical approach to lung health (PAL)

The Practical Approach to Lung health (PAL) is a syndromic approach to the management of patients who attend primary health care services for respiratory symptoms. It aims to ensure early diagnosis and improve management of TB and other respiratory conditions. The PAL strategy targets multi-purpose health workers, nurses, doctors, and managers in primary health care settings.