Tuberculosis Detection

The World Health Organization declared TB a global emergency in 1993. One-third of the world’s population is infected with tuberculosis, with more than 8.8 million new cases every year and 1.6 million deaths. More than 80% of tuberculosis cases occur in developing countries, where the disease contributes to 20% of all deaths. HIV, homelessness, immigration, overcrowding, drug-resistance, and widening disparities of health care access have contributed to the worsening tuberculosis crisis. A recent article in the New England Journal of Medicine (April 2011) shows that chest radiography is an important part of assessing the severity of tuberculosis, especially among at-risk populations such as the homeless, drug-abusers, and poor. 

In 2007, the world was amazed by the Andrew Speaker case, in which a carrier of tuberculosis traveled freely from the United States to Italy to Greece to Czech Republic and on to Canada before returning to the US, and his dangerous strain of tuberculosis had been identified in a rural town of South Africa one year earlier. These events demonstrated the global nature of this disease and the inadequate measures of containment from faulty international public health cooperation.

The first suggestion of Mr. Speaker’s diagnosis came from radiology, in a radiologist’s interpretation of his chest radiograph ( or ‘chest x-ray’) even though his laboratory specimens had been normal. This raises the question of what is radiology’s role in the epidemic of tuberculosis. More broadly, what is radiology’s role in public health networks?

Radiology’s role in tuberculosis diagnosis and management is important and evolving. The World Health Organization’s 2008 report, Implementing the Stop TB Strategy: A Handbook for National TB Programmes, advocates an important integral role of radiology in caring for tuberculosis patients, particularly in diagnosing those who are negative in laboratory sputum smears and whose symptoms suggest TB. The slippery slope for radiology in tuberculosis management is the common misperception that chest radiographs can substitute all other diagnostic measures of the disease, which can lead to overuse or misuse of this important resource. Instead, radiology enables physicians to assess for other diseases that have similar symptoms and also diagnose TB when laboratory measures are not available or non-diagnostic. Multiple standards in the International Standards for Tuberculosis Care refer to chest radiographs in the system of decision-making pathways.

It is acknowledged that radiographic findings in TB can be non-specific at times, which has been made more difficult by the increasing prevalence of HIV, in which TB often cannot be adequately differentiated on images from other infections. However, radiographs are still important for differentiating other common pulmonary processes, such as asthma and cancers. Moreover, the radiograph can illustrate the extent and severity of tuberculosis along with its complications such as abcess and pneumothorax, which can require other treatments. Therefore, in this context, radiology is a complement to the integrated health system for tuberculosis care, although most of the world does not have access to radiology resources.

RAD-AID is committed to the World Health Organization’s vision of eradicating TB. In this work, RAD-AID aims to advance the appropriate use of medical imaging for TB diagnosis. Appropriate use means optimizing radiology so that it plays the best clinical role possible without wasting resources on unnecessary imaging. In many clinics throughout the world, radiology is currently used in a fragmented and disorganized manner with inadequate training and inappropriate use. RAD-AID seeks to organize a global system of imaging to drive down costs via efficient collaboration, sharing of resources and economies of scale.

RAD-AID argues for a network of imaging that deploys the World Health Organization’s criteria for TB management while achieving operational efficiencies in imaging via personnel training and education so that limited resources are used effectively. The digital resources of uploading images enables transmission to specialists for teleradiology interpretation for a global team of health care providers. RAD-AID also proposes the creation of a world-wide database and analysis on the use of scarce resources for imaging TB. RAD-AID argues for a database that would also facilitate the tracking of disease incidence and the prevention of epidemic spread.

In summary, tuberculosis is a global crisis that is intensifying with concurrent problems of poverty and HIV, in which radiology plays an important and complementary role in the public health and medical care system. RAD-AID aims to contribute to the WHO’s goal of eradicating TB through its dedication to the WHO’s stated objectives of “universal access to high quality diagnosis and patient-centered treatment,” “support [for] the development of new tools and enable their timely and effective use,” and “to improve system-wide policy, human resources, financing, management, service delivery, and information systems.”