Jails, Chest Radiography, and the Elimination of Tuberculosis

Paul T. Davidson, M.D.

Director of Tuberculosis Control, Los Angeles County, Department of Health Services, Los Angeles, California

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The national goal for the United States is to eliminate tuberculosis from the population by the year 2010 (1). That is unlikely to occur. However, there has been a rather remarkable decline in the reported cases each year for the past 8 yr in the United States following a similar time period in which there had been no decline and many years of significant increases (2). The number of cases for 2000 was the lowest ever recorded in more than 50 yr. But as Jones and Schaffner point out in this issue of the American Journal of Respiratory and Critical Care Medicine, tuberculosis is increasingly concentrated in populations that are at high risk for disease and often difficult to access and evaluate (pp. 77-81) (3). Tuberculosis cannot be eliminated if transmission of the disease to the noninfected continues. This requires finding persons with disease as quickly as possible and rendering them noncontagious with effective medical treatment and environmental controls.

Jails and prisons, particularly within larger urban areas of the United States, remain an important source for transmission of tuberculosis affecting inmates as well as employees. This presents a potential threat for spread of tuberculosis to the general community where employees live and where inmates return following incarceration. Jails are often crowded and have a rapid turnover of inmates and employees. Screening for communicable diseases such as tuberculosis is a vexing challenge in such settings. Commonly suggested approaches such as screening by tuberculin skin testing or symptom review are often impractical or ineffective. And like many things in today's medical economy, there are the proverbial questions challenging the cost effectiveness of such public health screening endeavors. Jones and Schaffner, using a number of published data as well as calculated estimates of cost, have compared three methods of screening for tuberculosis in the jail setting: tuberculin skin testing, symptom review, and miniature chest radiography. No matter what cost factor they evaluated, their conclusion was that miniature chest radiography was the most cost effective. They readily admit that there are a number of barriers that make this approach more costly for smaller jails as well as areas in which the incidence of tuberculosis is much lower.

Screening for tuberculosis with chest radiography in unselected populations has not been recommended for many years by the Food and Drug Administration (FDA) because it is considered not productive and by today's inference likely not to be cost effective (4). This conclusion was reached when studies indicated that thousands of persons had to be screened by routine chest radiography on hospital admission or by mobile minichest radiography of the general population of the United States to find a single case of tuberculosis. Generally, statements were included recommending that when the incidence of tuberculosis is higher in a population, a better yield with radiography might occur making it a more productive means of screening. The latter has generally been overlooked because the United States has an overall low incidence of tuberculosis. It is interesting to note, however, that for years all adult legal immigrants to the United States have been required to have a chest radiograph to rule out active tuberculosis before they are allowed to immigrate (5). Other means of screening are considered impractical. A significant yield of active cases of tuberculosis has been a result of this requirement. As a consequence, considerable transmission of tuberculosis has been prevented.

In the past decade or so indications are that such generalizations regarding a screening process can have potential adverse effects. Radiographic screening as a means of detecting active disease can play an important role when targeted against high-risk populations in which access, timing, and adverse outcomes may not allow for more complex and time-consuming techniques such as tuberculin skin testing. We need to thank Jones and Schaffner for documenting the miniature chest radiograph as the most cost-effective way to get the task done in a high-risk jail population, particularly when a high percentage of newly reported cases in the community have a history of incarceration. Other populations such as recent immigrants and the homeless in larger urban areas should potentially be considered for this type of screening. It is true that radiography does not detect tuberculosis infection. However, the first step in controlling and eliminating tuberculosis is to stop transmission by the early detection of infectious cases. Dealing with tuberculosis infection with no current disease takes a secondary but critical priority in the eventual elimination of this disease.

Should society spend many thousands of dollars to detect an active (infectious) case of tuberculosis in a local jail? Depending on what numbers you use and the incidence of disease in the jail population, the cost may be as low as $5,700 or as high as $62,500 per case detected, according to Jones and Schaffner. Tuberculosis can kill or cripple a person if undetected, untreated, or neglected. It is my opinion that the general public supports spending whatever it takes to prevent the spread of communicable diseases. Tuberculosis in particular is of major concern because it is an airborne pathogen and infection can remain dormant for many years before becoming active and infectious. It also has not been effectively controlled with a vaccine. However, as the disease is perceived as declining and receding more and more into limited segments of the U.S. population such as jail and prison inmates, complacency becomes a real threat to the prospect of eliminating tuberculosis. The public as well as public health officials will need to persist in accepting the importance of tuberculosis as a public health threat not only for those in jails, as suggested by Jones and Schaffner, but for the local as well as world community until this dangerous and persistent disease is truly eliminated. Certain time-tested technologies such as targeted chest radiography will likely continue as a valuable tool in this endeavor.

	References

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1. Centers for Disease Control. A strategic plan for the elimination of tuberculosis in the United States. MMWR 1989;38(Suppl S-3):1-25.

2. Institute of Medicine. Division of Health Promotion and Disease Prevention. In: Geiter L, editor. Ending neglect: the elimination of tuberculosis in the United States. Washington DC: National Academy Press; 2000. Chapter 2, p. 23-50.

3. Jones T, Schaffner W. Miniature chest radiograph screening for tuberculosis in jails: a cost-effectiveness analysis. Am J Respir Crit Care Med 2001; 164: 77-81 [Abstract/Free Full Text].

4. National Center for Devices and Radiological Health. The selection of patients for x-ray examination: chest x-ray screening examinations. Rockville, MD: Food and Drug Administration, 1983, Health and Human Services Publication (FDA), 83-8204.

5. Centers for Disease Control and Prevention. Recommendations for prevention and control of tuberculosis among foreign-born persons: Report of the Working Group on Tuberculosis Among Foreign-Born persons. MMWR 1998;47(RR-16):1-26.