Once called “the captain of all these men of death,” tuberculosis continues to kill 1.8 million people globally each year. In 2014, the World Health Assembly embraced an ambitious resolution to reduce deaths from tuberculosis by 95% by 2035. But despite such global concern, tuberculosis has all but vanished from the U.S. public’s mind as a perceived threat. Although this lack of attention is understandable, given the substantial decrease in disease burden over the past several decades, it jeopardizes the prospect of tuberculosis elimination in the United States — a goal established by the Department of Health and Human Services in 1989. Critical ethical and policy questions must be addressed if elimination is to be pursued in earnest.
We have come a long way since 1953, when 84,304 tuberculosis cases and 19,707 deaths were reported in the United States and the case rate was 52.6 per 100,000. In 2016, the Centers for Disease Control and Prevention (CDC) reported 9287 new tuberculosis cases, for a case rate of 2.9 per 100,000. But there continue to be gross disparities in rates of disease. A total of 68% of newly reported cases in 2016 were in foreign-born persons, who had a case rate 14 times that among U.S.-born persons (see graph).
The case rate among foreign-born persons reflects the global distribution of tuberculosis. According to the World Health Organization 2016 Global Tuberculosis Report, the Southeast Asia and Africa regions accounted for most (71.8%) of the global tuberculosis cases (45.6% and 26.2%, respectively). The remaining cases occurred in the Western Pacific (15.3%), Eastern Mediterranean (7.2%), Europe (3.1%), and Americas (2.6%) regions. In the United States, in addition to the cases reported by the CDC, there are an estimated 13 million residents with latent tuberculosis infection, including 20.5% of foreign-born persons and 1.5% of U.S.-born persons.
Tuberculosis will ultimately develop in an estimated 5 to 10% of people with latent tuberculosis infection. The National Academy of Medicine (formerly the Institute of Medicine [IOM]), the CDC, and many state and local health departments have long publicly recognized the importance of targeting prevention efforts at people with latent infection. As recently as last year, the second priority of the New York City Department of Health and Mental Hygiene Bureau of Tuberculosis Control was to “ensure that individuals at high risk for progression from latent TB infection to TB disease complete treatment and do not develop disease.”
According to researchers at the CDC, because approximately 93% of tuberculosis cases in foreign-born persons in the United States were attributable to the reactivation of latent infection, targeted testing (and treatment) could be an effective strategy for eliminating tuberculosis.1 This finding is consistent with a 2016 review conducted by the U.S. Preventive Services Task Force, which “found adequate evidence that accurate screening tests for [latent tuberculosis infection] are available, treatment of [such infection] provides a moderate health benefit in preventing progression to active disease, and the harms of screening and treatment are small.”2 Scientific advances in the diagnosis of latent tuberculosis infection and shorter effective treatment courses should make it easier for these interventions to be scaled up.3Thus, the challenge for the public health community in the United States is now how to more effectively identify people with latent infection and ensure that they receive the recommended treatment.
The ethical and policy challenges related to identifying and treating asymptomatic latent tuberculosis infection are very different from those involved in responding to infectious tuberculosis disease, when the threat to people who are sick and others around them is immediate. There will be legitimate concerns that screening programs targeted at people with the highest risk of latent infection will inadvertently stigmatize or unfairly burden immigrant populations and will fuel xenophobic sentiments. Although these potential harms must be addressed — and efforts made to minimize their occurrence — we believe they do not justify failing to act effectively to realize the population-level promise of elimination.
Difficult policy questions related to the treatment of latent tuberculosis infection were addressed in a landmark report published by the IOM in 2000. The IOM committee, of which one of us was a member, proposed that immigrants applying to enter the United States who are found to have latent tuberculosis infection be permitted entry under the condition that they undergo therapy and that inmates also be screened and treated for latent tuberculosis infection.4 The decision to release the report at a time when there was still concern about the relative toxicity of treatment for latent tuberculosis infection reflects a judgment by the IOM committee that whatever clinical risks were posed by intervention, the prospect of a public health benefit should take priority. In a cautionary note, the committee also concluded that in the absence of additional evidence, dramatically enhancing outreach to groups with high rates of latent tuberculosis infection would fail; a heavy-handed recourse to coercion was neither ethically justified nor strategically wise.
But the kinds of public health campaigns envisioned by the IOM committee were never implemented. This failure is all the more remarkable given recent advances in the diagnosis and treatment of latent tuberculosis infection. Timidity and limited resources have hobbled efforts to reach and treat people with latent infection. The Comprehensive Tuberculosis Elimination Act of 2008 authorized the appropriation of $200 million in fiscal year 2009, increasing to $243 million in fiscal year 2013. However, the CDC Division of Tuberculosis Elimination received nearly 30 to 42% less funding than authorized during these years.
Inadequate outreach is only part of the problem. One study found that 83% of people in the United States and Canada who tested positive for latent tuberculosis infection accepted treatment — but only 39% of those who were offered the recommended course of therapy completed it.5 What would it take to radically improve rates of treatment acceptance and completion? Would the public health benefits justify the costs? It may be inevitable that in tuberculosis-elimination programs, the cost per case averted increases as the total number of cases decreases.
There are public health officials, health care providers, and activists committed to reducing the burden of tuberculosis in the United States — but we have not seen the type of mass movement that occurred when AIDS activists called on political, organizational, and financial resources to correct what the IOM called a “woefully inadequate response.” Instead, we seem to be recapitulating what Lee Reichman termed the “U-shaped curve of concern”: when investments in public health that are sparked by a sense of threat result in a decline in disease incidence, thereby reducing the perceived danger and leading to lower investments — ultimately setting the stage for disease resurgence.
To be sure, there are constraints on what public health policy in the United States can achieve as long as the global burden of tuberculosis persists. But we believe that there is no justification for the continued failure to press forward with interventions that could have a marked effect on the incidence of tuberculosis domestically. The late George Comstock famously stated that “TB anywhere is TB everywhere.” From the perspective of an ethics of public health, the lack of action to reduce rates of latent tuberculosis infection in the United States represents both the government’s failure to protect its people from infectious threats and society’s failure to provide care to its most vulnerable.