TB on a plane

In May, a series of developments gave meaning to dire public health predictions that emerging and re-emerging infectious diseases -- often considered the plight of lesser-developed nations and poorer populations -- are not so far removed from more mainstream American lives.

The events surround a case of extremely drug-resistant tuberculosis. The patient, a 31-year-old Atlanta lawyer, left the U.S. on a commercial flight May 12 for his European wedding and honeymoon.

Reports indicate he knew he had TB but was not aware of his resistance profile. Ultimately, his illness triggered a Centers for Disease Control and Prevention isolation order, the first since 1963, as well as a full investigation of the patient's level of contagiousness -- he maintains he was told there was no threat -- and the possible exposure of other travelers. At press time, the source of his XDR TB was still unknown and public health officials were urging testing of passengers in nearby rows on his longer flights. This XDR TB situation grabbed the headlines for days. But it also highlights a bigger issue: TB continues to pose a health threat in the U.S.

TB is a global epidemic. Annually, it kills nearly 2 million people worldwide and infects about 14,000 in this country. The challenge of controlling it is amplified by its treatment regimen -- which requires multiple medications over a long period. Failure to adhere leads to drug resistance.

According to the Stop TB Partnership, which includes the CDC and the World Health Organization, multidrug-resistant TB develops when effective drugs are misused or mismanaged. It is a classic example of why antibiotic resistance is a man-made problem. The resilient strain that results takes longer to treat with second-line therapies, which are more expensive and have more side effects. XDR TB, which still is relatively rare, ups the ante even further. It emerges as the bug gains strength over the second-line meds and severely limits treatment options, if any exist at all.

The World Health Organization estimates about a half million cases of MDR TB occurred in 2004. A global study concluded that in some areas, as much as 19% of the MDR TB cases are actually XDR TB. Evidence indicates these strains have been found in more than 30 countries. Based on CDC data, 49 U.S. cases of XDR TB were reported between 1993 and 2006.

Reaching this point is an unintended consequence of efforts to control regular TB. This scenario sometimes happens in poor nations that don't have access to the necessary medicines or the mechanisms to see the full course of treatment through. However, the highly resistant bacteria, transmitted just like regular TB, are very hard to kill, no less so within our borders. This makes TB both a critical domestic and international public health issue.

Here at home, for instance, many experts say federal funding for TB surveillance and treatment is lacking. The AMA has long-standing policy calling for significant increases in federal support for tuberculosis control and research to curtail its spread. It encourages development of effective diagnostics, drug therapies and vaccines. The AMA is also a liaison member of the federal Advisory Council for the Elimination of Tuberculosis.

As case rates in many U.S. locations have dropped, though, so has attention. Experts point to a nearly 10% cut in federal TB funding to most states since 2005, leaving public health programs sometimes with less-than-adequate staff to find and treat the still-occurring cases.

But it is not too late to take action.

Federal and state budgeters can attend to the funding needed to shore up this infrastructure, thereby providing critical safeguards to control both regular TB and to prevent these superpowered bacteria from gaining ground in the drug-resistance battle.

Additionally, health professionals who see TB cases can help prevent MDR and XDR TB by following recommended treatment guidelines, monitoring patients' responses and ensuring completion of therapy.

Finally, this recent experience is an object lesson in why judicious use of antibiotics in general should continue to be a priority.

The risks associated with XDR TB go beyond the 600 or so passengers who happened to be on the international flights last month with the patient in question. The situation is a wake-up call regarding drug resistance and the vulnerabilities people everywhere face from TB and other infectious diseases.