A hundred years ago Sir William Osler described acute pneumonia as “The Captain of the Men of Death,” a phrase he remembered from John Bunyan’s The Life and Death of Mr. Badman (the actual phrase is “Captain Consumption, with all his men of death”). In 17th century England it was indeed “consumption,” an older term for tuberculosis, which deserved the rank in Death’s Legion, and the day may come again when it will come out of retirement to lead a new regiment against us. Beginning in the late 1940s tuberculosis began to recede from the consciousness of the industrialized West, and now it is an infrequent but manageable disease. Mostly. But it still ravages the developing world and WHO estimates 8.8 million new cases a year (2005 data), 1.6 million deaths (about one person every 20 seconds). 195,000 also had HIV infection. None of that is good news, but if there was any good news it was that we did have drugs that could manage and control the disease. Did.
Because now we have drug resistant TB. Yes, we’ve had TB resistant to many of our first line drugs for a long time. That was multidrug resistant (MDR- TB). Now we have TB resistant to our second line drugs. That’s Extensively Drug Resistant TB, or XDR-TB. (The technical definitions: MDR-TB is resistant to isoniazid and rifampicin; in addition, XDR-TB is resistant to at least one of three injectable second line drugs (capreomycin, kanamycin, and amikacin). Of the 8.8 milliion new cases how many are XDR-TB we don’t know because most places where it occurs don’t have the laboratory capacity to diagnose it. We know it has been reported in 37 countries, including the US, and WHO’s estimate is about 27,000 new cases a year. Even when treatable, the drugs are expensive and treatment lasts up to two years requiring constant compliance.
WHO’s estimate of XDR-TB’s case fatality ratio is 50%, but when combined with HIV it is almost always fatal (CFR greater than 90%).
“The global concern is . . . we will face untreatable TB,” [Dr. Karin Weyer, of the tuberculosis research and policy unit of South Africa's Medical Research Council] said.
“It’s like TB in the ’20s,” [Emory University's Dr. Ruth] Berkelman said of that possibility, though she admitted with increased population density, global travel and HIV-AIDS, the problem of untreatable TB would actually be more complex in the 21st century. (Helen Branswell reporting for Canadian Press)
Our interest here in bird flu has been to use it as a lens for looking at public health. We could as easily have used XDR-TB wbich has been likened to bird flu in slow motion. Which is worse, bird flu or XDR-TB?
They are both bad. Really, really bad.