16

OUTLASTING THE DRUGS
Soon after streptomycin's glorious discovery, a troubling thing occurred. When some patients took the druge, they felt much better for the first couple of months: they gained weight, and the tuberculosis bugs they coughed up had been killed by the drug. Then, strangely, the drug stopped working, the coughing and weakness returned, and the bugs they coughed up were alive and kicking and no amount of streptomycin could kill them. With no other cure possible, these patients could go on to die, and anyone infected by their hardy germs could not be treated by streptomycin either. It appeared that tuberculosis was learning how to outsmart the drug!
Of course, tuberculosis is just a bacterium; it does not have a brain in its tiny rod-shaped body. It cannot learn anything, so how was it getting around streptomycin? The answer is this drug: drug-resistant strains were evolving. A person infected with tuberculosis is like an island nation of TB germs. When assaulted by an antibiotic, all the germs begin to die. However, in this nation, there might be some germs that are just a little different, as there are people in any crowd who are just a little different. These germs might be different in a way that makes them able to withstand streptomycin's assault. During drug treatment, as all the normal TB germs were killed, the abnormal strain would survive, with more room to grow and more food to eat because all the normal bugs were dead. After a few months, the abnormal germs would have filled the whole body with their drug-resistant offspring.
Doctors found they could overcome drug resistance if they gave patients several drugs at once: it was much rarer for bacilli to outwit three drugs at the same time, and if people with tuberculosis took the drugs long enough, for six months to a year, so few bacilli had a chance to survive that they were not a threat. Once more than one drug to fight tuberculosis was found, it seemed that this could be a solution. But there is another problem. Multidrug therapy seems to clear up tuberculosis rather quickly, relieving symptoms in a matter of weeks. Meanwhile, among these bacilli might be one that was weird enough to resist two of the three drugs. If bombarded long enough with all three, even this germ will die. But patients do not konw about this bacillus. What they know is that the strong drugs make them feel sick. So, out of discomfort - or forgetfulness, or poverty - people stop taking the drugs too soon. When they do, the weird TB germ has a chance to reproduce. Among its offspring could be an even weirder bug unable to be killed by any of the drugs being used. This has happened so many times there are now some strains of TB that are resistant to seven drugs.
It has been this ability to develop resistance, as well as tuberculosis's preference for attacking poeple when their defenses are down, that has led to a resurgence of tuberculosis just when we thought we had it defeated. In the United States, between 1953 and 1987 the overall number of tuberculosis cases declined by 73 percent. At the same time, however, among minorities in the United States, who were more likely to be poor, the decline was not nearly so steep, and in some developing countries rates were not falling at all. The discovery of an effective cure for tuberculosis was not enough. We still needed to get the drugs to people and to get them to take the drugs for the full six months or more necessary to be cured. Taking the expensive drugs for six months was especially difficult for the poor. Public funds were needed to get the drugs to people. However, as tuberculosis declined among many people, it seemed less and less important to spend money on it. In New York City, in the ten years between 1968 and 1978, the money spent to fight tuberculosis dropped by half.
It was in 1979 that the number of cases of tuberculosis in New York City began to rise again. By 1987, they had increased by 45