Triumph and Tragedy

"The story of tuberculosis during the past 30 years has been one of triumph and tragedy—the triumph of the scientists who provided the means to control and ultimately eradicate the disease, and the tragedy of the widespread failure to exploit their discoveries."
—J. R. Bignall, 1982.

Tuberculosis (TB) has been killing for a long time. It afflicted the Incas of Peru long before Europeans sailed to South America. It attacked Egyptians in the days when pharaohs ruled in splendor. Writings from of old show that TB stalked both great and small in ancient Babylon, Greece, and China.

From the 18th century until the early 20th century, TB was the leading cause of death in the Western world. Eventually, in 1882, German doctor Robert Koch officially announced his discovery of the bacillus responsible for the disease. Thirteen years later Wilhelm Röntgen discovered X rays, making it possible to scan the lungs of living persons for signs of tubercular lesions. Next, in 1921, French scientists created a vaccine against TB. Named after the scientists who discovered it, BCG (Bacillus Calmette-Guérin) remains the only available vaccine against the disease. Nevertheless, TB continued to exact a terrible toll.

At Last, a Cure!

Physicians sent TB patients to sanatoriums. These hospitals were frequently located in the mountains, where patients could rest and breathe fresh air. Then, in 1944, doctors in the United States discovered streptomycin, the first antibiotic found to be effective against TB. The development of other anti-TB drugs quickly followed. At last, TB patients could be cured, even in their own homes.

As infection rates plummeted, the future looked rosy. Sanatoriums closed down, and funding for TB research dried up. Prevention programs were scuttled, and scientists and doctors looked for new medical challenges.

Though TB was still taking a heavy toll in the developing world, surely things would improve. TB was history. That is what people thought, but they were wrong.

A Deadly Comeback

In the mid-1980's, TB began to make a dreadful and deadly comeback. Then, in April 1993, the World Health Organization (WHO) declared TB "a global emergency," adding that "the disease will claim over 30 million lives in the next decade unless immediate action is taken to curb its spread." It was the first declaration of its kind in WHO history.

Since then, no "immediate action" has bridled the spread of the disease. The situation, in fact, has worsened. Recently, WHO reported that more people perished from TB during 1995 than in any other year in history. WHO also warned that up to half a billion people might become ill with TB during the next 50 years. Increasingly, people would become victims of often-incurable, multidrug-resistant TB.

Why the Deadly Comeback?

One reason is that during the past 20 years, TB-control programs have deteriorated or disappeared in many parts of the world. This has led to delays in diagnosing and treating those with the disease. That, in turn, has resulted in more deaths and the spread of the disease.

Another reason for the reemergence of TB is the growing number of poor, malnourished people who live in crowded cities, notably the megacities of the developing world. While TB is not limited to poor populations-anyone can catch TB-unsanitary and crowded living conditions make it easier for infection to pass from person to person. They also increase the chances that people's immune systems will be too weak to resist the disease.

HIV and TB—Double Trouble

A major problem is that TB has formed a lethal partnership with HIV, the AIDS virus. Of the estimated one million people who died of AIDS-related causes during 1995, perhaps one third died of TB. This is because HIV weakens the body's ability to resist TB.

In most people TB infection never progresses to the point of causing sickness. Why? Because the TB bacilli are imprisoned within cells called macrophages. There, they are locked up by the person's immune system, particularly by the T lymphocytes, or T cells.

The TB bacilli are like cobras secured in baskets with tight-fitting lids. The baskets are the macrophages, and the lids are the T cells. When the AIDS virus arrives on the scene, however, it kicks the lids off the baskets. When that happens, the bacilli escape and are free to despoil any part of the body.

AIDS patients are, therefore, far more likely to develop active TB than are people who have healthy immune systems. "People who have HIV are fantastically susceptible," said a TB specialist in Scotland. "Two HIV patients at a clinic in London contracted the disease after sitting in a passage when a TB patient was wheeled past them on a trolley."

Thus, AIDS has helped fuel the TB epidemic. According to one estimate, by the year 2000, the AIDS epidemic will result in 1.4 million cases of TB that would not otherwise have occurred. An important factor in the increase of TB is not only that AIDS victims are highly susceptible to the disease but also that they can pass TB on to other people, including those who do not have AIDS.

Multidrug-Resistant TB

A final factor that is making the fight against TB more difficult is the emergence of drug-resistant strains of TB. These superstrains threaten to make the disease incurable again, as it was in the era before antibiotics.

Ironically, poorly managed administration of anti-TB drugs is the primary cause of multidrug-resistant TB. Effective treatment of TB extends over at least six months and requires that patients take four drugs with unerring regularity. The patient may need to swallow as many as a dozen pills a day. If patients do not take the drugs regularly or do not complete the treatment, strains of TB develop that are difficult or impossible to kill. Some strains are resistant to as many as seven of the standard TB drugs.

Treating patients with multidrug-resistant TB is not just difficult, it is also expensive. The cost can be nearly 100 times more than the cost of treating other TB patients. In the United States, for example, the medical bill for the treatment of a single case might exceed $250,000!

WHO estimates that about 100 million people worldwide may be infected with drug-resistant strains of TB, some of which cannot be cured by any known anti-TB drugs. These lethal strains are as contagious as the more common strains.

Prevention and Cure

What is being done to counter this global emergency? The best way to control the disease is to detect and cure infectious cases at an early stage. This not only helps those who are already sick but also stops the spread of the disease to others.

When TB is left untreated, it kills more than half its victims. When properly treated, however, TB is curable in almost every case if it is not caused by a strain that is resistant to a range of drugs.

As we have seen, effective treatment requires that the patients complete the entire course of medication. Frequently, they do not. Why not? Well, cough, fever, and other symptoms usually disappear a few weeks after treatment starts. So, many patients conclude that they have been cured and stop taking the medicines.

To counter this problem, WHO promotes a program called DOTS, which stands for "directly observed treatment, short-course." As the name suggests, health workers watch to make sure their patients swallow each dose of the medicines, at least for the first two months of treatment. Yet, this is not always easy to do because many of those afflicted with TB live on the fringes of society. Since their lives are often filled with turmoil and problems—some are even homeless—the challenge of regularly seeing to it that they take their medicines can be overwhelming.

So are there any prospects for finally conquering this plague on humankind? The following article will answer this question.