Only a few years ago it was left for dead, the presumed victim of modern miracle drugs. But today tuberculosis kills more young people and adults than any other infectious disease in the world.
It is a bigger killer than malaria and AIDS combined and it kills more women than all the combined causes of maternal mortality. More than 100,000 children succumb to the disease each year. Never in human history will so many people die of TB as in this year.
Five years ago it was declared a global emergency by the World Health Organisation. Yet things have gone from bad to worse since; it is estimated that between now and 2020, nearly one billion people will be newly infected, and 70 million will die of the disease.
TB is a classic example of the "one step forward, two steps back" scenario which so bedevils modern medicine. Doctors and pharmacists collaborate to create miracle drugs which all but wipe out a scourge in the developed world.
But poverty, a lack of political will and social upheaval combine to frustrate a similar success in the poor countries of the developing world.
Worse still, this failure provides a springboard for a resurgence of the disease, which then reinvades old territory. The fruits of modern technology, such as growing international travel, speed the process. This time the old enemy has learned new tricks, and new high-resistance strains develop which are hugely expensive or even impossible to treat.
The cost of this failure is phenomenal; treating ordinary TB costs a little more than £1,000 per patient, but dealing with the multi-drug-resistant (MDR) strain costs 100 times as much.
Embarrassed and angered by the lack of progress in fighting the disease, the World Health Organisation earlier this month engaged in a unique exercise in finger-pointing, by targeting eight middle-or upper-income countries which are failing to implement an anti-TB strategy. Brazil, Indonesia, Iran, Mexico, the Philippines, Russia, South Africa and Thailand all stand indicted for not doing enough to fight the epidemic.
In contrast, poorer countries such as Bangladesh, Vietnam and Peru have made progress towards controlling TB, according to WHO.
"Some governments did not take WHO's declaration of a global TB emergency seriously," said Dr Arata Kochi, director of the Global Tuberucolosis Programme. "If we seem impatient in again calling for action, it is because we have an effective solution to a disease which is needlessly claiming millions of lives."
Who sets great store by its DOTS (Directly Observed Treatment, Short Course) strategy, which has doubled cure rates and maintained low drug resistance. DOTS relies on the rapid identification of cases by health workers, who then ensure that anti-TB drugs are administered quickly and, most crucially, are taken for their full course.
TB is spread when people who have active untreated TB germs in their lungs or throat cough, sneeze or speak, and send their germs into the air. People who breathe in TB germs usually have had very close, day-to-day contact with a carrier. So those who live in insanitary or overcrowded conditions, such as refugees, the homeless or immigrants to the developed world, are most prone.
The disease is highly contagious, and each person with active TB will infect on average between 10 and 15 people each year. But those infected will not necessarily get sick. The immune system walls off the TB bacilli which, protected by a thick waxy coat, can lie dormant for years. When someone's immune system is weakened, the chances of getting sick are greater.
The spread of HIV/AIDS is spurring the resurgence of TB; together they form a lethal combination. Someone who is HIV-positive and infected with TB is 30 times more likely to fall sick with TB than someone who is HIV-negative. Tuberculosis is the main cause of AIDS deaths, especially in Africa and Asia.
TB is an excellent benchmark of social progress; thus, for example, it has become increasingly prevalent in Russia as social structures in that country have collapsed since the demise of the USSR. In the US, more than 25,000 people get the disease each year, many of them in New York.
Thankfully, there are no signs yet that the disease is making a comeback in Ireland. The number of new cases has fallen continually throughout the 1990s, from 640 in 1991 to 434 in 1996.