If it wasn't for tuberculosis, I would not have been born. My maternal grandparents met at a TB sanatorium in Cape Town in the early Forties. Their tryst resulted in the birth of my mother. My grandfather didn't do the honourable thing. He slunk away and wasn't heard from again until he was on his deathbed a couple of years ago. At four weeks of age, my mother was taken into care. In the interests of public health, TB sufferers were isolated in sanatoria until they got better or died.
Over the next 14 years, my mother would see my grandmother only briefly. After each visit she would be tested to see if she had caught the Mycobacterium tuberculosis bacterium. 'At Easter, she sent me a toy chicken that laid Easter eggs,' my mother recalls. 'But as everything was fumigated, the nuns wouldn't let me eat the eggs. I wasn't happy. As a boarder in the convent we were always starving.' My grandmother eventually succumbed to the disease and my mother was left in the nuns' charge.
My mother doesn't remember much about the sanatorium in Cape Town, except that there were lots of pine trees in the gardens. Pine trees were a common feature of TB sanatoria at the time, as they were believed to purify the air. Often, patients' beds would be taken out on to the veranda so they could benefit from the fresh air. Some of the other TB treatments seem primitive and cruel by today's standards. At certain sanatoria, patients had heavy sandbags strapped to their chests in the hope it would increase their chest power. Others had large chunks of lung excised and ribs removed. Life expectancy for TB sufferers was five years.
For TB patients, things could only get better. And they did seem to, for a while, anyway. By the time I went to school, the BCG (bacille Calmette-Guérin) vaccine was given routinely and everyone assumed they were safe. But BCG is only effective in 70 per cent of children, and the protection wears off within five to 15 years. After that, the vaccination is not given again because the benefits are unproven and the vaccine can cause a severe local reaction. What's more, BCG isn't very effective against pulmonary TB, the most contagious form of the disease. Some countries, such as the US, don't use the BCG vaccine at all, preferring to treat people once they've become infected.
Fortunately, TB isn't an easy disease to catch. You'd have to be in close proximity to a sufferer on a day-to-day basis to become infected. It is usually transmitted through sneezing or coughing. My grandmother was a nurse and probably caught the disease in hospital. But in spite of the apparent difficulty in catching it, one third of the world's population is infected with the TB pathogen. Thankfully, the bacterium remains dormant in nine out of 10 people, causing them no harm. The one in 10 who do develop the full-blown disease usually get it when they are run down.
Given the right cocktail of drugs, however, the disease is treatable, but the course has to be completed. Once people start taking the medication, the symptoms - coughing, night sweats, fever - disappear, but unless the six-month course of antibiotics is finished, the bacterium will return, mutated, tougher and primed to kill.
And it does. Each year, 2m people die from TB. In 1993, the WHO declared TB a 'global emergency'. Although consumption, as it was once called, used to kill one in three people in London, today it is rarely fatal if treated properly. In the West we have access to drugs and treatment programmes. But this is no reason to become complacent. In England and Wales, cases have increased by 27 per cent in the past 10 years. Today, there are about 7,000 reported TB cases a year in England and Wales; more than 40 per cent of which occur in London.
Mycobacterium tuberculosis is believed to have spread from cattle to humans about 10,000 years ago, around the time we domesticated the beasts. We have co-evolved.
Now, a growing problem is multi-drug-resistant tuberculosis (MDR TB), a virulent strain of the disease which has evolved due to poor treatment programmes. There are drugs that can treat MDR TB, but they are expensive and toxic. In the UK, it costs about £70,000 to treat one patient. It has been estimated that 50m people around the world are infected with a drug-resistant strain of the bacterium.
'In the very poorest parts of the developing world, MDR TB rates are low, because they haven't had any TB drugs there at all,' says Dr John Moore-Gillon, president of the British Lung Foundation. 'It's stopping and starting medication that breeds drug resistance. So, if you've got an extremely impoverished population that only gets basic TB drugs provided by aid programmes, you don't get much drug resistance. On the other hand, if you've got a moderate economy, such as in Eastern Europe, where there's enough money to buy some drugs but not others, where supplies are intermittent, that's where MDR TB is really increasing.'
But no new drugs have been developed for TB in 30 years. 'The fact that we refer to a six-month treatment as being a "short course" shows just how badly we've failed to invest in new treatments for TB,' says Dr Moore-Gillon. Although TB is a big 'market', with 16m sufferers worldwide, only five per cent of those can afford treatment. Not a good prospect for pharmaceutical companies. So TB treatments remain mired in Fifties research.
But things are looking up. Last month, Bill Gates doubled the global investment in TB research in one fell swoop when he gave $83m to Aeras Global TB Vaccine Foundation to help it develop new vaccines. Recently, two TB vaccines have entered phase-one clinical trials (phase one is where the toxicity of the drug is tested on healthy human volunteers). One of the candidate vaccines is an enhanced form of the BCG vaccine, which has been genetically modified to elicit a stronger immune response. The other is based on several proteins taken from the TB bacterium that are targets of the immune system. Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases, says, 'This is the first new TB vaccine to be tested in our country for more than 60 years.'
Some novel diagnostics are also being developed. This month, the World Bank gave a grant of $160,000 to the Apopo research centre at the University of Sokoine in Tanzania to set up more TB diagnostics clinics. The African giant-pouched rat, it turns out, can be trained to detect TB in spit samples. They are quicker and more accurate at determining the presence of TB than a laboratory technician with a microscope. In fact, the rat can process 100 times more sputum samples in a day and it is seven per cent more accurate than a lab technician. The World Bank's money will help fund more clinical trials and pay to train 400 more TB-sniffing rats.
My grandmother, if she were alive today, would be shocked to find that TB is on the up in southern Africa, fuelled mainly by the Aids epidemic. The WHO says HIV is the single most important factor determining the increase in TB in the past decade. It could be five to 10 years before we see a new TB vaccine on the market. Meanwhile, more money and government commitment are needed if we are to stop people dying of TB every 15 seconds.
