Thursday, March 18, 2010

Under The Radar, T.B. Comes Roaring Back

Strains of tuberculosis that are resistant to the normal drug treatments are spreading across the globe, according to the latest report from the World Health Organisation.

The report shows that one in four cases in parts of Russia are drug-resistant. The WHO estimates that 440,000 people worldwide had multi-drug-resistant forms of the disease (MDR-TB) in 2008, the last year for which there are complete figures, and that a third of them died. MDR-TB is defined as cases in which the two most commonly used and most effective drugs, isoniazid and rifampicin, do not kill the bacteria causing the disease.

More alarming is extensively drug-resistant tuberculosis (XDR-TB), which was first identified in 2006 in a small group of people with HIV in South Africa, almost all of whom died. It is resistant not only to the two basic drugs but also to the second-line antibiotics, including fluoroquinolone, amikacin, kanamycin and capreomycin.

In poor areas such as KwaZulu-Natal, where XDR-TB was first seen, aggressive chemotherapy treatment lasting two years, which can still save lives, is unavailable.

The report warns that not enough is known even about the extent of drug-resistant TB and that the cost of checking the spread of the disease will be high.

Not all countries have the surveillance systems to pick up cases of XDR-TB, but in the 40 that were able to submit data to the WHO, 5.4% of all their drug-resistant cases were XDR-TB. In eight countries, such strains accounted for 10% of all resistant cases. So far, 58 countries have confirmed at least one case of XDR-TB.
Drug resistance in general is running at an all-time high, at 3.6% of all TB cases. Almost half of all the cases are in China and India. In 2008, an estimated 150,000 people died of drug-resistant TB.
The highest levels of drug-resistant TB were on the edge of the EU, in Murmansk, west Russia, where 28% of newly diagnosed cases had a drug-resistant strain. The highest previously recorded level was 22% in Baku, Azerbaijan, in 2007.

The cost of drug resistance is high – both in terms of lives lost and treatment. It costs 50 to 200 times more to treat drug-resistant TB than nonresistant forms. There is also a real risk that resistant TB could spread globally out of control.


T.B. is one of the great killers of humanity since we climbed down from the trees over two million years ago. It has killed rich and poor; famous and obscure. It has even killed famous first ladies. Eleanor Roosevelt died in part due to bone marrow T.B.

Forget the romance of La Boheme, T.B. is a very nasty disease. The symptoms are various but it is the prolonged coughing attacks plus the fatigue that strike home. Mortality from T.B. is 50%.

The only good news about T.B. is most people exposed to the disease never develop symptoms. Only about 10% of people who have latent T.B. advance into the more dangerous active phase.

Still with infection rates hovering around 80% in Asian countries this is small comfort. A quick back of the envelope calculation exposes 8% of the population at risk. This is no small amount when populations are measured in billions, as they are in India and China. The resistant strains are prevalent in exactly the places that do not have the resources to combat them. Second line anti-biotics for T.B. carry a much bigger cost than front line medications. This is not a good state of affairs for the chronically destitute national coffers of nations like the Philippines. When you are too broke to pay attention, how are you going to afford to pay for expensive drug resistant T.B. medications?

The emergence of drug resistant T.B. is not as sexy as Iranian nukes or the antics of North Korean dictators, but it one of those sub rosa events that can have enormous real consequences. It is the type of thing that could not only slow down forward progress in a large portions of the globe, but send it reeling backwards.

Story From the Guardian UK