By Imogen Foulkes
BBC News, Geneva
Drug resistant tuberculosis has hit the highest levels ever recorded, according to a report on the disease from the World Health Organisation (WHO).
TB is not 'last century's disease', the WHO warns
In a survey of over 90,000 TB patients in 81 countries, the WHO found that levels of multi-drug resistant (MDR) TB were far higher then expected.
The survey also found cases of extensively drug resistant TB which is virtually untreatable in 45 countries.
The findings have taken the organisation by surprise.
MDR-TB is resistant to at least the two most powerful anti-TB drugs, isoniazid and rifampicin.
As a result patients do not respond to the standard six month treatment and have to take more expensive - and more toxic - drugs for up to two years.
It is especially prevalent in the former Soviet Union: in Azerbaijan's capital, Baku, almost a quarter of all new TB cases are multi-drug resistant.
Money 'well spent'
The new survey also reveals that the virtually untreatable form of TB is now present in dozens of countries.
MDR-TB AMONG TB CASES
Baku, Azerbaijan: 22.3%
Donetsk, Ukraine: 16%
Tomsk Oblast, Russia: 15%
Tashkent, Uzbekistan: 14.8%
The figures may well be higher: many African states do not have the diagnostic tools to identify the disease, so the exact level of this often fatal form of TB remains unknown.
The WHO is calling for a major expansion in TB surveillance for treatment programmes for drug resistant tuberculosis to be scaled up.
The $5bn needed would be money well spent, says the WHO.
TB, it notes, is not "last century's disease". There were nine million new cases in 2006 alone, of which 1.7m died.
And neither is it confined to poor countries. In parts of east London, rates of TB are higher then in some developing nations.
Dr Mario Raviglione, director of the WHO Stop TB Department, said: "TB drug resistance needs a frontal assault.
"If countries and the international community fail to address it aggressively now we will lose this battle.
"In addition to specifically confronting drug-resistant TB and saving lives, programmes worldwide must immediately improve their performance in diagnosing all TB cases rapidly and treating them until cured, which is the best way to prevent the development of drug resistance."
The report also found a link between HIV infection and MDR-TB.
Surveys in Latvia and Ukraine found nearly twice the level of MDR-TB among TB patients living with HIV compared with patients without HIV.