Experts have warned strains of drug-resistant Tuberculosis could become a serious global threat, with the potential to persist and spread.
The TB superbugs, which are virtually immune to treatment, are just as “fit” as normal strains and research at the University of New South Wales in Australia has found they “are likely to become highly prevalent”, despite previous research which suggested the strains did not transmit easily.
One in three people carries the TB bug, although in most cases it does not cause illness.
However, according to the World Health Organisation (WHO) there were 9.27 million new cases of TB in 2007 after a total of 1.6 million TB-related deaths were recorded in 2005.
Of the TB cases about 1.7% of patients have multi-drug resistant tuberculosis and in 2006 an “extensively drug-resistant tuberculosis” emerged that is immune to even more treatments.
Dr Mark Tanaka’s team investigated TB infections in Cuba, Estonia and Venezuela to gauge how fast drug resistance was appearing and work out the reproductive “fitness” of different strains.
Dr Tanaka said: “We found that the overall fitness of drug-resistant strains is comparable to drug-sensitive strains. This was especially so in Cuba and Estonia, where there is a high prevalence of drug-resistance.”
Copyright Press Association 2009