Data from South Africa showed that 996 or almost 6% of 17 615 MDR specimens collected between 2004 and October 2007 were extensively drug resistant (XDR) TB. In KwaZulu-Natal 656 (14%) of 4 701 MDR cases recorded in this time period were XDR-TB.
The World Health Organisation (WHO) report, ‘Anti-Tuberculosis Drug Resistance in the World’, is based on a survey of 90 000 patients in 81 countries conducted between 2002 and 2006.
Unlike Latvia and the Ukraine, the report said, South Africa reported a moderate proportion of XDR-TB among MDR-TB cases.
The report also found a link between HIV infection and MDR-TB. In South Africa, the underlying burden of MDR-TB is high and 44% of TB patients are estimated to be co-infected with HIV.
The WHO estimated that there are nearly half a million new cases of MDR-TB ‘ about 5% of the total 9-million new TB cases ‘ worldwide each year with more than 110 000 deaths.
The highest rates were recorded in Baku, the capital of Azerbaijan, where nearly a quarter of all new TB cases were multidrug-resistant.
‘TB drug resistance needs a frontal assault. If countries and the international community fail to address it aggressively now, we will lose the battle,’ said Dr Mario Raviglione, Director of the WHO Stop TB Department, at the release of the report in Washington last night (Tuesday).
‘In addition to specifically confronting drug-resistant TB and saving lives, programmes world-wide 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,’ said Raviglione.
The global survey for the first time included analysis of XDR-TB. XDR-TB has been recorded in 45 countries and the WHO estimates around 40 000 XDR-TB cases emerge every year.
However, few countries are equipped at present to diagnose it. South Africa is one of only two countries in Africa that can do so.
Only six countries in Africa ‘ the region with the highest incidence of TB in the world ‘ were able to provide drug resistance data for the report. Other countries in the region could not conduct surveys because they lack the equipment and trained personnel needed to identify drug-resistant TB.
‘It is likely that there are outbreaks of drug resistance going unnoticed and undetected,’ said Abigail Wright, principal author of the report.
Based on available information, it is estimated that there were 66 711 MDR-TB cases in the Africa region in 2006, with almost 90% of these cases emerging in high HIV prevalent settings.
The African region has the fewest settings for which trends can be identified. Only Botswana, Sierra Leone, CÃ´te d’Ivoire, and Mpumalanga Province in South Africa, have carried out repeat surveys.
In the surveys reported previously Botswana showed a significant increase in drug resistance among new cases, and an increase, though not significant, in the proportion of MDR-TB cases.
The report acknowledged that the large ‘outbreak’ of XDR-TB, in an HIV infected population in Tugela-Ferry in KwaZulu-Natal was associated with extremely high mortality and highlighted the vulnerability of TB patients co-infected with HIV.
‘Detection of this outbreak was only possible because of the extensive laboratory infrastructure available in the country. It is likely that similar outbreaks of drug resistance with associated high mortality are taking place in other countries, but currently going undetected due to insufficient laboratory capacity,’ the report said.
Botswana, Mauritania and Mozambique have nationwide surveys under way and Angola,
Burundi, Lesotho, Malawi, Namibia, South Africa, Uganda, and Zambia have plans to initiate nationwide surveys over the next year, the report said.
Speaking in Cape Town recently Dr Marcos Espinal, Executive Secretary for the Stop TB Partnership, said Africa would not achieve the United Nations sixth Millennium Development Goal (MDG) of halting and reversing the incidence of TB by 2015.
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