WHO report highlights growing numbers of drug-resistant tuberculosis
19 March 2010
Up to a quarter of people with tuberculosis in some regions can no longer be treated with standard drug regimens. This is the stark finding of a new World Health Organization report which estimates that 440,000 people had multidrug-resistant TB (MDR-TB) in 2008, a third of whom died.
Multidrug and Extensively Drug-Resistant Tuberculosis (M/XDR-TB): 2010 Global Report on Surveillance and Response presents data from 114 countries. It underlines that almost half of all cases of MDR-TB are estimated to occur in China and India. In Africa an estimated 69,000 cases emerged.
The report also explores the relationship between HIV and MDR-TB and notes that drug resistant TB among people living with HIV has been widely documented in certain settings, such as hospitals. It further states that TB patients co-infected with HIV in three Eastern European countries, Estonia, Latvia, and the Republic of Moldova, were found to be at greater risk of having multidrug-resistant tuberculosis compared to TB patients without HIV infection. Studies in Lithuania, Ukraine and Mozambique show similar results. More research is required to ascertain whether these findings would be replicated worldwide and the report notes that no data have been received from countries with the highest HIV prevalence.
According to UNAIDS, HIV-positive people are especially vulnerable to the impact of TB and MDR-TB. They are at increased risk of contracting the disease and experiencing serious side effects and are more likely to die if infected. HIV and TB are seen as so closely connected that they are often referred to as ‘co-epidemics’. To appropriately respond to both epidemics and avoid more widespread drug resistance, fully integrated TB/HIV services should be priority concern of all TB and HIV programmes.
Preventing people living with HIV dying from tuberculosis is one of the nine priority areas in the UNAIDS Outcome Framework 2009-11.
For the first time, the WHO global report includes an assessment of progress countries are making in the diagnosis and treatment of multidrug-resistant TB. Six countries are the subject of special focus. Bangladesh is one of the few developing nations carrying out continuous surveillance among TB cases which were previously treated in selected areas. China has reported results from its first ever drug resistance survey; Ethiopia was among the first countries to introduce rapid molecular laboratory tests. Nepal and Romania both have successful treatment programmes for MDR-TB and South Africa has introduced policy changes for improving management and care for those living with the disease.
Although there has been notable success in some countries, world-wide progress in controlling multidrug-resistant TB remains slow. According to the WHO report only an estimated 7% of all MDR-TB patients are diagnosed.
Of major concern is the very high cost of treating this form of the disease. The price of drugs alone is 50 to 200 times higher than treating a drug-susceptible TB patient. However, WHO maintains that treatment of MDR-TB has been shown to be cost-effective.
According to the report, there is an urgent need for drug regimens which are shorter than the current two year span, improvements in laboratory facilities and access to rapid diagnosis and treatment. WHO is undertaking a five-year project aimed at strengthening TB laboratories with rapid tests in some 30 countries. It is also working closely with a number of organisations to increase access to treatment so that more lives can be saved.
Note: Multi-drug resistant TB (MDR-TB) is tuberculosis that is resistant to at least Rifampicin and Isoniazid, the two most powerful anti-tuberculosis drugs. Extensively drug- resistant TB (XDR-TB) is MDR-TB that is also resistant to at least two out of the three classes of second line TB medicines.