The battle against tuberculosis (TB) has progressed well in the worst-hit countries of China and India, but the disease is spreading unabated in sub-Saharan Africa and parts of the former Soviet Union, the World Health Organisation (WHO) said Monday.

More than 10 million TB sufferers have been successfully treated under a control strategy known as DOTS in the last decade, WHO said in a statement to mark World TB Day on Monday. More than 90 percent of them live in developing countries, WHO said.

The growth in the global incidence rate of TB has slowed to 0.4 percent a year, and 155 countries out of WHO's 192 member states have now adopted the DOTS strategy.

In India, more than one million TB patients have been treated under DOTS since late 1998, and by early last year the programme was credited with saving 200,000 lives.

China has seen 1.3 million people with infectious TB treated under DOTS over the last 10 years and 90 percent of them cured.

In sub-Saharan African, however, the epidemic is closely linked to HIV/AIDS and poverty, WHO said.

In some countries in the region with high rates of HIV infection, TB rates have quadrupled since the mid-1980s.

DOTS stands for the Directly Observed Treatment Short Course and consists of five elements, including governments' commitment to sustained TB control and a proper drug supply system.