China's economic boom has managed to lift millions of people out of poverty but some parts of the country are still battling social problems, including soaring rates of drug addiction.<br /><br />One of the worst-affected areas is China's southern province of Yunnan on the border with Myanmar, one of the world's biggest sources of heroin. <br /><br />With a hit costing just a few cents, authorities there are fighting a losing battle to control the problem.<br /><br />Al Jazeera's Tony Birtley reports. (Mar 11, 2010)
