Monday is World Health Day. As the day approaches, we should recognize the huge progress the world has made in the response to HIV. Globally, new HIV infections have fallen by one-third since 2001. AIDS-related deaths have fallen to 1.6 million, compared with 2.3 million in 2005. More and more people living with HIV are leading long, healthy, productive lives.

In China, the coverage of lifesaving antiretroviral treatment has increased more than ten-fold during the past 10 years; new infections among people who inject drugs have fallen; and the number of women receiving treatment to prevent mother-to-child transmission of HIV has increased dramatically.

But despite these successes, we must continue to strengthen our efforts. In China there are still approximately 48,000 new HIV infections every year, with sexual transmission accounting for more than 80 percent of all new infections. As is the case in many countries, these are concentrated among the most vulnerable members of society, including men who have sex with men, sex workers, and people who inject drugs, populations which are heavily stigmatised and, in many cases, criminalized or otherwise subject to administrative arrest and detention.

HIV testing rates among these populations are low. Data from 2013 show that less than 40 percent of sex workers and people who inject drugs came forward to have themselves tested, and only 45.6 percent of men who have sex with men had received an HIV test during the past 12 months. As a result their risk exposure remains high. There is an urgent need to expand coverage of voluntary counselling and testing, prevention, treatment and care services among these most vulnerable populations.