Dr Bernhard Schwartlander, the country co-ordinator for the UN Aids agency in China, said about half of all Chinese will not share a meal with a person with HIV/Aids while a quarter will refrain from shaking hands.
"People will not come forward to be tested. They won't benefit from treatment. They won't talk to their partners and colleagues about HIV/Aids, putting themselves and others potentially at risk for HIV."
The topic also remains very sensitive with reported crackdowns on activists and patients seeking more support and rights.
The Aids epidemic has killed an estimated 25 million people around the world since the HIV/Aids virus was first recognised almost three decades ago.
|Aids remains taboo in China where 700,000 people infected by the virus live [Reuters]
There have been some gains against the disease: the US announced on Sunday that it had already met its goal of treating two million people living with HIV/Aids by the end of the year.
Washington's programme has mainly focussed on sub-Saharan Africa, which is still the most heavily affected region, accounting for about two-thirds of all HIV cases worldwide.
But Asia is facing a growing threat as the disease spreads rapidly in China, Indonesia and Vietnam.
Globally there are about 33 million people living with Aids, with an estimated 700,000 of them in China.
Nancy Fee, the UN Aids co-ordinator for Indonesia, told Al Jazeera that while the overall prevalence of Aids in Indonesia is low, there is a high infection rate among drug users and sex workers.
"We have very good policy direction in terms of the managements of Aids," she said.
"But while there are good programmes established, they are not yet on the scale to beat this epidemic, and the Indonesian government has acknowledged this."
UN estimates indicate five million Asians are already infected by the HIV virus, and the figure is expected to double by 2010.
Asian men are key drivers of the HIV/Aids epidemic in the Asia-Pacific region because, according to the UN Aids agency, 75 million of them "buy sex regularly".