He never thought his life would be turned upside down by the prick of a needle.

The 36-year-old man, who asked to be identified only by his surname Xu, has yet to recover from the shock he got after being pricked while in a Beijing taxi in August. The syringe had been left sticking out of the magazine rack behind the front seat and it stuck Xu in the leg. It contained some yellow liquid that was later tested as containing HIV antibodies.

Subsequent tests over the next three months cleared Xu of HIV/AIDS, but he said his life was completely disrupted. His girlfriend left him and he had to quit his job because of the emotional distress the incident caused him.

"I had heard stories about people using syringes contaminated with HIV to spread the disease but I never thought it would happen to me," said Xu.

The police have yet to find out where the syringe came from and whether someone was indeed trying to intentionally spread HIV.

Over the years there have been many concerns and stories about the intentional transmission of the disease, but most weren't substantiated.

While both willful and negligent transmissions do happen, people working in HIV/AIDS prevention caution against exaggerating such fear and point to the stigma and discrimination associated with the disease as the root of the issue.

Discrimination leads to revenge

Every year, reports surface claiming that some people have placed blood from AIDS patients into food or have injected others with contaminated needles. However, these are usually refuted as rumors. 

Even though such public health concerns are largely exaggerated and only showcase public fears, there are extreme cases where patients have sought vengeance on society.

Gao Yaojie, a doctor and one of the first in China to draw attention to AIDS, wrote in her book about a man who contracted AIDS during a blood transfusion. Unable to hold the hospital legally responsible, the man filled a syringe with his blood and targeted officials.

However, it is important to note that even though matters have vastly improved during the past two decades in terms of public awareness of HIV/AIDS, people living with the disease still face tremendous pressure and discrimination, said Meng Lin, coordinator of China Alliance of People Living with HIV/AIDS (CAP+).

These people's rights to employment, medical attention and travel are still frequently infringed upon.

Most recently a HIV carrier was refused surgery at a Tianjin hospital. The health authorities responded by emphasizing that hospitals should not turn away patients for having AIDS, but this is still a common occurrence all over the country.

In most cases, some HIV/AIDS sufferers have to falsify their medical records or lie about their condition to get needed medical treatment.

Zhao Bin, 22, was tested as being HIV-positive when donating blood in October 2011 but had had sex with only one partner. In July, he went to a hospital in Chongqing with a fever and cold-like symptoms. Doctors told him that he needed to be hospitalized and get IVs. But when Zhao told them he had AIDS, the hospital sent him packing to a designated hospital for infectious diseases.

"The doctors and nurses, despite all their medical knowledge, are still afraid," said Zhao, now a volunteer at Lanyu Group, a Chongqing-based NGO on HIV/AIDS intervention.

Official numbers show only a few hundred cases of occupational exposure to HIV virus among medical practitioners in China, with zero resulting infections.

While this does not necessarily justify certain behavior such as falsifying medical records, the difficult living conditions of HIV/AIDS patients sometimes leave them with no choice, NGO workers say.

"It's when their basic rights are flouted that they feel angry and may sometimes talk about revenge," said Meng, who was diagnosed with AIDS in 1995.

Who to tell

However a more pertinent issue is the spreading of HIV/AIDS among sexual partners. The latest statistics from the Ministry of Health suggest there were over 490,000 AIDS patients and HIV carriers by the end of October, and that sex had become the predominant means of transmission.

In September, a Web user who claimed to be a 19-year-old student wrote online that his former lover, a pilot at Hainan Airlines, had bragged about having unprotected sex with many people after being diagnosed with HIV/AIDS.

The airline later told media that the pilot identified in the post was HIV positive and had been suspended pending treatment. So far there has been no police involvement, nor is there any evidence to show that the pilot did intentionally spread the disease.

However, it still triggered debates over whether someone with AIDS should inform their sex partners.

Zhang Beichuan, a leading expert on HIV/AIDS intervention, said in most cases people engaging in sex without condoms either don't realize they have AIDS or think they can beat the odds. He added that sometimes, sufferers do intend to harm others or are simply seeking to stop their loved ones from leaving them.

Regulation on HIV/AIDS prevention and treatment states that people infected with HIV are obligated to inform doctors and sexual partners of their condition.

Some provinces such as Yunnan and Gansu have also passed measures to mandate that carriers inform their partners within a month of getting the test results or else the health authorities would. Such policies have been heavily criticized for violating patients' right to privacy.

"Whether you tell your partner or other people is not the issue here, the most important thing is to always use protection for yourself and for others," said Xiong Weixiang, the head of Lanyu. His NGO screens and tests about 1,000 people a month, finding about 100 new cases among these.

During that first month, people are still coping with the fact that they have HIV and may not know how to tell their loved ones. Instead of providing them with sufficient care and consultation about how their life is going to be affected in the future, such policies treat carriers as if they are nothing but a threat, said Xiong.

Many people say that after testing positive, they are most concerned about how the situation might affect their family, friends and co-workers.

Zhao admits that a lack of knowledge about AIDS and how to protect against it has led to the spread of the disease.

"Like most people infected with HIV/AIDS, I went through denial, fear and anger before finally accepting the fact," said Zhao.

When he first found out, Zhao was concerned that he might incidentally transmit the disease to his co-workers, so he carried sanitizers and band-aids with him at all times. Zhao said even though his current boyfriend doesn't mind, he is always concerned and cautious.

"We want the disease to stop here and not affect more people," said Zhao.

Split in criminalization

In the Chinese legal system, it is a crime to intentionally spread sexual transmitted diseases through prostitution, but this does not apply in a marriage or an ordinary relationship.

Yang Shaogang, a Shanghai lawyer and advisor to the local government, is among those legal experts who propose legislation to make the intentional transmission of HIV/AIDS a crime, as it already is in many countries.

Yang has taken on two cases where wives sued their ex-husbands, who were HIV positive, for infecting them. The court ruled in favor of the wives in both cases.

Yang believes concealing one's illness and infecting others should be a criminal offense.

However such proposals are met with strong objections from others working to eradicate discrimination. Many have pointed out that intentional transmission would be extremely difficult to prove and that the fear of criminalization may actually do more harm than good.

"It would marginalize the entire group of patients and HIV carriers," said Meng from CAP+, adding that in cases of intentional transmission, the current law is sufficient to punish the offenders on charges of intentional harm.

UNAIDS has also cautioned against the broad application of criminal law to HIV transmission as there is no data suggesting it would achieve its aims but rather risk undermining public health and human rights, according to a policy brief in 2008.

When he was pricked in the leg, Xu immediately thought of all the stories about HIV-contaminated needle attacks. After doctors told him HIV antibodies were found in the syringe, he started to take preventative medicine that caused severe physical discomfort. He couldn't eat for five days and felt constantly nauseous.

But the worst part was the mental distress. "Words can't describe the horror and fear I felt during that month. It felt like I was waiting for death," he recalled. He dared not tell his elderly parents.

Even though Xu did not contract HIV, he has yet to come to terms with the incident.

Xu said he hates the person who put the syringe on the taxi, but he could also see why someone might try to seek vengeance on society. He said he just hoped that person would stop.

When he first saw Love for Life, a film that touched upon the living condition of AIDS patients in China, Xu felt the discrimination portrayed in the movie was overstated.

"After I got pricked by that needle, I often thought about this movie and I watched it several times while I was waiting for my test results, said Xu, "and I cried over and over because I finally understood."