Other possibilities

FIGHTING DISEASE: Fabricating Elisa reagents for AIDS detection at the Pingxiang Municipal Center for Disease Control and Prevention in Guangxi Zhuang Autonomous Region on March 22 (ZHANG AILIN)

While medical experts believe the patients might suffer from a kind of psychological AIDS phobia, others said the possibility of finding a new virus in the future cannot be ruled out.

Wu Zunyou, Director of AIDS Prevention Department of the CDC, said after the ministry's announcement medical tests, especially for such complicated diseases, were not absolute.

In an earlier, yearlong blood test conducted by the Shanghai Institute of Virology, five people in the group were found to have the same unknown virus, Wu said.

"What I can say is that it is definitely not the virus that we know to cause AIDS. The virus' sequence from the five blood samples is similar, but we need more time to study exactly what it is," he said.

Zeng began contacting the patients through their Web support group in July 2009. He said, with two thirds of the samples remaining untested, there was still a chance the U.S. lab may find something the ministry missed.

"The patients are experiencing real symptoms which are not the result of a mental condition," Zeng said.

"I have AIDS-like chronic fatigue syndrome. It has been clinically diagnosed. I believe what makes me living proof of AIDS is similar to this mysterious autoimmune disorder. And yet medical authorities appear unable or unwilling to acknowledge the possibility," a patient with the pseudonym Lin Chang wrote on his online blog.

Two years ago, Lin became seriously ill with what appeared to be AIDS. Soon after, he developed swollen lymph nodes, subcutaneous bleeding, joint pain, fatigue and extreme weight loss.

Three months later, his wife developed similar symptoms. The couple decided to send their 13-year-old son to his grandparents.

"I can pinpoint exactly when my undiagnosed illness spread from my body to another. I am the link in a chain of systemically undiagnosed, sexually connected people. Whatever I am suffering, it strongly resembles the classic AIDS disease," he wrote.

He said many people with chronic fatigue syndrome do not like to talk about the immune abnormalities that they share with AIDS patients. Most patients would rather be told they have the loosely defined chronic fatigue syndrome than AIDS.

From March 31 to May 3, Zhong of the Guangzhou Institute of Respiratory Diseases led a team in conducting clinical investigations for 60 of these patients.

The team was made up of researchers from the No.1 Affiliated Hospital of the Guangzhou Medical University and the State Key Laboratory of Respiratory Disease.

They collected more than 260 samples from 60 patients from 16 provinces and municipalities, including 52 males, whose average age was 34.2.

The patients had shown symptoms for periods ranging from three months to 10 years.

After clinical observation, they decided to test the patients for six common bacteria or viruses. Their studies found 48 patients tested positive for at least one of the six pathogens.

Of these 48 patients, 33 tested positive for the Epstein-Barr virus (EBV), a very common virus of the herpes virus family. The other five viruses were related to high-risk sexual contact.

In the 24 patients examined for knee diseases, 10 showed abnormalities in their knees, and in the 38 examined for eye diseases, 20 were diagnosed with conventional eye diseases.

Zhong said 12 patients agreed to sit psychological tests and seven were found to have abnormal conditions.

The researchers did not detect HIV positive for all the patients, but Zhong did not entirely concur with the Ministry of Health's findings that the group was basically healthy apart from psychological issues.

"We admit that their conditions could be made worse due to psychological factors," he said. "But we do not agree there was nothing wrong with the patients. We have found them carrying viruses that could be contracted via unprotected sex. A large majority of these patients had extramarital sex and their symptoms were triggered or became obvious right after the sex act."

Zhong said he couldn't conclude they were simply suffering from sexually transmitted diseases. There was also no evidence suggesting there was a new, unknown virus affecting the patients and further studies and tests would be needed before they could confirm a diagnosis.

Zhong urged people to avoid unprotected sex and stop sharing dishes in order to prevent contact with such viruses.

Yang, a patient who participated in Zhong's research, said he was grateful for Zhong's efforts.

"At least, we now know we have been infected with known viruses," Yang said.

Referring to the EBV, Deng with the Ministry of Health said they had consulted Zeng Yi, an expert with the Chinese Academy of Sciences who has studied the EBV for more than 50 years. Zeng dismissed the possibility of the virus causing HIV-negative AIDS.

"Further research needs to be conducted in order to determine whether the EBV is the cause of the group's symptoms," Deng said.