Doctors have discovered China's first HIV-negative AIDS patient, reports said Wednesday.

Peking Union Medical College Hospital physicians published their rare case study in November's Clinical Respiratory Journal, revealing how a patient who tested negative for the HIV antibody later tested positive for AIDS.

When a 46-year-old Chinese man entered hospital with AIDS symptoms including a sore throat, labored breathing, blood-stained mucus, a high fever and lung nodules, doctors discounted AIDS after repeated HIV-negative antibody tests, The Beijing News reported.

After receiving treatment at Peking Union Medical College Hospital, the patient was confirmed to have AIDS with a nucleic acid test. He died two weeks after the diagnosis as his condition was too late to cure, the paper said.

Similar cases are rare but the case should alert doctors to the exception, Wu Zunyou, head of AIDS and HIV prevention in China's Center for Disease Control (CDC) in Beijing, told the Global Times on Wednesday.

The death showed that HIV antibody testing is not always fully reliable and that plasma HIV RNA testing can confirm HIV/AIDS, Wu Zunyou, head of AIDS and HIV prevention in China's CDC, told the Global Times on Wednesday.

But plasma HIV RNA testing should not be used regularly to screen AIDS patients because of technical barriers and costs, according to Li Taisheng, a co-author of the study and a doctor at the Beijing hospital's department of infectious diseases.

The test is recommended for those suspected of suffering an advanced HIV infection but still exhibiting HIV negative results, Xinhua quoted Li as saying.

The paper was completed by Peking Union Medical College Hospital including Li, Zhang Hong, Wang Huanling and Zhong Dingrong.

The discovery comes ahead of 30th World AIDS Day on Friday.

Close to 420,000 people were infected with HIV with 300,000 suffering AIDS in China as of June. More than 221,000 Chinese people have died of the virus since records were kept, Xinhua reported.

The case was the world's first HIV-negative AIDS patient to also suffer from Kaposi sarcoma, a cancer that sometimes develops in the advanced stages of the deadly disease.