Doctors have recently discovered China's first HIV/AIDS patient negative in antibody test but positive in nucleic acid test.

Doctors from Peking Union Medical College Hospital have made public their discovery in a paper published on the latest version of Clinical Respiratory Journal, which has attracted wide attention.

A man, 46, started visiting hospitals in 2011 as he had sore throat, fever, breathing difficulties and was spitting blood for two months. Though doctors suspected that he might be infected with HIV/AIDS, his antibody test was negative, and thus doctors treated him for lung infection, which did not relieve his symptoms.

The man finally sought treatment in Peking Union Medical College Hospital, where doctors found Kaposi sarcoma, a common type of opportunistic tumor among HIV/AIDS patients, in his lungs. Doctors decided to give him the nucleic acid test which came out positive.

Two weeks after the diagnosis, the man died.

The nucleic acid test has proven to be a significant tool in this case, but due to its cost and technology threshold, it is not recommended as a common way of diagnosis, said Li Taisheng, a doctor from the infection department of Peking Union Medical College Hospital.

Li suggested that people could take the nucleic acid test in some situations especially when people worry about the negative antibody test result and are at high risk of infection, such as babies born to mothers with HIV.