Wang has no idea how he was infected with severe acute respiratory syndrome (SARS).
"People who had been around me are all in good health," the 26-year-old government official said. "That's why I have been puzzled about the infection."
Wang shares a small isolation ward at the brand new 1,000-bed Xiaotangshan Hospital, 20km north of Beijing. His roommate, Liu, is more certain about how he contracted SARS.
Liu, 51, believes his elderly mother infected him while he was caring for her last month.
"At that time people did not know the seriousness of the infection and took personal care of the [SARS] patients," he said.
Liu's mother most likely contracted SARS during a hospital visit on April 10. "We guess that she was infected in People's Hospital."
She waited for over three hours before she could see a doctor.
The 1,020-bed People's Hospital was quarantined on April 24 because of fears over the spread of SARS. The closure followed a government admission on April 20 that it had hidden hundreds of SARS cases in Beijing. But it came too late for Liu and his mother, who has made a full recovery.
Liu hopes officials in China's capital will learn from their mistakes in hiding the SARS outbreak and allowing the disease to spread.
"So many doctors and nurses have been infected, which should teach us a good lesson," he said.
Beijing has recorded nearly 400 SARS infections among medical staff.
"I was very nervous when being isolated," Wang said. "I didn't worry about my health, but I was afraid that I would be infected by others in the isolation ward. I didn't believe I had got SARS at that time, because I had no contacts with any SARS patients."
The Chinese capital is the worst SARS-affected city in the world, with more than 110 deaths and scores more likely to follow among the 3,300 patients who remain in local hospitals.
Wang and Liu both say they are recovering, telling the kind of success stories promoted by the city government to restore public confidence after the scandal over hidden cases. But they will give only their surnames, perhaps worried by the stigma attached to the "killer" disease that has already sparked riots by frightened villagers in several rural areas of China.
Wang began to develop a fever on April 24, when his temperature rose to 39?C. He was admitted to a city hospital the next day and moved on May 1 to Xiaotangshan, becoming one of its first patients.
State media hailed the "miraculous" seven-day creation of the hospital by 7,000 workers. Some 500 SARS patients are now at Xiaotangshan, cared for by hundreds of army doctors and nurses transferred to the hospital to help Beijing cope with its SARS crisis.
Liu Xueqin normally works at the Jinan Military District General Hospital in Shandong Province. She is now a staff nurse supervising 20 other nurses in one of Xiaotangshan's isolation zones. The nurses work six-hour shifts in full protective suits and are not supposed to drink or go to the toilet while on duty.
"When we start work, we get covered in sweat. Two hours later, the sweat has more or less evaporated and you start to get cold," Liu told the official Xinhua news agency.
Hospital director Zhang Yanling runs Xiaotangshan like a military operation, preparing to receive transferred patients six to eight hours in advance. None of the hospital's 1,200 staff had been infected with SARS by Wednesday, he told the agency.