The letter in NEJM described a cluster of infections that began after a businesswoman from Shanghai visited a company near Munich on 20 and 21 January, where she had a meeting with the first of four people who later fell ill. Crucially, she wasn’t sick at the time: “During her stay, she had been well with no sign or symptoms of infection but had become ill on her flight back to China,” the authors wrote. “The fact that asymptomatic persons are potential sources of 2019-nCoV infection may warrant a reassessment of transmission dynamics of the current outbreak.”
But the researchers didn’t actually speak to the woman before they published the paper. The last author, Michael Hoelscher of the Ludwig Maximilian University of Munich Medical Center, says the paper relied on information from the four other patients: “They told us that the patient from China did not appear to have any symptoms.” Afterward, however, RKI and the Health and Food Safety Authority of the state of Bavaria did talk to the Shanghai patient on the phone, and it turned out she did have symptoms while in Germany. According to people familiar with the call, she felt tired, suffered from muscle pain, and took paracetamol, a fever-lowering medication. (An RKI spokesperson would only confirm to Science that the woman had symptoms.)