The 2019 Novel Coronavirus (2019-nCoV) has so far infected nearly 25,000 people and killed close to 500 as of February 5 [who.int], and has been declared a global health emergency [soylentnews.org] by the World Health Organization. Scientific investigation of the new disease and its properties continues, and there has been an alleged case of transmission of the virus from someone not exhibiting symptoms, from a paper published in the New England Journal of Medicine [nejm.org] last January 30. If true this would make controlling the spread of the disease more difficult. However, subsequent investigation has shown serious flaws in the report. From Science Magazine [sciencemag.org]:
A paper published on 30 January [nejm.org] in The New England Journal of Medicine (NEJM) about the first four people in Germany infected with a novel coronavirus made many headlines because it seemed to confirm what public health experts feared: that someone who has no symptoms from infection with the virus, named 2019-nCoV, can still transmit it to others. That might make controlling the virus much harder.
Chinese researchers had previously suggested asymptomatic people might transmit the virus but had not presented clear-cut evidence. “There’s no doubt after reading [the NEJM] paper that asymptomatic transmission is occurring,” Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, told journalists. “This study lays the question to rest.”
But now, it turns out that information was wrong. The Robert Koch Institute (RKI), the German government’s public health agency, has written a letter to NEJM to set the record straight, even though it was not involved in the paper.
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.)
Other reports from The Scientist [the-scientist.com] and Ars Technica [arstechnica.com]. This doesn't mean that asymptomatic transmission of 2019-nCoV is not happening, but even if it does, so far it appears that it is likely not a major driver of transmission [who.int].