The coronavirus which has infected 2,000 and killed 56 was today revealed by Beijing officials to be contagious even before symptoms show.
Speaking at a press conference this morning, health minister Ma Xiaowei said ‘it seems like the ability of the virus to spread is getting stronger’ and that it can be passed from person-to-person during its 14-day incubation period.
The announcement before a packed briefing hall of face-masked reporters sparked concern in Britain, where cases of the disease are likely.
Top scientists from British universities provided snap reaction to the news coronavirus is contagious during incubation:
Professor Paul Hunter, The Norwich Medical School, University of East Anglia
‘If person to person spread from people without symptoms became common then this would be extremely worrying. It would also be very surprising.
‘The consensus from the SARS outbreak was that only patients with symptoms spread the infection.
This map shows all the areas where coronavirus has been identified so far, including Canada
Director of the Chinese Center for Disease Control and Prevention Gao Fu speaks during a State Council Information Office press conference
‘Patients with influenza can transmit the infection before becoming ill but only for a day at most before symptoms develop.
‘The primary way that coronaviruses are spread is by aerosols generated by coughs and sneezes.’
‘By definition once a patient is coughing and sneezing they have already developed symptoms.
‘A description of the early cases suggest that on the current outbreak affected patients are less likely report upper respiratory symptoms such as sore throats and runny noses which may even reduce the risk of person to person spread early in the illness.’
Professor Sheila Bird, Honorary Professorship at Edinburgh University’s College of Medicine and Veterinary Medicine and formerly Programme Leader at MRC Biostatistics Unit, Cambridge
‘If transmission does occur pre-symptoms or is suspected to do so, at some point soon-ish it may be instructive and important for the Chinese health authorities to try to measure within-household transmission, taking account of household size and ages of members of the household.
‘Little has been said as yet about the estimated fatality-rate for patients whose clinical course is completed (ie recovered alive, or deceased) but I’m sure that public health official know how important it is to do so – even if only for hospitalized cases in the first instance.’
Medical staff wearing clothing to protect against the coronavirus walk outside a hospital in Wuhan, which was where the infection broke out
Professor Wendy Barclay, Department of Infectious Disease, Imperial College London
‘Many of the respiratory viruses that spread amongst humans do transmit even in the absence of symptoms, including influenza and other cold viruses.
‘They are carried into the air during normal breathing and talking by the infected person.
‘It would not be too surprising if the new coronavirus also does this. If this does prove to be the case then controlling the spread does become more of a challenge, and measures like airport screening are unlikely to stem the virus effectively.’
Michael Head , Senior Research Fellow in Global Health,Faculty of Medicine, University of Southampton
‘If “symptomless spreading” is confirmed, it would not be too surprising. Other respiratory infections such as measles and influenza can both be spread, without the infected person showing symptoms.
‘A key factor would be the extent of the person-to-person transmission. If transmission between people is not too extensive, then the impact of symptomless spreading would not be too great.
‘If there is significant levels of person to person transmission, this would make containment of the outbreak harder.’
Members of the media have their temperature checked before attending a news conference by the State Council Information Office about the outbreak of the new coronavirus in Beijing
Nathalie MacDermott, NIHR Academic Clinical Lecturer, King’s College London
‘While the suggestion that the (coronavirus) may be contagious during the incubation period, as reported by a doctor in Zhejiang province in relation to a cluster of cases linked to an individual who had yet to show any symptoms, is concerning it is not surprising.
‘It is known that several other coronaviruses and respiratory viruses from other virus families can be spread during the incubation period, the period during which a person is infected but has not yet developed symptoms.
‘This was taken account of in some of the modelling exercises undertaken by colleagues recently, and was likely given the degree of spread of the outbreak within China.
‘There is often the question of whether individuals who may be infected with the virus but never show any symptoms (asymptomatic or subclinical cases) may also be contagious to others.’