day before the first confirmed fatality from coronavirus outside mainland China was reported on 2 February this year, the death of the influential guitarist and musician Andy Gill was announced. The 64-year-old, who fronted the post-punk band Gang of Four, died of pneumonia after two weeks in St Thomas’ hospital in London. The trajectory of Gill’s illness, which took medics looking after him in January by surprise, is now familiar – sudden deterioration, low oxygen levels and organ failure. He had fallen sick after his band returned from a trip to China in late November. A short time later, his 26-year-old tour manager was taken to hospital in Leeds with a severe respiratory infection. As images started rolling in of wards in China and then Italy overwhelmed with Covid-19 patients, Gill’s widow Catherine Mayer – an author and co-founder of the Women’s Equality party – couldn’t shake the suspicion that her partner of nearly 30 years may have been an early victim of the virus. In a blogpost written last month, Mayer said she emailed Gill’s thoracic specialist to ask the question. “His response winded me,” she wrote. The consultant said: “It seemed to me at the time of Andy’s illness that we had not fully understood why he deteriorated as he did. Once we learned more about Covid-19, I thought there was a real possibility that Andy had been infected by Sars-Cov-2.” Genetic analyses of the new coronavirus suggest that the virus emerged in humans in China in late November to early December 2019. While China’s official submission to the World Health Organization (WHO) states the first infection was recorded on 8 December, government data seen by the South China Morning Post suggests the first known case was observed on 17 November. In the UK, the first confirmed cases of coronavirus came on 31 January when two Chinese nationals staying in a hotel in York tested positive. But as the crisis has rolled on, and the virus’s range of distinctive symptoms become more widely known, many – some in letters to the Guardian – have asked themselves if they or their loved ones could have had it earlier. “People are on heightened awareness about any sort of respiratory infection and it is easy to retrofit stories to things,” said Dr Stephen Baker at Cambridge University’s Infectious Diseases Institute. Colds, influenza and even pneumonia are, after all, common in the winter months. However, without clear information about what was happening in China in the final months of last year, it is hard to know how likely it is to have arrived in the UK earlier than the first confirmed case, he said. “Let’s say it was kicking off fairly substantially in Wuhan and people weren’t being informed: could there have been people travelling to and from China at that point who may have been infected by coronavirus? That is completely possible. Is it then possible that they transmitted the virus to other people when they were in the UK? Yes, of course that’s possible.” Earlier last month, the news emerged that a swab taken from a man treated in a hospital near Paris on 27 December for suspected pneumonia tested positive for Covid-19, raising the prospect that the virus arrived in Europe a month earlier than previously thought. Data gathered through the Covid-19 symptom-tracking app developed at King’s College London also suggests that people were falling ill from coronavirus in the UK from the beginning of January. “The reports I am getting are from people who were ill from early January onwards and strongly suggest they had Covid-19 but were not recognised as such,” the epidemiologist professor Tim Spector said last month. Recently released minutes from the meetings of the Scientific Advisory Group for Emergencies (Sage) show that in January that the group felt unable to plan for “the worst case scenario” because of the uncertainty around the data coming out of China. On 13 March, over a week before lockdown was introduced, the group concluded “there are more cases in the UK than previously thought and we may therefore be further ahead of the epidemic curve”. The WHO has urged countries to investigate any other early suspicious cases, so that the circulation of the virus can be better understood, encouraging doctors to check records for pneumonia cases of unspecified origin in late 2019. Public Health England has also acknowledged that it “cannot exclude the possibility that Covid-19 was in the UK in December or early January”. Andrew Soppitt, a retired hospital consultant from West Sussex, is convinced he became infected with coronavirus on a skiing trip to Austria in late January. The ski resorts he visited, St Anton and Bad Hofgastein, were the suspected locus of many subsequent infections. “I was really ill. I felt like death. I just couldn’t get out of bed. I could barely get up the stairs. I lost my sense of taste and smell. I started having sweats,” he said. Soppitt made repeated requests to be tested through the NHS 111 service, but was refused. Earlier this month, the former intensive care specialist, who is in his mid-50s, got the results back from a privately-bought antibody test, which showed he had had the disease at some point but can’t pinpoint when. He says he is certain, though. “It absolutely confirms that I had it February after the trip to Austria in January. It is now blindingly obvious that it was about before people admitted it.” But if there were cases in the UK earlier than previously thought, then why did the virus only start to escalate when it did? The answer, says Baker, is that it probably took an influx of infected people before the epidemic really started to grow in the UK. “It was around February half term, people coming back from skiing holidays in northern Italy – that’s probably what brought back a bulk of the [first] cases. It’s really at the point when you get a number of introductions in one go that onward transmission is more likely to happen … as soon as you get a certain number of the population infected in one go then you make that expansion of an epidemic [more likely].” Not everybody who has coronavirus is equally infectious and, if there were cases earlier in the year, they may not have had enough contact with others to form significant outbreaks, said Baker. “When you’re ill, you tend to stay at home, so people may have been self-isolating on the basis that they didn’t feel very well.” Another possibility, says Nathalie MacDermott, clinical lecturer in infectious diseases at King’s College London, is that the virus was “smouldering under the surface for a long time and we weren’t necessarily identifying it”. If, as some research suggests, a large proportion of coronavirus infections are asymptomatic, then the virus could have been spreading silently and gaining access to more vulnerable sections of the population. “The elderly population, generally speaking, are a little bit less likely in the first place to come into contact with it, because they are not in a workplace where they are having frequent contact with people. They go out, but it might be more limited … So maybe it took a while to get to widespread community transmission and to start affecting our older population.” The idea that coronavirus was spreading in Europe as early as December and January has serious public health implications, a fact that has propelled Catherine Mayer to look for answers after her husband’s death. She and the specialist who treated Gill hope to be able to do antibody tests on samples from him and his tour manager to establish whether they had the disease. “How many hundreds of thousands of Covid-19 deaths might have been prevented by greater transparency and quicker and better public health responses, and not just in China but elsewhere?” wrote Mayer.