Neil Ferguson, the man with the modelling evidence that underpins the government’s coronavirus strategy, believes he has contracted the bug himself.

Two days after attending the prime minister’s announcement calling for Britain to voluntarily self-isolate, where he stood next to the health secretary, Matt Hancock, Ferguson has the cough and fever symptomatic of Covid-19.

“Sigh. Developed a slight dry but persistent cough yesterday and self-isolated even though I felt fine. Then developed high fever at 4am today. There is a lot of Covid-19 in Westminster,” he wrote on Twitter.

Ferguson is a mathematician and an epidemiologist whose work on the spread of Covid-19 is informing policy in not only the UK but also France, the US and other countries as well. The centre he founded with colleagues at Imperial College, the MRC Centre for Global Infectious Disease Analysis, collaborates with the World Health Organization.

The massive shift in the UK response from essentially letting the virus spread through the population to the wholescale stay-at-home policy now in place resulted from Ferguson’s work, supported by other modellers especially at the London School of Hygiene and Tropical Medicine.

Ferguson has taken a lead, advising ministers and explaining his predictions in newspapers and on TV and radio, because he is that valuable thing, a good scientist who is also a good communicator.

Mathematical modelling is only as good as the data fed into the computers. It was new information on the high rate of patients needing critical care in Italy and on the limited ability of the NHS to respond to the pandemic that caused Ferguson and colleagues to recommend a switch from what they called scenario 1 – mitigation – to scenario 2 – suppression of the virus, including the drastic measures that have emptied the pubs, closed theatres and may yet shut all schools.

He is a workaholic, according to his colleague Christl Donnelly, a professor of statistical epidemiology based at Oxford University most of the time, as well as at Imperial. “He works harder than anyone I have ever met,” she said. “He is simultaneously attending very large numbers of meetings while running the group from an organisational point of view and doing programming himself. Any one of those things could take somebody their full time.

“One of his friends said he should slow down – this is a marathon not a sprint. He said he is going to do the marathon at sprint speed. It is not just work ethic – it is also energy. He seems to be able to keep going. He must sleep a bit, but I think not much.”

Donnelly met Ferguson when they were both working for Prof Roy Anderson’s epidemiology group at Oxford University. Their first project together was modelling the BSE epidemic in cattle in 1996 and then the variant CJD (Creutzfeldt-Jakob disease) outbreak in humans.

They came up with an estimate that was incredibly broad for the likely number of human deaths – between 50 and 50,000 – but that was at a time when some were predicting 2 million people would be infected. There were calls for the sort of NHS resources now going into Covid-19 to be directed towards vCJD. Ferguson and Donnelly’s modelling helped defuse that. In the end the UK had about 170 cases.

Next came foot and mouth, then Sars, then pandemic influenza. With every disease outbreak, governments have turned to the modellers. While Donnelly, with her statistical training, could have had a quiet life as a researcher in the pharmaceutical industry discovering new drugs, she is instead watching the predictions she and Ferguson have made hit the headlines on the TV news. She says both of them were attracted to “high-impact” projects.

Ferguson may have the symptoms of Covid-19 but he is still working. At 9am he joined an online meeting with his colleagues as usual. The stakes are too high for somebody with his dedication and central role in the crisis to stay in bed.