Science

What makes a ‘wave’ of disease? An epidemiologist explains

Daily deaths from Covid-19 have rarely been below 600 in the U.S. since March.

Panic about a second wave of coronavirus cases is “overblown,” Vice President Mike Pence wrote in June, implying the U.S. has Covid-19 under control. On the other hand, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, warns that the U.S. is still firmly within a first wave of cases.

As media broadcast information about daily increases in the number of cases, it’s hard not to wonder which way the country is headed. Have the weeks and months of lockdown really helped? What do the trends in diagnoses and deaths mean for the course of the pandemic? Is the U.S. stuck in a first wave? Through the worst of it? Headed for a second round?

Science

Coronavirus: asymptomatic people can still develop lung damage

Modern medicine rightly emphasizes the importance of science.

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Modern medicine rightly emphasizes the importance of science. The focus, however, too often displaces our attention from the real point of healthcare – to care. This is nicely captured by William Osler’s (1849-1919) admonition to attend to the patient rather than their disease – a sentiment treated as a quaint bromide by the unwary practitioner. I rediscovered the truth of his advice when two particular patients taught me about COVID-19 infection and challenged what expertise I thought I had in managing pneumonia.

The first patient with COVID-19 that presented to my hospital was probably typical of initial patients in many other hospitals at the time. He was an elderly man with pneumonia, as yet untested for the new coronavirus but presumed to have it. An expert team carefully assessed him, prescribed high-flow oxygen, and monitored him on a respiratory ward. He died unexpectedly that night.

More than half a million people have died from COVID-19 globally. It is a major tragedy, but perhaps not on the scale some initially feared. And there are finally signs that the pandemic is shuddering in places as if its engine is running out of fuel. This has encouraged many governments to relinquish lockdowns and allow everyday life to restart, albeit gingerly.

The spread of SARS-CoV-2 has been difficult to predict and understand. On the Diamond Princess cruise ship, for example, where the virus is likely to have spread relatively freely through the air-conditioning system linking cabins, only 20 percent of passengers and crew were infected. Data from military ships and cities such as Stockholm, New York, and London also suggest that infections have been around 20 percent – much lower than earlier mathematical models suggested.

Science

The science of how you sound when you talk through a face mask

Martin Rickett - PA Images/PA Images/Getty Images

The great face mask debate has been had, and most people agree that it’s a good idea to wear one to prevent the spread of Covid-19. And for as long as we do not have a vaccine, we can foresee that advice from national governments and the World Health Organization to wear one will be in place for some time.

This means we might communicate very differently with each other for months or even years to come. Having a conversation with a mask on can be awkward – it’s often harder to read a mask wearer’s attitudes and emotions, and difficulties faced by deaf people who cannot lipread from a masked talker’s mouth have been well documented.