People with coronavirus may be most infectious in the first week of symptoms
The news: People with coronavirus appear to be most infectious within their first week of experiencing symptoms, according to research published in Nature today.
The study: Researchers analyzed data from nine patients with “relatively mild” coronavirus symptoms in Munich, Germany, to see how infectious they were across a 14-day period. Specifically, they checked the viral load in samples from throat and lung swabs, sputum (coughed-up saliva and mucus), stool, blood, and urine.
What did they find? They found covid-19 was replicating in the throat, with concentrations of the virus peaking during the first five days after symptoms started—although it was still possible to detect it after symptoms stopped. They didn’t detect coronavirus in blood, stool, or urine samples. Notably, four of the nine patients also lost their sense of taste or smell, symptoms researchers at King’s College London recently found form a “strong predictor” that someone has been infected (although they have yet to be added to the World Health Organization’s covid-19 symptom list).
More on coronavirus
Our most essential coverage of covid-19 is free, including:
How does the coronavirus work?
What are the potential treatments?
What's the right way to do social distancing?
Other frequently asked questions about coronavirus
---
Newsletter: Coronavirus Tech Report
Zoom show: Radio Corona
See also:
Please click here to subscribe and support our non-profit journalism.
The researchers’ recommendations: It’s wise to avoid drawing too sweeping conclusions from such a small study. More research from a larger pool of patients is needed to confirm the results. However, the researchers say their findings suggest that measures to contain viral spread should focus on transmission from people’s mouths (droplets, in the scientific jargon), rather than objects, materials, or surfaces. That could lend more weight to the argument in favor of wearing a mask or other face covering while in public. The current official advice in the US is that it’s unnecessary, but officials are currently assessing whether it’s time to revise that stance.
Deep Dive
Biotechnology and health
Scientists are finding signals of long covid in blood. They could lead to new treatments.
Faults in a certain part of the immune system might be at the root of some long covid cases, new research suggests.
This baby with a head camera helped teach an AI how kids learn language
A neural network trained on the experiences of a single young child managed to learn one of the core components of language: how to match words to the objects they represent.
The next generation of mRNA vaccines is on its way
Adding a photocopier gene to mRNA vaccines could make them last longer and curb side effects.
Ready, set, grow: These are the biotech plants you can buy now
For $73, I bought genetically modified tomato seeds and a glowing petunia.
Stay connected
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.