Seven Months In: What’s the State of the Science?

Infection and Spread Staying Safe Testing and Contact Tracing

Andrew Joseph, Helen Branswell, and Elizabeth Conney of StatNews have pulled together a tour-de-force synthesis of what science does – and does not – yet know about SARS-CoV-2 and its companion disease, COVID-19. A truly terrific read

Some highlights:

SPACE AND PLACE MATTER. A LOT.
Transmission risk is greatly elevated in crowded indoor spaces with poor ventilation. Activity matters, too, with loud talking, singing, and heavy breathing all upping the risk.

PEOPLE CAN CONTINUE TO TEST POSITIVE (LONG) AFTER THEY’RE INFECTIOUS
The article explains that most people with “mild or uncomplicated infections shed active virus for somewhere up to 10 days after their symptoms started.” But the most common form of testing (PCR) can detect fragments of (non)infectious virus that continue to linger for weeks.

WHAT’S THE INFECTIOUS DOSE?
The “minimum infectious dose” required for infection remains a burning scientific question. The (amazing!) virologist Angela Rasmussen explains that “we don’t know the amount that is required to cause an infection, but it seems that it’s probably not a really, really small amount, like measles.”

A final reflection: Scientific discovery is proceeding at an amazing rate during this pandemic. A huge source of hope!

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