Identification of SARS-CoV-2 RNA in Healthcare Heating, Ventilation, and Air Conditioning Units (preprint) medrXiv. From the abstract: “The presence of SARS-CoV-2 RNA was detected in approximately 25% of samples taken from nine different locations in multiple air handlers. While samples were not evaluated for viral infectivity, the presence of viral RNA in air handlers raises the possibility that viral particles can enter and travel within the air handling system of a hospital, from room return air through high efficiency MERV-15 filters and into supply air ducts.”
The implications of silent transmission for the control of COVID-19 outbreaks PNAS. From the abstract: “[O]ver one-third of silent infections must be isolated to suppress a future outbreak below 1% of the population. Our results indicate that symptom-based isolation must be supplemented by rapid contact tracing and testing that identifies asymptomatic and presymptomatic cases, in order to safely lift current restrictions and minimize the risk of resurgence.”
I’m a U.S. Citizen. Where in the World Can I Go? NYT. Here’s the list; entry requirements differ: Albania, Antigua and Barbuda, Aruba, The Bahamas, Barbados, Bermuda, Croatia, Ecuador, French Polynesia, Jamaica, Kosovo, Maldives, Mexico, North Macedonia, St. Lucia, St. Maarten, St. Vincent and The Grenadines, Serbia, Tanzania, Turkey, Turks and Caicos, Ukraine, and the United Kingdom. I shouldn’t mock this; as a general matter, the very last thing the United States needs is to be more disconnected from the world.