Day 129: Aspreadomatic

The latest exciting semi-news out of the WHO is that asymptomatic cases of coronavirus do not contribute significantly to the spread of the disease. It's not really news in that the WHO noted back in April that not a single case of asymptomatic spread had been documented. But it does call into question wearing an ersatz mask that might protect others, on the off chance that you might cough or sneeze while you might be within six feet of another person, and you might be an asymptomatic carrier, and asymptomatic carriers might be infectious, and it might be possible to infect someone without having a prolonged conversation with them—even though none of those things are individually likely according to the science. They are even less likely in combination according to the math.

On the conspiracy front, PlagueBlog readers may recall some rumors of US intelligence about a disease circulating around Wuhan in the early fall. These reports have reentered the non-conspiracy news cycle on the heels of a paper appearing on at Dash, Harvard's preprint server. In Analysis of hospital traffic and search engine data in Wuhan China indicates early disease activity in the Fall of 2019, the authors analyzed both Baidu searches and satellite photos of the parking lots of hospitals in Wuhan from last fall, and discovered that the disease may go all the way back to August 2019:

In August, we identify a unique increase in searches for diarrhea which was neither seen in previous flu seasons or mirrored in the cough search data. While surprising, this finding lines up with the recent recognition that gastrointestinal (GI) symptoms are a unique feature of COVID- 19 disease and may be the chief complaint of a significant proportion of presenting patients. This symptom search increase is then followed by a rise in hospital parking lot traffic in October and November, as well as a rise in searches for cough. While we cannot conclude the reason for this increase, we hypothesize that broad community transmission may have led to more acute cases requiring medical attention, resulting in higher viral loads and worse symptoms. This temporal progression of clinical presentation from mild illness to more severe outcomes has been shown elsewhere.

Massachusetts cases are up 0.18% today. The Boston Globe has a running list of restaurants in eastern Massachusetts that have opened up with outdoor seating for Phase 2 where you can go out to celebrate our ever-dropping case counts. (Certain tin-pot-mayored cities are not featured on the list.)