It looks like Ontario might finally have run out of glitches and increased numbers from removing conditions to get tested. 243 new cases today, down from 415 yesterday. However yesterday had 223 older cases added, so actually it's up a bit, yet well down from the 400 avg we were starting to go over again. Hopefully this time the lower numbers will stick and continue to go down.

Quebec has continued to go down, now averaging 216 new cases a day. British Columbia hasn't reported since June 4th though (yet was sub 10 per day) and Alberta stopped reporting on Saturday. Canada is down to around 600 new cases a day.

Still a ways to go. This Friday bars, restaurants and hair salons will re-open except in the greater Toronto area. No time to waste to get things going again...


Edit: Ugh. So we're part of the early re-openings, yet 15 km away stays further restricted. No travel restrictions, guess what's going to happen...

We seem to have almost beaten it here in Australia.

Most states have gone some time without any new cases, and my own, Victoria, just reported no new cases over the last 24 hour period.

Nation-wide, we only have 19 people currently in hospital from it.

Our strategy, at least here in Vic, has been one of locking down early, widespread community testing, and rigorous tracing and isolation of contacts.

It's not only about the mask. All evidence so far pointing in the direction, that infection is more likely indoors than outdoors. So an office workplace with multiple people speaking for 8 hours in the same room with low to none airflow means you breathe a lot of air that was in other peoples lungs. A one-hour protest outdoors where breathed out particles are quickly dispersed by airflow means much less of a risk.

I just got called for for friday noon to the widespread testing campaign here in Luxembourg. Let's see if I'm really not having the virus or if it's possibly asymptomatic.

I don't think I'm affected, however. Luxembourg is down to 29 cases, and all apart from one are treated in the hospital (to reduce the risk or further infections going out from them).

Tracing the start of the pandemic
https://www.ctvnews.ca/health/coronavirus/satellite-images-of-wuhan-may-suggest-coronavirus-was-spreading-as-early-as-august-1.4975822

Satellite images of hospital parking lots in Wuhan as well as internet search trends, show the coronavirus may have been spreading in China as early as last August, according to a new study from Harvard Medical School.

Researchers saw "a steep increase in volume starting in August 2019 and culminating with a peak in December 2019," Using images from October 2018, the researchers counted 171 cars in the parking lots at one of Wuhan's largest hospitals, Tianyou Hospital. Satellite data a year later showed 285 vehicles in the same lots, an increase of 67%, and as much as a 90% increase in traffic during the same time period at other Wuhan hospitals.

"Individual hospitals have days of high relative volume in both fall and winter 2019. However, between September and October 2019, five of the six hospitals show their highest relative daily volume of the analyzed series, coinciding with elevated levels of Baidu search queries for the terms 'diarrhea' and 'cough',".

"The data is actually especially compelling because we saw increases in people searching for gastrointestinal disease -- diarrhea -- which were increasing at a level that we hadn't seen at all, historically, and we now know now that gastrointestinal symptoms are a really important marker for COVID,". "A huge percentage of people that actually end up testing positive in Wuhan actually had presented symptoms of diarrhea."

This ties in to military athletes getting sick during the Wuhan military games end of October and possibly bringing it back as early as November. The virus has possibly slowly been spreading, undetected since then. On a reality show my wife was watching last night, one person (American) said they were in the hospital for over a month, in an induced coma on a respirator at the end of December. But they told her it was just the flu and she never got tested.

What this could mean is that Sars-Cov-2 actually spreads slower naturally than so far assumed, since when you start testing you find a lot of older ongoing cases. It has also been shown that covid19 can last a long time in people even with mild to no symptoms. (Has that women in Italy finally tested negative, fine and in quarantine for over 2 months) https://www.newsweek.com/italian-woman-tests-positive-covid-19-after-60-days-quarantine-swabbing-1500202

Europe, North America, infected early from military athletes bringing it back in November. They showed (perhaps false) fast growth when testing started in March. Other continents, infected later, testing caught up earlier, show slower growth, Africa being the slowest.

This would be good news (lower R0) since it will be easier to keep Rt under 1 and also explains why countries like Sweden aren't exploding with minimal measures. Total lock down is not necessary, yet a little bit more than Sweden is doing. And of course still more in very densely populated areas with people working on top of each other. Stay safe, stay outside if you go anywhere.

For indoor spaces, central air should get strong UV-C light 'filters' to make sure no virus particles can be circulated around in the building. They already use UV light systems for pools. It also exists already for central air https://hvactraining101.com/best-hvac-uv-lights/ https://www.joneca.com/uv-c-air-sanitizer/

I wonder how effective or powerful a unit like that is though

A short-wave spectrum called UV-C is much more dangerous to all genetic material. It’s a germicide, which means it can kill up to 99.99 per cent of bacteria and viruses. The UV-C emitted by the sun is stopped by the ozone layer, so we aren’t directly exposed to it. That’s a good thing because our fragile skin and eyes couldn’t handle it. When produced artificially, UV-C breaks up the genetic material of the pathogens floating in air or water and sticking to surfaces so that they cannot function or reproduce.

Tha does not sound compatible with a do it yourself installation which states check if the light bulb glows blue...

Good news

https://www.ctvnews.ca/health/coronavirus/asymptomatic-spread-of-covid-19-appears-to-be-rare-who-official-1.4975927

The spread of COVID-19 by someone who is not showing symptoms appears to be rare, Maria Van Kerkhove, the World Health Organization's technical lead for coronavirus response and head of the emerging diseases and zoonoses unit, said during a media briefing in Geneva on Monday.

"From the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual," Van Kerkhove said on Monday. "We have a number of reports from countries who are doing very detailed contact tracing. They're following asymptomatic cases, they're following contacts and they're not finding secondary transmission onward. It is very rare -- and much of that is not published in the literature," she said. "We are constantly looking at this data and we're trying to get more information from countries to truly answer this question. It still appears to be rare that an asymptomatic individual actually transmits onward."

However

A study in April found that viral shedding -- when people may be able to infect others -- could begin two to three days before symptoms appeared. In addition, the U.S. Centers for Disease Control and Prevention estimates in planning scenarios that 40% of coronavirus transmission is occurring before people feel sick.

"These patients weren't asymptomatic," Juthani said. Rather, they were "spreading disease before becoming symptomatic."



So maybe not good news. There's no way to tell if someone is getting sick in 3 days...

Overall, "these findings suggest that if we quarantine and contact trace symptomatic people, we can make a significant dent in the pandemic," Juthani said.

Making this distinction between asymptomatic and pre-symptomatic infections remains important -- but also between "paucisymptomatic infections," which refers to having atypical or very mild symptoms, Babak Javid, a principal investigator at Tsinghua University School of Medicine in Beijing and consultant in infectious disease at Cambridge University Hospitals, said in a written statement distributed by the U.K.-based Science Media Centre on Monday.

"Detailed contact tracing from Taiwan as well as the first European transmission chain in Germany suggested that true asymptomatics rarely transmit. However, those (and many other) studies have found that paucisymptomatic transmission can occur, and in particular, in the German study, they found that transmission often appeared to occur before or on the day symptoms first appeared," Javid said in the statement.

"Other data available, from studies in several continents confirming that presymptomatic transmission does occur, would suggest that being well does not necessarily mean one cannot transmit SARS-CoV-2," Javid said in part. "This has important implications for the track/trace/isolate measures being instituted in many countries."


- Infected and not getting any symptoms, chance you can / could have spread it is very rare.
- Infected and you are going to get atypical, mild symptoms or worse, you can spread the infection 3 days before symptoms show.


The good news is, that if you have tested positive but still don't have any symptoms after 2 weeks, you most likely will not have infected anyone else nor are contagious even though still testing positive.

There are outliers. The average incubation time is 5 days, 97.5% show symptoms within 11.5 days, longest recorded is 27 days.
https://www.sciencedaily.com/releases/2020/03/200317175438.htm
https://www.news-medical.net/news/20200224/Coronavirus-incubation-period-could-be-27-days-longer-than-previously-thought.aspx

What would you estimate the R number to be if left unchecked. Now that it might have been spreading since november? Estimates right now puts it somewhere at 2.

That sounds more plausible atm. It's hard to tell since it depends so much on population density and general behavior of people. It will also accelerate when more people are contagious within the same building. More virus particles circulating around in a closed environment.

Very crude unscientific assesment
Late August start, we're about 300 days in, reaching 7.2 million reported infections world wide, representing perhaps 70 to 100 million actual infections. To reach 100 million today from a patient zero 300 days ago, 1.063x increase per day, global R of 1.37 with lock downs.

China had 1287 reported cases on Janurari 24 (lock down) yet likely at least 20x as many with spotty early testing.
150 days from late August to Jan 24th.
25K cases (20x more than detected) would be 1.070x daily increase, R of 1.41
50K cases (40x more than detected) would be 1.075x daily increase, R of 1.44
130K cases (100x more than detected) would be 1.081x daily increase, R of 1.5

Changing the start to late September (120 days)
25K cases (20x more than detected) would be 1.088x daily increase, R of 1.54
50K cases (40x more than detected) would be 1.094x daily increase, R of 1.58
130K cases (100x more than detected) would be 1.103x daily increase, R of 1.65

Changing the start to late October (90 days)
25K cases (20x more than detected) would be 1.119x daily increase, R of 1.78
50K cases (40x more than detected) would be 1.128x daily increase, R of 1.85
130K cases (100x more than detected) would be 1.140x daily increase, R of 1.95

It all depends on how many cases were missed and when the infection actually started.
The first confirmed cases was traced back to November 17th, but that was not patient zero.

Calibrated molecular clocks and genetic analysis indicate all SARS-CoV-2 viral strains descend from the basal types found in Wuhan at the beginning of the year, though, with the earliest possible spread sometime in December (and the virus jumping from animal to human hosts between October and December). Besides, we have data from register offices, adjusted to the day of death, strongly suggesting very rapid spread in the preceding weeks. Bergamo lost 0.4% of its population in a few weeks in March, for instance, with dramatic peaks of abnormal mortality also happening in New York City and Spain soon after.

I think we can confidently argue spread began before everyone was paying attention in a lot of places, but the exceptions like Taiwan and New Zealand would also mean the virus spreading that early wouldn't really make sense in the context of their success. For some reason, the reproduction rate seems just that different from place to place, so there isn't much we can make of it. Why the attack hate was 60% in Bergamo but 10% in Wuhan, for instance?

Coronavirus spread by asymptomatic people 'appears to be rare,' WHO official says

"We have a number of reports from countries who are doing very detailed contact tracing. They're following asymptomatic cases, they're following contacts and they're not finding secondary transmission onward. It is very rare -- and much of that is not published in the literature," she said. "We are constantly looking at this data and we're trying to get more information from countries to truly answer this question. It still appears to be rare that an asymptomatic individual actually transmits onward."

"When we actually go back and we say how many of them were truly asymptomatic, we find out that many have really mild disease," Van Kerkhove said. "They're not quote-unquote Covid symptoms, meaning they may not have developed fever yet, they may not have had a significant cough, or they may not have shortness of breath -- but some may have mild disease," she said. "Having said that, we do know that there can be people who are truly asymptomatic."

"Detailed contact tracing from Taiwan as well as the first European transmission chain in Germany suggested that true asymptomatics rarely transmit. However, those (and many other) studies have found that paucisymptomatic transmission can occur, and in particular, in the German study, they found that transmission often appeared to occur before or on the day symptoms first appeared," Javid said in the statement.

https://edition.cnn.com/2020/06/08/health/coronavirus-asymptomatic-spread-who-bn/index.html