Here's something that looks like big spin:
Measures to control coronavirus have brought flu infections to 'historic lows.' Scientists want to keep it that way.
Thinking of various things:
- There are widespread claims that other problems are being wrongly diagnosed as covid-19
- there's a big overlap between flu and covid symptoms
- Flu cases are way down
Just connecting the dots. I don't have any medical qualifications to base any claims on.
Hi tigerwillow, that was an interesting article. Thanks for posting it.
There's a big overlap indeed in flu symptoms and those from COVID-19, and also RSV for that matter. So much so that diagnostics companies are releasing tests that can do all three (actually, four since influenza A and B are different) at once from one sample, lowering cost and reducing inconvenience for patients.
Here's an example.
But, almost all COVID-19 diagnoses (and thus, most recorded cases of it) come from a positive PCR test. The flu won't cause a positive test for COVID-19. So, it's easy to rule out that many of the COVID-19 cases are just the flu, with flu being under-reported.
What's really interesting is this line from the article, referring to the prevelance of influenza in the US population:
"The weekly average of positive lab results is now 0.2 percent, compared with 2.35 percent in 2019. The positive rate is usually between 1 and 2 percent. "
So, if it's normally 1-2% this time of year, and it's 0.2% now, that means the amount of flu circulating is about 1/5 to 1/10 normal. Flu and COVID-19 spread the same way: people breathe on each other and spread droplets when they talk, cough, sneeze, pick their noses... We are using masks and social distancing this year, and from the numbers above, this has contributed to a dramatic 5-10x reduction in the flu prevalence. Since flu and COVID-19 spread the same way, it's reasonable to conclude that at least to an approximation, the distancing measures we are taking are having a similar effect on COVID-19 spread as is being seen on influenza.
In other words, the measured impact on influenza spread can be used as a strong proxy to extrapolate how much more COVID-19 spread there would be if we hadn't been doing lockdowns and social distancing and masks and such. There may be subtle differences between effectiveness of masks and other distancing measures between flu and COVID-19, but they should be in the same ballpark since the key in both cases is droplet containment. So, by this logic, if the US hadn't done what it did, we might be seeing 5x-10x as many infectious people circulating.
Yesterday I talked about Sweden (relatively little done initially, with a light touch) versus Norway/Finland (a lot done quickly, quite strongly) and the difference in cases and death rates was ... you guessed it... 10X.
I know a lot of people are looking for proof that the measures we took either worked, or didn't work, so we can make good decisions about what to do between now and vaccine time. The reasoning I propose above suggests that what we've done so far has been effective.
