(C) Daily Kos This story was originally published by Daily Kos and is unaltered. . . . . . . . . . . The Pandemic is Officially Over: Why the CDC Probably Got it About Right. [1] ['This Content Is Not Subject To Review Daily Kos Staff Prior To Publication.', 'Backgroundurl Avatar_Large', 'Nickname', 'Joined', 'Created_At', 'Story Count', 'N_Stories', 'Comment Count', 'N_Comments', 'Popular Tags'] Date: 2023-05-19 The pandemic officially ended about a week ago. A lot of people are, understandably, upset. For many people, in a very real sense, the pandemic will never be over. People who lost loved ones, people with post acute sequelae, people for whom vaccines or approved treatments may not work as well — it’s going to be a long haul for them, and none of what I’m about to write should in any way diminish that. Civilized society means we look out for one another, period. So how can I possibly believe that and believe, simultaneously, that the CDC and WHO got it about right? In a word, math. In the edifice of human knowledge, observable facts are the bricks, and math is the mortar. Without math, we’d be left with a useless pile of bricks and stones. Without further ado, here’s the math lesson. To see why it’s safe to think of the pandemic as “over”, we need to start by getting a good fix on the prevalence. A lot of folks are, understandably, bummed that the CDC is no longer reporting case counts. But here’s the thing — we’ve also got three plus years of historical data that can allow us to bootstrap from mortality data to credible estimates of case counts. Based on the WHO’s data, the cumulative case fatality rate is stuck at about 1.09%. That’s pretty awful, actually, and we can only hope that over time we discover better treatments, better vaccines, and so forth. Now, let’s combine that with the CDC’s latest mortality data. According to the CDC, there have been 1,128,903 deaths in the past week, 1.5% of them with covid (some people make a big deal about “of” versus “with” — I think that’s a stupid distinction, because it misses the human tragedy of drawing one’s last breath with a miserable disease, regardless of what the cause of death might be). Putting it all together: my estimate is that we’re averaging about 222,000 cases a day. I realize that other people have different favorite key risk indicators, like wastewater surveillance. I’m not convinced that wastewater surveillance is quite ready for prime time as a sole measure of prevalence (although it’s still great for early detection — I’m happy to get into the weeds on this point, in the comments). At any rate, according to the U.S. census, the current population is a bit over 334 million. So that’s a prevalence of about 0.07%. Now for another math lesson. Rapid tests have been a boon for much of 2022 and early 2023, and i have no doubt that they were used very effectively to help people isolate when it was most needed — especially for reducing household spread, which we’ve known all along is a big deal, not just for covid, but for all infectious diseases. Compared to PCR tests, rapid tests have a low sensitivity, meaning that if you’re a true positive, the probability of testing positive is less than 100% — specifically, 65.3%, according to one study. What’s less appreciated is that the specificity is also short of 100%. Specificity is the probability that if you’re a true negative, you test negative. According to that same study, it’s 99.9%. That’s high, but it’s still not 100%. And here’s where it gets fun. If nobody had covid, and you started testing everyone, based on that specificity, you’d end up with an estimated prevalence of 0.1% — higher than the above prevalence estimate, extrapolating from mortality rates. In other words, a positive test would mean you’re more likely to have covid than if you didn’t have any information at all — but it’s still more likely than not that you don’t have it. Stated another way, despite having a high specificity, the positive predictive value of a rapid test these days is probably less than 50%. Pretty wild, huh? That phenomenon is called the accuracy paradox. At this point in the pandemic, if you haven’t had any known exposures and you aren’t experiencing symptoms, a positive rapid test is like making it into the World Series — but not necessarily winning it. We are well on our way back to a semblance of normality, where we can go back to worrying about other existential crises — like catastrophic global warming, of which horrible pandemics are just one manifestation. [END] --- [1] Url: https://www.dailykos.com/stories/2023/5/19/2170333/-The-Pandemic-is-Officially-Over-Why-the-CDC-Probably-Got-it-About-Right Published and (C) by Daily Kos Content appears here under this condition or license: Site content may be used for any purpose without permission unless otherwise specified. via Magical.Fish Gopher News Feeds: gopher://magical.fish/1/feeds/news/dailykos/