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You may feel fine, but you could still have COVID

Volume 6, Issue 2 | August 24, 2022 Mara G. Aspinall and Liz Ruark Aug 24

IN THIS ISSUE What’s coming this fall: New variants, new booster What’s coming next year: No free vax, tests, or treatment More than 50% of Omicron cases asymptomatic Does underreporting of self tests matter? It’d be great if you could still screen SOME of the kids New and Noteworthy The most dangerous three words today: “I feel fine.” Okay, yeah, you feel fine, but that doesn’t tell you anything, COVID-wise. A recent study reminded us of something that’s always been true about this virus: LOTS of people who have it never know that they’re infected. How many? A small study published last week in JAMA Network Open found that 56% of health care workers infected with Omicron were totally unaware of their status (including 10% who had cold-like symptoms but figured it was something other than COVID). Thanks for reading Sensitive & Specific: The Testing Newsletter! Subscribe for free to receive new posts and support my work. Subscribe And yes, it’s possible that this after-the-fact self-reporting was affected by the vagaries of memory and personal and/or institutional needs to return to work. But still. Do some people get COVID without symptoms? Yes. Do asymptomatic people then spread the virus? Yes. Commentary: We hope that, by now, this is obvious, but this is exactly why screening / regular testing is so important - it catches people that are infectious and don’t know it. Enjoy this booster - it’s the last one you get for free Virtually all testing, vaccination, and treatment for COVID has been paid for by the federal government since the beginning of the pandemic. It looks like - barring some unlikely act of Congress - that’s about to change. Last week, White House COVID Coordinator Ashish Jha announced that by 2023, these products and services will move to a commercial model and won’t be paid for by the federal government. The transition will begin in the fall - likely after the arrival of the new bivalent Omicron-specific booster, which the administration expects to be available soon after Labor Day for everyone 12 and over. (PS - Our skepticism was misplaced - the feds have clearly opted for speed.) Does it matter that self-test results are underreported? CDC says no . . . well, maybe yes. We’ve been warning for months that the rise of OTC self tests (whose results most often go unreported), while super-helpful for individuals, has made it impossible for the nation’s public-health watchers to know the true number of COVID cases in the country. We’ve seen estimates that cases have been undercounted by anywhere from 5x to 31x - our best guess has been roughly a factor of 7 to 8x. This week the CDC came out with two MMWR studies that look at this issue and come to oddly conflicting conclusions. One study looked at the results from 10.7 million voluntarily reported self-tests from four manufacturers (who collectively produced 393 million tests during the same time period). It compared that data to 361.9 million PCR and POC antigen test results received by CDC during the same time frame. The authors’ results and conclusions:

  1. The test positivity trends reported by self tests tracks with that reported by lab and POC tests, and

  2. Plenty of lab and POC tests are still being reported, particularly those that reflect serious disease (which are, according to the report, the ones that we really need to know about), plus the CDC tracks all sorts of other COVID trend data, so

  3. The fact that self tests in general are being undercounted doesn’t matter all that much.

The other study looked at the ratio of New York State’s K-12 school-reported test results (which include both the results of tests done at the schools and the results of self-tests reported to the schools) to the state’s lab test results for school-aged kids (5 - 17 years old). Until January 2022, the ratio hovered near 1.0. But starting in that month - when access to self tests shot up - the ratio began to change. By April 2022, it was 3.64. The conclusions from that study? If we rely only on lab-reported data for this age group, we could be underestimating cases, and the data that comes from our case numbers could be off. Places that prioritize self testing should probably find a way to incorporate results beyond just lab tests when estimating case numbers. (No mention here about whether those self-testing numbers are underreported or not.) COMMENTARY: So, can we rely on lab-reported data alone, or not? Does it matter only for kids? As far as we can tell, K-12 schools really want to be out of the testing business, so pretty much everywhere is going to be prioritizing self-testing for the 2022/ 23 school year. What do we lose without complete data? #1 - Accurate perception of COVID rates. When cases are underreported, published charts from CDC and popular press give the impression that COVID rates are relatively low. While this may be good for the psyche, it is not reality. #2 - An accurate sense of COVID epidemiology. While wastewater surveillance is a reliable data source, it is still only spottily performed in practice. Food for Thought What can we expect of a possible winter 2022/23 COVID-19 surge? Our eyes are on whether a new variant will emerge and disturb our apparent truce with COVID BA.5 (as cases seem to be plateauing). Two other Omicron sub-variants are on the radar screen: In the US, BA.4.6 has grown to 6.3% of cases in three months. In India, BA.2.75 (aka Centaurus) has grown to 65% of cases currently (Centaurus evades Delta particularly effectively. Since India suffered the world’s worst Delta infection in late 2021, that may explain Centaurus’s dominance there.) Both of these variants have unique immune escape profiles, but neither one has yet demonstrated an ability to outcompete the BA.4/BA.5 variants that are still globally dominant. A quiet plea from CDC for just a little bit of screening testing in schools We wanted to highlight one small note in the recently updated CDC guidelines that hasn’t received a lot of press. While the agency no longer recommends screening testing in schools on a regular basis, there is still one group in the K-12 bracket that they’d like to see screened when COVID-19 Community Levelsare high: kids and adults who participate in high-risk activities, specifically close-contact sports, band, singing, and theater. It makes sense - people exhale a lot during those activities, and anecdotally, that’s where schools have seen outbreaks. But in practice, this would mean that schools would need to maintain the ability to screen a potentially large percentage of a student body, and would need to enforce that whenever Community Levels pop to the top. Will be interesting to see if schools notice this fine print and take action. Quick Hits

  1. Monkeypox cases reach 15,000+ in the US, with cases in all 50 states. Two variants - Clade I and Clade II - have been recognized by the WHO.

  2. N95 masks work twice as well as traditional surgical/procedure masks among health care workers.

  3. Good news: Hospitalization for COVID is now rare, and only ~9% of those hospitalized go to the ICU, where less than 1% require mechanical ventilator support (current CDC data). By comparison, in winter 2021/22, 24% of hospital patients were sent to ICU, where 64% required mechanical ventilation.

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