COVID-19 Data Dispatch

Category: Variants

  • National numbers, May 28

    National numbers, May 28

    The CDC is now updating its variant estimates every two weeks.

    In the past week (May 14 through 20), the U.S. reported about 8,300 new COVID-19 patients admitted to hospitals, according to the CDC. This amounts to:

    • An average of 1,200 new admissions each day
    • 2.5 total admissions for every 100,000 Americans
    • 11% fewer new admissions than last week (May 7-13)

    Additionally, the U.S. reported:

    • A 16% lower concentration of SARS-CoV-2 in wastewater than last week (as of May 24, per Biobot’s dashboard)
    • 54% of new cases are caused by Omicron XBB.1.5; 19% by XBB.1.16; 18% by XBB.1.9 (as of May 27)

    The COVID-19 plateau continues, with hospital admissions and viral levels in wastewater (the two main metrics I’m looking at these days) both trending slightly down at the national level. Newer Omicron variants are still on the rise, but don’t seem to be impacting transmission much yet.

    Hospitalizations continue to trend slightly down across the board, though hospitals are still reporting more than 1,000 new COVID-19 patients each day. The vast majority of U.S. counties have low hospitalization levels, according to the CDC, with just 14 counties in the medium or high categories.

    Coronavirus levels in wastewater are following a similar pattern: trending down very slightly, continuing the middling plateau of the last couple of months. All four major regions are still in this holding pattern, according to Biobot’s data.

    We have new variant data this week, as the CDC is now on a biweekly schedule for updates. XBB.1.5 caused just over half of new cases in the U.S. in the two weeks ending May 27, as it slowly gets outcompeted by newer versions of Omicron. XBB.1.16 and XBB.1.9 continue to rise, causing 19% and 18% of hew cases respectively.

    XBB.1.16 is most prevalent on the West Coast, the Northeast, and the Gulf Coast states, while XBB.1.9 is most prevalent in the Midwest, according to the CDC—though these estimates are becoming less reliable over time, since so few COVID-19 samples are sequenced.

    The CDC has also recently added national and regional COVID-19 test positivity data back to its dashboard, representing tests conducted by labs in the CDC’s National Respiratory and Enteric Virus Surveillance System.

    Nationally, test positivity is trending down, at just under 5% of COVID-19 tests (in this lab network) returning positive results in the most recent week of data. Test positivity is trending up slightly in the Northeast and New York/New Jersey regions; I’ll be following to see if this continues in the coming weeks.

    Finally, a bit of good news: excess deaths in the U.S. have returned to baseline in the last couple of months. While hundreds are still dying from COVID-19 every day, the excess death trend suggests that the disease is currently not causing a significant ripple effect on overall mortality the way that it did in earlier stages of the pandemic. (Of course, this could change with a new surge.)

    more national numbers
  • National numbers, May 14

    National numbers, May 14

    The CDC and its partners are sequencing far fewer coronavirus samples than they have at prior periods of the pandemic, making it harder to spot new variants of concern.

    In the past week (April 30 through May 6), the U.S. reported about 9,500 new COVID-19 patients admitted to hospitals, according to the CDC. This amounts to:

    • An average of 1,400 new admissions each day
    • 2.9 total admissions for every 100,000 Americans
    • 7% fewer new admissions than last week (April 22-29)

    Additionally, the U.S. reported:

    • A 14% lower concentration of SARS-CoV-2 in wastewater than last week (as of May 10, per Biobot’s dashboard)
    • 64% of new cases are caused by Omicron XBB.1.5; 13% by XBB.1.9; 14% by XBB.1.16 (as of May 13)
    • An average of 70,000 vaccinations per day

    COVID-19 spread continues to trend down in the U.S., though our data for tracking this disease is now worse than ever thanks to the end of the federal public health emergency. If newer Omicron variants cause a surge this summer, those increases will be hard to spot.

    As a result of the PHE’s conclusion this week, the CDC is no longer collecting national case counts or testing data. Instead, the agency now recommends using hospitalization data to monitor how hard COVID-19 is hitting your community—even though this metric typically lags behind actual infection patterns—while variant data and wastewater surveillance may provide warnings about new surges.

    My national updates will take a similar approach. This week, hospital admissions continue their national plateau, with a decrease of about 7% from the week ending April 29 to the week ending May 6. The CDC’s national map show that admissions are low across the country, with 99% of counties reporting fewer than 10 new admissions per 100,000 residents.

    Wastewater surveillance also suggests that, while there’s still a lot of COVID-19 in the U.S., disease spread is still on a plateau or slight decline in most of the country. Biobot’s data show a minor national downturn in recent weeks; trends are similar across the four major regions, though the decline is a bit steeper on the West Coast.

    The variant picture also hasn’t changed much: XBB.1.5 caused about two-thirds of new cases in the last two weeks, according to the CDC’s estimates. XBB.1.6 caused about 14% and XBB.1.9 caused 13%; these newer versions of Omicron are gaining ground, but fairly slowly. Regionally, XBB.1.6 is most prevalent in the Northeast and on the West Coast, while XBB.1.9 is most prevalent in the Midwest.

    It’s worth noting, though, that the CDC has switched its variant reporting from weekly to every other week, as fewer patient specimens are going through sequencing for variant identification. The agency and its surveillance partners are sequencing around 5,000 samples every week, compared to over 80,000 a week at the height of the first Omicron surge.

    Limited sequencing efforts will make it harder for the CDC to quickly identify (and respond to) new variants of concern. The same challenge is happening around the world, as PCR tests become less broadly available. Sequencing coronavirus samples from wastewater may help, but that’s only happening in a small subset of sewage testing sites right now.

    One last bit of good news: vaccine administration numbers are up in the last couple of weeks, as seniors and other eligible high-risk people get their second bivalent boosters. About 70,000 people received vaccines each day this week, compared to around half that number a few weeks ago. If you’re eligible for a second booster, this is a good time to make an appointment!

    more national numbers
  • The federal public health emergency ends next week: What you should know

    The federal public health emergency ends next week: What you should know

    A chart from the CDC’s recent report on surveillance changes tied to the end of the federal public health emergency.

    We’re now less than one week out from May 11, when the federal public health emergency (or PHE) for COVID-19 will end. While this change doesn’t actually signify that COVID-19 is no longer worth worrying about, it marks a major shift in how U.S. governments will respond to the ongoing pandemic, including how the disease is tracked and what public services are available.

    I’ve been writing about this a lot in the last couple of months, cataloging different aspects of the federal emergency’s end. But I thought it might be helpful for readers if I compiled all the key information in one place. This post also includes a few new insights about how COVID-19 surveillance will change after May 11, citing the latest CDC reports.

    What will change overall when the PHE ends?

    The ending of the PHE will lead to COVID-19 tests, treatments, vaccines, and data becoming less widely available across the U.S. It may also have broader implications for healthcare, with telehealth policies shifting, people getting kicked off of Medicaid, and other changes.

    Last week, I attended a webinar about these changes hosted by the New York City Pandemic Response Institute. The webinar’s moderator, City University of New York professor Bruce Y. Lee, kicked it off with a succinct list of direct and indirect impacts of the PHE’s end. These were his main points:

    • Free COVID-19 vaccines, tests, and treatments will run out after the federal government’s supplies are exhausted. (Health experts project that this will likely happen sometime in fall 2023.) At that point, these services will get more expensive and harder to access as they transition to private healthcare markets.
    • We will have fewer COVID-19 metrics (and less complete data) to rely on as the CDC and other public health agencies change their surveillance practices. More on this below.
    • Many vaccination requirements are being lifted. This applies to federal government mandates as well as many from state/local governments and individual businesses.
    • The FDA will phase out its Emergency Use Authorizations (EUAs) for COVID-19 products, encouraging manufacturers to apply for full approval. (This doesn’t mean we’ll suddenly stop being able to buy at-home tests—there’s going to be a long transition process.)
    • Healthcare worker shortages may get worse. During the pandemic emergency, some shifts to work requirements allowed facilities to hire more people, more easily; as these policies are phased out, some places may lose those workers.
    • Millions of people will lose access to Medicaid. A federal rule tied to the PHE forbade states from kicking people off this public insurance program during the pandemic, leading to record coverage. Now, states are reevaluating who is eligible. (This process actually started in April, before the official PHE end.)
    • Telehealth options may become less available. As with healthcare hiring, policies during the PHE made it easier for doctors to provide virtual care options, like video-call appointments and remote prescriptions. Some of these COVID-era rules will be rolled back, while others may become permanent.
    • People with Long COVID will be further left behind, as the PHE’s end leads many people to distance themselves even more from the pandemic—even though long-haulers desperately need support. This will also affect people who are at high risk for COVID-19 and continue to take safety precautions.
    • Pandemic research and response efforts may be neglected. Lee referenced the “panic and neglect” cycle for public health funding: a pattern in which governments provide resources when a crisis happens, but then fail to follow through during less dire periods. The PHE’s end will likely lead us (further) into the “neglect” part of this cycle.

    How will COVID-19 data reporting change?

    The CDC published two reports this week that summarize how national COVID-19 data reporting will change after May 11. One goes over the surveillance systems that the CDC will use after the PHE ends, while the other discusses how different COVID-19 metrics correlate with each other.

    A lot of the information isn’t new, such as the phasing out of Community Level metrics for counties (which I covered last week). But it’s helpful to have all the details in one place. Here are a few things that stuck out to me:

    • Hospital admissions will be the CDC’s primary metric for tracking trends in COVID-19 spread rather than cases. While more reliable than case counts, hospitalizations are a lagging metric—it takes typically days (or weeks) after infections go up for the increase to show up at hospitals, since people don’t seek medical care immediately. The CDC will recieve reports from hospitals at a weekly cadence, rather than daily, after May 11, likely increasing this lag and making it harder for health officials to spot new surges.
    • National case counts will no longer be available as PCR labs will no longer be required to report their data to the CDC. PCR test totals and test positivity rates will also disappear for the same reason, as will the Community Levels that were determined partially by cases. The CDC will also stop reporting real(ish)-time counts of COVID-associated deaths, relying instead on death certificates.
    • Deaths will be the primary metric for tracking how hard COVID-19 is hitting the U.S. The CDC will get this information from death certificates via the National Vital Statistics System. While deaths are reported with a significant lag (at least two weeks), the agency has made a lot of progress on modernizing this reporting system during the pandemic. (See this December 2021 post for more details.)
    • The CDC will utilize sentinel networks and electronic health records to gain more information about COVID-19 spread. This includes the National Respiratory and Enteric Virus Surveillance System, a network of about 450 laboratories that submit testing data to the CDC (previously established for other endemic diseases like RSV and norovirus). It also includes the National Syndromic Surveillance Program, a network of 6,300 hospitals that submit patient data to the agency.
    • Variant surveillance will continue, using a combination of PCR samples and wastewater data. The CDC’s access to PCR swab samples will be seriously diminished after May 11, so it will have to work with public health labs to develop national estimates from the available samples. Wastewater will help fill in these gaps; a few wastewater testing sites already send the CDC variant data. And the CDC will continue offering tests to international travelers entering the country, for a window into global variant patterns.
    • The CDC will continue tracking vaccinations, vaccine effectiveness, and vaccine safety. Vaccinations are generally tracked at the state level (every state health agency, and several large cities, have their own immunization data systems), but state agencies have established data sharing agreements with the CDC that are set to continue past May 11. The CDC will keep using its established systems for evaluating how well the vaccines work and tracking potential safety issues as well.
    • Long COVID notably is not mentioned in the CDC’s reports. The agency hasn’t put much focus on tracking long-term symptoms during the first three years of the pandemic, and it appears this will continue—even though Long COVID is a severe outcome of COVID-19, just like hospitalization or death. A lack of focus on tracking Long COVID will make it easier for the CDC and other institutions to keep minimizing this condition.

    On May 11, the CDC plans to relaunch its COVID-19 tracker to incorporate all of these changes. The MMWR on surveillance changes includes a list of major pages that will shift or be discontinued at this time.

    Overall, the CDC will start tracking COVID-19 similar to the way it tracks other endemic diseases. Rather than attempting to count every case, it will focus on certain severe outcomes (i.e., hospitalizations and deaths) and extrapolate national patterns from a subset of healthcare facilities with easier-to-manage data practices. The main exception, I think, will be a focus on tracking potential new variants, since the coronavirus is mutating faster and more aggressively than other viruses like the flu.

    What should I do to prepare for May 11?

    If you’ve read this far, you’re probably concerned about how all these shifts will impact your ability to stay safe from COVID-19. Unfortunately, the CDC, like many other public agencies, is basically leaving Americans to fend for themselves with relatively little information or guidance.

    But a lot of information sources (like this publication) are going to continue. Here are a few things I recommend doing this week as the PHE ends:

    • Look at your state and local public health agencies to see how they’re responding to the federal shift. Some COVID-19 dashboards are getting discontinued, but many are sticking around; your local agency will likely have information that’s more tailored to you than what the CDC can offer.
    • Find your nearest wastewater data source. With case counts basically going away, wastewater surveillance will be our best source for early warnings about surges. You can check the COVID-19 Data Dispatch list of wastewater dashboards and/or the COVIDPoops dashboard for sources near you.
    • Stock up on at-home tests and masks. This is your last week to order free at-home/rapid tests from your insurance company if you have private insurance. It’s also a good time to buy tests and masks; many distributors are having sales right now.
    • Figure out where you might get a PCR test and/or Paxlovid if needed. These services will be harder to access after May 11; if you do some logistical legwork now, you may be more prepared for when you or someone close to you gets sick. The People’s CDC has some information and links about this.
    • Contact your insurance company to find out how their COVID-19 coverage policies are changing, if you have private insurance. Folks on Medicare and Medicaid: this Kaiser Family Foundation article has more details about changes for you.
    • Ask people in your community how you can help. This is a confusing and isolating time for many Americans, especially people at higher risk for COVID-19. Reaching out to others and offering some info or resources (maybe even sharing this post!) could potentially go a long way.

    That was a lot of information packed into one post. If you have questions about the ending PHE (or if I missed any important details), please email me or leave a comment below—and I’ll try to answer in next week’s issue.

    More about federal data

  • National numbers, April 23

    National numbers, April 23

    Coronavirus concentrations are trending down in Boston’s wastewater, a promising signal.

    In the past week (April 13 through 19), the U.S. officially reported about 94,000 new COVID-19 cases, according to the CDC. This amounts to:

    • An average of 13,000 new cases each day
    • 7% fewer new cases than last week (April 6-12)

    In the past week, the U.S. also reported about 12,000 new COVID-19 patients admitted to hospitals. This amounts to:

    • An average of 1,700 new admissions each day
    • 3.7 total admissions for every 100,000 Americans
    • 8% fewer new admissions than last week

    Additionally, the U.S. reported:

    • 1,200 new COVID-19 deaths (170 per day)
    • 74% of new cases are caused by Omicron XBB.1.5; 11% by XBB.1.9; 10% by XBB.1.16 (as of April 22)
    • An average of 35,000 vaccinations per day

    Across the U.S., COVID-19 spread continues at a moderately high plateau as newer versions of Omicron compete with XBB.1.5. Officially-reported cases and new hospitalizations declined by 7% and 8% respectively, compared to the prior week.

    Wastewater surveillance data from Biobot and from the CDC similarly show that COVID-19 spread is at a plateau. Nationally, coronavirus concentrations in sewage are higher than they were at this point in 2021 (when the initial vaccine rollout was in full swing), but lower than at this point in 2022 (when BA.2 had started spreading widely).

    Of course, it’s important to flag that official case counts are becoming even more unreliable these days, as PCR testing becomes increasingly difficult to access and state health departments no longer prioritize timely reporting to the CDC. According to CDC, five states didn’t report COVID-19 cases and deaths last week: Arkansas, Florida, Iowa, Mississippi, and Pennsylvania. (Iowa has permanently stopped reporting.)

    These case reporting issues are likely to continue—and perhaps accelerate—when the federal public health emergency ends next month. I’m thinking about how to adjust these National Numbers reports when that happens; that will likely involve foregrounding wastewater data and hospitalizations rather than cases.

    Regionally, Biobot’s surveillance shows a slight uptick in coronavirus spread on the West Coast and declines in the other major regions. Some counties in California have reported recent increases in wastewater, according to Biobot and WastewaterSCAN, but it’s currently tough to tell if this is a sustained surge or isolated outbreaks.

    The West Coast and Midwest continue to be hotspots for newer versions of Omicron, according to the CDC’s estimates, with XBB.1.9 still most prevalent by far in the region including Iowa, Kansas, Missouri, and Nebraska. Nationwide, the CDC estimates that XBB.1.9 caused about 11% of new cases in the last week and that XBB.1.16 caused 10% of new cases.

    XBB.1.16 (also called “Arcturus”) was recently classified as a variant of interest by the World Health Organization because it can spread significantly faster than other Omicron lineages. The variant is likely to “spread globally and contribute to an increase in case incidence,” according to the WHO.

    While I’m wary of the new variants, I have been heartened to see coronavirus levels in wastewater remain mostly at plateaus—or even decline—in many places across the U.S. In Boston, for example, coronavirus levels have been on a downward trend since early 2023. I hope to see this trend continue. 

    more national numbers
  • National numbers, April 16

    National numbers, April 16

    New subvariants XBB.1.16, XBB.1.9.1, and XBB.1.9.2 are on the rise, according to the CDC’s estimates.

    In the past week (April 6 through 12), the U.S. officially reported about 100,000 new COVID-19 cases, according to the CDC. This amounts to:

    • An average of 15,000 new cases each day
    • 17% fewer new cases than last week (March 30-April 5)

    In the past week, the U.S. also reported about 13,000 new COVID-19 patients admitted to hospitals. This amounts to:

    • An average of 1,900 new admissions each day
    • 3.9 total admissions for every 100,000 Americans
    • 14% fewer new admissions than last week

    Additionally, the U.S. reported:

    • 1,300 new COVID-19 deaths (190 per day)
    • 78% of new cases are caused by Omicron XBB.1.5; 9% by XBB.1.9; 7% by XBB.1.16 (as of April 15)
    • An average of 35,000 vaccinations per day (CDC link)

    COVID-19 spread appears to be at a continued plateau nationally, with slight declines in cases, hospitalizations, and viral concentrations in wastewater. New variants are on the horizon, though, at a time when data are becoming increasingly less reliable. 

    The CDC reported about 100,000 new cases this week, the lowest this number has been since early summer 2021. Unlike that period, however, PCR tests are much less available and reporting infrastructures are being dismantled.

    Wastewater surveillance data from Biobot show that transmission is actually several times higher now than it was at that previous low point. We’re in an undercounted plateau, rather than a real lull. Even so, less COVID-19 is spreading now than we’ve seen throughout the last few months.

    To get a more accurate picture of potential COVID-19 case counts in your area, I recommend going to the Iowa COVID-19 Tracker, an independent dashboard run by Sara Anne Willette. Willette has mapped out “likely cases per 100,000 people” by county, by multiplying the CDC’s data by 20 to account for underreporting.

    Wastewater data suggest that most parts of the U.S. are seeing steady (though slight) declines in transmission, with the exception of the West coast. Some counties in California have reported increased coronavirus levels in wastewater in the last week, according to Biobot and WastewaterSCAN, including parts of the Bay Area.

    One culprit for the increases could be newer Omicron subvariants, particularly XBB.1.9 and XBB.1.16. The CDC added XBB.1.16—which has drawn international concern, due to its connection with a recent surge in India—to its variant proportion estimates, along with XBB.1.9.2, a relative of XBB.1.9.1. (Yes, we’re getting into alphabet soup territory again here.)

    Nationally, the CDC estimates that XBB.1.16 caused about 7% of new cases in the last week, while the XBB.1.9s together caused 9%. At the regional level, XBB.1.16 is more prevalent in the West and Southwest (at over 20% of new cases in the region including Texas and other Gulf coast states), while the XBB.1.9s are more prevalent in the Midwest.

    The CDC published its second-to-last data update yesterday (which is still called the “Weekly Review,” even though it is far from weekly at this point). According to this update, most of the CDC’s public COVID-19 data “won’t be affected by the end of the public health emergency,” though the agency says it’ll provide more details in its final update on May 12.

    I personally expect that, while the national data systems might remain in place, more state and local health agencies will stop reporting, as we saw from Iowa recently. This will, of course, make the numbers less and less reliable.

    more national numbers
  • National numbers, April 9

    National numbers, April 9

    COVID-19 spread is at a plateau in all four major regions of the U.S., according to wastewater data from Biobot.

    In the past week (March 30 through April 5), the U.S. officially reported about 120,000 new COVID-19 cases, according to the CDC. This amounts to:

    • An average of 17,000 new cases each day
    • 37 total new cases for every 100,000 Americans
    • 12% fewer new cases than last week (March 23-29)

    In the past week, the U.S. also reported about 15,000 new COVID-19 patients admitted to hospitals. This amounts to:

    • An average of 2,100 new admissions each day
    • 4.5 total admissions for every 100,000 Americans
    • 12% fewer new admissions than last week

    Additionally, the U.S. reported:

    • 1,800 new COVID-19 deaths (250 per day)
    • 88% of new cases are caused by Omicron XBB.1.5; 5% by XBB.1.9.1; 2% by XBB.1.5.1; 0.4% by CH.1.1 (as of April 8)
    • An average of 40,000 vaccinations per day

    COVID-19 spread in the U.S. remains at a high plateau, according to reported cases, hospitalizations, and wastewater surveillance. Experts are watching new variants that mutated from XBB as potential drivers of more transmission this spring.

    While the case numbers may seem low, remember that cases are now severely undercounted—potentially by up to 20 times. So, when the CDC reported about 37 new cases per 100,000 people last week, the true number could be closer to 700 new cases per 100,000. It’s becoming harder and harder to get a PCR test, as sites shut down and the federal health emergency’s end approaches, which will further drive undercounting.

    Wastewater data, on the other hand, continue to show that coronavirus levels in the U.S. are significantly higher than they were at this time in 2022 and 2021. Last week, I wrote that Biobot’s dashboard showed a slight increase in COVID-19 spread across the country; after this week’s data updates, that appears to have been a blip, with the company’s national surveillance again showing a plateau.

    Biobot’s regional data also indicates that COVID-19 spread has remained relatively consistent in the last few weeks. The Northeast and Midwest have slightly higher coronavirus levels than the South and West, but there aren’t significant differences between these regions.

    As I wrote last week, new subvariant XBB.1.9.1 remains more prevalent in the Midwest, particularly the region including Iowa, Kansas, Missouri, and Nebraska (where it caused about 18% of new cases in the last week, per CDC estimates). Some wastewater testing sites in these states have reported increases recently, but there isn’t a consistent increase across the board.

    Nationally, the CDC estimates that XBB.1.9.1 caused about 5% of new cases nationwide in the week ending April 8, compared to 88% caused by XBB.1.5. XBB.1.9.1 has been growing relatively slowly, so it may be a few more weeks before we see it either outcompete XBB.1.5 or die out at low levels. Experts are also watching XBB.1.16, which drove a surge in India recently but has not shown up in large numbers in the U.S. yet.

    Will the U.S. see a new surge this spring? It seems possible, thanks to Omicron’s continued evolution and our lack of collective safety measures. But continued declines in data reporting will make it harder to see this surge than it’s ever been.

    In this environment, wastewater surveillance is growing more and more valuable. It’s also probably a good idea to keep taking some basic precautions (like masking in public indoor spaces, or regularly testing) no matter how low the reported cases get in your community.

    more national numbers
  • National numbers, April 2

    National numbers, April 2

    New subvariant Omicron XBB.1.9.1 is most prevalent in the Midwest, according to CDC estimates.

    In the past week (March 23 through 29), the U.S. officially reported about 140,000 new COVID-19 cases, according to the CDC. This amounts to:

    • An average of 20,000 new cases each day
    • 43 total new cases for every 100,000 Americans
    • 9% fewer new cases than last week (March 16-22)

    In the past week, the U.S. also reported about 17,000 new COVID-19 patients admitted to hospitals. This amounts to:

    • An average of 2,400 new admissions each day
    • 5.1 total admissions for every 100,000 Americans
    • 5% fewer new admissions than last week

    Additionally, the U.S. reported:

    • 1,600 new COVID-19 deaths (230 per day)
    • 88% of new cases are caused by Omicron XBB.1.5; 5% by XBB.1.9.1; 2% by XBB.1.5.1; 0.4% by CH.1.1 (as of March 18)
    • An average of 40,000 vaccinations per day

    While official COVID-19 cases and hospitalizations continue to trend ever-so-slightly downward, wastewater surveillance data show potential new upticks in transmission. Despite continued minimal safety measures in most places, we have to remain wary of a potential spring surge.

    Official data from the CDC suggested that cases and new hospital admissions dropped very slightly last week, compared to the week prior. But case data continue to be plagued with reporting delays; again this week, multiple states (Florida, Delaware, Mississippi, Oklahoma) reported no cases or had other issues. These delays make it difficult to assess patterns at state or county levels.

    Wastewater surveillance data provide more accurate early warnings about potential rising transmission. This week, Biobot’s data suggest slight increases in all four major regions of the country. It’s worth noting, though, that Biobot’s most recent data are preliminary. I’ll be closely watching the dashboard’s next updates, this coming Tuesday and Thursday.

    The latest Omicron variant of concern, XBB.1.9.1, could be one reason for increasing coronavirus levels. This subvariant caused an estimated 5% of new cases across the country nationwide last week, according to the CDC’s Nowcast analysis. At the same time, XBB.1.5 has declined for the first time since it emerged a couple of months ago, suggesting XBB.1.9.1 might slowly outcompete it.

    XBB.1.9.1 is most prevalent in the Midwest, particularly the region including Iowa, Kansas, Missouri, and Nebraska. Some counties in this region are also reporting significant coronavirus increases in their wastewater, according to Biobot and WastewaterSCAN. Missouri’s wastewater dashboard similarly shows increases across the state.

    In our current era of high background coronavirus spread (and few-to-no widespread safety measures), a new variant can easily cause concerning outbreaks. It’s important to remember that, no matter how much the virus evolves, simple measures like masks and ventilation can still make transmission less likely.

    more national numbers
  • National numbers, March 26

    National numbers, March 26

    Data from WastewaterSCAN suggest that most sites in its network saw downward coronavirus trends or plateaus in recent weeks.

    In the past week (March 16 through 22), the U.S. officially reported about 130,000 new COVID-19 cases, according to the CDC. This amounts to:

    • An average of 19,000 new cases each day
    • 41 total new cases for every 100,000 Americans
    • 13% fewer new cases than last week (March 9-15)

    In the past week, the U.S. also reported about 17,000 new COVID-19 patients admitted to hospitals. This amounts to:

    • An average of 2,400 new admissions each day
    • 5.2 total admissions for every 100,000 Americans
    • 9% fewer new admissions than last week

    Additionally, the U.S. reported:

    • 2,000 new COVID-19 deaths (300 per day)
    • 90% of new cases are caused by Omicron XBB.1.5; 3% by XBB.1.9.1; 2% by XBB.1.5.1; 0.4% by CH.1.1 (as of March 18)
    • An average of 40,000 vaccinations per day

    Nationally, we continue to see the same slow decline of COVID-19 spread across the U.S., as shown by official case data, hospitalizations, and wastewater surveillance.

    Reported cases dropped by 13% last week compared to the week prior, while new hospital admissions dropped by 9%. As I’ve noted in the last couple of updates, the CDC continues to deal with reporting delays from different state health departments. This week, Texas, Arkansas, Florida, and Indiana did not report cases to the CDC.

    Wastewater surveillance data from Biobot and the WastewaterSCAN project suggest that COVID-19 levels are at slow declines or plateaus in most parts of the country, but some places may be seeing small increases. Biobot’s dashboard shows slight upticks in the Northeast, Midwest, and West coast regions, as of its March 22 update. 

    Overall, Biobot’s data suggests that national coronavirus concentrations are lower than they’ve been in about a year—but still higher than we’ve seen at this point in 2021 and 2022. The low case numbers that health departments are putting out mask a high baseline of infections, in which many people are not getting PCR tests or reporting their cases to the healthcare system.

    Data from the WastewaterSCAN project suggest that most of the project’s 148 monitoring sites reported downward trends or plateaus in coronavirus levels over the last three weeks. A few places have reported upticks, though, including sites in Kansas, Michigan, South Carolina, Massachusetts, and Oklahoma. 

    One reason for these upticks could be XBB.1.9.1, the latest Omicron subvariant to draw concern among virologists. The CDC started reporting estimates for XBB.1.9.1 in its latest variant update (this Friday): the agency estimates that this variant caused 2.5% of new cases nationwide last week, with higher prevalence (about 13%) in the Midwest region that includes Iowa, Kansas, Missouri, and Nebraska.

    XBB.1.9.1 is doubling “roughly every 8 days,” according to Marc Johnson, a virologist at the University of Missouri who leads the state’s wastewater surveillance program. Johnson predicts that this subvariant will be dominant in the U.S. by the end of April, but it could face competition from XBB.1.16—another descendant of XBB that has been spreading rapidly in India. 

    Could the spread of these XBB sublineages across the U.S. cause a significant rise in cases and hospitalizations? It’s hard to say, given the complex picture of immunity in the country, with millions of people recently infected by a variety of variants. “Future waves are getting harder and harder to forecast,” Katelyn Jetelina wrote in Your Local Epidemiologist this week. Regardless, the same safety measures (masks, testing, etc.) continue to work against all new versions of the virus.

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  • National numbers, February 12

    National numbers, February 12

    National COVID-19 cases have reached a plateau. Note that the cases reported to the CDC are a significant undercount of actual infections.

    In the past week (February 2 through 8), the U.S. officially reported about 280,000 new COVID-19 cases, according to the CDC. This amounts to:

    • An average of 40,000 new cases each day
    • 86 total new cases for every 100,000 Americans
    • 1% fewer new cases than last week (January 26-February 1)

    In the past week, the U.S. also reported about 26,000 new COVID-19 patients admitted to hospitals. This amounts to:

    • An average of 3,700 new admissions each day
    • 7.8 total admissions for every 100,000 Americans
    • 6% fewer new admissions than last week

    Additionally, the U.S. reported:

    • 3,200 new COVID-19 deaths (450 per day)
    • 75% of new cases are caused by Omicron XBB.1.5; 20% by BQ.1 and BQ.1.1; 1% by CH.1.1 (as of February 11)
    • An average of 80,000 vaccinations per day

    Nationwide, COVID-19 spread appears to be in a plateau: not substantially increasing, but not substantially decreasing, either. Officially-reported cases dropped by only 1% this week compared to the week prior, while wastewater data shows that the coronavirus concentration in our sewage hasn’t changed significantly for the last month.

    Hospitalizations continue to decline for flu and RSV as well as COVID-19, according to the CDC’s data from emergency departments. But the COVID-19 decline has slowed, remaining consistent at a higher level than the flu and RSV declines. About 3,700 people were newly hospitalized for COVID-19 every day last week.

    At the regional level, COVID-19 spread is still declining (from a relatively higher winter peak) in the Northeast, and is solidly in a plateau in the South and West, per Biobot’s regional data. The Midwest reported a slight uptick this past week, continuing a trend that I noted in last weekend’s National Numbers.

    Some of the highest case, wastewater, and hospitalization increases reported right now are coming from the upper Midwest: Montana, North Dakota, South Dakota, and Idaho. COVID-19 spread is also trending up in Alabama, Kansas, New Hampshire, and West Virginia, along with other states in the Midwest and South, per the latest Community Profile Report.

    Omicron XBB.1.5, the latest and most contagious version of the virus, is spreading across these regions and may be contributing to increased cases. According to the CDC’s latest estimates, XBB.1.5 now accounts for more than half of new cases in every region of the country, and about 75% of new cases nationwide.

    No other variants are trending up right now; XBB.1.5 has solidly outcompeted the rest of the “variant soup” in the U.S. Experts will doubtless be watching for this subvariant to further evolve, while we also look out for any new variants from other parts of the world.

    Meanwhile, the daily average of new COVID-19 vaccinations in the U.S. has dropped under 100,000 for the first time since the country’s vaccination campaign started in winter 2020. New booster doses continue to be heavily underutilized.

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  • National numbers, February 5

    National numbers, February 5

    XBB.1.5, the Omicron lineage that’s been dominant in the Northeast for several weeks now, is spreading through the rest of the country. Chart from the CDC, estimates as of February 3.

    In the past week (January 26 through February 1), the U.S. officially reported about 280,000 new COVID-19 cases, according to the CDC. This amounts to:

    • An average of 40,000 new cases each day
    • 86 total new cases for every 100,000 Americans
    • 7% fewer new cases than last week (January 19-25)

    In the past week, the U.S. also reported about 27,000 new COVID-19 patients admitted to hospitals. This amounts to:

    • An average of 3,900 new admissions each day
    • 8.4 total admissions for every 100,000 Americans
    • 8% fewer new admissions than last week

    Additionally, the U.S. reported:

    • 3,500 new COVID-19 deaths (500 per day)
    • 66% of new cases are caused by Omicron XBB.1.5; 27% by BQ.1 and BQ.1.1; 2% by CH.1.1 (as of February 4)
    • An average of 100,000 vaccinations per day

    COVID-19 spread in the U.S. continues to decline—but the decline continues to get slower, following the trend that I wrote about last week. Official COVID-19 cases, hospital admissions, and wastewater surveillance all indicate decreased transmission, leading into potential plateaus.

    New hospital admissions for COVID-19, for example, decreased by 8% this week (ending February 1) compared to the prior week (ending January 25). This is a smaller decrease than the prior two weeks, when admissions went down by 13% and 18%. Overall, new hospitalizations are at a similar level to what the U.S. faced in early summer 2022, as BA.5 started spreading across the country.

    Wastewater surveillance from Biobot suggests that COVID-19 spread is decreasing in all four major regions. But the decrease is steeper in the Northeast and South than it is in the Midwest and West coast, suggesting potential plateaus in the latter regions. Wastewater data from the CDC continues to show decreased transmission in about half of sites reporting to the agency and increased transmission in the other half.

    Where is COVID-19 spread increasing right now? Some northern Midwest states are reporting the most significant upticks. According to the latest Community Profile Report, new COVID-19 hospitalizations went up last week in South Dakota, Idaho, and Minnesota. Wastewater monitoring sites in Idaho and Minnesota also reported increased coronavirus concentrations, according to the WastewaterSCAN project.

    In the Midwest and West coast, Omicron subvariant XBB.1.5 continues to outcompete other versions of the virus. Per the CDC’s estimates, it accounted for about 44% of new cases in the region including the Dakotas and Minnesota this week, compared to 32% last week. XBB.1.5 already dominates the East coast, so its rise in the rest of the country could be one reason why COVID-19 is starting to go up again.

    Nationally, XBB.1.5 caused about two-thirds of new COVID-19 cases in the U.S. last week, according to the CDC’s estimates. It’s the only variant on the rise right now, as it drives out the BQ lineage and others. CH.1.1, the subvariant currently spreading fast in the U.K. and other countries, is less of a threat in the U.S. so far (at under 2% of new cases).

    While XBB.1.5 contributes to new infections across the country, the number of Americans who’ve received an updated booster shot remains stubbornly low. Only 52 million people have received the Omicron-specific booster, representing just 20% of the eligible population, according to CDC data.

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