COVID-19 Data Dispatch

Tag: xbb.1.16

  • 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. 

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  • 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.

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  • 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.

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  • 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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