Thread by @beowulf888

12-1/ My pathogen update for epi weeks 11-12 of 2025. The XEC COVID wave hasn't fully receded yet. Biobot shows that as of March 15, SARS2 wastewater levels haven't fallen to previous interwave gaps except for the Western region of the US.

12-2/ The CDC's ww numbers indicate a long tail for this wave, but it shows the West and NE back to interwave levels. These numbers are all normalized to the previous year's numbers, so I don't know if this long tail may be an artifact of the way they normalize. I trust Biobot.

12-3/ If there is a long tail, it's due to the LP.8.1x brood that continues to gain traction against XEC.x. I expected the LP.8.1x's to top out at about 30%, but CoV-Spectrum shows they've reached 50%. O/c, there were only 3 LP.8.1x descendants a month ago. Now there are 19.

12-4/ If previous wastewater patterns hold, SARS2 will continue circulating at low levels during the interwave gaps. I wonder if these aren't mostly chronic infections, as seen by Marc Johnson @SolidEvidence in wastewater?

@SolidEvidence 12-5/If previous US patterns hold, we'll see probably see another wave peak in late summer. Maybe I'm an optimist, but I suspect the next wave's hospitalization rates won't exceed 5/100,000, and the weekly death rate will be lower than 0.25/100,000. We'll see.

@SolidEvidence 12-6/ On the HPAI A(H5) front, the CDC released it's monthly update. As of 19 March, there's still no sign of human-to-human transmission. Likewise there's nothing to indicate that our milk supply is a vector for A(H5) infections.

cdc.gov/bird-flu/spotl…

@SolidEvidence 12-7/ OTOH, the measles outbreak is still spreading. It's now grown to 309 cases in 14 TX counties, and 42 cases in 2 NM counties. And it has spread south of the border... (h/t to vaxopedia for the map)

@SolidEvidence 12-8/ The state of Chihuahua has a growing number of cases, with 400+ suspected and at least 32 confirmed cases. Mexico has issued a warning to its citizens asking them not to travel to Texas and seven other states in the U.S. due to a measles outbreak.

tinyurl.com/3ect9uej

12-9/ The Mexican outbreak evidently started in a Mennonite community in Chihuahua whose members had visited infected communities in Texas. Likewise, Canada is seeing a big measles outbreak (h/t to Global News for the graphic).

12-10/ The Canadian outbreak started at a Mennonite gathering in New Brunswick last fall. It's spread o other Mennonite communities in Ontario and to the rest of the country. The NB case didn't catch it in the US, but brought it back from the Philippines.
tinyurl.com/ms733yju

12-11/ The WHO publishes a monthly measles update for the world. The case numbers for Feb are still coming in, but January seems to have been a relatively "mild" month. And notice how the COVID pandemic interrupted suppressed measles transmission 2020-21.

tinyurl.com/56y8tn2p

12-12/ That's it for this update. See you in two weeks. Cheers!

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