16/ And if you're curious about how I reported this story, learn more here:
www.propublica.org/article/meth... /🧵>

15/ And the "severely ill" patient in Washington State confirmed to be infected with bird flu last week highlights the threat of a virus that has the potential to spark a pandemic.

Read more about this deep-dive into the Ohio/Indiana outbreak here: www.propublica.org/article/bird...

14/ Meanwhile, this fall has proven even worse than last year. Right now, the virus is spreading in northern Indiana, hitting 43 duck and chicken farms just in the last month, after wiping out dozens of turkey flocks in Minnesota.

13/ USDA also said its "biosecurity and epidemiological framework remains rooted in real-time data, internationally recognized best practices, and a commitment to transparency and continuous improvement."

12/ Indeed, USDA dismissed the airborne theory. "At this time, there is no compelling evidence that indicates aerial transmission poses a greater risk than other known transmission routes," a spokesman told me.

11/ If airborne spread proves to be "a major risk factor, then vaccine is absolutely a critical mitigation to put on the table,” one expert told me. “And that, of course, is something USDA still is not, after a decade, prepared to do.”

10/ That's because vaccinating chickens against bird flu would endanger export markets, mostly for meat chickens (which are rarely affected by the virus). USDA says it is "proactively assessing" the possibility of allowing poultry to be vaccinated.

9/ One tool could help: vaccines. After researchers in France discovered bird flu was traveling on dust and aerosols, they turned to vaccinating the country’s ducks. The results: A near-total reduction in cases. But USDA hasn't authorized their use in poultry here in the U.S.

8/ It's worth noting that experts told me this doesn't prove that the virus moved between farms on the wind, and that over the course of the outbreak, the virus likely took multiple routes between farms.

But the USDA's current paradigm of biosecurity won't address airborne spread, some said.

7/ By mid-March, the outbreak had hit 83 farms across six counties and two states, leaving over 20 million chickens dead, most no further than 15 miles from the first infected farm.

6/ The simulation showed that where the wind blew, the virus followed.

In the first few weeks of the virus’ spread, I found that farms downwind were 20x as likely to see outbreaks.

5/ The virus raged at Howe’s Hens, the center of the outbreak, from at least Dec. 22 to Dec. 31, when all the birds on the farm had been killed. Using weather data from that period, I simulated where dust from the site could have blown.

4/ Some thought it might have moved on the wind, not just because of biosecurity failures. To try and understand this better, I built out a list of 200+ chicken and turkey farms in the 12-mile radius that USDA establishes around an outbreak to look for where else the virus may have spread.

3/ I was able to trace the outbreak using genomic data sampled from the farms with infected poultry. This data told another story: hens in one egg farm got infected, and then the contagion spread from there, lighting up one of the most poultry-dense areas of the country within weeks.

2/ The U.S. Department of Agriculture typically attributes bird flu outbreaks to cases where farmers have not done enough to protect flocks from contamination by wild birds.

But that's not what happened here.
www.propublica.org/article/bird...

And this isn't meant to be an ad. I think there's sometimes a tendency, at least among journalists working with satellite imagery, to immediately go for the highest resolution possible. But there's an awful lot of stories inside those daily 3.5m multispectral collects.