Thread by @angie_rasmussen

Very important to note here that qPCR positives are not the same as "virus particles." It's much easier to detect viral RNA by qPCR than it is to detect infectious virus or intact virus particles (as the article correctly notes).

This finding does have some big implications:

https://twitter.com/statnews/status/1782903822018359327

1. This suggests there are undetected herds shedding virus into the milk supply. Viral RNA does not materialize out of thin air—it is the product of a current or very recent viral infection.

No virus replicating in cows, no viral RNA in milk.

No viral RNA, no PCR positives.

1+. qPCR detects virus by amplifying small specific fragments of the viral genome. There's no indication that they pulled entire H5N1 genome sequences out of this, which would likely require signaling. Influenza is segmented, however, so no word on which segments they amplified.

1+. A qPCR product shows that virus was ONCE present in the sample, but not that an intact virus is present now. However, as is now standard for this outbreak, it's hard to say more as no raw data was shared, so we just have to take their word for it (more on that below).

2. That further suggests that our current quality control for identifying milk that may be from infected cows may not be adequate. As best as I understand, if milk production drops or the milk is off in terms of color or consistency, it's excluded from the milk supply.

2+. If viral RNA is detected in pasteurized milk, it means that milk was not identified through current procedures and is going on to be pasteurized for commercial use. This suggests either asymptomatic shedding from cows or inadequately disinfected milk processing equipment.

3. If cows are infected and shedding virus while showing no detectable clinical signs of infection, then the epidemic (technically epizootic) may be much broader than previously thought. This is, IMO, very bad news that makes surveillance and ultimately containment much harder.

4. I do agree the milk supply is safe to consume. Viral RNA is not infectious for influenza & it persists after heat inactivation at pasteurization temperatures. There's no reason to think pasteurization doesn't magically work for H5N1 only when it does for other viruses.

5. It would be nice to have reassurances that @US_FDA and @USDA/@USDA_APHIS are on top of this. However, this information was shared with no supporting data, characteristic of the current response. It's very unclear why all the relevant data has not been shared rapidly.

5+. I'm not attributing this to malice, incompetence, territorialism, bureaucracy, or anything else, but it's very clear that this apparent lack of transparency and urgency to share these relevant data are greatly harming both the US and global capacity to respond.

We know that if you don't want an outbreak to become an epidemic or a pandemic, it needs to be contained quickly. This news further shows that it has neither been contained and there is no evident rush to do so.
This is both alarming and profoundly depressing.

Many have correctly commented about the loss of trust in public health that this is furthering, but the problem goes beyond that. Here the agencies leading this response have forfeited leveraging the full capacity of the international scientific community to respond.

Pandemics are global events by definition. The US—the country where I am from, was trained, still work extensively in, and once claimed leadership in pandemic preparedness—is not the only country impacted. It's a matter of time before we find infected cows elsewhere.

Cattle—both dairy and beef production—is big business around the world. There are billions of cows. Failing to share information rapidly not only hurts food security, the economy, and human/animal health in the US, it's preventing a global response to a major global threat.

I am frequently asked to comment on "lessons learned" from SARS-CoV-2. Now I have yet another example of a critical lesson that has decidedly not been learned: if there's an emerging pandemic threat, you leverage all your resources to respond as fast and effectively as possible.

The lack of data and information sharing occurring here is disgraceful and inexcusable. The global scientific community is eager to leverage what we've learned from the last pandemic—at devastating cost to us all—to prevent another one.

The government needs to help, not hinder.

Post-script: The work continues, despite the obstacles. I remain hopeful that more data will be shared and our contributions and those of our colleagues around the world will continue.

https://x.com/MichaelWorobey/status/1782929298149851605

*Sequencing, not signaling. The edit window that returned with my blue check has closed, however, so I have to correct in the replies.

Detecting evidence of H5N1 in commercial milk is consistent with the finding described (and effort led) by @MichaelWorobey above: it’s been in cows—potentially a lot of cows—for a lot longer than we initially thought. And likely spilling back to birds.

statnews.com/2024/04/23/h5n…

@MichaelWorobey More on that here:

https://twitter.com/michaelworobey/status/1782880126042271931