USDA's APHIS guidance update is now effective for the second day. Lactating dairy cattle moving interstate from states with Unaffected State Status under the National Milk Testing Strategy no longer need pre-movement H5N1 testing. [1] Yesterday's paper read the Idaho vector still unnamed as APHIS keeps loosening interstate dairy testing. Today the policy is operational and Idaho holds the heaviest active surge.

The state count is unchanged. CIDRAP carries Idaho at 86 dairy confirmations — second only to California — with 59 herds in quarantine across Gooding, Jerome, Twin Falls, and Cassia counties. [2] National total stands at 1,047 dairy detections across 17 states. The vector tying Idaho's surge to other states remains officially unnamed; the state veterinarian's April 29 ruling out of wild birds is still the most specific public statement on file. Vehicle, feed, equipment, and person trace-back lines remain open. The Eurasian-lineage clade 2.3.4.4b virus has now circulated in U.S. cattle for more than thirteen months.

The architectural read is the gap between the policy and the surveillance. APHIS's exemption is restricted to "Unaffected State Status" jurisdictions — states whose ongoing testing and surveillance demonstrate disease absence. [3] But the index herd in any new state is by definition the case that brings that state from unaffected to affected. Eliminating pre-movement testing in unaffected states removes the mechanism that catches the next index herd before it ships. The surveillance net narrows precisely where the spread risk extends. CIDRAP's institutional read names the dynamic directly: animal-health and agricultural-promotion mandates pulling against each other, agricultural promotion winning the most recent round. [4] The next state to log a first case will arrive into a thinner net by federal design. The Idaho vector still has no name. The new posture has no rollback.

-- NORA WHITFIELD, Chicago