State veterinarians and NDA say HPAI incident in Churchill County dairies largely contained; testing, quarantines continue

Nevada Department of Agriculture staff told the Board of Agriculture on March 19 that a cluster of highly pathogenic avian influenza detections at dairy operations in Churchill County has been contained to a limited set of premises and that most affected dairies have met criteria for release from quarantine.

State veterinary and public‑health staff described a response that included expanded bulk‑tank testing, farm‑level biosecurity measures, targeted starling abatement near affected facilities and coordination with federal and local partners. Department leaders said they acted early to test widely and to work with producers to limit onward spread while investigators completed epidemiology and wildlife sampling.

The department reported that 10 of 13 dairies initially identified in the Churchill County cluster had been impacted and that three operations had completed three consecutive weeks of negative bulk‑tank tests and been released from quarantine. At the meeting NDA veterinary leadership described a virus variant that — in the cases observed to date — produced milder clinical signs and shorter durations of detectable virus in milk than earlier HPAI strains seen elsewhere in the U.S. Board members heard that testing and trace investigations are ongoing and that wildlife sampling remains part of the effort to determine likely sources.

Agency response highlights described to the board: - Testing strategy: NDA moved to expanded bulk‑tank sampling after initial detections; the approach prioritized early identification and control. - Quarantine and release criteria: Affected dairies were placed under quarantine; release required serial negative bulk‑tank results over a specified period before movement and other restrictions were lifted. - Starling abatement and wildlife work: NDA and partner agencies conducted targeted starling abatement around some operations and obtained wildlife samples; staff cautioned that wildlife sampling takes time and that some questions about sources remain unanswered. - Public guidance: NDA reiterated that pasteurization renders milk safe for consumption and that standard food‑safety measures protect consumers. The department also advised backyard flock owners to double‑bag and dispose of dead birds and to report unusual mortality through the department’s channels.

Board and staff comments Director Gregor Cheah thanked the field teams and outside partners for a coordinated response and said the department sought to contain spread while minimizing disruption to the wider dairy industry. NDA said it would continue statewide surveillance testing for a period the agency determines appropriate and then step testing frequency down as risk permits.

No change to consumer guidance: NDA staff continued to recommend pasteurization for milk intended for human consumption and urged producers and the public to follow standard biosecurity practices.

What remains open: Investigations into the initial source of the detections are ongoing. Staff said they have hypotheses based on field epidemiology and genetic analysis of viral samples but that the department would not conclude a definitive source until further data — including wildlife test results and detailed movement tracing — are complete.

The board asked staff to keep members informed as dairies move through quarantine release and as surveillance results are reported.