The Emory PLOS Biology study found H5N1 in submicron aerosol particles in milking-parlour air, wastewater, and exhaled cow breath across 14 California farms. Cows shed virus before showing clinical signs.Source: PLOS Biology / Emory University

Does the Emory study mean dairy workers need different face masks?

The study suggests aerosol exposure is a real route, which is prevented by respiratory protection rather than the contact precautions (gloves, eye shields) in current CDC guidance. CDC had not updated guidance as of 7 May 2026.Source: Emory / CIDRAP

Is Emory University connected to the CDC?

Emory's Atlanta campus is a few miles from CDC headquarters and the two institutions have deep institutional ties, including joint faculty appointments and shared research programmes on Ebola, influenza and HIV.

Background

Emory University is a private research university in Atlanta, Georgia, founded in 1836. Its medical school and public health programmes rank among the leading research institutions in the United States. Emory is home to the Rollins School of Public Health and the School of Medicine, and has longstanding institutional ties with the CDC, which is headquartered a few miles from campus. Emory researchers have played significant roles in Ebola clinical care in the US (2014), HIV research, and pandemic influenza modelling. Its infectious disease faculty publish regularly in high-impact peer-reviewed journals including PLOS Biology, the New England Journal of Medicine, and The Lancet.

Emory University researchers published a PLOS Biology study in early May 2026 based on sampling across 14 California dairy farms with confirmed H5N1. The study detected H5N1 in submicron aerosol particles in milking-parlour air, in farm wastewater, and in the exhaled breath of cows. The clade detected in air samples was 2.3.4.4b B3.13, the same lineage behind 71 known US human H5N1 cases, confirming the dairy reservoir as the active human-spillover route. The findings are directly in tension with CDC's current dairy-worker guidance, which addresses contact transmission but not submicron aerosol exposure. As of publication, neither CDC, USDA nor PAHO had updated worker guidance to address the Emory findings.

Source Material

Emory University — Official Website Emory University

How the World Sees Them

United States

Emory's proximity to CDC amplifies the political salience of the aerosol findings; the CDC has not yet acted on guidance revisions as of publication, creating a reputational tension for a neighbouring institution.

Dairy industry

The finding that cows shed virus before clinical signs appear undermines visual herd monitoring and implies operational changes to milking protocols regardless of PPE updates.

Global public health

Aerosol transmission in an agricultural setting carrying the same H5N1 clade as human cases is a data point that WHO's technical working groups on H5N1 risk assessment will need to address formally.