State of California—Health and Human Services Agency
California Department of Public Health

February 27, 2025

TO:

Local Health Jurisdictions

SUBJECT:

Testing of influenza A virus in raw milk and raw milk products frequently asked questions (FAQs)

What type of sample should I be submitting?

Mainly raw milk, however solid dairy products from raw milk such as sour cream, butter and cheese can be accommodated per FDA protocol.

How much should I submit? And in what type of container?

If possible, 50 ml or 50 g of raw milk (or products). Samples submitted in sterile conical tubes (50 ml) or specimen cups are acceptable. If already opened, wrap with Parafilm if possible and double bag the sample. It's best that the sample sent unopened and with its original seal intact.

How should the specimen containers be labeled?

Make sure lot numbers, dairy, relevant sell by dates, etc., are included on the tube. Sample ID number or a unique identifier number is needed. In addition, date and time of collection, name and contact information source (firm, store, etc.), as well as the specimen submission form. It is important that all labels are clear, legible and attached firmly to both containers and/or samples.

Does the sample container need to be sealed/unopened?

If it is already opened - it will be received as is. If purchased from a store, it should be intact and sealed.

Can I send open containers of product?

Yes. Just make sure all relevant information is provided and the contained is properly sealed (Parafilm or double bagged).

What temperature should I be sending the product?

Preferably cold, in ice packs, if possible (as close as possible to 4°C). If frozen product, keep sample frozen and ship on dry ice (again, if possible). Milk specimens must be stored at 2-8°C (refrigerated) and transported to the laboratory within 48 hours of collection. If transportation will exceed 48 hours, freeze the sample at -20°C and ship it on dry ice to maintain the cold chain.

What regulations do I need to follow to ship these samples?

Publication 45 and 52 in the USPS regulations list.

What is the turnaround time for results?

Samples submitted to FDLB will be screened for Flu A virus per FDA protocol. Results will be available within 7 business days. For confirmation, screened positive Flu A samples will be sent to CDFA laboratory in Davis, CA.