Microbiological Surveillance Sampling: FY25 Aged Raw Cow’s Milk Cheese Collection and Analysis for HPAI
Microbiological Surveillance Sampling
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Raw Cow’s Milk Cheese Sampling
The U.S. Food and Drug Administration (FDA) has begun a domestic sampling assignment to collect and test aged raw cow’s milk cheese for Highly Pathogenic Avian Influenza (H5N1). The objectives of the assignment are:
- To determine whether viable H5N1 virus is present in the cheese; and
- To take follow-up action(s) as needed to address contaminated product and protect consumers.
An outbreak of H5N1 in multiple states precipitated this assignment. The FDA is working with the U.S. Department of Agriculture (USDA), the Centers for Disease Control and Prevention (CDC) and state partners to investigate and respond to the outbreak, which is impacting poultry, dairy cows, and people in the United States. The FDA’s sampling assignment complements research efforts that the agency is carrying out with its federal and state partners, as well as select research universities. Unlike the research efforts, the FDA’s sampling assignment is a regulatory activity.
Raw milk cheese is made with unpasteurized milk. In the United States cheese allowed to be made from raw milk must be aged for a minimum of 60 days to mitigate the risk from any pathogens, if present.
Questions & Answers
What is the duration of the assignment?
The sample collection may begin as soon as the end of December and is anticipated to be complete by the end of March 2025. The agency may extend the assignment duration to achieve the collection target, if needed.
When will the FDA collect samples?
The FDA will collect samples Monday to Friday, during business hours.
Where will the samples be collected from?
FDA field staff will collect samples from warehouses and distribution hubs throughout the United States. To avoid overburdening distributors, the agency will collect no more than five samples at each collection site. The scope of this assignment does not include collection of samples at retail.
What exactly does the FDA plan to collect?
The FDA will collect 300 samples of raw cow’s milk cheese that has been aged for at least 60 days, along with the label information. Each sample will consist of two packages of product, weighing at least 100 grams.
How will the FDA identify the targeted product (aged raw cow’s milk cheese) when it is not required to be labeled?
The agency’s field staff will collect product that is labeled as aged raw cow’s milk cheese. In identifying the product, they also may use shipping documentation, such as a bill of lading, to aid in their determination, and may speak with the distributors.
What should industry expect when the FDA collects samples?
See detailed information on what to expect when the FDA collects samples.
What test methods will be employed?
The FDA initially will test the samples using a PCR test. Samples that indicate the presence of H5N1 genetic material (either RNA or DNA) following a PCR test will be subject to viability testing. The viability test method is an egg inoculation test developed by USDA.
When will the FDA provide notice to dealers of the test results?
| Finding | Time to Notification |
|---|---|
Negative Results PCR Positive Results | Typically, within one week of sample collection. |
| Confirmation of Viability | Typically, within one month of sample collection. |
What happens if the FDA finds a sample to be positive following a PCR test?
The FDA will not require any action from a firm solely in response to a PCR positive result. Additional testing is needed to determine viability.
If the viability testing confirms the presence of viable HPAI in a product sample, what follow-up action(s) will the FDA take?
If the FDA detects viable virus in a sample, the agency will take follow-up action as warranted to protect consumers. Any samples that test positive for viable virus will be evaluated on a case-by-case basis. This means that depending on the findings, the FDA will consider next steps, which may include actions needed to address contaminated product, such as a recall, follow-up inspection, or other possible responses to protect public health. The FDA will also notify the U.S. Department of Agriculture (USDA) and public health officials in the relevant state(s) of the positive test result.
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When will the FDA publicize the assignment test results?
The FDA plans to publicize the assignment findings on FDA.gov after all testing and analysis are complete.