A new study warns that raw cheese made from milk of cows infected with bird flu (H5N1) can keep the virus alive for months, raising health risks. Here’s what you should know.
What Is Raw Cheese?
- Definition: Raw cheese is made from milk that hasn’t been pasteurized (heat-treated to kill germs).
- U.S. Law: Raw cheese is legal nationwide if aged for at least 60 days. This rule, from 1949, was meant to reduce contamination by letting natural acids kill pathogens.
Key Study Findings
A Cornell University study (funded by the FDA) tested raw cheese’s safety during bird flu outbreaks:
- Virus Survival: H5N1 stayed infectious in raw cheese for up to 60 days (the required aging period).
- Lab Tests: Researchers made mini cheeses with added H5N1 at different acidity levels (pH 6.6, 5.8, and 5.0):
- Higher pH (less acidic): Virus survived the full 60 days.
- Lower pH (more acidic, pH 5.0): No live virus detected.
- Real-World Example: Cheese from a farm with infected cows also showed the virus stayed active for 60 days.
Why Does H5N1 Survive in Cheese?
- Protected Environment: The virus is shielded by proteins and fats in milk/cheese, helping it survive refrigeration.
- Strain Matters: The study tested the B3.13 strain (mild in humans), but a newer strain (D1.1) linked to severe human cases is now in cows.
Can Bird Flu Spread Through Food?
- Conflicting Statements:
- U.S. Health Secretary Robert F. Kennedy Jr. claims food (eggs, milk, meat) isn’t a risk.
- Reality: No confirmed human cases from food, but:
- Animals (cats, etc.) have been sickened by raw milk.
- Three human cases had unknown sources of exposure.
- Dairy workers got infected via raw milk splashes.
- Expert Warning: Study leader Dr. Diego Diel (Cornell) says eating contaminated food could pose a risk, depending on the dose and strain.
Are Pasteurized Products Safer?
- Yes! Pasteurization (heat treatment) kills H5N1.
- FDA Tests
- 464 pasteurized dairy products (milk, cheese, ice cream) tested negative for live virus.
- 96 of 110 raw cheese samples tested negative; 14 results pending.
What Should You Do?
- Avoid Raw Milk Products: Until more is known, skip raw cheese/milk.
- Choose Pasteurized: Opt for heat-treated dairy to reduce risk.
- Stay Updated: Follow FDA guidelines as the outbreak evolves.
Sources & References
- Cornell University Study (preprint, not yet peer-reviewed)
- FDA Statement on Dairy Safety
- Expert Quotes: Dr. Diego Diel (Cornell), Dr. Seema Lakdawala (Emory University).
Note: This study highlights potential risks, but more research is needed. Always consult health officials for the latest advice.
Stay safe and stick to pasteurized dairy during the bird flu outbreak! 🥛🚫