The spread of the A(H5N1) virus, or avian flu, has forced the Centers for Disease Control and Prevention (CDC) to warn people away from drinking raw milk contaminated with the virus as a way to acquire antibodies against the disease.
While consumption of raw milk seldom cracks more than 5% of the U.S. population, according to the Journal of Food Protection, avian flu’s recent presence in Texas has sparked new interest in the dangerous practice.
The notion of drinking raw milk to acquire avian flu immunity came about in part because of the way the disease spread in Texas. In April, a dairy worker became infected after working with infected cows. Fortunately, the person infected – one of only four so far in the U.S. as of this writing – had conjunctivitis as a symptom and was treated successfully.
“We discourage people from drinking raw milk to build up antibodies,” said Janeana White, MD, deputy public health authority and chief physician for the Houston Health Department as well as a member of the Texas Medical Association’s Committee on Infectious Diseases. “We’re still learning a lot about this [avian flu] virus, so we don’t know all the consequences of drinking [raw milk]. But there are so many other bacterial organisms [in raw milk] that it’s still very risky when you’re thinking of trying to induce exposure.”
While all states allow limited raw milk sales, federal law prohibits the sale of it for human consumption across state lines. In Texas, only dairies can sell raw milk. Texas law requires licensed dairies to have their raw milk sampled on a quarterly basis for pathogenic bacteria and for the presence of antibiotics in the milk, according to the Texas Department of State Health Services (DSHS).
Without proper pasteurization of raw milk, the risk for contamination outbreaks increases 24%, DSHS says. With proper pasteurization of raw milk, the number of contamination outbreaks drops to less than 1%. Between 1998 and 2018, 202 U.S. disease outbreaks and 2,645 illnesses were linked to unpasteurized milk, including 228 hospitalizations and three deaths, according to a Cambridge University study.
However, those numbers are an undercount because “outbreaks linked to unpasteurized milk can be difficult to identify and trace to a production source,” the study said. “As part of unpasteurized milk sales agreements … customers may not report product consumption and may withhold information about the source of the milk, which prevents traceback and implementation of farm-level interventions.”
CDC provides more information about how physicians can talk with patients about bird flu and raw milk.