As the fourth human case of H5N1 avian flu in a US farmworker in Colorado was confirmed Wednesday by the US Centers for Disease Control and Prevention (CDC), so far, only farm workers, and not consumers, have reported avian flu infections.

This is likely due, at least in part, to the successful inactivation of the virus during the milk pasteurization process, experts say. And yet one-half or more Americans seem to have little idea about the dangers of drinking raw milk, according to a recent poll conducted by the University of Pennsylvania researchers.

The survey, which included a demographically representative sample of the US adult population, found that less than half (47% percent) of the U.S. adults surveyed understood that drinking raw milk not as safe as drinking pasteurized milk. Conversely, 53% of respondents don’t actually believe that pasteurized milk is safer. And 9% of respondents actually believed raw  milk is safer, while 15% said it was just as safe and 30% were unsure.  

Nearly a quarter (24%) of Americans either do not believe that pasteurization is effective at killing bacteria and viruses in milk products (4%) or are not sure whether this is true (20%), according to the survey of over 1000 US adults, conducted by the Annenberg Public Policy Center (APPC). The survey has a 3-3.5% statistical error rate.

That, despite the fact that studies report that pasteurized milk limits hospitalizations for related illnesses by an order of 45, according to the APPC report. 

The French Scientist Louis Pasteur invented the pasteurization process 160 years ago, after recognizing that it killed off otherwise dangerous bacteria present in unheated wine. The process, which soon became a milk industry standard in the United States, successfully inactivates the modern-day avian flu virus, significantly limiting the risk of infection for the general public. 

Politics and milk 

In fact, only about 2% of Americans report drinking raw milk at least once a month, according to a Food and Drug Administration (FDA) study based on 2019 data.

Paradoxically, however, raw milk sales in the US have increased in recent months, according to some US media reports, despite the recent risks posed by a widening circle of avian influenza among dairy cattle.

Debate has been spurred  by the increased anti-science bent of some US political leaders. Presidential candidate Robert F. Kennedy Jr., for instance, who also has been a staunch opponent of COVID vaccination, has been quoted saying that he drinks raw milk exclusively.

The APPC survey also found that Republicans are more likely than Democrats to believe that drinking raw milk is as safe as pasteurized milk (57% vs. 37%). People living in an urban environment also are more likely to believe that pastuerized milk is safer than raw milk as compared to people in a rural environment (49% vs. 32%).

“The difference in views of raw milk that we see between Democrats and Republicans is difficult to disentangle from the difference between rural and urban dwellers,” said Kathleen Hall Jamieson, director of the Annenberg Public Policy Center. “Those in rural areas are both more likely to identify as Republicans and to consume raw milk.”

55 more dairy herds reported infected in last 30 days

Some 55 more cattle herds in seven states have been infected with the virus over the past 30 days, according to CDC tracking. Infections in the past 30 days represent 40% of the total of 138 cattle herds infected in 12 states since the outbreak in dairy cattle was first reported on 25 March, the CDC reported. 

The real number of infections of both humans and cattle is very likely underestimated, insofar as farmers have been reluctant to have their staff or herds tested, experts warn.

Even so, the CDC maintained that infection risks for the general public remain low. 

“Based on the information available at this time, this infection does not change CDC’s current H5N1 bird flu human health risk assessment for the U.S. general public, which the agency considers to be low,” the CDC said in a statement.

Image Credits: Cotonbro studio, APCC, CDC.