What is the likelihood of acquiring a parasitic infection from consuming unpasteurized (raw) milk?

From the Guidelines

The risk of acquiring a parasitic infection from consuming unpasteurized milk is high, and I strongly recommend avoiding unpasteurized milk products entirely to prevent parasitic infections. The evidence suggests that raw milk and milk products can be a source of bacterial and parasitic infections, including Listeria monocytogenes, Campylobacter jejuni, Salmonella species, Brucella species, Escherichia coli O157, and parasites like Cryptosporidium, Toxoplasma, and Giardia 1. According to a study published in Pediatrics in 2014, consumption of raw milk or milk products in the United States resulted in 93 illness outbreaks, 1837 illnesses, 195 hospitalizations, and 2 deaths from 1998 to 2009 1.

Key Points to Consider

• The risk of parasitic infections from unpasteurized milk is particularly high for pregnant women, children, elderly individuals, and those with weakened immune systems 1.
• Pasteurized milk confers equivalent health benefits compared with raw milk, without the additional risk of bacterial and parasitic infections 1.
• Treatment for parasitic infections typically involves antiparasitic medications, with specific dosing determined by a healthcare provider based on the parasite identified.
• The simple solution is to consume only pasteurized milk products, which provide the same nutritional benefits without the parasitic risk.

Prevention and Treatment

If you consume unpasteurized milk and develop symptoms such as diarrhea, abdominal pain, nausea, or fever, seek medical attention promptly. Avoiding unpasteurized milk products entirely is the best way to prevent parasitic infections, and this is especially important for high-risk individuals such as pregnant women, children, and those with weakened immune systems 1.

From the Research

Risk of Parasitic Infection from Unpasteurized Milk

• The likelihood of acquiring a parasitic infection from consuming unpasteurized (raw) milk is significant, as raw milk can harbor a variety of microorganisms, including bacteria, viruses, and parasites 2, 3, 4.
• Several studies have shown that unpasteurized milk and dairy products can be contaminated with pathogens such as Escherichia coli, Salmonella spp., Listeria monocytogenes, and Campylobacter spp., which can cause foodborne illnesses 5, 6.
• The risk of infection is higher for unpasteurized milk and dairy products, with some studies suggesting that unpasteurized dairy products can cause up to 840 times more illnesses and 45 times more hospitalizations than pasteurized products 5.
• Outbreaks of disease have been linked to the consumption of unpasteurized milk and dairy products, resulting in significant morbidity and mortality, particularly among vulnerable populations such as pregnant women and immunocompromised individuals 6.

Pathogens Associated with Unpasteurized Milk

• Common pathogens associated with unpasteurized milk include:
  • Bacteria: Escherichia coli, Salmonella spp., Listeria monocytogenes, and Campylobacter spp. 2, 5, 6
  • Viruses: Rotavirus, Norovirus, and Hepatitis A virus 3
  • Parasites: Cryptosporidium parvum, Giardia lamblia, and Toxoplasma gondii 4

Prevention and Control Measures

• Pasteurization is the most effective method of enhancing the microbiological safety of milk, and it does not change the nutritional value of milk 4.
• Other prevention and control measures include:
  • Improving sanitation during milking and storage of milk 3
  • Developing uniform regulations and microbial standards for raw milk 3
  • Enhancing and targeting educational efforts to reduce the risk of raw milk-associated foodborne illness 3