The Data on Salmonella and Raw Milk
Public health agencies, including the CDC and FDA, caution against drinking raw milk due to the risk of contamination with harmful bacteria. While raw milk accounts for a very small fraction of total milk consumption in the U.S., it is responsible for a disproportionately large number of foodborne illnesses. This is because the pasteurization process, which heats milk to kill pathogens, is skipped for raw milk. Even with stringent safety practices, it is impossible to guarantee that raw milk is free from contamination.
Why Counting Every Case is Impossible
The CDC acknowledges that most foodborne illnesses occur outside of recognized outbreaks and that many more go unreported. This makes it difficult to state an exact number for how many people get sick from raw milk each year. Statistics primarily focus on documented outbreaks, which represent only the "tip of the iceberg." For every case confirmed in an outbreak, many more illnesses likely occur. This underreporting is a major factor in understanding the true scope of the risk.
Notable Salmonella Outbreaks from Raw Milk
While raw milk can harbor several dangerous pathogens, Salmonella is a common culprit. A major multistate Salmonella Typhimurium outbreak linked to commercially distributed raw milk occurred between September 2023 and March 2024, sickening 171 people across five states, with most cases in California. Notably, 70% of the cases involved children and adolescents under 18. From 2013–2018, there were 13 reported Salmonella outbreaks linked to raw milk, causing 109 illnesses.
The Hidden Dangers in Unpasteurized Dairy
Unpasteurized milk can become contaminated with pathogens at numerous points on the farm, including from animal feces, the milking process, and the farm's general environment. Unlike pasteurized milk, which is heated to eliminate these microorganisms, raw milk contains an uncontrolled mix of bacteria.
Other Harmful Pathogens in Raw Milk
In addition to Salmonella, raw milk can carry other harmful bacteria that cause serious foodborne illnesses:
- Campylobacter spp.: A common cause of illness from raw milk, with symptoms including diarrhea, fever, and stomach cramps.
- Shiga toxin-producing E. coli (STEC): Can cause severe illness, including hemolytic uremic syndrome (HUS), which can lead to kidney failure.
- Listeria monocytogenes: Especially dangerous for pregnant women, newborns, the elderly, and immunocompromised individuals, as it can cause serious, life-threatening infections.
- Brucella: A pathogen that can be transmitted through raw milk, causing an infection with flu-like symptoms.
- Cryptosporidium: A parasite found in raw milk that can cause gastrointestinal distress.
Raw Milk vs. Pasteurized Milk: A Comparison
| Feature | Raw Milk (Unpasteurized) | Pasteurized Milk | Key Differences |
|---|---|---|---|
| Safety Risk | High; contains potential pathogens like Salmonella, E. coli, and Listeria. | Low; pasteurization kills harmful bacteria, making it significantly safer to consume. | Pasteurization eliminates the risk of illness from milk-borne pathogens. |
| Consumption Rate | Consumed by a small percentage of the U.S. population (estimated 1–2%). | Consumed by the vast majority of the population. | Widespread consumption of pasteurized milk is standard due to public health consensus. |
| Outbreak Contribution | Causes a disproportionately high percentage of dairy-related foodborne illnesses (up to 96%). | Causes very few outbreaks; most are linked to post-processing contamination. | Despite low consumption, raw milk is responsible for most dairy-related illness outbreaks. |
| Nutritional Value | No evidence of superior nutritional content. Pasteurization does not significantly alter nutritional quality. | Same nutritional value as raw milk; rich in calcium and vitamin D. | Nutritional benefits are identical, debunking the myth that raw milk is healthier. |
| Allergy Risk | Contains milk proteins that can trigger allergic reactions. | Contains milk proteins that can trigger allergic reactions. | The pasteurization process does not cause lactose intolerance or allergic reactions. |
Vulnerable Populations at Disproportionate Risk
The bacteria in raw milk can cause severe and sometimes life-threatening illness, particularly in certain high-risk groups. The CDC has noted that children, older adults, pregnant women, and individuals with weakened immune systems are especially vulnerable to serious complications.
Why Children are More Susceptible
Recent outbreaks highlight the heightened risk for children. The 2023-2024 Salmonella outbreak saw 70% of its cases among children and adolescents. From 2013 through 2018, nearly half (48%) of illnesses linked to raw milk outbreaks reported to the CDC were in people aged 0–19. Infections in young children can lead to serious conditions like hemolytic uremic syndrome (HUS), a type of kidney failure.
Risks for Other At-Risk Groups
- Pregnant women: Can experience miscarriage, stillbirth, or serious illness for their newborn if infected with Listeria.
- Immunocompromised individuals: Those with conditions like HIV/AIDS or cancer face a higher risk of severe illness and complications.
The Role of State Laws in Outbreak Occurrence
State laws governing the sale of raw milk have a direct impact on the number of outbreaks. A study analyzing data from 2013 to 2018 found that states allowing raw milk sales had a significantly higher number of outbreaks than those where sales were prohibited. This is a clear indicator that increased availability correlates with increased risk and illness.
Conclusion: The Clear Safety Choice
There is no safe level of contamination in raw milk. While some consumers are drawn to unproven health claims, scientific evidence and decades of public health data confirm the serious risks. Pasteurization remains the only effective method to eliminate harmful pathogens from milk. For guaranteed safety, especially for vulnerable populations, opting for pasteurized milk and dairy products is the unequivocal recommendation from health authorities. The risk of getting sick from Salmonella or other dangerous bacteria in raw milk far outweighs any alleged benefits, and the increasing number of outbreaks confirms the ongoing threat to public health.
For more information on food safety and raw milk, consult the CDC's official guidance: https://www.cdc.gov/food-safety/foods/raw-milk.html.
