​6 Most Common Foodborne Pathogens and How to Prevent Them

Foodborne pathogens infect over 600 million people each year, with an estimated 420,000 patients dying as a result of their illness, according to the World Health Organization. This broad category of microorganisms encompasses bacteria, parasites, and viruses, each presenting their own symptoms for consumers and challenges to food safety. Despite their small size, very low levels of contamination can have an impact on public health.   

Foodborne pathogens and illness outbreaks can be devastating to communities and economies, not to mention people’s lives, but all are preventable with the right food safety practices. It’s key for manufacturers to understand the foodborne pathogens most likely to pose a risk in their operation, and take necessary steps to prevent contamination.  

6 Most Common Foodborne Pathogens 

There are hundreds if not thousands of bacteria, parasites, and viruses that impact human health, but only some of them have emerged as common threats in the food and beverage sector. Here are six of the most prevalent foodborne pathogens implicated in foodborne illness outbreaks and product recalls — and how to prevent them: 

1. Listeria 

The listeria monocytogenes bacteria is a foodborne pathogen that can lead to severe illness in pregnant women, newborns, elderly, and those with weakened immune systems. Common sources of infection include contaminated ready-to-eat deli meats and soft cheeses, unpasteurized dairy products, and improperly processed vegetables.  

Listeria outbreaks can be dangerous, and often spread far and fast. A multi-year, multistate outbreak of listeria monocytogenes was reportedly linked to queso fresco and cotija cheeses manufactured by Rizo Lopez Foods Inc. of Modesto, California. The outbreak ended on April 9, 2024, as reported by the CDC.  

Preventing listeria requires frontline workers to:  

• Rigorously clean and sanitize food contact surfaces 
• Maintain proper refrigeration temperatures to inhibit bacterial growth 
• Follow strict hygiene protocols in compliance with Good Manufacturing Practices (GMP)  

Manufacturers should regularly test for listeria species, as an indicator organism, in the processing environment, (including drains) as part of your EMP (environmental monitoring program) to ensure all protocols are being followed.  

2. Salmonella 

Salmonella is found in raw poultry, eggs, unpasteurized dairy, and contaminated fruits and vegetables. The pathogen is known for causing symptoms like diarrhea, fever, and abdominal cramps.  

The government takes salmonella outbreaks seriously, and multiple agencies often work together to track down and end them. During February 2024, the FDA and CDC, in collaboration with state and local partners, investigated an outbreak of salmonella infections linked to recalled Infinite Herbs-brand and Melissa's-brand fresh organic basil. The outbreak ended on June 18, 2024 as reported by the CDC. 

For manufacturers and food processors, preventing salmonella requires rigorous cleaning and sanitation of food contact surfaces and processing equipment, as well as ingredient segregation to avoid cross-contamination. Strict personal hygiene practices by employees are also critical to preventing spread.  

Because salmonella is so prevalent throughout the food supply, consumers need to practice proper handling and cooking to truly avoid risk. Manufacturers can help by putting safe handling and preparation instructions on their packaging.  

3. E. coli 

Escherichia coli (E. coli) is a diverse group of bacteria, with some strains causing severe foodborne illness marked by symptoms like stomach cramps, diarrhea, and vomiting. Common sources of infection include undercooked ground beef, raw vegetables, unpasteurized milk, and contaminated water.  

E.coli strains thrive well in cheese, too, especially if it hasn’t gone through the pasteurization process. A multistate outbreak of E. coli O157:H7 linked to all sizes of RAW FARM-brand Raw Cheddar cheese blocks and shredded cheeses were investigated by the FDA and CDC during February 2024. The outbreak ended on March 26, 2024 as reported by the CDC. 

Manufacturers and food processors can prevent E. coli spread with regular cleaning and sanitizing of equipment and surfaces, along with proper handwashing protocols for employees. Routine testing for E. coli in the processing environment can help detect and address potential contamination early, before it threatens public health or triggers a recall.  

4. Norovirus 

Norovirus is easy to transmit from infected individuals through food or water. As a result, it’s typically contracted from raw or undercooked shellfish, leafy greens, and ready-to-eat foods handled by infected individuals.  

To prevent norovirus, manufacturers and food processors need to be strict about handwashing, frequently sanitize food preparation areas, and ensure employees who are ill do not handle open foods. Supplier audits are also recommended to ensure facilities are only intaking high-quality and safe ingredients, particularly when it comes to shellfish. 

5. Hepatitis A 

Hepatitis A virus (HAV) is the pathogen that causes hepatitis A, a serious infection that attacks the liver. It's typically transmitted through consuming food or water with fecal matter from an infected animal or person. Like norovirus, the most common sources are contaminated raw or undercooked shellfish, produce, and food handled by infected individuals. 

Other sources of this disease are contaminated, unpeeled, and uncooked fruits and vegetables. In fact, a multistate outbreak of hepatitis A infections linked to fresh, organic strawberries were investigated by the FDA, along with the CDC. These potentially contaminated strawberries were imported from Baja California, a state in northern Mexico.  

In addition to standard adherence to hygiene and sanitation protocols, it’s important for workers to maintain their hepatitis A vaccinations to reduce their risk of both contracting and spreading the virus. 

6. Staphylococcus Aureus 

Staphylococcal (staph) food poisoning occurs when you eat something contaminated with toxins produced by the bacterium Staphylococcus aureus. 

Staph food poisoning causes distressing gastrointestinal symptoms, including significant vomiting and nausea. To prevent staphylococcal food poisoning, manufacturers should implement a strict personal hygiene culture.  

Good Manufacturing Practices: The Key to Mitigating Foodborne Pathogen Risk 

Regardless of the type of foodborne pathogen creating risk in your operation, control and mitigation always begins with proper sanitation and hygiene practices. All of these are enshrined in GMP, and your frontline staff’s diligent adherence to protocols. 

Want to improve compliance with GMP? AIB International offers world-class auditing and inspection services to help you avoid future food safety breaches.