In the summer of 2020, a major outbreak of Salmonella Newport was linked to red onions grown in California, causing over 1,600 reported cases across the U.S. and Canada. The FDA’s investigation identified potential contributing factors, including the use of contaminated irrigation water, adjacent livestock grazing, and wildlife intrusion in the onion fields. Packinghouse practices, such as inadequate sanitation and pest control, were also noted as possible sources of contamination. Despite extensive testing, the exact root cause of contamination could not be conclusively determined, though the onion producer Thomson Onions was widely believed to be the source of the salmonella adulterated onions. The FDA stated, in part:
“… visual observations and records review of packing house practices confirmed numerous opportunities for spread of foodborne pathogens such as Salmonella, including signs of animal and pest intrusion as well as food contact surfaces which had not been inspected, maintained, cleaned, or sanitized as frequently as necessary to protect against the contamination of produce. Thomson International Inc. cooperated with FDA throughout the investigation and is continuing to engage with FDA on the agency’s findings and recommendations.”
For full details, visit the FDA report.
Salmonella Newport: A common Salmonella Strain in Food Borne Illness Outbreaks
Salmonella Newport is a bacterial strain of Salmonella responsible for causing foodborne illness, primarily through contaminated food sources such as raw fruits, vegetables, and undercooked meats. It can lead to salmonellosis, which typically causes symptoms like diarrhea, abdominal cramps, fever, nausea, and vomiting. These symptoms usually appear within 6 to 72 hours after exposure and can last for 4 to 7 days.
Severe cases, especially in immunocompromised individuals, can lead to complications like septicemia. Salmonella Newport has been linked to significant outbreaks, including one from red onions in 2020, affecting over 1,600 people across North America. The pathogen is particularly concerning due to its ability to spread through contaminated irrigation water, farm animal waste, and poor food handling practices.
Transmission and Risk Factors
Like other strains of Salmonella, Newport can be transmitted through the consumption of contaminated food or water. It is commonly associated with:
- Raw or undercooked meats
- Contaminated vegetables and fruits, often exposed to contaminated water or nearby animal operations [When you think Salmonella Newport, think Onions!]
- Cross-contamination in food preparation
Livestock, wildlife, and unsanitary agricultural practices often contribute to the spread of Salmonella Newport, especially in large-scale farming operations. Additionally, improper food handling and storage can exacerbate the spread.
Symptoms and Health Impact
Most people infected with Salmonella Newport will experience mild to moderate symptoms of salmonellosis, which include:
- Diarrhea
- Abdominal cramps
- Fever
- Nausea and vomiting
While these symptoms generally resolve on their own within a week, severe cases may require hospitalization, particularly for the elderly, young children, pregnant women, and immunocompromised individuals. In rare cases, the bacteria can enter the bloodstream and cause life-threatening complications such as sepsis or infections in other organs.
Prevention and Control
Preventing infection from Salmonella Newport requires stringent food safety measures, including:
- Properly cooking meats to a safe internal temperature
- Thoroughly washing fruits and vegetables, especially those consumed raw
- Avoiding cross-contamination by separating raw meat from other foods
- Maintaining good hygiene practices during food preparation
In agricultural settings, controlling animal waste, managing irrigation practices, and ensuring clean processing environments are essential in minimizing the risk of contamination. Public health agencies also play a key role in monitoring outbreaks and implementing recalls when contamination occurs.
Outbreaks
One of the most significant Salmonella Newport outbreaks occurred in 2020, linked to red onions from California. This outbreak affected over 1,600 individuals across the U.S. and Canada. Investigations pointed to contaminated water and unsanitary agricultural practices as potential causes, though the exact source of contamination remained undetermined. The outbreak underscored the challenges of controlling foodborne pathogens in large-scale agricultural systems and highlighted the importance of rigorous food safety practices across the supply chain.
Treatment
Most infections caused by Salmonella Newport do not require antibiotic treatment and resolve with supportive care, such as rest, hydration, and a bland diet. However, severe cases may require hospitalization and antibiotic therapy, particularly if the infection spreads beyond the intestines.
Conclusion
Salmonella Newport remains a significant foodborne pathogen, with outbreaks posing a serious public health risk. While most infections are mild, the potential for severe complications emphasizes the need for both personal and agricultural vigilance in preventing contamination.
