On March 13, 2025, the Centers for Disease Control and Prevention (CDC) published a comprehensive report analyzing foodborne illness outbreaks in the U.S. from 2014 to 2022. The report, released in the Morbidity and Mortality Weekly Report (MMWR),  examined 2,677 outbreaks and identified key contributing factors that led to contamination. 

Below are a few takeaways from the report:  

• The report showed a rise in bacterial outbreaks (41.9 percent in 2014-2016 to 48.4 percent in 2020-2022) and a decline in viral outbreaks (33.3 percent in 2014-2016 to 23.2 percent in 2020-2022). 

• The report found that contamination from animal or environmental sources occurring before food reaches the final point of preparation was the most common factor in outbreaks (26 percent of the time). This is especially important for fresh produce, as it is intended to be consumer law, highlighting the importance of good agricultural and processing practices.  

• In terms of outbreak size: 60.6 percent of outbreaks affected 2–10 people. Medium-sized outbreaks (11–20 cases) accounted for 17.4 percent, while larger outbreaks (21–30 cases) made up 7.7 percent. Outbreaks involving 31 or more cases represented 14.3 percent of the total.  

• The most implicated food sources included aquatic animals (15.7 percent), land animals (15.4 percent) and plant-based foods (9.7 percent), though 38.1 percent of outbreaks had no identified food source. 

• Restaurants were the most frequent preparation sites (60.1 percent), with institutional and commercial locations accounting for smaller shares. 

• The CDC report highlights that temperature control issues were other major contributing factors to foodborne illness outbreaks, particularly in food proliferation and survival. Allowing food to remain out of temperature control for prolonged periods during preparation (13.1 percent) and food service/display (11.5 percent) were among the top proliferation factors, along with improper cold holding (10.2 percent) and hot holding (10.1 percent) due to incorrect practices 

The CDC report underscores the critical role of proper food handling, temperature control and hygiene practices in preventing foodborne illness outbreaks. While contamination before final preparation remains the leading contributing factor, issues with temperature abuse, improper cooling and inadequate cooking or reheating continue to pose significant risks. 

View the report in full at: https://www.cdc.gov/mmwr/volumes/74/ss/ss7401a1.htm?s_cid=ss7401a1_w.