FDA Investigation Reveals How Romaine Lettuce Outbreak Likely Occurred

Following a months long E. coli outbreak, which sickened dozens of people across the United States, federal health officials have released a report that tracks the illnesses to tainted romaine lettuce, indicating that the source of contamination may have caused other food poisoning outbreaks as well. 

The FDA released a E. coli romaine lettuce outbreak investigation summary this week, detailing the findings of the agency’s investigation, and steps that could have stopped the spread of the outbreak sooner, as well as proactive measures that could have prevented the contamination from entering the food supply.

In early November 2018, the FDA and Centers for Disease Control and Prevention (CDC) began receiving reports of E. coli illnesses across several states. The agencies quickly opened an investigation and subsequently released a Food Safety Alert on November 20, 2018, advising Americans not eat any romaine lettuce, and for retailers and restaurants to immediately stop serving or selling it until more information became available.

CDC officials issued the alert after confirming at least 32 cases of E. coli O157:H7 illnesses in 11 different states, including at least 13 reports involving hospitalizations and one severe case that resulted in kidney failure. Another 18 people in Ontario and Quebec had fallen ill with the same strain of E. coli by this time.

The agencies ultimately discovered the source of contamination was an agricultural water reservoir on Adams Bros Farming Inc., farm in Santa Maria, California, where romaine lettuce products were grown and distributed nationwide. However, by this time, a total of 62 people across 15 states had fallen ill, resulting in 23 hospitalizations.

The FDA reports that Adams Bros Farm had procedures in place to sanitize and test bacteria levels in the water used for irrigation. However, testing records were unclear as to whether these procedures were upheld during the harvesting and post-harvesting season by the facility.

Inspections of the water tank sanitizers on Adams Bros Farms revealed that the treatment systems had undissolved sanitizer cakes and that some of the tanks were constructed in a manner that likely would not allow for optimal sanitation, leaving untreated water to be sprayed on crops and the roadways that farm field equipment traveled on. Officials indicated the source of contamination could have been spread by a variety of reasons due to the lack of sanitation procedures.

A deeper evaluation of the romaine lettuce outbreak discovered previously recorded E. coli outbreaks in the United States and Canada in the fall of 2016 and the fall of 2017 had a closely related rare genetic fingerprint of the outbreak strain. Through whole genome sequencing, officials stated these outbreaks could have been related in some manner.

Officials are strongly encouraging the entire supply chain of leafy greens to adopt a more traceable practice and include state-of-the-art technology to assure quick, accurate and easy access to key data elements from farm to fork when they are involved in a potential recall or outbreak. Adopting this process would involve assigning production lot codes to all leafy greens to allow officials to determine which farm and growing regions are responsible for supplying the contaminated product, and the time frame when product was supplied.

E. coli is a foodborne bacteria that causes mild to severe diarrhea and abdominal cramps, bloody stools, and sometimes minor fevers lasting between five and 10 days. For individuals like young children, the sick and the elderly, the consequences may be more severe due to weakened immune systems, potentially resulting in the infection causing a serious condition known as Hemolytic Uremic Syndrome (HUS), which may lead to kidney failure or even death.