By: Heather Van Tassell
Finally! We have answers! Unfortunately, we still do not have all of the answers. The U.S. Food and Drug Administration (FDA), the Center for Disease Control and Prevention (CDC), along with affected state and local health department partners are investigating a multistate outbreak of a Shiga toxin-producing E. coli or STEC known as E. coli O157:H7 that has been linked to romaine lettuce originating from the Yuma, Arizona growing region.
This outbreak is not related to the recent multistate outbreak that we saw from November to December 2017 that also linked E. coli O157:H7 to leafy greens. The DNA fingerprint of the E. coli from those cases in 2017 does not match the DNA fingerprint found in the strain of E. coli currently under investigation.
As of the last update on April 26, 2018 a total of 98 people has been reported as being infected with the outbreak strain of E. coli O157:H7. This multistate outbreak comes from 22 different states, including: Alaska, Arizona, California, Colorado, Connecticut, Georgia, Idaho, Illinois, Louisiana, Michigan, Mississippi, Missouri, Montana, New Jersey, New York, Ohio, Pennsylvania, South Dakota, Tennessee, Virginia, Washington, and Wisconsin. The majority of cases comes from California, with 16 cases and Idaho with 10 cases. The newer cases from Alaska account for 8 cases, some of which have been responsible for identifying one farm responsible for the outbreak.
Illness onset shows dates ranging from March 13, 2018 through April 20, 2018. There have been 46 reported hospitalizations and 10 cases that have resulted in a special complication known as hemolytic uremic syndrome, which is a type of kidney failure associated with STEC. No deaths have been reported related to this outbreak at this time.
Unfortunately, more cases may be reported soon. Illnesses occurring after April 7, 2018 may not yet be reported due to the average time it often takes between illness onset and when the illness is definitively reported as being connected to the outbreak. This can take anywhere from 2 to 3 weeks.
The FDA has some answers, though investigations continue. While the chopped romaine lettuce from the Yuma, Arizona growing region has yet to be identified, the FDA has identified one particular farm as the source of the whole-head romaine lettuce cases at the correctional facility in Alaska. They are still working to identify the impacted distributional channels that can explain this nation-wide outbreak. This is problematic with traceback activities associated with multiple groupings of sickened patients originating in diverse geographic areas. Contamination could have occurred anywhere along the process from growing to harvesting to packaging to the distribution chain to the final product destination.
Harrison Farms of Yuma, Arizona is the grower identified as the sole source of the whole-head romaine lettuce contaminated with E. coli in this outbreak. All of the lettuce in questions was reported to be harvested during March 5 to March 16, 2018. This product generally has about a 21-day shelf life. With all product beyond this shelf life and the growing season in the Yuma region coming to a close, the farm is not growing any more lettuce at this time. This means that there should not be any new cases of people consuming infected product. Though more cases may be trickling in from those who had already consumed the contaminated lettuce.
The Search Continues
Most patients interviewed indicated eating a salad from a restaurant. Romaine lettuce has been the only common ingredient identified. These restaurants indicated only using bagged, chopped romaine lettuce for their salads. Unfortunately, traceback investigation does not indicate the Harrison Farms facility as the source of the chopped romaine lettuce. There have been dozens of other fields identified as possible sources for the remaining outbreaks. With the growing season in this region coming to an end, answers seem to be slipping further and further from grasp.
In an update, the FDA explains:
“When we are executing a full traceback investigation, as we are currently, we are working to identify multiple distribution channels that can explain the entirety of the outbreak. We are tracing back from multiples groupings of ill people located in diverse geographic areas. The reason for this is to find unique distribution channels that converge on a single source or grower. Our investigations are constantly evolving, with new information coming in and we communicate this information as appropriate.”
The complication arises in how romaine lettuce is handled. With many outbreak sources specific lot numbers are tracked and once the product is identified, appropriate measures can be taken to recall the affected product. With this particular romaine outbreak, even though romaine has been identified as the common food source, there is very little packaging. This makes the investigation a bit more time consuming. According to the FDA’s outbreak notice, “FDA scientists and investigators are working with federal and state partners as quickly as possible to collect, review and analyze hundreds of records in an attempt to traceback the source of the contaminated romaine lettuce.” To date, available information only indicates the romaine lettuce originated from the Yuma, Arizona growing region, but was supplied though multiple farms, grower/shipper companies, processors to restaurants and retailers.
What to Look For. Symptoms of STEC.
While anyone of any age or background can become infected with STEC, certain groups of the population are more susceptible than others to falling ill or experiencing additional complications. The very young (under 5 years old), adults over 65 years old, and those with a compromised immune system fall into this category.
Symptoms include severe stomach cramps and bloody diarrhea. The illness does not always produce a fever, though when it does, the fever is usually not very high (often less than 101⁰F). In most cases symptoms are mild and resolve within 5 to 7 days without medical intervention.
A small percentage of those diagnosed with STEC infections (about 5 to 10%) develop a potentially life-threatening complication known as hemolytic uremic syndrome (HUS). HUS symptoms are often associated with fever, abdominal pain, and feeling very tired. Most notably symptoms include decreased frequency of urination, paleness, and small unexplained bruises or bleeding. While most will recover within a few weeks, some may suffer more permanent kidney damage or even die. Those with HUS symptoms should seek medical care immediately. Additional long-term side affects of HUS include chronic kidney disease, hypertension, and neurologic problems.
Stay Vigilant: Updated Guidance
If you have symptoms of STEC infection, you should contact your healthcare provider. While your symptoms may resolve in 5 to 7 days, you should be monitored for HUS to prevent long-term damage.
Do not eat or buy romaine lettuce unless you can be sure it does not originate from the Yuma, Arizona growing region. If you cannot be sure, it is best to choose another type of lettuce. This consumer guidance applies to all romaine lettuce, including whole heads and hearts of romaine, chopped romaine, baby romaine, or even salad mixes that contain romaine lettuce. If you are unsure whether the salad mix contains romaine lettuce, opt for a different mix.
Guidance to retailers and restaurants continues this avoidance policy. The CDC recommends restaurants and retailers to not serve or sell any romaine coming from the Yuma, Arizona growing region. They should ask their suppliers about the source of their romaine lettuce. If in doubt, do not serve or sell romaine lettuce.