How romaine lettuce turned deadly
Among the myriad advantages of living in modern civilization is access to safe, nutritious food, something so commonplace that it is taken for granted in resource-rich countries.
However, safety of that food is not a guarantee, even in the wealthiest pockets of our world.
The entire process of how food arrives on your fork is fraught with opportunities for potentially dangerous microbes to stow away and reach the stomachs of the public with serious consequences.
The current multistate outbreak of E.coli — the biggest in the United States in over a decade — is a reminder of the necessity for health officials to quickly provide public guidance. Pinpointing the origin of such an outbreak can be extremely challenging.
The source of this outbreak is believed to be romaine lettuce grown in the Yuma, Ariz., region, but the exact origins remain an important mystery to solve. Cases in Pennsylvania, the second most impacted state, currently number 20. These twenty include an Altoona case that resulted in hospitalization, as well as one linked to a local restaurant that sparked a lawsuit.
As of Friday, the outbreak sickened 121 people with one fatality. More than half of those infected have been hospitalized and about 10 percent have the dreaded complication known as hemolytic uremic syndrome (HUS). But the heightened concern regarding this particular outbreak stems from the fact that it is caused by a particular strain of E.coli known as O157:H7. This strain, which rose to prominence with the deadly and extensive burger-related Jack in the Box outbreak in 1993, is naturally found in the digestive system of cattle. When it finds its way into food products through fecal contamination, it can infect humans.
Because this particular strain has the capacity to release toxins that can have cascading effects on multiple organ systems, most prominently the kidney and blood, it can lead to a permanent need for dialysis or even death in up to 5 percent of those infected. This is such a well-characterized problem for ground beef and produce that a special spray laden with viruses targeted specifically to E.coli O157:H7 was developed for use on foods particularly prone to contamination. It is unclear how many facilities use this spray.
Cases of E.coli O157:H7 are not unheard of in the region: in 2015, 19 cases were reported to the Allegheny County Health Department and 2013 was notable for an outbreak linked to an Oakland restaurant.
If you are infected, the symptoms of this infection begin about 3-4 days after ingestion of as little as 100 organisms and start with abdominal cramps, bloody diarrhea, nausea and vomiting. Antibiotics are not given for this infection and, in fact, are thought to worsen the condition as they may lead to enhanced toxin production, thus supportive care such as intravenous fluids are the mainstay of therapy.
The biggest challenge with this current outbreak is the inability of public health authorities, grocery stores and restaurants to be able to rapidly determine whether particular romaine lettuce products are safe or unsafe to eat. Lettuce is a product that has many avenues for contamination, which complicates the investigation. However, in an era in which a package can be tracked almost minute-to-minute from its origin to delivery, it is baffling that the origin of food often remains elusive. Hopefully, technological solutions will be able to mitigate the trajectory of future outbreaks.
Consumers can take steps on their own to protect themselves until this outbreak subsides. Most important: refrain from eating romaine lettuce unless you can positively determine it came from somewhere other than Yuma. Additionally, if you develop abdominal cramps and bloody diarrhea, seek medical attention immediately.
Cases are expected to continue to rise for a few more weeks but then will likely drop off as expiration dates loom and romaine production shifts out of Yuma. Nevertheless, it will be crucial to determine how this contamination occurred, how widespread it was and how to guard it against it in the future.
Dr. Adalja is a Pittsburgh-based infectious disease physician and a senior scholar at the Johns Hopkins Center for Health Security. Follow him on Twitter @AmeshAA.