The number of victims in an E. coli outbreak linked to romaine lettuce jumped almost 60 percent in the past week as public health officials struggled to determine the source or sources of the implicated produce.

Three more states have laboratory-confirmed victims, federal officials reported Wednesday. The 19 states now involved in the outbreak have a total of 84 people with E. coli O157:H7 infections, according to an updat from the U.S. Centers for Disease Control and Prevention. That’s up from the 53 victims the agency reported in its April 18 update. 

Both the CDC and the Food and Drug Administration reiterated their warnings urging consumers, retailers, restaurants and other foodservice operations to not eat or sell romaine in any form if it is from the Yuma AZ, area. If the origin of romaine lettuce is unknown or cannot be /confirm/ied, it should be thrown away. 

The warnings include chopped romaine and any products containing chopped romaine, such as bagged salads and packaged salad bowl style products. Whole heads and romaine hearts are also covered by the warnings. 

Additional outbreak victims will likely be identified. The most recent illness onset date is April 12. But, the CDC updat on Wednesday said people who became sick after April 5 may not yet be included in the case count. It takes an average of two to three weeks from the time people become sick and their illnesses are confirmed by states and reported to the CDC.

The outbreak strain of the bacteria is proving particularly dangerous, with 42 of the infected people having been admitted to hospitals. Nine of the victims have developed a type of kidney failure called hemolytic uremic syndrome. That’s up from four with kidney failure as of April 18. No deaths have been confirmed in relation to the outbreak.

Connecting the dots
Epidemiologists report 64 of the 67 victims interviewed thus far said they ate romaine lettuce during the week before they became ill. That’s a 96 percent connection rate between the sick people and romaine. Many of the people said they ate romaine in restaurants. Romaine lettuce was the only common ingredient identified among the salads.

The victim reports are not, however, the final step in the outbreak investigation. 

Tracking down specific growers, packers and distributors of fresh produce commodities is difficult. There is limited use of labeling codes on many of the fresh fruits and vegetables that are available to consumers through retailers or restaurants, partly because of a lack of packaging.

Without traceability codes on packaging to provide transparency, the Food and Drug Administration’s staff is left in a dense fog as the agency tries to navigate the supply chain. The investigators are also slowed down by some businesses’ incomplete and missing shipping and receiving records.