USDA Study Clears Cross-Country Romaine Shipping; Critics Say It Misses the Field

A federally funded study found no significant difference in E. coli O157:H7 survival between romaine processed near the field and romaine shipped raw across the country before washing. The two-paragraph public summary from the USDA's Agricultural Research Service concluded that forward processing is safe and industry can skip a costly supply-chain overhaul. Food safety attorney Bill Marler, who has litigated E. coli cases since the 1993 Jack in the Box outbreak, calls that framing a useful answer to a narrow question — not a safety certificate.

What did the study actually test?

Scientists led by Xiangwu Nou at the Environmental Microbial and Food Safety Laboratory ran the project from 2022 to 2023, funded through the Center for Produce Safety, the produce industry's research group. They followed romaine from one commercial field down two paths: one to a nearby processor, one cross-country to an East Coast plant, with data loggers in the bins. In the lab, they inoculated romaine with outbreak strains and simulated both trips.

The results cut two ways:

• No significant difference in O157:H7 growth or survival between the two routes.
• Forward-processed lettuce carried a much higher total bacterial load and aged faster in storage.

Marler's critique is specific. O157:H7 does not need to grow to sicken anyone. The infectious dose runs as low as 10 to 100 cells. A cold truck to Maryland does not make contaminated lettuce safer; it simply does not make it much worse.

What did the summary leave out?

The project title promised findings on antimicrobial susceptibility and infectivity. The public summary says nothing about either. Marler also notes the page cites "tons" of lettuce discarded annually over E. coli concerns — with no number and no source. That figure would show how often contaminated product gets caught before it reaches consumers. By implication, it would show how often it does not.

The biggest omission, he argues, is the question of origin. Truck routes did not put cattle manure on romaine. The field did.

What do outbreak investigations show?

The record points at cattle and water, not logistics. Spring 2018: Yuma romaine sickened 210 people in 36 states, hospitalized 96, caused 27 HUS cases and killed five. Investigators found the strain in a 3.5-mile irrigation canal near a feedlot holding up to 100,000 head. Fall 2018 and 2019: a reoccurring O157:H7 strain from Santa Maria and Salinas caused 234 illnesses in 33 states, linked to a contaminated water reservoir and then to cattle on adjacent land. Fall 2020: FDA found the outbreak strain in cattle feces roughly 1.3 miles upslope from a tied farm and told Central Coast growers to treat the strain as a reasonably foreseeable hazard.

CDC now tracks these as REP strains. REPEXH02 keeps returning to the California Central Coast each fall, surfacing in patients, bagged salad, reservoir sediment, a cattle trough and cattle feces. November 2024 brought the latest chapter: 89 illnesses in 15 states, 36 hospitalizations, seven HUS cases, one death. Fifty cases were in Missouri, many tied to salads at a St. Louis County high school. FDA traced the lettuce to a single grower and closed the investigation in January 2025 without naming the firm. Marler identified Taylor Farms through litigation.

What is being petitioned?

Marler is filing three citizen petitions with FDA:

• Feedlot access. Require sampling access to animal feeding operations implicated in outbreaks, using Section 361 of the Public Health Service Act — the authority behind the 1975 pet turtle ban. FDA's own 2025 review of farm investigations from 2009 through 2021 found livestock nearby in every single-farm investigation where the data was recorded, and confirmed the agencies lack authority to enter private livestock land.
• Name the firm. End treatment of outbreak firm identities as confidential. On September 10, 2026, FDA closed a fourteen-person romaine investigation and named no grower, processor, brand or state. The Justice Department's Office of Legal Counsel told HHS in October that FDA's own regulations are the obstacle, and FDA can change them.
• Retail consignee lists. Publish store, restaurant, school and hospital lists in every Class I recall, as USDA has done for meat since 2008, and classify recalls within ten days.

What else is on the list?

Marler also wants enforcement of the pre-harvest agricultural water rule, which reached large farms in April 2025 and small farms in April 2026, and an end to the traceability delay — the rule, originally set for January 2026, now sits at July 2028. He wants routine market sampling of the kind USDA ran before killing its Microbiological Data Program in 2012. Lettuce has no kill step. Nobody cooks a Caesar salad.

Forward processing did not make romaine more dangerous. Until research, regulation and transparency target the field — often near cattle, often by water — Marler's closing judgment stands: moving forward with lettuce safety will look a lot like standing still.