Keene included in the e-mail an epidemiological analysis of cantaloupe consumption in the United States and how it relates to the U.S. share of cantaloupe from a farm in Guatemala that supplies Del Monte Fresh Produce. He used this analysis to explain the high probability that the contaminated cantaloupe originated from the farm, located in AsuncionMita.
“In our world, these numbers are considered pretty good evidence, however circumstantial,” he wrote.
The Oregon cases were the first confirmed victims of an outbreak involving a rare strain of salmonella that eventually reached 10 states — from California and Nevada to Pennsylvania and Maryland — and was linked to 20 illnesses this spring. The cases are unrelated to the current listeria outbreak linked to cantaloupes from a Colorado farm that have killed eight people, including one in Maryland.
In a series of e-mail exchanges with Keene, obtained through public records requests, Del Monte Fresh Produce defended practices at its farm. “I cannot imagine how [salmonella] could be coming from our Mita operation, but I am available to assist you in your investigation,” Thomas Young, Del Monte Fresh Produce’s vice president of research and agricultural services, wrote in one e-mail.
But under pressure from the Food and Drug Administration, the company issued a limited, voluntary recall of nearly 60,000 imported cantaloupes on March 22.
Now, in an action that could have a significant impact on how authorities investigate and try to contain foodborne illnesses, the company is challenging the decisions and conclusions of the FDA, the Oregon public health department and its senior epidemiologist.
In court actions against the FDA and Oregon, Del Monte Fresh Produce contends its cantaloupes never tested positive for salmonella and, as a result, federal and state investigators did not have proof of the contamination. The company said the FDA did not exhaust other possibilities of contamination, including when the product was in the hands of retailers or during transit.
“In a way, epidemiology is on trial,” said David Acheson, former FDA associate commissioner of foods.
It’s rare for scientists investigating foodborne illness outbreaks to test the exact food suspected of carrying pathogens, said Kirk Smith, epidemiology supervisor for the Minnesota Department of Health. By the time symptoms occur and a foodborne illness is reported and confirmed, the product in question has likely been consumed or has exceeded its shelf-life and been thrown away.
Instead, scientists, like detectives, interview victims, collect data, analyze patterns and match food “fingerprints” to determine the likely source of an outbreak.