[Market-farming] FDA launches Salinas Valley E. coli probe

Steve Diver steved at ncat.org
Sat Sep 16 16:56:24 EDT 2006

Since an organic grower-packer has been implicated
in the E. coli outbreak in bagged spinach, a lot of people
in agriculture are wondering about the source of

The following article published by Center for Infectious
Disease Research & Policy at University of Minnesota
provides relevant background notes on the situation
with production of greens in the Salinas Valley. You might
recall they had tremendous flooding earlier this growing

Steve Diver


FDA launches Salinas Valley E coli probe
Jim Wappes - Associate Managing Editor

Sep 14, 2006 (CIDRAP News) - Outbreaks of Escherichia coli
in recent years have spurred federal and California officials to
launch a broad investigation into farms and processors of lettuce
and other leafy greens in California's Salinas Valley, according
to the US Food and Drug Administration (FDA) and news sources.

Of 19 US outbreaks of E coli O157:H7 from lettuce and spinach
since 1995, eight have been traced to Salinas Valley, dubbed
the "Salad Bowl of the World," according to a Sep 11 Los Angeles
Times article. These eight outbreaks have affected 217 people
in eight states, including two elderly patients from northern
California who died in 2003.

In response to these outbreaks, the FDA announced its Lettuce
Safety Initiative on Aug 23 of this year. In its announcement,
the FDA said it will, in conjunction with California agencies,
"visit farms and cooling and packing facilities, and inspect
processors, focusing on good agricultural practices and
good manufacturing practices," identifying "practices that
potentially lead to product contamination."

The initiative in Salinas Valley began Aug 28 and is scheduled
to wrap up next month, a food safety official from the FDA's
Center for Food Safety and Applied Nutrition (CFSAN) told
CIDRAP News via e-mail. "We will be compiling the findings
in the following months and hope to have a summary by
next spring," he said.

In addition to CFSAN, the Salinas Valley investigation involves
the FDA Office of Regulatory Affairs, the California Department
of Health Services, and the California Department of Food
and Agriculture, according to the official. He characterized
the initiative as cooperative: "This is an important example
of industry, government, and academia working together
to understand a problem so that meaningful interventions
can be identified."

About 40 farms, packers, and processors will be visited,
he said.

Possible source for outbreaks

When asked about a likely source for the contamination,
the official responded, "There are many possible sources
of the contamination. There may not be one source, but
a combination of sources [and] factors."

Craig Hedberg, PhD, a University of Minnesota expert on
foodborne disease, said of the outbreaks, "I would suspect
there might be a link between dairy production and lettuce
contamination, but what that might be is unknown."
Hedberg, of Minneapolis, is an associate professor of
environmental and occupational health.

Past, smaller-scale investigations have identified a number
of possible sources of contamination in Salinas Valley.
The valley, located in Monterey County, grows nearly
$1 billion in lettuce and other leafy greens each year,
according to a story yesterday from the Monterey County

In a Nov 4, 2005, letter to California lettuce growers,
packers, processors, and shippers, CFSAN director
Robert Brackett, PhD, mentioned intermittent flooding
from Salinas Valley creeks and rivers as a possible
source of contamination. He cited a 2005 report that
identified O157:H7 E coli in the valley's watershed and
stated that any ready-to-eat crop that comes in
contact with floodwaters is not fit for human consumption.

In addition, in a January letter to the Western Growers
Association, California Public Health Officer Mark Horton,
MD, MSPH, wrote that his staff will be reassessing
manure composting and septic system regulations.
In addition to citing the possible flooding problem, the
letter also specified assessment of workers' access
to toilets and hand-washing facilities, as well as adherence
to other health-safety rules.

Other possible contamination sources listed in the
Los Angeles Times article include bird and other
animal droppings and dust from nearby cattle fields.

Rare E coli strain in Utah

In related news, Utah health officials implicated Salinas
Valley lettuce as a possible source for an E coli outbreak
in their state in June, according to an Aug 20 Monterey
County Herald story.

The Utah outbreak affected 73 people, including three who
experienced kidney failure. It involved a different,
rare strain: O121:H19.

Both the O121:H19 and O157:H7 strains occur naturally in
the digestive system of cattle and humans. But eating food
contaminated by the bacteria can cause abdominal pain,
diarrhea, other serious symptoms such as kidney failure,
and death, according to the Herald story.

Which underscores the importance of the just-launched
probe. The CFSAN spokesperson said of the effort, "We
do not know why we are seeing E coli O157:H7 in leafy
greens. . . . We hope that research [from the Lettuce
Safety Initiative] will better explain what is going on."

See also:

Aug 23, 2006, FDA announcement of its Lettuce Safety Initiative

Jan 25, 2006, California Department of Health Services letter

Nov 4, 2005, CFSAN letter


For reference, see the following CIDRAP technical
report on Diarrheagenic Escherichia coli.

Diarrheagenic Escherichia coli
CIDRAP, Univ of Minnesota


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