found to be unlikely E. coli culprits
of Article: http://www.latimes.com/news/local/la-me-ecoli11-2009apr11,0,3453734.story
Two years of testing show that wild animals are not 'Typhoid Marys,'
California biologist says.
By Bettina Boxall
April 11, 2009
After wild pigs were linked to the
deadly E. coli outbreak in California spinach nearly three years
ago, Central Coast growers started shooting and poisoning wildlife.
Workers on one large farm killed 33 deer in a single year. Farmers
poisoned ponds to get rid of frogs, ripped out trees and bushes and
erected miles of expensive fencing.
But two years of testing wild animals
and birds in the region suggests that only a small fraction actually
carry the strain of Escherichia coli responsible for the
The results, released by the state Department of Fish and Game this week,
"show that wildlife are not the Typhoid Marys some people think they
are and some of the extreme measures are not necessary," said state
wildlife biologist Terry Palmisano.
As part of an ongoing study of the pathogen, researchers collected
samples from 866 animals, including 311 black-tailed deer, 184 feral
pigs, 73 birds, 61 rabbits, 58 tule elk, squirrels, mice, skunks and
Only four -- from a pig, a coyote and
two elk -- tested positive for the lethal bacterium, E. coli
0157:H7. That is slightly less than half of 1%.
Three people, including a toddler, died in the spinach outbreak in the
late summer of 2006. Federal authorities estimated that several thousand
people were sickened across the country.
The contamination was traced to spinach grown on a cattle ranch east of
Salinas. Although the precise source was never determined, the virulent E.
coli was found in river water as well as in feces from cattle and
wild pigs on the ranch.
The produce industry later adopted a voluntary set of standards for
growing and handling leafy greens that amounted to a big "Keep
Out" sign for any wildlife considered potential carriers of E.
Big produce buyers also struck their own safety agreements with farmers,
calling for even more precautions.
Requests jumped for state depredation permits allowing farmers to shoot
wildlife damaging their crops. Growers who might otherwise have tolerated
a deer browsing some lettuce shot the animals, fearing they couldn't sell
a crop if safety auditors found droppings or tracks in a field.
"The buyers don't want even mice getting close," Palmisano
Baited PVC pipes with traps are a common sight along the edge of fields.
Much of the Salinas River has been fenced. Grass along irrigation and
runoff ditches has been dug up, leaving wide strips of bare ground.
"Folks are having to do stuff they don't want to do in order to sell
their crop," said Paul Robins, executive director of the Monterey
County Resource Conservation District.
In a 2007 survey by the district, one grower reported he had lost $17,500
worth of a crop because there were deer tracks in a field. A harvest was
stopped when frogs and tadpoles were found in a creek.
The district's program director, Melanie Beretti, said farmers are
resisting anti-erosion and water quality projects that involve vegetation
that could attract wildlife.
She cited a strawberry grower who wanted to plant a hedgerow next to a
long ditch. He dropped the idea because another farmer sometimes grew
leafy greens in the field and couldn't plant within 50 feet of the
Hank Giclas, vice president of the Western Growers Assn., said farmers
are caught in a bind between satisfying wholesalers' demands and
"We're very supportive" of the E. coli study, he added.
"We want to fundamentally understand where the risks are -- and are
not -- and have designs that minimize the risk with the least negative
impact on the environment in which people farm."
But he said his group, which helped draw up the voluntary standards,
would wait until the research was finished before taking any action on
the guidelines. In the meantime, an effort is underway to expand the
safety program nationally.
The E. coli testing is part of a broader investigation by
government and university scientists that will sample livestock, water
and soil. More wildlife will also be tested.
"You can't make the interpretation yet that there is not a problem
with wildlife," said Robert Mandrell, the lead researcher and a
microbiologist with the U.S. Department of Agriculture. "But so far
the data don't indicate there is a major red flag here."
For the survey, fish and game workers collected fecal samples from
freshly killed deer and live animals and birds that were trapped and
released. One technique is to place birds in a brown paper bag to collect
droppings. But for the most part, fish and game spokesman Harry Morse
said, "gloves and little bitty jars" are used.