Agriculture Reference
In-Depth Information
Table 20.2.
1999 U.S. outbreaks of Shiga-toxin producing
E. coli
linked to leafy greens
Date
Product
Pathogen
Cases
Setting/Dish
State
Feb - 99
Lettuce
E. coli
O157:H9
65
Restaurant
NE
Jun - 99
Salad
E. coli
O111:H8
58
Texas camp
TX
Sep - 99
Lettuce
E. coli
O157:H11
6
Iceberg
WA
Oct - 99
Lettuce
E. coli
O157:H7
40
Nursing home
PA
Oct - 99
Lettuce
E. coli
O157:H7
47
Restaurant
OH
Oct - 99
Salad
E. coli
O157:H7
5
Restaurant
OR
Table 20.3.
Leafy green outbreaks of Shiga-toxin producing
E. coli
, 2000-2002
Date
Product
Pathogen
Cases
Setting
State
Oct - 00
Salad
E. coli
O157:H7
6
Deli
IN
Nov - 01
Lettuce
E. coli
O157:H7
20
Restaurant
TX
Jul - 02
Lettuce
E. coli
O157:H8
55
Bagged tossed
WA
Nov - 02
Lettuce
E. coli
O157:H7
13
Restaurant
IL
Dec - 02
Lettuce
E. coli
O157:H7
3
Restaurant
MN
Table 20.4.
Leafy green Shiga-toxin producing
E. coli
outbreaks, 2003-2005
Date
Product
Pathogen
Cases
Setting
State
Sep - 03
Lettuce
E. coli
O157:H7
51
Restaurant
CA
Nov - 03
Spinach
E. coli
O157:H7
16
Nursing Home
CA
Nov - 04
Lettuce
E. coli
O157:H7
6
Restaurant
NJ
Sep - 05
Lettuce
E. coli
O157:H7
11
Dole bagged
multiple
O157:H7 cells, suggesting that irrigation water of unknown microbial quality should
be avoided in lettuce production (Solomon and others 2002a). In a follow-up experi-
ment, Solomon and others (2002b) explored the transmission of
E. coli
O157:H7 from
manure-contaminated soil and irrigation water to lettuce plants. The researchers recov-
ered viable cells from the inner tissues of the lettuce plants and found that the cells
migrated to internal locations in plant tissue and were thus protected from the action
of sanitizing agents. These experiments demonstrated that
E. coli
O157:H7 could enter
the lettuce plant through the root system and migrate throughout the edible portion of
the plant (Solomon and others 2002b). Such results were widely reported in the general
media.
During this time, several outbreaks of
E. coli
were again linked to lettuce and salad
(Table 20.3 ).
In 2003, according to Mexican growers, the market impact of an outbreak of hepa-
titis A traced to exported green onions lasted up to 4 months while prices fell 72%
(Calvin and others 2004). Roma tomatoes were identifi ed as the source of a salmonel-
losis outbreak that resulted in over 560 cases in both Canada and the U.S. (CDC 2005).
During 2003-2005, several additional outbreaks of
E. coli
O157:H7 were linked
to fresh leafy greens, including one multistate outbreak involving Dole bagged lettuce
(Table 20.4 ).
