Half of those sickened in a multistate outbreak of Salmonella linked to alfalfa sprouts were from Illinois, the Centers for Disease Control and Prevention reports in its final update on the investigation.

The final outbreak toll was 140 people in 26 states and the District of Columbia infected with the outbreak strain —  Salmonella serotype I 4,[5],12:i:-.

Seventy Illinois residents were among the outbreak victims, whose onset dates ranged from Nov. 1, 2010 through Feb. 9, 2011. There were 23 people in Missouri and 13 in Indiana identified with the outbreak strain, along with four in Wisconsin and Pennsylvania; two in Massachusetts, New York, Tennessee and Virginia; and single cases in Arkansas, California, Colorado, Connecticut, District of Columbia, Georgia, Hawaii, Iowa, Kentucky, Louisiana, Maryland, Nebraska, Nevada, New Jersey, North Carolina, Oregon, South Carolina and South Dakota, although the CDC cautions that because this is a fairly common Salmonella strain, a few of the illnesses might not have been related to the outbreak.

Case patients ranged in age from 1 to 85. Nearly a quarter were hospitalized.

Many of those who became ill in Illinois ate sandwiches containing sprouts at various Jimmy John’s sandwich outlets, according to the CDC.

Collaborative efforts of local, state, and federal public health investigators and regulatory agencies linked the outbreak to sprouts served on the Jimmy John’s sandwiches — Tiny Greens alfalfa sprouts or a blend of alfalfa, radish and clover sprouts marketed as “Spicy Sprouts.”

The CDC said the sprouts were also distributed to farmers’ markets, restaurants and groceries in Illinois, Indiana, Iowa and Missouri and may have been distributed to other Midwestern states. 

Tiny Greens Organic Farm of Urbana, IL, recalled specific lots of its sprouts on Dec. 29, 2010, after the U.S. Food and Drug Administration identified the farm as the possible source of the outbreak, and advised consumers not to eat its products.

As reported in earlier investigation updates, the U.S. Food and Drug Administration later  found that a sample of water run-off from the organic farm was contaminated with Salmonella that matched the outbreak strain, but product samples tested by FDA were negative.

Tiny Greens Organic Farm owner Bill Bagby objected to that report, telling a trade publication that the sample testing positive for the outbreak strain was collected outside his indoor growing operation, in runoff from the compost pile. 

In its Form 483 report on the investigation, the FDA said inspectors found that Tiny Greens sprouts were being grown in “soil from the organic material decomposed outside” without any “kill step” to rid them of the Salmonella that led to the outbreak.

The inspection report also cited multiple other issues, including inadequate documentation of antimicrobial seed treatment, employee lunches in the sprouts cooler, work surfaces with questionable sanitation, condensation dripping from the ceiling, a water and sprouts test not validated for detecting Salmonella, and an amphibian/reptile housed in the reception area adjoining the production room.

The FDA frequently reminds consumers that sprouts are a known source of foodborne illness.  Since 1996 there have been at least 30 reported outbreaks, mostly of Salmonella and E. coli, associated with different types of raw and lightly cooked sprouts. In many of the outbreaks, according to the FDA, the sprout seeds have been the source of the harmful bacteria.

The FDA advises children, the elderly, pregnant women, and persons with weakened immune systems to avoid eating raw sprouts of any kind (including alfalfa, clover, radish and mung bean sprouts). To reduce the chance of foodborne illness, cook sprouts thoroughly and  request that raw sprouts not be added to food such as sandwiches.