E coli outbreak spreads to 114 patients in 21 states

Lisa Schnirring

Sep 18, 2006 (CIDRAP News) – The number of people affected by a nationwide Escherichia coli O157:H7 outbreak, apparently linked to fresh spinach, has climbed to 114 in 21 states, the US Food and Drug Administration (FDA) said today.

Infections involving the virulent strain have claimed one life and led to hemolytic uremic syndrome (HUS), which can cause kidney failure and death, in 18 patients, said David Acheson, MD, chief medical officer of the FDA's Center for Food Safety and Applied Nutrition, at a press conference this afternoon. Nationwide, he said, 60 patients have been hospitalized with the illness.

Today's case count is more than double the 50 cases the FDA reported when it first warned about the outbreak on Sep 14. At that point there were eight cases of HUS.

A second death possibly linked to the outbreak, that of a patient from Ohio, has not been confirmed as of today, said Acheson.

The FDA has advised consumers to avoid eating fresh spinach or any products that contain fresh spinach, because early evidence suggested that bagged fresh spinach was the only food that all patients had in common.

Rinsing contaminated spinach with water or other cleaning solutions won't destroy the E coli, said Acheson, because the organism can get inside the plant.

People who experience diarrhea after eating fresh spinach or salad blends containing fresh spinach should contact their healthcare provider and ask that their stool sample be tested for O157:H7, the Centers for Disease Control and Prevention (CDC) said in a press release yesterday.

Recalls expand
Natural Selection Foods of San Juan Bautista, Calif., yesterday recalled all of its products that contain spinach with best-if-used-by dates between Aug 17 and Oct 1. The recall affects 31 different brands. Natural Selection products are distributed in the United States, Canada, and Mexico.

In a press release yesterday, Natural Selection Foods voiced its concern for people who are ill and said that so far, packaging retained by patients is only from its nonorganic spinach products.

At a news conference yesterday, Acheson said samples from the states matched genetically and that an investigative team from California and the FDA has been gathering grower and distribution information. Indications so far are that contaminated spinach came from California, he said today.

In the preliminary analysis, the team determined that a separate company, River Ranch, had obtained bulk mixed spring greens for its products from Natural Selections Foods. The FDA said River Ranch is recalling its spring mix, which contains spinach. Three River Ranch brands are involved: Farmers Market, Hy Vee, and Fresh and Easy.

The team will be looking at sources of E coli infection including irrigation, harvest conditions, agricultural production, food storage conditions, topography, and wild bird activity, Acheson said, adding that the FDA will investigate all possibilities, including terrorism.

"There's no indication that the contamination was deliberate, but if we see things that don't add up, we'll pursue that possibility," he said.

Serious health concerns
Acheson reported that the E coli outbreak is one of the largest in US history. He said he was particularly alarmed by the number of patients who developed HUS. The O157:H7 strain produces a toxin that typically causes bloody diarrhea and abdominal cramps but no fever.

Of the infected patients, 75% are women, Acheson said today, adding that women are likely to have greater exposure to fresh spinach. He said the age range of the patients is from 20 to 64 years.

The infection resolves in 5 to 10 days but causes HUS in 2% to 7% of patients. Children and older people are most likely to develop HUS.

Acheson estimated that people's exposure to spinach dropped late last week, and with an average 7-day incubation period for the infection, he predicted that new cases will begin to drop off by the end of this week.