(June 18, 5:26 p.m.) As the Centers for Disease Control and Prevention on June 18 upped the number of reported salmonella cases in tomatoes by 106 cases from two days earlier, the Food and Drug Administration is focusing on a cluster of nine cases in one geographic area in its traceback investigation of a multistate outbreak.

David Acheson, the FDA’s associate commissioner for foods, has said the cluster is the agency’s “most fruitful lead to date,” but has declined to elaborate on the location of the cluster.

However, The Chicago Tribune reported June 18 that the Chicago Department of Public Health said nine of the city’s 17 cases were reported by people who fell ill after eating at Adobo Grill’s two restaurants on Chicago’s north side.

The cluster is significant because 17 of the 30 states affected by the outbreak have five or fewer reported cases. Acheson has said that one patient in one area is far less likely to provide a break in the case.

Acheson, who again declined to discuss the location of the cluster during a June 18 conference call with media, said he hopes the cluster will provide information about where the tainted tomatoes came from.

OUTBREAK SPREAD

Meanwhile, the CDC said June 18 that the number of reported cases has swelled to 383 in 30 states, up from 277 reported cases in 28 states on June 16.

At least 48 people have been hospitalized.

Robert Tauxe, deputy director of the CDC’s Division of Foodborne, Bacterial and Mycotic Diseases, said the dramatic increase was not a result of recent infections. The numbers, he said, jumped because of completed lab tests and stepped up surveillance for salmonella by state health agencies.

Acheson said he hopes that additional clusters of cases will emerge with the new reported cases. He reiterated there is a “high likelihood” that Florida or Mexico is the source of the outbreak. Nineteen Florida counties and Baja California have been cleared in those areas.

REMAINS OPTIMISTIC

Acheson, however, acknowledged state and federal investigators might never be able to pinpoint the source of the outbreak.

“I’m still optimistic,” he said, “but I’m trying to be realistic.”

Tauxe said the most recent illness had an onset date of June 5.

“It’s ongoing,” he said of the outbreak. “It’s too early to say it’s peaked. It’s certainly not over.”

Cluster of cases could shed light on outbreak