Health officials seek to determine the source of E. coli-linked outbreak

State and federal public health are collecting data to identify the food source of a multistate outbreak of E. coli O157:H7 infections, the Centers for Disease Control and Prevention said Feb. 2.

In announcing its investigation, the CDC reported that as of Feb. 1, a total of 16 people infected with the outbreak strain have been reported from five states.

Illnesses started on dates ranging from Dec. 23 to Jan. 7, according to the CDC. Recent illnesses may not yet be reported as it usually takes two to four weeks to link illnesses to an outbreak.

The outbreak has sickened people from age 10 to 95 years, with a median age of 31; 88% are female. 

Of 12 people with information available, 9 have been hospitalized, the CDC said. One death has been reported from Washington.

The CDC report said state and local public health officials are interviewing people to find out what foods they ate in the week before they got sick.
Public health investigators are using the PulseNet system to identify illnesses that may be part of this outbreak, the CDC said.

CDC PulseNet manages a national database of DNA fingerprints of bacteria that cause foodborne illnesses. DNA fingerprinting is performed on bacteria using a method called whole genome sequencing (WGS).

WGS showed that bacteria from sick people’s samples are closely related genetically. This means that people in this outbreak likely got sick from eating the same food, according to the CDC.

The CDC said WGS also showed that this outbreak strain has been previously linked to various sources, including romaine lettuce, ground beef, and recreational water. More information is needed to identify the source of this outbreak, the CDC said.