King County – Washington’s most populous county and the one in which Seattle is located – has seen a recent increase in Shiga-toxin producing E. coli infections among children under the age of five, according to a county health advisory issued this week.
The county reports that “three cases of E. coli O157 infection have been reported” in King County children under the age of five “since late May.” At first blush, three cases may seem to be relatively insignificant; however, the development of a potentially fatal complication called Hemolytic Uremic Syndrome (HUS) in two of the three cases is what makes the increase in cases both significant and alarming.
An Alarmingly High Frequency of Potentially Fatal E. coli Complication
Hemolytic Uremic Syndrome (HUS) is the most common cause of acute kidney failure in young children. HUS occurs when, through a series of events, the E. coli bacteria travels from the intestines of a person with an E. coli infection to their kidneys. Once there, the bacteria destroys red blood cells and causes blood clots to develop in the kidney’s smaller vessels. These clots ultimately result in kidney injury and failure.
Typically, approximately 10%, (one out of every ten) people infected with E. coli O157:H7 develop HUS. The cases described in the county’s health alert have developed the condition at at rate of 67%, or two of every three infections. In other words, young children with these infection are developing the condition at six times the normal rate (600%).
The two children that developed HUS were hospitalized, while the third child (that did not develop HUS) remains home and is recovering at this time.
King County Investigating Source of Infections
The investigation into the increased number of cases and high rate of HUS is currently ongoing, and a “common food food source has not been identified at this time.” However, the King County also stated that “the cases have reported consumption of fresh produce,” but restates that the investigation is “in progress and no common source has been identified.”
The county asks health care providers and professionals report any confirmed or suspected STEC cases to King County Public Health.
To aid in identifying the source of the illnesses, providers are requested to obtain information about “possible risk factors” during the ten days before the onset of symptoms. In addition to assessing the individual’s history of contact with people experiencing diarrhea during that 10 day period, the county wants details about a number of categories historically associated with E. coli infections, including dietary history (consumption of meats, fresh fruits and vegetables from grocery stores, farms, farmers’ markets; restaurants visited), travel (travel history with travel dates and destinations), and animals (animal contact and/or exposure, including pets, farms, etc.).