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Dec
04

Cluster of Shiga-toxin producing E. coli infections among children in King County ― Unknown source

Highlights, updated May 12, 2021

Summary

Genetic fingerprinting results (whole genome sequencing) have come back on some of these King County cases indicating they are related to cases in other counties within Washington. The Washington State Department of Health will provide updates about this multijurisdictional outbreak investigation and we will no longer update the information on this page.

Summary, last updated May 4, 2021

Public Health is investigating a new cluster of seven children infected with Shiga toxin-producing E. coli (also known as STEC) in King County. All cases are currently under 15 years of age, and three are under 5 years of age. Cases have been reported during April 22–May 1, 2021.

Our investigation is ongoing. We have identified multiple types of fresh produce, mostly organic, in common among the majority of cases but cannot yet rule out other possibilities. We are still uncertain if these cases share the same source of their infection or not. Updates will continue to be posted when more information is available.

Illnesses

All 7 children developed symptoms consistent with STEC, including diarrhea (often bloody), abdominal cramping, nausea, and vomiting. Illness onsets occurred during April 17–29, 2021. Six children have been hospitalized; this includes two children who developed a type of kidney complication called hemolytic uremic syndrome (HUS) and both are recovering.

Public Health actions

Public Health is conducting interviews with cases and their parents/guardians to help identify any common exposures. We are also working with the Washington State Department of Health to complete further testing, to help identify possible related cases in other counties, and to begin traceback of any products in common.

Public Health message

Fruits and vegetables can sometimes have germs like STEC on them, and many types have been associated with outbreaks in the past. You should always wash all fresh produce well before consuming. See this CDC link on fruit and vegetable safety for more details.

If you or your child develop painful or bloody diarrhea, diarrhea that lasts more than 3 days or is accompanied by a high fever or decreased urine, contact your healthcare provider to see if testing for STEC is indicated.

STEC and other foodborne infections occur throughout the year but may increase in frequency during late spring and summers months.

Anyone ill with suspected or known STEC should not work in or attend childcare or preschool, or work in food handling or healthcare until cleared by Public Health.

Laboratory testing

Six of the cases have preliminary testing indicating infections with E. coli O157 via PCR, and the seventh case has a positive EIA test for STEC. Further testing to confirm the strain and do genetic fingerprinting (whole genome sequencing or WGS) is underway at the Washington State Public Health Laboratory. These WGS results will help determine whether these cases were infected with the same strain of STEC.

About STEC

E. coli bacteria normally live in the intestines of humans and animals. Many strains of E. coli bacteria exist, and most of them are harmless or beneficial to human health. STEC are strains of E. coli that produce Shiga toxin (such as E. coli O157:H7) and can cause serious illness in people.

Infection with STEC can occur through consumption of undercooked ground beef and other beef products; unpasteurized (raw) milk, cheese, and juice; contaminated raw fruits, vegetables, sprouts and herbs; water contaminated with animal feces, or by direct contact with farm animals or their environment. Ready-to-eat foods can also be contaminated with STEC through contact with raw beef or raw beef juices in the kitchen.

Symptoms of STEC include diarrhea (which often becomes bloody) and stomach cramps, with mild or no fever. Illness typically lasts several days and people can spread infection to others even after symptoms resolve.

  • STEC infections usually resolve in 5-7 days but recovered individuals may still spread the bacteria. Up to one-third of children may continue to shed STEC for as long as 3 weeks.
  • Around 5–10% of those who are diagnosed with STEC infection develop a potentially life-threatening complication known as hemolytic uremic syndrome (HUS). Clues that a person is developing HUS include decreased frequency of urination and feeling very tired. People with HUS should be hospitalized because their kidneys may stop working and they may develop other serious problems. Most people with HUS recover within a few weeks, but some suffer permanent damage or die.
  • Ill people with suspected STEC infection should not work in food handling, patient care, or childcare settings, and ill children with suspected STEC infection should not attend daycare until they have seen a healthcare provider and been tested for STEC infection, even if their illness is mild. People with STEC infections who work in or attend these sensitive settings must be cleared by Public Health before returning.

Prevention

General advice for reducing risk of getting STEC:

  • Avoid eating high-risk foods, especially undercooked ground beef and other beef products, unpasteurized (raw) milk or juice or cheese, and raw sprouts
  • Wash hands with soap and water before preparing food for yourself or your children, before eating food, after going to the bathroom or changing diapers, and after contact with cows, sheep, or goats, their food or treats, or their living environment.
  • If soap and water aren't available, use an alcohol-based hand sanitizer with at least 60% alcohol (check the product label to be sure). These alcohol-based products can quickly reduce the number of germs on hands in some situations, but they are not a substitute for washing with soap and running water.
  • Thoroughly wash fresh produce before eating.
  • Wash cutting boards and counters used for meat or poultry preparation immediately after use to avoid cross contaminating other foods.
  • Cook all meats thoroughly, especially ground beef. Use a food thermometer to make sure meats have reached a safe internal temperature.
    • Cook ground beef and pork to a minimum internal temperature of 160°F.
    • Cook beef steaks and roasts to an internal temperature of at least 145°F and allow to rest for 3 minutes after you remove meat from the grill or stove.

More information

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