The Snohomish Health District said Tuesday it has identified two cases of Shiga toxin-producing E. coli (STEC) in Snohomish County residents. Following public health interviews, these cases do appear to be connected to a cluster of STEC cases among seven children in King County.

The local cases involve a woman in her 20s and a child under 10 years of age from separate households. The child has been hospitalized, but no further information will be shared on the cases due to patient privacy.

Accordign to the health district, 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 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.

“The exact source of E. coli contamination can be difficult to pinpoint, but public health interviews lead us to believe the cases may be linked to eating fresh produce,” said Dr. Chris Spitters, Health Officer for the Snohomish Health District. “While we continue working with our partners on this investigation, it’s an important reminder to always wash produce items well before eating them, to avoid unpasteurized dairy products, and to fully cook beef and other animal meats to the proper temperature.”

The symptoms of STEC infections vary for each person but often include severe stomach cramps, diarrhea (often bloody), and vomiting. Onset of illness is usually about 3-4 days after exposure but can be as short as 1 day or as long as 10 days. If there is fever, it usually is not very high (less than 101°F). Most people get better within 5–7 days as infections can be mild, but others can be severe or even life-threatening. Young children, people with weakened immune systems, pregnant women and the elderly are more likely to experience serious illness.

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, feeling very tired, and losing pink color in cheeks and inside the lower eyelids. Persons 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 it can be fatal or cause permanent damage.

“If you or your child develop cramps, diarrhea, or vomiting with or without a fever or decreased urine, contact your healthcare provider to see if testing for STEC is recommended,” Spitters said.

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.

STEC and other foodborne infections occur throughout the year but may increase in frequency during late spring and summer months. In addition to proper food handling, cleaning, and thorough cooking, handwashing is another effective way to reduce chances of getting sick from germs like STEC. Adults should supervise young children to make sure they don’t put their hands in their mouths and ensure that their hands are washed thoroughly, especially after using the bathroom or petting animals.

Other ways to prevent STEC include:

• Avoiding eating high-risk foods, especially undercooked ground beef and other beef products, unpasteurized (raw) milk or juice or cheese, and raw sprouts.
• Thoroughly washing fresh produce before eating.
• Washing cutting boards and counters used for meat or poultry preparation immediately after use to avoid cross contaminating other foods.
• Cooking all meats thoroughly, especially ground beef. Use a food thermometer to make sure meats have reached a safe internal temperature. Ground beef and pork should be cooked to a minimum internal temperature of 160°F, and beef steaks and roasts to an internal temperature of at least 145°F and allowed to rest for 3 minutes after being removed from the grill or stove.

The Health District will continue to work with Public Health – Seattle & King County and the Washington State Department of Health on the ongoing investigation.