05/21/2026
Actions Requested
- Be alert for patients with symptoms of STEC.
- Consider STEC infection in patients presenting with acute diarrheal illness, especially bloody diarrhea or severe abdominal cramping.
- Stool specimens should be submitted for culture and Shiga toxin testing as early as possible in the course of illness.
- Report STEC cases immediately to Yakima Health District using the Reportable Disease Fax Form.
- Antibiotics and anti-motility agents are generally not recommended for suspected STEC infections due to the potential increased risk of HUS development. Children younger than 5 years of age are at a higher risk for HUS development.
- Most E. coli infections can be managed symptomatically. Patients with profuse diarrhea or vomiting should be rehydrated.
- Counsel patients on hand hygiene and exclusion from work, childcare, and food handling while symptomatic.
Situation
The Yakima Health District is currently investigating an increase in STEC cases in Yakima County. From April through May, we have identified six STEC cases, compared to only one case during the same period last year. None of the individuals have reported any recent travel. We have not identified any common exposure sources and initial testing has indicated the cases are not linked by serotype.
Healthcare providers are requested to remain vigilant for patients presenting with acute gastrointestinal illness and to promptly test and report.
About STEC
E. coli are bacteria commonly found in the intestines of humans and animals. While most strains are harmless, STEC strains can cause severe gastrointestinal illness and complications.
Groups of people who are at increased risk for E. coli infection include:
- Children younger than 5
- Adults 65 and older
- People with weakened immune systems
- International travelers
Symptoms of E.coli
Most people with E. coli infection have:
- Diarrhea that can be bloody or watery
- Stomach cramps that can be severe
Some people also have vomiting or a low fever.
Diagnosis of E. coli
E. coli infection is diagnosed when the bacteria are identified from the sample of a patient with an acute diarrheal illness. Stool samples should be routinely cultured for E. coli O157 and simultaneously assayed for non-O157 STEC with a test that detects Shiga toxins (or the genes that encode them).
All presumptive E. coli O157 isolates and Shiga toxin-positive specimens should be sent to a public health laboratory for further characterization.
Treatment for E. coli
Hydration
- Most E. coli infections can be managed symptomatically. Patients with profuse diarrhea or vomiting should be rehydrated.
- Evidence from studies of children with STEC O157 infection indicates that early use of intravenous fluids (within the first 4 days of diarrhea onset) may decrease the risk of renal failure.
Antibiotics
- Antibiotics used to treat infection with diarrheagenic E. coli other than STEC include fluoroquinolones (such as ciprofloxacin), macrolides (such as azithromycin), and rifaximin.
- Clinicians treating a patient whose clinical syndrome suggests STEC infection (see a clinical syndrome table) should be aware that administering antimicrobial agents may increase the risk of hemolytic uremic syndrome.
- Resistance to antimicrobials is increasing worldwide. The decision to use an antibiotic should be carefully weighed against the severity of illness, the possibility that the pathogen is resistant, and the risk of adverse reactions, such as rash, antibiotic-associated colitis, and vaginal yeast infection.
Antimotility agents
- Antimotility agents should be avoided for patients with bloody diarrhea; treatment should be reassessed if symptoms have not improved in 48 hours. Antimotility agents also should not be given to patients with STEC infection because these agents may increase the risk of complications, including toxic megacolon, HUS, and neurologic complications.
- No known data show that kaolin-pectin compounds (e.g., Kaopectate®) or lactobacillus slow diarrhea or relieve abdominal cramping.
Reporting
STEC is a notifiable condition in Washington State. Providers and laboratories should:
- Report suspected or confirmed STEC cases immediately
- Notify public health promptly of suspected clusters or outbreaks
Reporting Contact:
Yakima Health District
(509) 249-6541 during business hours or (509) 575-4040 after business hours
Fax: (509) 381-3526
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