Washington County Public Health is investigating three cases of diarrheal illness caused by Shiga toxin producing E.coli (STEC) O157 infections. The source of the infection has not been identified, but all cases did have contact with livestock at the Washington County Fair (July 26-31). There are county and state fairs still to come this season.
Most persons with STEC report bloody stools, however, mild, non-bloody diarrheal illness and asymptomatic infections also occur. Symptoms usually begin 3-4 days after exposure (range 1 to 10 days) and include abdominal pain and cramping. Nausea and vomiting are also common but fever is generally absent.
Treatment for STEC is supportive; neither antibiotics nor antidiarrheal agents should be used since they may worsen illness course. Most people recover within 5–10 days but 10-20% can develop hemolytic uremic syndrome (HUS) characterized by microangiopathic hemolytic anemia, renal injury, and low platelet count.
Public health officials urge you to consider STEC in your differential diagnosis for all persons with compatible symptoms especially when there is a history of contact with farm animals or attendance at county or state fairs.
In patients with symptoms compatible with STEC infection, collect a stool specimen for testing by culture and Shiga toxin test. If STEC is detected then also obtain a complete blood count, serum electrolytes, BUN, and creatinine as a screen for hemolytic uremic syndrome (HUS).
Secondary spread is a serious concern with STEC infections as bacteria can be shed for weeks. Because lab confirmation can be delayed, please educate suspected cases on how to prevent spread of this highly contagious pathogen at home and in the community by staying home when sick, washing hands after toileting or handling diapers, and avoiding food handling for others. Suspected cases should be restricted from attendance at school or childcare and from food handling jobs.
Please report suspected cases of STEC or HUS immediately to the appropriate county public health department listed below: