Shiga toxin-producing E. coli

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On June 28, 2019, the County of San Diego Health and Human Services Agency (HHSA) reported four confirmed or probable pediatric cases of Shiga-toxin-producing Escherichia coli (STEC) that may be related to contact with animals at the San Diego County Fair.

As of October 9, 2019, the County investigation of this outbreak has concluded. There were 11 confirmed cases and two probable cases reported in this outbreak. Three people were hospitalized and one child has died. The outbreak has been determined to be caused by a specific strain of STEC O157:H7.

San Diego County Department of Environmental Health Food Inspectors conducted investigations of the food booths associated with the reported foods consumed by the ill cases. There were no commonalities between food items and food booths. Any major violations observed were addressed at the time of the site visit and fixed. Re-inspections were conducted to ensure those violations remained fixed. Inspectors also conducted site visits at non-foodborne illness reported booths to conduct focused inspections on sanitizing procedures for consumer counters and self-service condiment containers, handwashing procedures, handwashing supplies and hot water.

All cases in this outbreak did report visiting the animal areas, which included the petting zoo, or had other animal contact at the fair. Animal and environmental testing conducted to date by the County and State has found no STEC O157:H7 bacteria. This investigation included testing of all petting zoo animals, all pony ride horses, and two cattle from the livestock barn that were present throughout the possible timeframe that the cases visited the fair. In addition, 32 environmental samples from the petting zoo and livestock barn showed no signs of STEC bacteria.

STEC Symptoms 
Preventing STEC Infection
Data and Reports

Symptoms of STEC infection

People with a STEC infection usually start feeling sick 3-4 days after eating or drinking something that contains the bacteria. However, illness can start anywhere from 1-10 days following exposure. Symptoms vary, but often include:

  • Severe abdominal cramps
  • Watery or bloody diarrhea (3 or more loose stools in a 24-hour period)
  • Vomiting

Fever, if present, is usually not very high (less than 101˚F/38.5˚C). Most people get better within 5-7 days. However, some infections can be severe or life-threatening. Please contact your health care provider if you have experienced these symptoms on or after June 8, and especially if you have diarrhea that lasts for more than 3 days or diarrhea that is accompanied by a fever higher than 102˚F, or blood in the stool, or so much vomiting that you cannot keep liquids down and you pass very little urine.

Preventing STEC infection

One of the best ways to help prevent infection with STEC is frequent and proper handwashing. Always wash your hands thoroughly after contact with animals or their environments (at farms, petting zoos, fairs, even your own backyard). Everyone, especially young children, older individuals, and people with weakened immune systems, should wash their hands before eating or drinking. Thorough handwashing means using plenty of soap, warm water, and scrubbing all surfaces of the hands (including between the fingers), for at least 20 seconds. 

For more information about STEC infection and how to prevent it, please see the sections below.

Data and Reports

County of San Diego HHSA
STEC Data Summary
Monthly Communicable Disease Report—May 2018 (Shiga Toxin-Producing E. Coli)


Centers for Disease Control and Prevention
Shiga toxin-producing E. coli (STEC) Questions and Answers  

California Department of Public Health
Shiga toxin-producing E. coli Information