E. coli O121 is similar to the more prevalent E. coli O157:H7 in that it is a Shiga toxin-producing E. coli (STEC).  The Shiga toxins made by the bacteria can cause serious injury or death.  This strain is part of a group of E. coli serotypes called non-O157 STEC or non-O157 E coli.

It is harder to identify E. coli O121 than E. coli O157. Most health departments have to send samples to the Centers for Diseases Control and Prevention (CDC) for a confirming O121 test. Because identification is difficult, these infections are most likely underreported.

Bacteria Test on Quad Plate

“If you or a family member is diagnosed with this deadly bacterial illness, it is likely that contaminated food, contaminated water, or animal contact was the source of the infection,” said attorney Fred Pritzker, who has represented people in almost every state in E. coli lawsuits. “We need to discover the source of the bacteria and if unsanitary conditions were at the center of the outbreak.”

E. coli O121 Outbreaks

  • Iceberg Lettuce – In 2006, an outbreak in Utah sickened four people, three of whom developed hemolytic uremic syndrome (HUS). Epidemiological evidence found that the source was iceberg lettuce prepared at a fast food facility.1
  • Water – Eleven people contracted E. coli infections after swimming in a lake. Three of the eleven were children who contracted HUS. Microbiological evidence pointed to E. coli O121. The illnesses were associated with swallowing water while swimming during one week in July.2

This pathogen has been associated with cases of bloody and non-bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS).

Reference: 1. Weber-Morgan Health Department press release, 2006, August 7.
2. McCarthy, T. A., Barrett, N. L., Hadler, J. L., Salsbury, B., Howard, R. T., Dingman, D. W., Brinkman, C. D., Bibb, W. F., Cartter, M. L. (2001). Hemolytic-Uremic Syndrome and Escherichia coli O121 at a Lake in Connecticut, 1999. Pediatrics 108: e59-59.