“widespread environmental contamination”

Can we dare mention water contamination, feedlots and dairy farms – well, cows generally?

A mind-spinning article landed in my inbox today – “Shiga Toxin-Producing E. coli Infections Associated with Romaine Lettuce — United States, 2018.” 

CDC had reported only 210 ill – https://www.cdc.gov/ecoli/2018/o157h7-04-18/index.html – apparently it was larger?

And, the genetic pattern found in 2018 may well be surfacing again in late 2019.

ciz1182– Read full article

Here are the highlights:

The largest multi-state leafy green-linked STEC O157 outbreak in several decades. The investigation highlights the complexities associated with investigating outbreaks involving widespread environmental contamination.

A case was defined as an infection between March 13 and August 22, 2018 with one of the 22 identified outbreak-associated E. coli O157:H7 or E. coli O61 pulsed-field gel electrophoresis pattern combinations, or with a strain STEC O157 that was closely related to the main outbreak strain by whole genome sequencing.

240 case-patients from 37 states; 104 were hospitalized, 28 developed hemolytic uremic syndrome, and five died. Of 179 people who were interviewed, 152 (85%) reported consuming romaine lettuce in the week before illness onset. Twenty sub-clusters were identified. Product traceback from sub-cluster restaurants identified numerous romaine lettuce distributors and growers; all lettuce originated from the Yuma growing region. Water samples collected from an irrigation canal in the region yielded the outbreak strain of STEC O157.

  • 240 case-patients from 37 states (238 of them were infected with STEC O157; 1 was co-infected with STEC O157 and STEC O61, and 2 were infected with only STEC O61).
  • 104 hospitalizations
  • 28 victims with hemolytic uremic syndrome

Here is the takeaway:

This outbreak was the largest multistate STEC O157 outbreak in several decades, eclipsing in magnitude a 2006 outbreak linked to fresh spinach [3]. As there are an estimated 26 unreported illnesses for every STEC O157 case reported to PulseNet, the true size of this outbreak was likely much larger than the 240 illnesses reported through PulseNet, suggesting that thousands of people were actually sickened in this outbreak [5]. This outbreak was also much larger than any of the 28 multistate leafy green outbreaks reported from 1998–2016, which saw a mean size of 40 case patients [15]. It is unclear why the size of the current outbreak exceeded that of previous similar outbreaks, but the volume of contaminated product may have played a role. This is supported by the fact that the outbreak strain was identified along multiple points of a 3.5-mile stretch of an irrigation canal and that traceback led to 36 romaine fields.

Readers, we have work to do.