A total of 25 persons infected with the outbreak strain of Shiga toxin producing E. coli (STEC) O26 have been reported from 8 states.

The U.S. Centers for Disease Control says results of the epidemiologic and traceback investigations indicate eating raw clover sprouts at Jimmy John's restaurants is the likely cause of this outbreak.
March 8, 2012

The 11 new ill persons have been reported from Alabama, Michigan, and Ohio. Of the 24 ill persons with available information, 21 (87%) reported consuming sprouts at Jimmy John's restaurants in the 7 days preceding illness.

 Excerpts from an article in today’s U.S. Centers for Disease Control Morbidity and Mortality Weekly Report.

On April 20, 2010, the Colorado Department of Public Health and Environment (CDPHE) was notified by correctional authorities regarding three inmates with bloody diarrhea at a minimum-security correctional facility. The facility, which houses approximately 500 inmates, is a designated work center where inmates are employed or receive vocational training. Approximately 70 inmates work at an onsite dairy, which provides milk to all state-run correctional facilities in Colorado. CDPHE immediately began an investigation and was later assisted by the High Plains Intermountain Center for Agricultural Health and Safety at Colorado State University and by CDC. This report describes the results of the investigation, which determined that the illnesses were caused by Shiga toxin–producing Escherichia coli O111 (STEC O111) infections.

During April–July, 2010, 10 inmates at the facility received a diagnosis of laboratory-confirmed STEC O111 infection, and a retrospective prevalence study of 100 inmates found that, during March–April, 14 other inmates had experienced diarrheal illness suspected of being STEC O111 infection. Pulsed-field gel electrophoresis (PFGE) testing indicated that STEC O111 isolates from inmates matched STEC O111 isolates from cattle at the onsite dairy. An environmental investigation determined that inmates employed at the dairy might have acquired STEC O111 infection on the job or transported contaminated clothing or other items into the main correctional facility and kitchen, thereby exposing other inmates. To prevent similar outbreaks in correctional facilities, authorities should consult with public health officials to design and implement effective infection control measures.

CDPHE staff also inspected the correctional facility's kitchens and living areas and identified the following conditions conducive to STEC O111 transmission: poor adherence to standard food-service protocols and hygiene practices, including food handlers working while ill with diarrhea; inconsistent availability of hand soap throughout the facility; dairy employees wearing soiled work clothes into the kitchen and living areas; and transport of potentially fecally contaminated lunch coolers and water containers from the dairy into the kitchen.

CDPHE hypothesized that the outbreak was associated with environmental contamination and propagated by person-to-person transmission, possibly through food preparation. On learning of these results, the correctional facility immediately implemented the following public health recommendations: 1) prohibiting potentially contaminated material (e.g., lunch coolers, water containers, and work clothing from the dairy) in the kitchen area, 2) excluding from work all food handlers reporting diarrheal illness since April 1, 3) requiring food handlers with a confirmed STEC O111 test result to have two consecutive negative stool specimens before returning to work, and 4) limiting transfers of inmates to other facilities until they were cleared by the medical staff.

The complete report is available at: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6109a1.htm?s_cid=mm6109a1_x

I sorta cringe, or maybe sigh, every time someone faithfully repeats the dogma that factory-farmed cattle are the source of E. coli O157:H7 and other shiga-toxin producing E. coli (STEC).

All ruminants carry STEC naturally, and there are well-documented and tragic outbreaks involving deer, goats, sheep, elk and others.

German researchers report on the occurrence of STEC in deer in Germany in the current issue of Epidemiology and Infection.

Deer poop has been directly or indirectly linked to several outbreaks:

• 1 dead and 14 sickened from E. coli O157:H7 from deer feces contaminating strawberries in Oregon in Aug. 2011;

• deer feces were a possible source of E. coli O157 in Oregon hazelnuts that sickened 8 in March 2011;

• 29 Minnesota high school students sickened with E. coli O103 and E. coli O145 after butchering and processing deer into venison in 2010;

• deer meat was involved in at least two recognized E. coli outbreaks; and,

• an E. coli O157:H7 outbreak in Oct. 1996 that killed a 16-month-old and sickened 76 others who drank juice which contained unpasteurized apple cider that was probably contaminated with deer feces.

In the current study, the Germans studied the virulence genes eae, e-hlyA and saa, thestx subtypes, pulsed-field gel electrophoresis (PFGE) patterns and serovars. In total, 120 samples of 60 animals were screened by real-time polymerase chain reaction (PCR). The PCR results showed a high detection rate of stx genes (83%). Mainly faecal samples, but also some lymphatic tissue samples, tested stx-positive. All isolates carried stx2, were eae-negative and carried e-hlyA in 38% and saa in 9% of samples. Serovars (O88:[H8], O174:[H8], O146:H28) associated with human diseases were also identified. In some animals, isolates from lymphatic tissue and faecal samples showed undistinguishable PFGE patterns. The examined deer were shown to be relevant reservoirs of STEC with subtype stx2b predominating.

The complete paper is available at http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8501556.

Chase-Topping et al. report in the current issue of Emerging Infectious Disease that Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections.

To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx2 in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk.

However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx2 phage acquisition.

The complete report is available at http://wwwnc.cdc.gov/eid/article/18/3/11-1236_article.htm.