# Presentation: 744410

## Non-O157 STEC: What We Know and What’s Next

*Elisabeth Hagen, M.D.*
*Office of Public Health Science*
*FSIS, USDA*

## Where we left off:

- Public Meeting, October 17, 2007
- Co-sponsored by FSIS, FDA, and CDC
- Data presented on epidemiology, prevalence in food animals, detection and surveillance challenges, and processing interventions

## What we learned:

- Non-O157 illness spectrum: diarrhea, bloody diarrhea, HUS, and death
- 6 serogroups cause 3⁄4 of illnesses:
- O26, O111, O103, O121, O45, O145
- Reported illnesses increasing
- Increasing prevalence vs. improved surveillance

## FoodNet, 2000 – 2006, 575 non-O157 isolates
35 in 2002;  209 in 2006
Studies in some non-FoodNet states show % of non-O157 > O157:H7 (VA, ID)
Non-O157’s predominate in other countries

- 35 in 2002;  209 in 2006
- Studies in some non-FoodNet states show % of non-O157 _>_ O157:H7 (VA, ID)
- Non-O157’s predominate in other countries

## True incidence of non-O157 human illness difficult to define
Limited awareness in clinical community
Non-uniform surveillance
Detection challenges

- Limited awareness in clinical community
- Non-uniform surveillance
- Detection challenges

## Many outbreaks worldwide, varied food and non-food vehicles, including meat

23 in U.S. since 19901
None attributed to meat products

1CDC Data

- 23 in U.S. since 19901
- None attributed to meat products
- 1CDC Data

## Cattle prevalence data varies:
0-19%, dairy cattle1,2,3,4
19.4 – 56.3% 5,  beef cattle feces/hides
Food prevalence data very limited:
Pre-evisceration beef carcasses >50%5,6
Retail ground beef, 2.3%7
Limited validated detection/identification methodologies

- 0-19%, dairy cattle1,2,3,4
- 19.4 – 56.3% 5,  beef cattle feces/hides
- Food prevalence data very limited:
- Pre-evisceration beef carcasses >50%5,6
- Retail ground beef, 2.3%7
- Limited validated detection/identification methodologies

- 1Wachsmuth *et al.*, 1991  2Wells *et al*., 1991  3Cray *et al*., 1996  4Thran *et al*., 2001
- 5Barkocy-Gallagher, *et al*., 2003   6Arthur *et al*., 2002    7Samadpour *et al*., 2006

## Summary: why FSIS is moving forward:

- Increasing reported incidence of human disease
- Cattle primary animal reservoir
- Share virulence factors with *E.coli* O157:H7; can cause equal severity of disease

## FSIS Plans:

- FSIS will begin testing ground beef and ground beef components for the presence of non-O157 STEC’s
- Determine to what extent non-O157 STEC’s are present in various products
- If needed, implement a regulatory program

## Methodology development underway:

In collaboration with ARS scientists
Focus on 6 serogroups of greatest public health concern
Two step PCR screening, followed by IMS, isolation, and further characterization

- In collaboration with ARS scientists
- Focus on 6 serogroups of greatest public health concern
- Two step PCR screening, followed by IMS, isolation, and further characterization

## First step: 2-step PCR on regulatory O157:H7 positives
Next step, O157:H7 negatives
Continue development of cultural confirmation methodology
Results = study data only during this phase

- Next step, O157:H7 negatives
- Continue development of cultural confirmation methodology
- Results = study data only during this phase

## There are challenges to gathering and applying data on non-O157 STEC’s in a regulatory setting.

## Slide 13