Progress towards STEC clinical diagnostic guidelines

Transcription

1 Progress towards STEC clinical diagnostic guidelines STEC Working Group Meeting April 3, 2008 CDC

2 STEC Working Group Quest Diagnostics Sharon Rolando Shea, MHS, MT (ASCP) Rosemary Humes, MS, MT(ASCP) SM Vickie Baselski Vickie Baselski, ASM PhD, Vickie D(ABMM), Baselski, FAAM PhD, ASM DABMM, FAAM ASM Raymond L. Kaplan, L. Kaplan PhD Sharon Rolando Shea Rosemary Humes APHL APHL Patricia A. Somsel, DrPH Michigan Department of Community Health Sharon Hurd Sharon Hurd, MPH Connecticut Emerging Infections Program Melissa Tobin-D Angelo Frances Tyrell Georgia Division of Public Health Patricia A. Somsel Robyn Atkinson Robyn Tennessee Atkinson, Dept PhD of Tennessee Health Dept of Robyn Atkinson, Health PhD L. Hannah Gould, MS, PhD Roberta Roberta Carey, Carey PhD, Cheryl Bopp, Bopp MS. Nancy Strockbine, PhD Peter Peter Gerner-Smidt, Gerner-Smidt MD, PhD Patricia Griffin, MD Patricia Griffin CDC CDC Claudia Crandall California Dept of of Public Health Barbara Body LabCorp Marguerite A. Neill Warren Alpert Med. School Brown University L. Hannah Gould Claudia Crandall

3 Action Item: Write practice and procedural guidelines for STEC diagnosis History July 2007 First draft of outline September 2007 Assembled working group October 2007 First working group conference call First draft of practice guidelines paragraph January Set date of April 3-4, 2008 for meeting, Role of Clinical Diagnostic and Public Health Laboratories in Enteric Disease Surveillance and Response April First draft of procedural guidelines document

4 Goals Recommendations would be the focus Broad audience clinical and public health microbiologists physicians Venues for publication MMWR (Recommendations and Reports) IDSA ASM/Cumitech CAP Advertise/Outreach Medical Laboratory Observer (MLO) CAP Today Clinical Microbiology Newsletter

5 Background Working Outline Diagnostic recommendations Testing algorithms Specimen selection Specimen collection and handling Non-culture assays for STEC Immunoassays PCR assays Isolation, Identification and Reporting Forwarding Specimens and Isolates to PHLs Interpretation of Final Results from Public Health Laboratories Guidelines for clinicians

6 Recommendation: Test all stools from acute, communityacquired diarrhea and cases of HUS and TTP for STEC as part of routine stool culture algorithm. How should this be accomplished?

7 Three Proposed Algorithms Algorithms balance Patient care Public health needs Available technology

8 Primary diagnostic laboratory will simultaneously culture for E. coli O157:H7 and test for non-o157 STEC notify physician and public health authorities promptly forward to PHL: PHL will E. coli O157 isolates Stx/stx+ specimens negative for E. coli O157 confirm STEC results subtype STEC O157 Ideal Algorithm isolate and subtype non-o157 STEC

9 Ideal Algorithm Advantages rapid detection of STEC O157 infection and isolate for subtyping and outbreak detection (48 hours) rapid presumptive detection of STEC non-o157 infection (24 hours) Disadvantages costly in terms of laboratorian time and reagents

10 Acceptable Algorithm Primary diagnostic laboratory will test for STEC with non-culture method reflexively culture + specimens for E. coli O157 notify physician and public health authorities promptly forward to PHL: E. coli O157 isolates Stx/stx+ specimens negative for E. coli O157 PHL will confirm STEC results subtype STEC O157 isolate and subtype non-o157 STEC

11 Acceptable Algorithm Advantages rapid presumptive detection of STEC infection (24 hours) less costly than Best Practice algorithm because only Stx/stx+ specimens are cultured Disadvantages delay in detection of STEC O157 and availability of isolate for subtyping and outbreak detection (72 hours) STEC O157 selective agar and latex reagents must be kept on hand and may expire before use

12 Minimally Acceptable Algorithm Primary diagnostic laboratory will test for STEC with non-culture method notify physician and public health authorities promptly forward to PHL: Stx/stx+ specimens PHL will Confirm STEC results Isolate and subtype STEC O157 Isolate and subtype non-o157 STEC

13 Minimally Acceptable Algorithm Advantages rapid detection of STEC infection (24 hours) less costly in terms of laboratorian time and reagents because only reagents for STEC testing must be kept on hand Disadvantages delay in availability of STEC isolates for subtyping and outbreak detection (96 hours)

14 Evidence in support of culturing all stools from individuals with acute, community-acquired diarrhea: Frequency of pathogens in diarrheal stools Minnesota HMO, N = 10,030 specimens Campy Salm STEC Shig Besser, Hunt, Smith, Sullivan, Bartkus, unpublished

15 Evidence in support of culturing all stools from individuals with acute, community-acquired diarrhea: 2.5 Frequency of pathogens in diarrheal stools New Mexico, April-October, Campy Salm STEC Shig Nims, et al., ASM 2001 (Abstract C165,)

16 Incidence of Laboratory-confirmed infections at selected FoodNet Sites, CO CT NY OR MN STEC Shigella Campy Salm

17 Incidence of Laboratory-confirmed infections at selected FoodNet Sites, CO CT NY OR MN STEC Shigella Campy Salm

18 Is testing for O157 STEC and non-o157 STEC necessary? O157 STEC causes: ~50% STEC illnesses most STEC outbreaks most cases of severe disease Non-O157 STEC can also cause bloody diarrhea, HUS, and outbreaks

19 Incidence and Illness Proportion of STEC isolates that were O157 vs non-o157 State STEC O157 non-o157 MN (55%) 60 (45%) CT (59%) 13 (41%) NM NE (40%) 7 (50%) 21 (60%) 7 (50%) Total (53%) 101 (43%) MN Besser, Hunt, Smith, Sullivan, Bartkus, unpublished CT Fiorentino, Hurd, Howard, et al., ASM 2001 (Abstract C166) NM Nims, et al. ASM 2001 (Abstract C165) NE Fey et al. EID 6: , 2000

20 Background Working Outline Diagnostic recommendations Testing algorithms Specimen selection Specimen collection and handling Non-culture assays for STEC Immunoassays PCR assays Isolation, Identification and Reporting Forwarding Specimens and Isolates to PHLs Interpretation of Final Results from Public Health Laboratories Guidelines for clinicians

21 Guidelines for Clinicians When to perform STEC testing Which diagnostic test to request Evaluation and management of patients with positive stool cultures for E. coli O157:H7 (?broaden to Stx2-positive STEC) Clinical aspects in symptomatic patients Identify day of onset of diarrhea as day 1 Clinical and laboratory follow-up Reasons for hospitalization Infection control in the home Public health aspects Follow-up stool cultures Cultures of family, household members or close contacts Return to work, school, daycare or congregate residential setting

22 Thank you Comments and Questions Welcome!