Update on infections with and clinical lab guidelines for Shiga toxin-producing E. coli (STEC) in the United States

Transcription

1 Update on infections with and clinical lab guidelines for Shiga toxin-producing E. coli (STEC) in the United States Patricia M. Griffin, MD Enteric Diseases Epidemiology Branch Centers for Disease Control and Prevention Joint OutbreakNet & PulseNet Meeting, Snowbird, Utah, September 2009

2 Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157, HUS) Clinical lab guidelines Transmission (O157, non-o157) Summary

3 Sequence of events in STEC infection STEC ingested 3-4 days non-bloody diarrhea, abdominal cramps 1-2 days more bloody diarrhea resolution 5-6 days more HUS Mead, Lancet 1998 HUS = hemolytic uremic syndrome

4 Complications of E. coli O157 infection, FoodNet sites, (n= 3,464) 42% hospitalized highest rate (66%) in >60 years old 6.3% hemolytic uremic syndrome (HUS, a complication that includes kidney failure) highest rate (15%) in <5 year olds 0.6% died highest rate (3%) in >60 year olds 5% persons with HUS died

5 Comparison of characteristics of non-o157 and O157 STEC cases, FoodNet, Non-O157 O157 (n=1,113) 113) (n=4,776) Similar Female 52% 53% Median age, years Different Part of outbreak 10% 19% HUS 1.7% 6.3% Hospitalized 12% 42% Died 0.1% 0.6% Traveled internationally 15% 3% All data are preliminary, HUS data is through 06, travel data collected 04-08

6 Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157) Clinical lab guidelines Transmission (O157, non-o157) Summary

7 Average annual incidence of E. coli O157 isolations, by age group, United States, (n=23,432) 3 p Incidence per 100,000 persons < Age Categories Public Health Laboratory Information System

8 Average annual incidence of E. coli O157 isolates, by state, Data from Public Health Laboratory Information System 2.0 isolates per 100,000 persons isolates per 100,000 persons <1.0 isolates per 100,000 persons

9 Incidence of E. coli O157 infections, by year, FoodNet, Incidence per 100,000 population About 20 illnesses occur for every one reported Year

10 Incidence of E. coli O157 infections, by year, FoodNet, Incidence per 100,000 population lowest in Healthy People 2010 objective: 1.0 case/100,000 persons Year

11 Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157) Clinical lab guidelines Transmission (O157, non-o157) Summary

12 Human isolates of non-o157 STEC serotyped by CDC, by serogroup, (n = 3,258 isolates) % of isolates 95 O groups, each <2% other und O Group Strockbine, unpublished, Enteric Diseases Epidemiology Lab

13 Human isolates of non-o157 STEC serotyped by CDC, by serogroup, (n = 3,258 isolates) % of isolates 95 O groups, % each <2% other und O Group Strockbine, unpublished, Enteric Diseases Laboratory Branch

14 Shiga toxin profiles of O157 and non-o157 STEC, FoodNet, 2007 Shiga toxin type O157 (n=260) % Non-O157 (n=146) % 1 only and only An additional 285 O157 and 114 non-o157 isolates had missing or unknown data

15 Shiga toxin profiles of O157 and non-o157 STEC, FoodNet, 2007 Shiga toxin type O157 (n=260) % Non-O157 (n=146) % 1 only and only Strains that produce only Shiga toxin 1 have rarely been isolated from persons with HUS

16 Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157) Clinical lab guidelines Transmission (O157, non-o157) Summary

17 % of labs Percent of clinical labs screening all stools for E. coli O157 National sample 60 Western states 50 outbreak FoodNet sites 72% Boyce, J Clin Micro 1995; Voetsch CID 2004; and unpublished preliminary data

18 Percent of labs that test stools routinely for Shiga toxin using enzyme immunoassay (EIA), FoodNet sites Increased >2-fold from 1.9% in 2003 to 4.4% in 2007 We have a long way to go

19 Number of non-o157 STEC reported in FoodNet sites, Number of non- O157 STEC reported CDC, C unpublished preliminary data,

20 Number of non-o157 STEC has increased at same time number of labs doing non-culture tests has increased Number of non- O157 STEC reported Number of labs using nonculture tests non-o157 STEC Number of labs testing for non-o157 CDC, unpublished preliminary data, 2009

21 A challenge arising from use of the Shiga toxin EIA Some clinical labs discard Shiga toxin- positive specimens without obtaining an isolate, so simply report Shiga toxin positive to doctor without sending isolate to health department, so some doctors think the patient has Shigella infection serogroup (e.g., O157 or O111) not determined but whether it s O157 should be important for clinicians subtype (e.g., PFGE pattern) not determined but subtype is important for outbreak detection PFGE = pulsed-field gel electrophoresis

22 New Recommendations for diagnosis of STEC Will be published in CDC s Morbidity Mortality Weekly Report in 2009 Authors from CDC State t and local l health departments t Emerging Infections Program academia a major clinical laboratories American Society for Microbiology Association of Public Health Laboratories

23 New Recommendations for diagnosis of STEC by clinical labs All stools submitted for diagnosis of acute community-acquired diarrhea should be simultaneously cultured for E. coli O157, and tested for Shiga toxins All specimens or broths with findings positive for STEC from which E. coli O157 was not recovered should be quickly sent to a public health lab Morbidity Mortality Weekly Report, in press

24 New Recommendations for diagnosis of STEC -- by public health labs Public health labs should isolate and identify all presumptive STEC sent to them by clinical labs or send isolates to CDC Morbidity Mortality Weekly Report, in press

25 Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157, HUS) Clinical lab guidelines Transmission (O157, non-o157) Summary

26 E. coli O157 outbreaks, (n = 525 outbreaks) # of outbreaks 60 Enhanced outbreak reporting began Year Rangel, Rangel, Emerg Emerg Infect Infect Dis, Dis, and and CDC unpublished electronic Foodborne CDC dataoutbreak Reporting System

27 E. coli O157 outbreaks, (n = 525 outbreaks) # of outbreaks 60 Enhanced outbreak reporting began Year Rangel, Rangel, Emerg Emerg Infect Infect Dis, Dis, and and CDC unpublished electronic Foodborne CDC dataoutbreak Reporting System

28 Proportion of illnesses due to each mode of transmission in 344 E. coli O157 outbreaks, Mode Illnesses in outbreaks (n=7,864 illnesses) Foodborne 69 Waterborne 18 Animals or their environment 8 Person-to-person 6 Lab-acquired <0.1% %

29 Proportion of illnesses due to each mode of transmission in 344 E. coli O157 outbreaks, Illnesses in Mode outbreaks (n=7,864 illnesses) Foodborne 69 Waterborne 18 Animals or their environment 8 Person-to-person 6 Lab-acquired <0.1% %

30 Commodities causing illness in outbreaks of E. coli O157 infections due to foods containing only one commodity, Commodity 1 st 5 years ( ) (n=2,053 ill) % Beef 33 Leafy vegetables 11 Dairy 13 Fruits-nuts 41 Sprouts 1 Game - Poultry 2

31 Commodities causing illness in outbreaks of E. coli O157 infections due to foods containing only one commodity, st 5 years 2 nd 5 years ( ) ( ) Commodity (n=2,053 ill) (n=1,312 ill) % % Beef Leafy vegetable Dairy Fruits-nuts 41 2 Sprouts 1 2 Game - 1 Poultry 2 -

32 The reservoir

33 Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157, HUS) Clinical lab guidelines Transmission (O157, non-o157) Summary

34 Outbreaks of non-o157 STEC infections, United States, (n=22) Shiga toxin Non-O157 STEC No. outbreaks EIA available nationally reportable

35 Serogroups in non-o157 STEC outbreaks, (n = 22 outbreaks) Serogroup Outbreaks no. O O121 5 O26 3 O45 2 O103 1 O104 1

36 Serogroups in non-o157 STEC outbreaks, (n = 22 outbreaks) Serogroup Outbreaks Outbreaks with >1 pathogen no. no. O O O O45 2 O103 1 O104 1

37 Food commodities implicated in the 6 outbreaks of non-o157 STEC infections with known food commodity, Commodity Outbreaks Food items no. Fruits-nuts 3 juice, apple cider, berries Dairy 2 milk, cheese & margarine Leafy vegetables 1 lettuce No outbreaks due to beef

38 Summary Features of illness E. coli O157 <5 year olds have highest rate of illness and HUS >60 year olds have highest rate hospitalized and died Non-O157 STEC compared with O157, have lower % part of outbreak, hospitalized, died higher % with international travel

39 Summary of STEC in United States (continued) Surveillance E. coli O157 lowest incidence in 2004 Non-O157 STEC 6 serogroups comprise ~3/4 of isolates very few clinical labs test routinely new recommendations should increase testing

40 Summary of STEC in United States (continued) Transmission of most STEC in outbreaks is by food E. coli O157 outbreaks beef remains major vehicle leafy vegetables consumed raw are a new major challenge Non-O157 STEC outbreaks beef has not been implicated

41 Acknowledgments This work was conducted by current and former staff of CDC, especially Enteric Diseases Epidemiology Branch Enteric Diseases Laboratory Branch Division of Foodborne, Bacterial, and Mycotic Diseases Epidemic Intelligence Service Training Program State and local health departments, special thanks for Lab-based surveillance Outbreak investigation and reporting FoodNet sites US Department of Agriculture US Food and Drug Administration

42 The Farm (2000) by Alexis Rockman The findings and conclusions in this presentation are those of the author and do not necessarily represent the views of the Centers for Disease Control and Prevention

43