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
Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157, HUS) Clinical lab guidelines Transmission (O157, non-o157) Summary
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
Complications of E. coli O157 infection, FoodNet sites, 2000-20062006 (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
Comparison of characteristics of non-o157 and O157 STEC cases, FoodNet, 2000-2008 2008 Non-O157 O157 (n=1,113) 113) (n=4,776) Similar Female 52% 53% Median age, years 14 16 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
Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157) Clinical lab guidelines Transmission (O157, non-o157) Summary
Average annual incidence of E. coli O157 isolations, by age group, United States,1996-2006 (n=23,432) 3 p Incidence per 100,000 persons 3 2.5 2 15 1.5 1 05 0.5 0 <5 5-9 10-19 20-29 30-39 40-49 50-59 60-69 70+ Age Categories Public Health Laboratory Information System
Average annual incidence of E. coli O157 isolates, by state, 1996-2006 Data from Public Health Laboratory Information System 2.0 isolates per 100,000 persons 1.0-1.9 isolates per 100,000 persons <1.0 isolates per 100,000 persons
Incidence of E. coli O157 infections, by year, FoodNet, 1996-2008 Incidence per 100,000 population 3 2.5 About 20 illnesses occur for every one reported 2 1.5 1 0.5 0 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Year
Incidence of E. coli O157 infections, by year, FoodNet, 1996-2008 Incidence per 100,000 population 3 2.5 2 1.5 lowest in 2004 1 0.5 Healthy People 2010 objective: 1.0 case/100,000 persons 0 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 Year
Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157) Clinical lab guidelines Transmission (O157, non-o157) Summary
Human isolates of non-o157 STEC serotyped by CDC, by serogroup, 2003-2008 2008 (n = 3,258 isolates) % of isolates 95 O groups, 25 20 15 10 5 each <2% 0 26 103 111 121 45 145 other und O Group Strockbine, unpublished, Enteric Diseases Epidemiology Lab
Human isolates of non-o157 STEC serotyped by CDC, by serogroup, 2003-2008 2008 (n = 3,258 isolates) % of isolates 95 O groups, 25 20 15 10 5 71% each <2% 0 26 103 111 121 45 145 other und O Group Strockbine, unpublished, Enteric Diseases Laboratory Branch
Shiga toxin profiles of O157 and non-o157 STEC, FoodNet, 2007 Shiga toxin type O157 (n=260) % Non-O157 (n=146) % 1 only 5 60 1 and 2 55 6 2 only 40 34 An additional 285 O157 and 114 non-o157 isolates had missing or unknown data
Shiga toxin profiles of O157 and non-o157 STEC, FoodNet, 2007 Shiga toxin type O157 (n=260) % Non-O157 (n=146) % 1 only 5 60 1 and 2 55 6 2 only 40 34 Strains that produce only Shiga toxin 1 have rarely been isolated from persons with HUS
Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157) Clinical lab guidelines Transmission (O157, non-o157) Summary
% of labs 100 90 80 70 40 Percent of clinical labs screening all stools for E. coli O157 National sample 60 Western states 50 outbreak 30 20 10 0 FoodNet sites 72% 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 Boyce, J Clin Micro 1995; Voetsch CID 2004; and unpublished preliminary data
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
Number of non-o157 STEC reported in FoodNet sites, 2000-2007 300 Number of non- O157 STEC reported 250 200 150 100 50 CDC, C unpublished preliminary data, 2009 0 2000 2001 2002 2003 2004 2005 2006 2007
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 300 60 250 200 50 40 Number of labs using nonculture tests 150 100 50 0 2000 2001 2002 2003 2004 2005 2006 2007 30 20 10 0 non-o157 STEC Number of labs testing for non-o157 CDC, unpublished preliminary data, 2009
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
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
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
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
Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157, HUS) Clinical lab guidelines Transmission (O157, non-o157) Summary
E. coli O157 outbreaks, 1982-2007 (n = 525 outbreaks) # of outbreaks 60 Enhanced outbreak reporting began 50 40 49 30 20 10 0 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 Year Rangel, Rangel, Emerg Emerg Infect Infect Dis, Dis, 2005 2005 and and CDC unpublished electronic Foodborne CDC dataoutbreak Reporting System
E. coli O157 outbreaks, 1982-2007 (n = 525 outbreaks) # of outbreaks 60 Enhanced outbreak reporting began 50 40 49 30 20 10 0 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 Year Rangel, Rangel, Emerg Emerg Infect Infect Dis, Dis, 2005 2005 and and CDC unpublished electronic Foodborne CDC dataoutbreak Reporting System
Proportion of illnesses due to each mode of transmission in 344 E. coli O157 outbreaks, 1998-2007 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% %
Proportion of illnesses due to each mode of transmission in 344 E. coli O157 outbreaks, 1998-2007 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% %
Commodities causing illness in outbreaks of E. coli O157 infections due to foods containing only one commodity, 1998-2007 Commodity 1 st 5 years (1998-2002) (n=2,053 ill) % Beef 33 Leafy vegetables 11 Dairy 13 Fruits-nuts 41 Sprouts 1 Game - Poultry 2
Commodities causing illness in outbreaks of E. coli O157 infections due to foods containing only one commodity, 1998-2007 1 st 5 years 2 nd 5 years (1998-2002) (2003-2007) Commodity (n=2,053 ill) (n=1,312 ill) % % Beef 33 42 Leafy vegetable 11 41 Dairy 13 13 Fruits-nuts 41 2 Sprouts 1 2 Game - 1 Poultry 2 -
The reservoir
Topics Features of illness (O157, non-o157 ) Surveillance (O157, non-o157, HUS) Clinical lab guidelines Transmission (O157, non-o157) Summary
Outbreaks of non-o157 STEC infections, United States, 1990-2007 (n=22) Shiga toxin Non-O157 STEC No. outbreaks EIA available nationally reportable 4 3 2 1 0 1990 1992 1994 1996 1998 2000 2002 2004 2006
Serogroups in non-o157 STEC outbreaks, 1990-2007 (n = 22 outbreaks) Serogroup Outbreaks no. O111 10 O121 5 O26 3 O45 2 O103 1 O104 1
Serogroups in non-o157 STEC outbreaks, 1990-2007 (n = 22 outbreaks) Serogroup Outbreaks Outbreaks with >1 pathogen no. no. O111 10 5 O121 5 1 O26 3 1 O45 2 O103 1 O104 1
Food commodities implicated in the 6 outbreaks of non-o157 STEC infections with known food commodity, 1990-2007 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
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
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
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
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
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