Gert van der Hoek
In Memoriam - Editor, Senior Moderator
Snip from CIDRAP-news:
One infectious disease expert, Michael T. Osterholm, PhD, MPH, said the report of 276 HUS cases raises several questions, including whether the HUS diagnoses are accurate. Osterholm is director of the University of Minnesota Center for Infectious Disease Research and Policy, publisher of CIDRAP News.
"Are clinicians now diagnosing people with HUS when in fact they don't have it—they have bloody diarrhea but not HUS?" Osterholm asked. "Since HUS is a clinical case definition, we have to be very careful." He also noted that that few labs are equipped to test for non-O157 strains of E coli, such as O104.
If all the reported HUS cases are real, he said.
CIDRAP
The Robert Koch Institut (German CDC) published the case-definition :
Case definition for HUS-cases associated with the outbreak
in the spring 2011 in Germany
The following case definition should be applied to HUS-cases associated with the EHEC/HUS outbreak
in the spring of 2011 in Germany. It is based on the case definition for “haemolytic uraemic
syndrome (HUS), enteropathogenic” defined in the 2007 edition of the “Case definitions for reporting
communicable diseases of the Robert Koch-Institute”, modified to reflect features of the current
outbreak.
Important modifications are:
1. Limitations of time, place and person concerning exposure,
2. Omission of epidemiological confirmation as a basis for case classification,
3. Inclusion of suspected cases in the definition.
Cases of HUS that are not associated with this outbreak should be defined according to the case
definition of 2007.
Detailed explanation of definitions marked with the sign „►“ are provided below.
Exposure
The relevant exposure period is defined as the period from (and including) April 21, 2011 to the date
of ►illness onset. “During the exposure period” is defined as any time-period that overlaps with the
relevant exposure period.
Symptomatic patients are identified as associated with this outbreak if they meet at least one of the
following criteria:
E1. Residence or permanent stay in Germany during the exposure period; except patients are known
to have been outside of Germany during the entire exposure period,
E2. Temporary stay in Germany at any time during the exposure period,
E3. Consumption of a food item that was acquired in Germany during the exposure period,
E4. Close contact (e.g., in a household) with a HUS case belonging to case category Cat 1 or Cat 2
who meets at least one of the criteria E1 to E3.
Clinical criteria
►Illness onset on or after Mai 1, 2011 and a clinical picture of acute enteropathogenic HUS defined
by the presence of at least two of the following three criteria:
C1. Hemolytic anemia,
C2. Thrombocytopenia ≤ 150,000 cells/mm
3
,
C3. ►Renal dysfunction. Case_Definition_for_HUS OutbreakHUS-Outbreak_Case-Definition_2011-05-26_ENG.doc 2 / 3
Laboratory criteria
Positive result in at least one of the following four tests:
[Detection of toxin:]
L1. Culture of the pathogen and isolation only from stool AND detection of Shigatoxin Stx2 using
ELISA on the E. coli culture,
L2. Mixed culture of the pathogen, enriched stool cultures or isolation of E.coli AND ►nucleic acid
amplification test (e.g. PCR) for detection of the shigatoxin gene stx2 from the same sample.
[Indirect (serological) detection:]
L3. Detection of anti-LPS-IgM-antibodies against E.coli Serogroups (once ► markedly increased
titre/concentration, e.g., using ELISA, Western-Blot),
L4. ►Marked change between two consecutive samples in titre/concentration of anti-LPS-IgGantibodies against E.coli Serogroups (e.g., using ELISA).
Cases are classified into the following categories:
Cat 1. Clinically confirmed HUS case
Clinical picture of acute enteropathogenic HUS without laboratory confirmation.
Cat 2. Clinically and laboratory confirmed HUS case
Clinical picture of acute enteropathogenic HUS with laboratory confirmation.
Cat 3. Suspected HUS case
Cases with a clinical picture of acute enteropathogenic HUS as assessed by the attending physician,
but not formally meeting the clinical criteria (at least 2 of C1 to C3) identified above, are classified as
suspected cases regardless of laboratory confirmation.
When reporting without specifying exact case categories, cases from the category 1 and 2 will be
classified as „confirmed HUS cases“ and cases from the categories 1 to 3 - as „HUS cases
including suspected cases”.
Read more in PDF document
PDF in German
One infectious disease expert, Michael T. Osterholm, PhD, MPH, said the report of 276 HUS cases raises several questions, including whether the HUS diagnoses are accurate. Osterholm is director of the University of Minnesota Center for Infectious Disease Research and Policy, publisher of CIDRAP News.
"Are clinicians now diagnosing people with HUS when in fact they don't have it—they have bloody diarrhea but not HUS?" Osterholm asked. "Since HUS is a clinical case definition, we have to be very careful." He also noted that that few labs are equipped to test for non-O157 strains of E coli, such as O104.
If all the reported HUS cases are real, he said.
CIDRAP
The Robert Koch Institut (German CDC) published the case-definition :
Case definition for HUS-cases associated with the outbreak
in the spring 2011 in Germany
The following case definition should be applied to HUS-cases associated with the EHEC/HUS outbreak
in the spring of 2011 in Germany. It is based on the case definition for “haemolytic uraemic
syndrome (HUS), enteropathogenic” defined in the 2007 edition of the “Case definitions for reporting
communicable diseases of the Robert Koch-Institute”, modified to reflect features of the current
outbreak.
Important modifications are:
1. Limitations of time, place and person concerning exposure,
2. Omission of epidemiological confirmation as a basis for case classification,
3. Inclusion of suspected cases in the definition.
Cases of HUS that are not associated with this outbreak should be defined according to the case
definition of 2007.
Detailed explanation of definitions marked with the sign „►“ are provided below.
Exposure
The relevant exposure period is defined as the period from (and including) April 21, 2011 to the date
of ►illness onset. “During the exposure period” is defined as any time-period that overlaps with the
relevant exposure period.
Symptomatic patients are identified as associated with this outbreak if they meet at least one of the
following criteria:
E1. Residence or permanent stay in Germany during the exposure period; except patients are known
to have been outside of Germany during the entire exposure period,
E2. Temporary stay in Germany at any time during the exposure period,
E3. Consumption of a food item that was acquired in Germany during the exposure period,
E4. Close contact (e.g., in a household) with a HUS case belonging to case category Cat 1 or Cat 2
who meets at least one of the criteria E1 to E3.
Clinical criteria
►Illness onset on or after Mai 1, 2011 and a clinical picture of acute enteropathogenic HUS defined
by the presence of at least two of the following three criteria:
C1. Hemolytic anemia,
C2. Thrombocytopenia ≤ 150,000 cells/mm
3
,
C3. ►Renal dysfunction. Case_Definition_for_HUS OutbreakHUS-Outbreak_Case-Definition_2011-05-26_ENG.doc 2 / 3
Laboratory criteria
Positive result in at least one of the following four tests:
[Detection of toxin:]
L1. Culture of the pathogen and isolation only from stool AND detection of Shigatoxin Stx2 using
ELISA on the E. coli culture,
L2. Mixed culture of the pathogen, enriched stool cultures or isolation of E.coli AND ►nucleic acid
amplification test (e.g. PCR) for detection of the shigatoxin gene stx2 from the same sample.
[Indirect (serological) detection:]
L3. Detection of anti-LPS-IgM-antibodies against E.coli Serogroups (once ► markedly increased
titre/concentration, e.g., using ELISA, Western-Blot),
L4. ►Marked change between two consecutive samples in titre/concentration of anti-LPS-IgGantibodies against E.coli Serogroups (e.g., using ELISA).
Cases are classified into the following categories:
Cat 1. Clinically confirmed HUS case
Clinical picture of acute enteropathogenic HUS without laboratory confirmation.
Cat 2. Clinically and laboratory confirmed HUS case
Clinical picture of acute enteropathogenic HUS with laboratory confirmation.
Cat 3. Suspected HUS case
Cases with a clinical picture of acute enteropathogenic HUS as assessed by the attending physician,
but not formally meeting the clinical criteria (at least 2 of C1 to C3) identified above, are classified as
suspected cases regardless of laboratory confirmation.
When reporting without specifying exact case categories, cases from the category 1 and 2 will be
classified as „confirmed HUS cases“ and cases from the categories 1 to 3 - as „HUS cases
including suspected cases”.
Read more in PDF document
PDF in German