Wisconsin Division of Public Health Disease Surveillance Manual (EpiNet, February 2005)
I. IDENTIFICATION
A. CLINICAL DESCRIPTION: Hemolytic uremic syndrome (HUS) is characterized by the acute onset of microangiopathic hemolytic anemia, renal injury, and low platelet count. Thrombotic thrombocytopenic purpura (TTP) is also characterized by these features but can also include central nervous system involvement and fever, and may have a more gradual onset. Most cases of HUS (but few cases of TTP) occur after an acute gastrointestinal illness (usually diarrhea). Therefore, criteria for diagnosing TTP on the basis of central nervous system involvement and fever are not provided because cases diagnosed clinically as post diarrheal TTP should also meet the criteria for HUS. These cases are reported as post diarrheal HUS.
B. REPORTING CRITERIA: An acute illness diagnosed as HUS or TTP that both meets the laboratory criteria and began within three weeks of onset of an acute or bloody diarrhea.
C.LABORATORY CRITERIA FOR CONFIRMATION:
The following are both present at some time during the illness:
- Anemia (acute onset) with microangiopathic changes (e.g., schistocytes, burr cells, or helmet cells) on peripheral blood smears, AND
- Renal injury (acute onset), evidenced by either:
1. Hematuria , OR
2. Protenuria , OR
3. Elevated creatinine level (e.g., ³ 1.0 mg/dl in a child <13 years of age or ³ 1.5 mg/dl in an adult, or ³ 50% increase over baseline).NOTE: A low platelet count can usually, but not always, be detected early in the illness, however, it may then become normal or even high as the disease progresses. If a platelet count obtained within 7 days after onset of the acute gastrointestinal illness is not <150,000/mm 3, other diagnoses should be considered.
D. WISCONSIN CASE DEFINITION: A case that is laboratory confirmed.
II. ACTIONS REQUIRED / PREVENTION MEASURES
A. WISCONSIN DISEASE SURVEILLANCE CATEGORY II: Report to the patient's local health officer on an Acute and Communicable Disease Case Report (DPH 4151) or other means within 72 hours of the identification of a case or suspected case.
B. EPIDEMIOLOGY REPORTS REQUESTED:
- Acute and Communicable Diseases Case Report (DPH 4151).
- Routine Enteric Follow-up Worksheet (All sections requested)
C. PUBLIC HEALTH INTERVENTIONS:
- Conduct case control investigation if two or more cases occur in a close geographic or temporal setting or if cases share a common potential exposure (e.g., food establishment, recreational water, community event, farm animal-related exposure).
III. CONTACTS FOR CONSULTATION
A. BCDP / COMMUNICABLE DISEASE EPIDEMIOLOGY SECTION: (608) 267-9009 or (608) 267-7422.B. REGIONAL STAFF: See Epinet Introduction: “REGIONAL STAFF CONTACTS”.
1. “Hemolytic Uremic Syndrome (HUS)” DPH Disease Fact Sheet Series: View a list of all current Communicable Disease Fact Sheets
2. Heymann DL, ed. DIARRHEA CAUSED BY ESCHERICHIA COLI 1. DIARRHEA CAUCED BY ENTEROHEMORRHAGIC STRAINS. In: Control of Communicable Diseases Manual. 18 th ed. Washington , DC : American Public Health Association, 2004:161-162.
3. Pickering LK, ed. Escherichia coli Diarrhea (Including Hemolytic-Uremic Syndrome). In: Red Book: 2003 Report of the Committee on Infectious Diseases. 26 th ed. Elk Grove Village , IL : American Academy of Pediatrics, 2003:275-279.
V. DISEASE TRENDS
Between 1999 through 2003 there were 37 cases of HUS reported in Wisconsin . Of these, 29 (78%) were associated with E. coli O157:H7 infections. The etiologic agent for the nine other cases could not be determined. The majority of cases (57%) occurred in children 6 years or younger). Twenty-four cases (65%) had an onset of illness between June and September.