An illness characterized by fever, headache, and myalgia, and less frequently by conjunctival suffusion, meningitis, rash, jaundice, or renal insufficiency. Symptoms may be biphasic.
Clinical presentation includes history of fever within the past two weeks and at least two of the following clinical findings: myalgia, headache, jaundice, conjunctival suffusion without purulent discharge, or rash (i.e. maculopapular or petechial); OR at least one of the following clinical findings:
Diagnostic testing should be requested for patients in whom there is a high index of suspicion for leptospirosis, based either on signs and symptoms, or on occupational, recreational or vocational exposure to animals or environments contaminated with animal urine.
Confirmatory:
Probable:
Involvement in an exposure event (e.g., adventure race, triathlon, flooding) with associated laboratory-confirmed cases.
Confirmed: A case with confirmatory laboratory results, as listed above.
Probable:
A clinically compatible case with at least one of the following:
For this disease/condition, Confirmed and Probable case statuses are included in the released case count.
S = This criterion along is Sufficient to classify a case.
N = This criterion is Necessary in conjunction with all other “N” and any “O” criteria in the same column is required to classify a case.
O = At least one of these “O” (Optional) criteria in each category (e.g., clinical evidence and laboratory evidence) in the same column—in conjunction with all “N” criteria in the same column—is required to report a case.
O† = At least two of these “O” criteria in each category (e.g., clinical evidence and laboratory evidence) in the same column—in conjunction with all other “N” criteria in the same column—is required to report a case.
| Criterion for Leptospirosis | Confirmed | Probable | |
|---|---|---|---|
| Clinical Evidence: | |||
| History of fever > 100.4° F within 2 weeks | N | N | |
| Myalgia | O† | O† | |
| Headache | O† | O† | |
| Jaundice | O† | O† | |
| Conjunctival suffusion without purulent discharge | O† | O† | |
| Rash (i.e., maculopapular or petechial) | O† | O† | |
| Aseptic meningitis | O | O | |
| GI symptoms (abdominal pain, nauseau, vomiting, diarrhea) | O | O | |
| Pulmonary complications (e.g., cough, breathlessness, hemoptysis) | O | O | |
| Cardiac arrhythmias, ECG abnormalities | O | O | |
| Renal insufficiency (e.g., anuria, oliguria) | O | O | |
| Hemorrhage (e.g., intestinal, pulmonary, hematuria, hematemesis) | O | O | |
| Jaundice with acute renal failure | O | O | |
| Laboratory Evidence: | |||
| Isolation of Leptospira from a clinical specimen | S | ||
| Fourfold or greater increase in Leptospira agglutination titer between acute- and convalescent-phase serum specimens | S | ||
| Demonstration of Leptospira in tissue by direct immunofluorescence | S | ||
| Leptospira total agglutination titer of ≥ 800 by Microscopic Agglutination Test (MAT) in one or more serum specimens after onset of symptoms | S | ||
| Detection of pathogenic Leptospira DNA (e.g., by PCR) from a clinical specimen | S | ||
| Leptospiral total agglutination titer of ≥ 200 but < 800 by MAT in one or more serum specimens after onset of symptoms | O | ||
| Demonstration of anti-Leptospira antibodies in a clinical specimen by indirect immunofluorescence | O | ||
| Demonstration of Leptospira in a clinical specimen by darkfield microscopy | O | ||
| Detection of IgM antibodies against Leptospira in an acute-phase serum specimen | O | ||
| Epidemiological Evidence: | |||
| Involvement in an exposure event (e.g., adventure race, triathlon, flooding) with known associated cases | N | ||
Date Posted: