Criteria
Centers for Disease Control and Prevention: anaplasmosis case definition[112]
Clinical criteria
Objective clinical evidence: fever (as reported by patient or healthcare provider); anaemia; leukopenia; thrombocytopenia; any hepatic transaminase elevation; or raised C-reactive protein.
Subjective clinical evidence: chills/sweats; headache; myalgia; or fatigue/malaise.
Laboratory criteria
Confirmatory laboratory evidence:
detection of Anaplasma phagocytophilum DNA in a clinical specimen via amplification of a specific target by polymerase chain reaction (PCR) assay, nucleic acid amplification tests (NAAT), or other molecular testing; OR
serological evidence of a fourfold change in IgG-specific antibody titre to A phagocytophilum antigen by indirect immunofluorescence assay (IFA) in paired serum samples (one taken in the first 2 weeks after illness onset and a second taken 2-10 weeks after acute specimen collection); OR
demonstration of anaplasmal antigen in a biopsy or autopsy sample by immunohistochemical methods; OR
isolation of A phagocytophilum from a clinical specimen in cell culture with molecular confirmation (e.g., PCR or sequencing).
Presumptive laboratory evidence:
serological evidence of raised IgG antibody reactive with A phagocytophilum antigen by IFA at a titre ≥1:128 in a sample taken within 60 days of illness onset; OR
microscopical identification of intracytoplasmic morulae in leukocytes in a sample taken within 60 days of illness onset.
Case classification
Suspect:
meets confirmatory or presumptive laboratory evidence with no or insufficient clinical information to classify as a confirmed or probable case (e.g., laboratory report only).
Probable:
meets presumptive laboratory evidence with fever (as reported by patient or healthcare provider) and at least one other objective or subjective clinical evidence criterion (excluding chills/sweats); OR
meets presumptive laboratory evidence without a reported fever but with chills/sweats and at least one objective clinical evidence criterion, or two other subjective clinical evidence criteria.
Confirmed:
meets confirmatory laboratory evidence and at least one of the objective or subjective clinical evidence criteria.
A person previously reported as a probable or confirmed case may be counted as a new case when there is an episode of a new clinically compatible illness with confirmatory laboratory evidence.
Centers for Disease Control and Prevention: ehrlichiosis case definition[113]
Clinical criteria
Objective clinical evidence: fever (as reported by patient or healthcare provider); anaemia; leukopenia; thrombocytopenia; or any hepatic transaminase elevation.
Subjective clinical evidence: chills/sweats; headache; myalgia; nausea/vomiting; or fatigue/malaise.
Laboratory criteria
Confirmatory laboratory evidence:
detection of Ehrlichia chaffeenis, Ehrlichia ewingii, Ehrlichia muris eauclairensis, unspeciated Ehrlichia spp., or other Ehrlichia spp. DNA in a clinical specimen via amplification of a specific target by PCR assay, NAAT, or other molecular testing; OR
serological evidence of a fourfold change in IgG-specific antibody titre to Ehrlichia spp. antigen by IFA in paired serum samples (one taken in the first 2 weeks after illness onset and a second taken 2-10 weeks after acute specimen collection); OR
demonstration of ehrlichial antigen in a biopsy or autopsy sample by immunohistochemical methods; OR
isolation of E chaffeenis, E ewingii, E muris eauclairensis, unspeciated Ehrlichia spp., or other Ehrlichia spp. from a clinical specimen in cell culture with molecular confirmation (e.g., PCR or sequencing).
Presumptive laboratory evidence:
serological evidence of raised IgG antibody reactive with Ehrlichia spp. antigen by IFA at a titre ≥1:128 in a sample taken within 60 days of illness onset; OR
microscopical identification of intracytoplasmic morulae in leukocytes in a sample taken within 60 days of illness onset.
Case classification
Suspect:
meets confirmatory or presumptive laboratory evidence with no or insufficient clinical information to classify as a confirmed or probable case (e.g., laboratory report only).
Probable:
meets presumptive laboratory evidence with fever (as reported by patient or healthcare provider) and at least one other objective or subjective clinical evidence criterion (excluding chills/sweats); OR
meets presumptive laboratory evidence without a reported fever but with chills/sweats and at least one objective clinical evidence criterion, or two other subjective clinical evidence criteria.
Confirmed:
meets confirmatory laboratory evidence and at least one of the objective or subjective clinical evidence criteria.
A person previously reported as a probable or confirmed case may be counted as a new case when there is an episode of a new clinically compatible illness with confirmatory laboratory evidence.
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