Fever as reported by the patient or a healthcare provider, AND at least one
of the following: rash, eschar, headache, myalgia, anemia, thrombocytopenia,
or any hepatic transaminase elevation (ALT or AST).
Laboratory Criteria
Confirmatory laboratory evidence:
A fourfold increase in IgG-specific antibody titers reactive with SFGR
antigen by IFA between paired serum specimens. Acute specimen taken within 2
weeks after illness onset, and second specimen 2-10 weeks after acute
specimen collection. (It is acceptable if the 4-fold rise in titer is in
acute and convalescent specimens collected within 2 weeks of one another.)
OR
Detection of R. rickettsii or other spotted fever group rickettsia
(SFGR) nucleic acid by PCR in a clinical specimen. OR
Isolation of SFGR from a clinical specimen in cell culture.
OR
Demonstration of SFGR antigen in a biopsy or autopsy specimen by
immunohistochemistry (IHC).
Presumptive laboratory evidence:
Elevated IgG antibody titer ≥:128 in a sample taken within 60 days of
illness onset. (This includes paired serum specimens without evidence
of fourfold rise in titer, but with at least one single titer
≥1:128.)
Supportive laboratory evidence:
CSTE has used this lab evidence to classify cases as suspects,
however, this criterion will not be used for spotted fever rickettsiosis
surveillance in Alabama.
Has serologic evidence of elevated IgG antibody at a titer <1:128
reactive with SFGR antigen by IFA in a sample taken
within 60 days of illness onset.
Case Classification
Confirmed: A clinically compatible case (meets clinical criteria)
with confirmatory laboratory evidence.
Probable: A clinically compatible case (meets clinical criteria)
that has presumptive laboratory evidence.
Suspect: (a) A case with confirmatory or presumptive laboratory
evidence of infection with no clinical information available, OR
CSTE has used this lab evidence to classify cases as suspects, however,
this criterion will not be used for spotted fever rickettsiosis surveillance
in Alabama.
(b) A clinically compatible case (meets clinical criteria)
that has supportive laboratory evidence.
Criteria to distinguish a new case of this disease or condition from
reports or notifications which should not be enumerated as a new case for
surveillance
A person previously reported as a probable or confirmed case-patient may be
counted as a new case-patient when there is an episode of new clinically
compatible illness and the person meets laboratory criteria of a Confirmed
case.