Ehrlichia chaffeensis (HME) Antibody, IgG (Sendout)

Useful For:

• An adjunct in the diagnosis of ehrlichiosis

• Seroepidemiological surveys of the prevalence of the infection in certain populations

Testing Algorithm:

• Mayo Acute Tick-Borne Disease Testing Algorithm

Reference Values: <1:64

Interpretation:

A positive immunofluorescence assay (titer > or =1:64) suggests current or previous infection. In general, the higher the titer, the more likely the patient has an active infection. Four-fold rises in titer also indicate active infection.

Previous episodes of ehrlichiosis may produce a positive serology although antibody levels decline significantly during the year following infection.

Cautions:

Serology for IgG may be negative during the acute phase of infection (<7 days post-symptom onset), during which time detection using targeted nucleic acid amplification testing (eg, polymerase chain reaction: PCR) is recommended.

Detectable IgG-class antibodies typically appear within 7 to 10 days post-symptom onset.

IgG-class antibodies may remain detectable for months to years following prior infection. Therefore, a single time point-positive titer needs to be interpreted alongside other findings to differentiate recent versus past infection.

Other members of the Ehrlichia genus (eg, Ehrlichia ewingii) may not be detected by this assay.

Outside Laboratories: Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.

Stability: Refrigerated (preferred): 14 days; Frozen: 14 days; Ambient: Unacceptable.

Reject Due To: Gross hemolysis, gross lipemia, gross icterus, heat-inactivated specimen.

Centrifuge sample and transfer serum to a separate plastic vial. Refrigerate serum.

Login: SPMSND-;REFRIG

• MSNDTO: MAYOSD
• MSPTYP: SERUM
• MTSTRQ: ;Ehrlichia Chaffeensis Antibody, IgG (Mayo Test EHRC)

Sendouts:

• Order Mayo Test: EHRC.

Stability: Refrigerated (preferred): 14 days; Frozen: 14 days; Ambient: Unacceptable.

Reject Due To: Gross hemolysis, gross lipemia, gross icterus, heat-inactivated specimen.