Serum

Parallel testing is preferred and convalescent specimens must be received within 30 days from receipt of the acute specimens. Mark specimens plainly as acute or convalescent.

Preferred Minimum: 1 mL serum
Absolute Minimum: 0.3 mL serum

Contaminated, hemolyzed, or severely lipemic specimens.

1-5 days upon receipt at reference laboratory

Ehrlichia chaffeensis Antibody, IgG by IFA:
< 1:64  Negative-No significant level of Ehrlichia chaffeensis
  IgG antibody detected.
1:64-​1:128  Equivocal-Questionable presence of Ehrlichia chaffeensis
  IgG antibody detected.  Repeat testing in 10-​14 days may be helpful.
≥1:256  Positive-​Presence of IgG antibody to Ehrlichia chaffeensis
  detected, suggestive of current or past infection.

Ehrlichia chaffeensis Antibody, IgM by IFA:
< 1:16  Negative-​No significant level of Ehrlichia chaffeensis
  IgM antibody detected.
≥ 1:16  Positive-​Presence of IgM antibody to Ehrlichia chaffeensis
  detected, suggestive of current or recent infection.

Anaplasma phagocytophilum (HGA) Antibody, IgG:
Less than 1:80 - No significant level of IgG antibodies to
  A. phagocytophilum detected.
Greater than or equal to 1:80 - Suggestive of a recent or past
  infection with A. phagocytophilum

Anaplasma phagocytophilum (HGA) Antibody, IgM:
Less than 1:16 - No significant level of IgM antibodies to
  A. phagocytophilum detected.
Greater than or equal to 1:16 - Suggestive of a current or recent
  infection with A. phagocytophilum.

Human ehrlichiosis is a tick-borne disease caused by rickettsial-like agents. Two forms, human monocytic ehrlichiosis (HME) and human granulocytic ehrlichiosis (HGE), have been described. HME is often referred to as "spotless" or rashless Rocky Mountain spotted fever, and has been reported in various regions of the United States. The causative agent of HME has been identified as Ehrlichia chaffeensis. Infected individuals produce specific antibodies to Ehrlichia chaffeensis which can be detected by an immunofluorescent antibody (IFA) test.

Acceptable test for acute or convalescent phase of infection from Anaplasma phagocytophilium. May be useful when PCR testing is not an option (eg, outside the 2 week window for acute phase). However, PCR testing is generally preferred; refer to Tick-Borne Disease Panel by PCR, Blood or Ehrlichia and Anaplasma Species by Real-Time PCR.

Semi-Quantitative Indirect Fluorescent Antibody

Ehrlichia Chaffeensis 86666 x2
Anaplasma 86666 x2

See also:
Ehrlichia and Anaplasma Species PCR, Whole Blood