Sign in →

Test ID EHBAP Ehrlichia/Babesia Antibody Panel, Immunofluorescence, Serum


Advisory Information


This test may be nonreactive during the acute phase of the infection. For patients presenting with suspected acute infections of Ehrlichia chaffeensis or Anaplasma phagocytophilum, consider EHRL / Ehrlichia/Anaplasma, Molecular Detection, PCR, Blood.



Specimen Required


Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Specimen Volume: 0.6 mL


Useful For

As an adjunct in the diagnosis of infection with Anaplasma phagocytophilum, Ehrlichia chaffeensis or Babesia microti

 

Seroepidemiological surveys of the prevalence of the infection in certain populations

Profile Information

Test ID Reporting Name Available Separately Always Performed
ANAP Anaplasma phagocytophilum Ab, IgG,S Yes Yes
EHRC Ehrlichia Chaffeensis (HME) Ab, IgG Yes Yes
BABG Babesia microti IgG Ab, S Yes Yes

Testing Algorithm

See Acute Tick-Borne Disease Testing Algorithm in Special Instructions.

Method Name

Immunofluorescence Assay (IFA)

Reporting Name

Ehrlichia/Babesia Ab Panel, S, IFA

Specimen Type

Serum

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  14 days

Clinical Information

Anaplasma phagocytophilum:

Anaplasma phagocytophilum, an intracellular rickettsia-like bacterium, preferentially infects granulocytes and forms inclusion bodies, referred to as morulae. A phagocytophilum is transmitted by Ixodes species ticks, which also transmit Borrelia burgdorferi and Babesia species. Infection with A phagocytophilum is also referred to as human granulocytic anaplasmosis (HGA) and symptoms in otherwise healthy individuals are often mild and nonspecific, including fever, myalgia, arthralgia, and nausea. Clues to the diagnosis of anaplasmosis in a patient with an acute febrile illness after tick exposure include laboratory findings of leukopenia or thrombocytopenia and elevated liver enzymes. HGA is most prevalent in the upper Midwest and in other areas of the United States that are endemic for Lyme disease.

 

Ehrlichia chaffeensis:

Ehrlichia chaffeensis is an intracellular rickettsia-like bacterium that preferentially infects monocytes and is sequestered in parasitophorous vacuoles referred to as morulae. Infections with E chaffeensis are also referred to as human monocytotropic ehrlichiosis (HME). E chaffeensis is transmitted by Amblyomma species ticks, which are found throughout the southeastern and south central United States.

 

Babesia microti:

Many cases of HME are subclinical or mild; however, the infection can be severe and life-threatening, particularly in immunosuppressed individuals. Reported mortality rates range from 2% to 3%. Fever, fatigue, malaise, headache, and other "flu-like" symptoms occur most commonly. Leukopenia, thrombocytopenia, and elevated hepatic transaminases are frequent laboratory findings.

 

Babesiosis is a zoonotic infection caused by the protozoan parasite Babesia microti. The infection is acquired by contact with Ixodes ticks carrying the parasite. The deer mouse is the animal reservoir, and overall, the epidemiology of this infection is much like that of Lyme disease. Babesiosis is most prevalent in the Northeast, upper Midwest, and Pacific coast of the United States.

 

Infectious forms (sporozoites) are injected during tick bites and the organism enters the vascular system where it infects red blood cells (RBC). In this intraerythrocytic stage it becomes disseminated throughout the reticuloendothelial system. Asexual reproduction occurs in RBC, and daughter cells (merozoites) are formed, which are liberated on rupture (hemolysis) of the RBC.

 

Most cases of babesiosis are probably subclinical or mild, but the infection can be severe and life threatening, especially in older or asplenic patients. Fever, fatigue, malaise, headache, and other flu-like symptoms occur most commonly. In the most severe cases, hemolysis, acute respiratory distress syndrome, and shock may develop. Patients may have hepatomegaly and splenomegaly.

 

A serologic test can be used as an adjunct in the diagnosis and follow-up of babesiosis, when infection is chronic or persistent, or in seroepidemiologic surveys of the prevalence of the infection in certain populations. Babesiosis is usually diagnosed by observing the organisms in infected RBC on Giemsa-stained thin blood films of smeared peripheral blood. Serology may also be useful if the parasitemia is too low to detect or if the infection has cleared naturally or following treatment.

Reference Values

ANAPLASMA PHAGOCYTOPHILUM

<1:64

Reference values apply to all ages.

 

EHRLICHIA CHAFFEENSIS

<1:64

Reference values apply to all ages.

 

BABESIA MICROTI

<1:64

Reference values apply to all ages.

Interpretation

Anaplasma phagocytophilum:

A positive result of an immunofluorescence assay (IFA) test (titer ≥1:64) suggests current or previous infection with human granulocytic ehrlichiosis. In general, the higher the titer, the more likely it is that the patient has an active infection.

 

Seroconversion may also be demonstrated by a significant increase in IFA titers.

 

During the acute phase of the infection, serologic tests are often nonreactive, polymerase chain reaction (PCR) testing is available to aid in the diagnosis of these cases (see EHRL / Ehrlichia/Anaplasma, Molecular Detection, PCR, Blood).

 

Ehrlichia chaffeensis:

A positive immunofluorescence assay (titer ≥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.

 

Babesia microti:

A positive result of an indirect fluorescent antibody test (titer ≥1:64) suggests current or previous infection with Babesia microti. In general, the higher the titer, the more likely it is that the patient has an active infection. Patients with documented infections have usually had titers ranging from 1:320 to 1:2,560.

Clinical Reference

Centers for Disease Control and Prevention: Tickborne Diseases of the United States: A Reference Manual for Health Care Providers. 4th ed. Department of Health and Human Services; 2017

Day(s) and Time(s) Performed

Monday through Friday; 9 a.m.

Analytic Time

Same day/1 day

Test Classification

This test was developed using an analyte specific reagent. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

86666 x 2

86753

LOINC Code Information

Test ID Test Order Name Order LOINC Value
EHBAP Ehrlichia/Babesia Ab Panel, S, IFA In Process

 

Result ID Test Result Name Result LOINC Value
81157 Anaplasma phagocytophilum Ab, IgG,S 23877-4
81128 Babesia microti IgG Ab, S 16117-4
81478 Ehrlichia Chaffeensis (HME) Ab, IgG 47405-6