Test Catalog

Test Id : ECHNG

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Echinococcus Antibody, IgG, Serum

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Detection of antibodies to Echinococcus species, including Echinococcus multilocularis and Echinococcus granulosus

Method Name
A short description of the method used to perform the test

Enzyme Immunoassay (EIA)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Echinococcus Ab, IgG, S

Aliases
Lists additional common names for a test, as an aid in searching

Alveolar echinococcal disease

Cystic echinococcal disease

Echinococcosis

Hydatic disease

Hydatiosis

Specimen Type
Describes the specimen type validated for testing

Serum

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into plastic vial.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.4 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia Reject
Heat-inactivated Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 30 days
Frozen 30 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Detection of antibodies to Echinococcus species, including Echinococcus multilocularis and Echinococcus granulosus

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Echinococcosis, also referred to as hydatidosis or hydatid disease, is 1 of the 17 neglected tropical diseases recognized by the World Health Organization and affects over 1 million people worldwide. Echinococcus species are tapeworms or cestodes, and 2 main species infect humans: Echinococcus granulosus and Echinococcus multilocularis.

 

With respect to geographic distribution, E granulosus can be found worldwide but, more frequently, is found in rural grazing areas where dogs may feed on infected sheep or cattle carcasses. E multilocularis is largely localized to the northern hemisphere. The definitive hosts for E granulosus are dogs or other canids, while the definitive host for E multilocularis are foxes and, to a much lesser extent, canids. Echinococcus tapeworms reside in the small intestine of definitive hosts and release eggs that are passed in the feces and ingested by an intermediate host, typically sheep or cattle in the case of E granulosus or small rodents for E multilocularis. The eggs hatch in the small bowel, releasing an oncosphere that penetrates the intestinal wall and migrates through the circulatory system to various organs where it develops into a cyst that gradually enlarges, producing protoscolices and daughter cysts, which fill the interior. The definitive host becomes infected following ingestion of these infectious cysts. Humans become accidentally infected following ingestion of Echinococcus eggs.

 

In humans, E granulosus (cystic echinococcal disease) cysts typically develop in the lungs and liver. The infection may remain silent or latent for years (5-20 years) prior to cyst enlargement and symptom manifestation. Symptomatic manifestations include chest pain, hemoptysis, and cough for pulmonary involvement and abdominal pain and biliary duct obstruction for liver infection. E multilocularis (alveolar echinococcal disease) infections manifest more rapidly than those of E granulosus and similarly to a rapidly growing, destructive tumor, resulting in abdominal pain and biliary obstruction. Rupture of cysts can produce fever, urticaria, and anaphylactic shock.

 

Diagnosis of echinococcal infections relies on characteristic findings by ultrasound or other imaging techniques and serologic findings. Fine-needle aspirates of cystic fluid may be performed; however, they carry the risk of cyst puncture and fluid leakage, potentially leading to severe allergic reactions. Importantly, infected individuals do not shed eggs in stool.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Negative

Reference values apply to all ages.

Interpretation
Provides information to assist in interpretation of the test results

Negative:

The absence of antibodies to Echinococcus species suggests that the individual has not been exposed to this cestode. A single negative result should not be used to rule out infection (see Cautions).

 

Equivocal:

Consider repeat testing on a new serum sample in 1 to 2 weeks.

 

Positive:

Results suggest infection with Echinococcus. False-positive results may occur in settings of infection with other helminths or in patients with chronic immune disorders. Results should be considered alongside other clinical findings (eg, characteristic findings on imaging) and exposure history.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Depending on cyst location, individuals may not develop high enough antibody titers to be detectable by serologic assays, leading to false-negative results. Cysts localized to the lungs, central nervous system, or spleen or cysts that are senescent, calcified, or dead are associated with lower serologic reactivity.

 

False-positive results may occur in patients with other helminth infections, including with Taenia species, Schistosoma species, and Strongyloides. Careful correlation with imaging findings and exposure history is required.

 

This assay may not detect antibodies to other species of Echinococcus, including Echinococcus vogeli and Echinococcus oligarthrus, both fairly uncommon causes of hydatid disease in humans.

Supportive Data

This assay is considered a modification from the FDA-cleared version due to extended specimen stability.

 

The Mayo Clinic Infectious Disease Serology laboratory evaluated the accuracy of the RidaScreen Echinococcus IgG enzyme-linked immunosorbent assay (ELISA) (as performed in our laboratory) using 58 serum samples previously tested by the serologic assays offered at Focus Diagnostics. A comparison of the result is shown in Table 1.

 

Table 1. Accuracy of the RIDASCREEN Echinococcus IgG assay compared to the Focus (Quest) Diagnostics assays

n = 58

Focus (Quest) Diagnostics ELISA/WB

Positive

Negative

RIDASCREEN

IgG ELISA

Positive

19

5

Negative

0

28

Equivocal

2

4

 

Positive agreement (95% CI): 90.5% (69.9-98.6)

Negative agreement (95% CI): 86.5% (71.6-94.6)

Overall agreement (95% CI): 87.9% (76.8-94.3)

 

The Mayo Clinic Infectious Disease Serology laboratory also evaluated the analytic specificity of the RidaScreen Echinococcus IgG ELISA by testing 36 serum samples positive for antibodies to other helminth and protozoa. The results are shown in Table 2.

 

Table 2. Analytical specificity studies

Specimen

Number of specimens tested

Number of specimens positive by the Echinococcus IgG ELISA

Entamoeba histolytica IgG Antibody (Ab)

6

1

Schistosoma mansoni IgG Ab

6

1

Strongyloides ratti IgG Ab

6

0

Taenia solium IgG Ab

6

4

Trichinella spiralis IgG Ab

6

0

Trypanosoma cruzi IgG Ab

6

0

 

The reference range for the RidaScreen Echinococcus IgG ELISA was evaluated by testing serum from 50 normal donors; 49/50 (98%) of healthy individuals were negative by this assay.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Agudelo Higuita NI, Brunetti E, McCloskey C: Cystic echinococcosis. J Clin Microbiol. 2016 Mar;54(3):518-523

2. Sarkari B, Rezaei Z: Immunodiagnosis of human hydatid disease: Where do we stand? World J Methodol. 2015 Dec 26;5(4):185-195

Method Description
Describes how the test is performed and provides a method-specific reference

Purified antigens are bonded to a microwell plate. Antibodies that are present in the patient samples attach themselves to the antigens and are determined during the second phase of the test by using enzyme-labeled antihuman antibodies (the conjugate). The enzyme converts the colorless substrate (urea peroxide/TMP) to a blue end product. The enzyme reaction is stopped by adding sulfuric acid. The color of the mixture then switches from blue to yellow. A final measurement is carried out in a photometer at 450 nm using a reference wavelength of 620 nm or more.(Package insert: RIDASCREEN Echinococcus IgG. R-Biopharm AG; 10/2015)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Tuesday, Thursday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

Same day/1 to 5 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

14 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been modified from the manufacturer's instructions. 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 US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

86682

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
ECHNG Echinococcus Ab, IgG, S 32171-1
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
ECHNG Echinococcus Ab, IgG, S 32171-1

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports

Test Update Resources

Change Type Effective Date
New Test 2023-01-26