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Test Catalog

Test ID: CHIKV    
Chikungunya IgM and IgG, Antibody, Serum

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

Aiding in the diagnosis of recent infection with Chikungunya virus in patients with recent travel to endemic areas and a compatible clinical syndrome

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

See Mosquito-borne Disease Laboratory Testing in Special Instructions.

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

Chikungunya virus (ChikV) is a single-stranded RNA alphavirus and a member of the Togaviridae family of viruses. The name Chikungunya is derived from the language of the Makonde ethnic groups in southeast Africa and means "that which bends" or "stooped walk." This is in reference to the hunched-over appearance of infected individuals due to the characteristically painful and incapacitating arthralgia caused by the virus. ChikV is endemic throughout Africa, India, and more recently the Caribbean islands. In 2014, the first case of autochthonous or local transmission in the United States occurred in Florida.

 

Humans are the primary reservoir for ChikV and Aedes species mosquitos are the primary vectors for transmission. Unlike other mosquito-borne viruses such as West Nile virus (WNV) and Dengue, the majority of individuals who are exposed to ChikV become symptomatic, with the most severe manifestations observed at the extremes of age and in those with suppressed immunity. Once exposed to ChikV, individuals develop lasting immunity and protection from reinfection.

 

Prior to development of symptoms, the incubation period ranges, on average, from 3 to 7 days. Infected patients typically present with sudden onset high fever, incapacitating joint pain, and often a maculopapular rash lasting anywhere from 3 to 10 days. Notably, symptom relapse can occur in some individuals 2 to 3 months following resolution of initial symptoms. Currently, there are no licensed vaccines and treatment is strictly supportive care.

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.

IgM: Negative

IgG: Negative

Reference values apply to all ages.

Interpretation Provides information to assist in interpretation of the test results

IgM and IgG Negative:

-No serologic evidence of exposure to Chikungunya virus. Repeat testing on a new specimen collected in 5 to 10 days is recommended if clinical suspicion persists.

 

IgM and IgG Positive:

-IgM and IgG antibodies to Chikungunya virus detected, suggesting recent or past infection. IgM antibodies to Chikungunya virus may remain detectable for 3 to 4 months post-infection.

 

IgM Positive, IgG Negative:

-IgM antibodies to Chikungunya virus detected, suggesting recent infection. Repeat testing in 5 to 10 days is recommended to demonstrate anti-Chikungunya virus IgG seroconversion to confirm current infection.

 

IgM Negative, IgG Positive:

-IgG antibodies to Chikungunya virus detected, suggesting past infection.

 

IgM and/or IgG Borderline:

-Repeat testing in 10 to 14 days is recommended.

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

Specimens collected too early following infection may be negative for antibodies to Chikungunya virus.

 

Chikungunya and Dengue viruses currently co-circulate in endemic areas and infections can present similarly in symptomatic patients. It is therefore recommended to evaluate at-risk patients for infection with both viruses.

Supportive Data

Accuracy:

IgM Antibodies to Chikungunya Virus:

Originally 87 serum samples tested by the Focus Diagnostics Inc. anti-Chikungunya virus IgM immunofluorescence assay (IFA) were also evaluated by the EuroImmun anti-Chikungunya virus IgM enzyme-linked immunofluorescence assay (ELISA) and the results are indicated below.

 

Comparison of the EuroImmun ChikV IgM ELISA and the Focus Diagnostics ChikV IgM IFA

 

Focus Diagnostics ChikV IgM IFA

Positive

Negative

EuroImmun ChikV IgM EIA

Positive

43

0

Negative

3

41

Borderline

0

0

 


 

Positive Agreement: 93.5 (43/46); 95% Confidence Index (CI): 81.9%-98.4%

Negative Agreement: 100% (41/41); 95% CI: 89.8%-100%

Overall Agreement: 96.6% (84/87); 95% CI: 89.9%-99.2%

 

IgG Antibodies to Chikungunya Virus:

Originally 101 serum samples tested by the Focus Diagnostics Inc. anti-Chikungunya virus IgG IFA were also evaluated by the EuroImmun anti-Chikungunya virus IgG ELISA and the results are indicated below.

 

Comparison of the EuroImmun ChikV IgG ELISA and the Focus Diagnostics ChikV IgG IFA

 

Focus Diagnostics ChikV IgG IFA

Positive

Negative

EuroImmun ChikV IgG EIA

Positive

39

2

Negative

7*

50

Borderline

0

3

 


 

*All 7 samples were positive by both the Focus and EuroImmun IgM assays. Also, 4 of 7 samples had low titers (< or =1:20) by the IFA assay.

Positive Agreement: 84.8 (39/46); 95% CI: 71.5%-92.7%

Negative Agreement: 90.9% (50/55); 95% CI: 80.0%-96.5%

Overall Agreement: 88.1% (89/101); 95% CI: 80.2%-93.2%

 

Reference Range:

Of serum samples collected from normal donors, 74/75 (98.7%) and 90/90 (100%) were negative by the EuroImmun anti-Chikungunya virus IgG and IgM assays, respectively.

 

Analytical Specificity:

1. Sixty serum samples previously characterized as positive for IgG-class antibodies to West Nile virus (n=29), Dengue virus (n=15), St. Louis encephalitis virus (n=8), California encephalitis virus (n=6), and Western equine encephalitis virus (n=2) were analyzed by the EuroImmun anti-Chikungunya virus IgG assay. One sample, positive for IgG antibodies to Dengue virus was also positive by the Chikungunya IgG assay, giving an overall specificity of 98.3% (59/60).

 

2. Thirty three serum samples previously characterized as positive for IgM-class antibodies to West Nile virus (n=8), Dengue virus (n=11), St. Louis encephalitis virus (n=6), California encephalitis virus (n=6), and Western equine encephalitis virus (n=2), were analyzed by the EuroImmun anti-Chikungunya virus IgM assay. Two samples, positive for IgM antibodies to Dengue virus were also positive by the Chikungunya IgM assay, giving an overall specificity of 93.9% (31/33).

 

Note: Dengue and Chikungunya virus cocirculate in endemic areas and are transmitted by the same mosquito genera, so the 3 specimens with antibodies to both viruses may indicate coinfection or past exposure to both viruses.

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

Pan American Health Organization. Preparedness and Response for Chikungunya virus. Introduction into the Americas. Washington, DC, PAHO 2011

Special Instructions Library of PDFs including pertinent information and forms related to the test