Diagnostic Testing

Chikungunya virus infection should be considered in patients with acute onset of fever and polyarthralgia, especially travelers who recently returned from areas with known virus transmission.

Laboratory diagnosis is generally accomplished by testing serum or plasma to detect virus, viral nucleic acid, or virus-specific immunoglobulin (Ig) M and neutralizing antibodies. Viral culture may detect virus in the first 3 days of illness; however, chikungunya virus should be handled under biosafety level (BSL) 3 conditions. During the first 8 days of illness, chikungunya viral RNA can often be identified in serum. Chikungunya virus antibodies normally develop toward the end of the first week of illness. Therefore, to definitively rule out the diagnosis, convalescent-phase samples should be obtained from patients whose acute-phase samples test negative.

What type of tube should I collect blood in?

The best type of tube is serum separator (typically tiger/speckled-top). The blood should be allowed to coagulate and tubes should be spun to separate the serum from the clot prior to shipping.

If a red-top is used (no additive), the blood must be allowed to coagulate, the tube centrifuged, and the serum drawn off into a clean tube prior to shipping. Heparin (green top) and EDTA (purple top) are unsuitable for CHIK testing.

Where and how should I send the samples to CDC?

Please refer to the instructions for sending diagnostic specimens to CDC, which also includes detailed instructions for completing the on-line CDC specimen submission form 50.34 [PDF – 2.5 MB].

Please note: because chikungunya virus testing is not listed in the drop-down menu for the Test Order Name field of form 50.34 (located on 1st page, top left), you will need to select “ARBOVIRUS SEROLOGY” and then type “CHIK testing” in the Brief Clinical Summary field located at the top of the second page of the form

When will results be available?

Test results are normally available 4 to 14 days after specimen receipt. Reporting times for test results may be longer during summer months when arbovirus activity increases. Receipt of a hard copy of the results will take at least 2 weeks after testing is completed. Initial serological testing will be performed using IgM-capture ELISA and IgG ELISA. If the initial results are positive, further confirmatory testing will be performed and it may delay the reporting of final results. ALL RESULTS WILL BE SENT TO THE APPROPRIATE STATE HEALTH DEPARTMENT. Notify your state health department of any direct submissions to CDC.