How to Diagnose Chikungunya

The symptoms of chikungunya fever are similar to dengue fever and several other viral illnesses hence laboratory confirmation is critical to establish the diagnosis. If your doctor suspects chikungunya infection, tests to confirm the diagnosis may be recommended.

Laboratory tests for chikungunya fever: The laboratory tests used for diagnosing chikungunya fevers include:

• Virus isolation.
• Serological tests.
• Molecular technique of polymerase chain reaction (PCR).

In most cases, blood or serum is used as sample but in patients with neurological involvement (that is in cases of the meningo-encephalitic) CSF may also be sent as specimen.

Virus isolation: This is the most definitive test and it is performed on the blood sample. Recently, a reverse transcriptase, RT-PCR technique has also been used for diagnosing chikungunya virus (CHIK virus).

Serological diagnosis: For serological diagnosis, paired blood samples are obtained. One sample is taken immediately after the onset of illness and the second sample (that is the convalescent phase sample) is taken 10-14 days later. A fourfold rise in antibody titre in acute and convalescent sera (fourfold increase in CHIK IgG titer) or presence of IgM antibodies specific for CHIK virus indicates a positive test. The results are available within 2-3 days. As in many cases paired sera is not obtained, demonstration of IgM antibodies specific for chikungunya virus in acute-phase sera is considered diagnostic for infection with chikungunya virus.

Proper collection, processing, storage and transportation of the specimens are important during testing of sample for infection with chikungunya virus in any patient.

Read more articles on Understand Chikungunya.