INTENDED USE

The Chikungunya IgM Rapid Test is a lateral flow chromatographic immunoassay for the qualitative detection of Chikungunya virus IgM antibody in human serum ,plasma or whole blood. It is intended to be used as a screening test and as an aid in the diagnosis of infection with Chikungunya viruses. Any reactive specimen with the Chikungunya IgM Rapid Test must be confirmed with alternative testing method(s) and clinical findings.

SUMMARY AND EXPLANATION THE TEST

Chikungunya is a rare viral infection transmitted by the bite of an infected Aedes aegypti mosquito. It is characterized by a rash, fever, and severe joint pain (arthralgias) that usually lasts for three to seven days. The name is derived from the Makonde word meaning “that which bends up” in reference to the stooped posture developed as a result of the arthritic symptoms of the disease. It occurs during the rainy season in tropical areas of the world, primarily in Africa, South-East Asia, southern India and Pakistan. The symptoms are most often clinically indistinguishable form those observed in dengue fever. Indeed, dual infection of dengue and chikungunya has been reported in India. Unlike dengue, hemorrhagic manifestations are relatively rare and most often the disease is a self limiting febrile illness. Therefore it is very important to clinically distinguish dengue from CHIK infection. CHIK is diagnosed based on serological analysis and viral isolation in mice or tissue culture. An IgM immunoassay is the most practical lab test method. The Chikungunya IgM Rapid Test utilizes recombinant antigens derived from its structure protein5, it detects IgG/IgM anti-CHIK in patient serum or plasma within 20 minutes. The test can be performed by untrained or minimally skilled personnel, without cumbersome laboratory equipment.

PRINCIPLE

The Chikungunya IgM Rapid Test is a lateral flow chromatographic immunoassay. The test cassette consists of: 1) a burgundy colored conjugate pad containing Chikungunya recombinant envelope antigens conjugated with colloid gold (dengue conjugates) and rabbit IgG-gold conjugates,2) a nitrocellulose membrane strip containing test band (T band) and a control band (C band). The T band is coated with antibody for the detection of IgM anti-Chikungunya virus, and the C band is pre-coated with goat anti rabbit IgG.

When an adequate volume of test specimen is dispensed into the sample well of the test cassette, the specimen migrates by capillary action across the cassette. IgM anti-Chikungunya virus, if present in the specimen, will bind to the Chikungunya conjugates. The immunocomplex is then captured by the reagent pre-coated on the M band, forming a burgundy colored M band, indicating a Chikungunya virus IgM positive test result and suggesting a fresh infection. Absence of any test band (T) suggests a negative result.The test contains an internal control (C band) which should exhibit a burgundy colored band of the immunocomplex of goat anti rabbit IgG/rabbit IgG-gold conjugate regardless of the color development on any of the T bands. Otherwise, the test result is invalid and the specimen must be retested with another device.