Establishment of one-step SYBR green-based real time-PCR assay for rapid detection and quantification of chikungunya virus infection

Chikungunya virus disease or chikungunya fever, is a viral disease transmitted to humans by the bite of infected Aedes_aegypti (yellow fever mosquito) and Aedes albopictus (tiger mosquito) [1]. Chikungunya virus (CHIKV) is a member of the genus alphavirus, in the family Togaviridae [2]. CHIKV contains a non-segmented monomeric, positive-sense RNA genome that is approximately 12 Kb. CHIKV genome is arranged in the order of 5' cap-nsP1-nsP2-nsP3-nsP4-(junction region)-C-E3-E2-6K-E1-poly(A)3' where nsP1 is RNA-capping enzyme, nsP2 contains the protease, triphosphatase, NTPase and helicase, nsP3's function is currently unknown and nsP4 contains RNA dependant RNA polymerase. The capsid (C) forms the nucleocapsid that enclosed the viral RNA and E1, E2 as well as E3 encodes for the envelope protein of the virus [2].CHIKV was first isolated from the blood of a febrile patient in Tanzania in 1953 [3,4], and has since been identified repeatedly in west, central and southern Africa and many areas of Asia, and has been cited as the cause of numerous human epidemics in those areas since that time [5].CHIKV produces an illness in humans that is often characterized by a sudden onset of fever, headache, fatigue, nausea, vomiting, rash, myalgia, and severe arthralgia (joints pain) [6]. Symptoms are generally self-limiting and last 1 to 10 days. However, arthralgia may persist for months or years [7]. These clinical symptoms mimic those of dengue fever and malaria, and therefore, many cases of Chikungunya fever are misdiagnosed as dengue virus infections [8]. At present, there is no vaccine or anti-viral therapy available against CHIKV infection, but analgesics and anti-inflammation medication are usually used to reduce the swelling and pain.Routine assays for the detection and quantification of CHIKV are essential tools in research areas addressing the replication biology of CHIKV, clinical diagnostic applications and the development of effective anti-viral strategies. Virus isolati