A reverse transcription recombinase polymerase amplification (RT-RPA) assay was able to quickly and effectively identify chikungunya virus (CHIKV), according to a study published in PLOS Neglected Tropical Diseases.
Using chikungunya virus RNA samples, the RT-RPA assay detected down to 80 genome copies per reaction within 15 minutes, a time period four to six times faster than other molecular diagnostic techniques, such as reverse transcription-polymerase chain reaction (RT-PCR). In a sensitivity test involving all chikungunya serotypes and various alphaviruses, flaviviruses, and one phlebovirus, the RT-RPA assay identified all virus genotypes, with the only cross-reaction occurring with O’nyong’nyong virus.
CDC/Cynthia Goldsmith
In a test involving 58 plasma samples of suspected chikungunya fever from a trial in Thailand, two real-time RT-PCR tests identified 36 out of 58 samples (62%) as positive for chikungunya. The RT-RPA test successfully detected the virus in all 36 positive samples and did not detect the virus in any of the negative samples, giving a sensitivity and specificity of 100%.
“The CHIKV RPA assay presented here is a promising tool for CHIKV diagnostics at the point of need,” the investigators wrote. “Integration into a multimer or multiplex assay for simultaneous and differential detection of CHIKV, Dengue virus, and Zika virus, as well as an internal positive control would improve outbreak investigations, since the three viruses induce the same clinical picture upon infection and increasingly cocirculate in many parts of the world.”
Find the full study in PLOS Neglected Tropical Diseases (doi: 10.1371/journal.pntd.0004953).