Rapid detection of equine infectious anaemia virus nucleic acid by insulated isothermal RT‐PCR assay to aid diagnosis under field conditions

• DOI: 10.1111/evj.13032
• Publication Date: 2018-10-24T20:08:47Z
• Authors: R. F. Cook; M. Barrandeguy; P.‐Y. A. Lee; C.‐F. Tsai; Y.‐H. Shen; Y.‐L. Tsai; H.‐F. G. Chang; H.‐T. T. Wang; U. B. R. Balasuriya
• Keywords: Equine infectious anemia

Summary Background Control of equine infectious anaemia ( EIA ) currently depends on serological diagnosis infected equids. However, recently equids may not produce detectable anti‐ EIAV antibodies up to 157 days post infection and so present a high transmission risk. Therefore, direct nucleic acid detection methods are urgently needed improve surveillance management programs in counties where the disease is endemic. Objectives To evaluate field‐deployable, reverse transcription‐insulated isothermal PCR RT ‐ii assay targeting conserved 5′ untranslated region (5′ UTR )/exon 1 tat gene . Study design The analytical clinical performance newly developed was evaluated by comparison with real‐time RT‐PCR (RT‐qPCR) along AGID test. Methods Analytical sensitivity determined using vitro transcribed RNA containing target area / samples from two ‐positive horses. Specificity verified nine common viruses. Clinical ‐ qPCR derived 196 inapparent carrier Results did react other commonly encountered viruses had equivalent (95% limit eight genome equivalents), concordance 95.41% conventional sensitivities 43.75 50.00%, respectively, when compared Main limitations Low viral loads carriers diagnostic ‐based tests. Conclusions Although sufficiently sensitive replace current test, it can augment control efforts identifying exposed or “serologically silent” equids, particularly as latter often represent significant risk because loads. Furthermore, relatively low cost field‐deployable enable utilisation even remote regions.