Although the Zika virus was first identified in 1947, yet the once obscure virus came to the forefront due to the recently occurring outbreaks in tropical and subtropical America. It emerged as a rapidly spreading disease which was transmitted by mosquitos Aedes, typically in Brazil (Benelli and Mehlhorn, 2016). The World Health Community declared the spread of the virus as a public health emergency, when certain correlations in the areas affected by the virus and the instances of fetal microcephaly and Guillain Barre Syndrome on the rise were found (Calvet et al., 2016; Galindo-Fraga et al., 2015; Victora et al.
, 2016; WHO, 2016).A number of different strategies have been used for the detection of ZKV which include a diagnosis based on serological tests, such as MAC- ELISA (Zika IgM Antibody Capture Enzyme-linked Immunosorbent Assay). However, the major problem of this kind of diagnosis is cross-reactivity of similar flaviviruses such as Dengue or Chikungunya and sensitivity. Additionally, the detectable concentration of the IgM antibodies is not attained within 4 days following infection and therefore, it is deemed to be unsuitable for rapid and accurate early diagnosis of the viral infection (Priyamvada et al., 2016; Stettler et al.
, 2016).On the other hand, nucleic acid-based tests such as Trioplex real-time PCR have been listed as recommended methods for diagnosis as it can detect viral infection specifically within a few days of the onset of infection, but requires expensive equipment and is time-consuming (Baden et al, 2016).A paper-based technique developed by (Pardee et al.
, 2016) involves the novel synthetic biology in which programmable RNA sensors can be produced and embedded on paper to detect the clinically critical amount of viral RNA. The programmable RNA switches which are known as toehold switches can be designed to target theoretically any RNA sequence. It is termed as a riboregulator which controls the expression of an indicator protein by regressing the availability of the ribosome binding site and the start codon by forming a hairpin loop and resumes the expression upon the binding of the cognate target RNA which leads to the expression of the gene which can hence provide a colorimetric indication of expression and hence, the diagnosis (Green et al.
, 2014). Although, the toehold switch holds a promising output, yet it requires NASBA which requires hours to complete and hence, it is not considered suitable for on-site and rapid diagnosis (Cheng et al., 2017).Alternatively, RPA is a proprietary technology of TwistDx Inc.
This technique can help us detect and amplify the target nucleic acid in a resource limited field settings. It is suitable for point of care analysis with limited resources and hence, ideal for establishing a technique to be used in developing countries. The advantage of this technique is that it is rapid, sensitive, specific, can operate at a constant low temperature, high sample tolerance, broad applicability and multiplexing. It is an easily adaptable technique and has been used in diverse applications including diagnosis of infectious diseases, food contamination tests, identifying plant pathogens, water testing, microfluidics, etc.
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