A CRISPR-Cas13 system based diagnostic tool for arboviruses

Abstract

The unpredictability of the emergence and re-emergence of arboviruses underscores the need for enhancing global preparedness in surveillance capacity for tracking and predicting the growth of arboviral epidemics and case-specific arboviral disease management. In particular, the development of a more advanced clinical diagnostic tool is important for low-resource countries with a higher chance of occurrence of new arboviral epidemics. Despite rapid improvements, the current diagnostic approaches still have limitations and are incapable of meeting the increasing demand for an ideal diagnostics for routine clinical diagnosis of arboviruses. Furthermore, the global incidence of common arboviruses like mosquito-borne dengue viruses (DENV) and Zika viruses (ZIKV) continues to increase dramatically over the years due to globalization, natural and demographic changes. The co-circulation of these arboviruses and different serotypes of the same arbovirus presenting similar clinical symptoms in the tropical regions of the world have further challenged the limits of current diagnostics. In addition to being a programmable gene-editing platform, the recent CRISPR-Cas system has demonstrated itself to be a promising diagnostic tool through its capability to directly detect viruses in clinical samples in an inexpensive, rapid, sensitive and specific manner. The SHERLOCK (specific high-sensitivity enzymatic reporter unlocking) platform exploits the CRISPR-Cas13 endonucleases system in prokaryotes. It has the unique ability to specifically cleave the target followed by subsequent non-specific cleavage of all transcripts in proximity of the target, known as collateral effects, which enables the system to detect the viral genome target upon amplification of the non-specific cleavage of reporter molecules in proximity of the target. This article will explore the currently approved molecular and serological diagnostic tools for arboviruses (specifically ZIKV and DENV) and compare them with the SHERLOCK platform by investigating their advantages and disadvantages in a clinical setting. This article will further explore the current potential and limitations of the SHERLOCK platform to be developed as a universal point-of-care test for arboviral infection, which may drastically change the future of diagnostics for infectious and non-infectious diseases.