A Low-Cost Tool to Rapidly Detect Dengue Virus in the Field
Abstract
Overview: In this proposal, chemical chain reactions will be used instead of PCR reactions to amplify a detectable signal. This signal will react with a pH-sensitive dye to produce a visual signal, which can be used to develop an equipment-free, rapid-diagnostic, low-cost, high-sensitivity and high-specificity tool for detection of four dengue virus serotypes in the field. Dengue is the most rapidly spreading endemic viral disease in the world and threatens the health of US military personnel. Dengue virus infection can cause a severe systemic disease and result in a fatality rate as high as 10% in one week without proper treatment. To date, no specific drug or vaccine against dengue virus has been successfully developed. However, the early recognition of dengue virus and proper treatment reduce the fatality rate to lower than 1%. Thus, early detection of dengue infection is extremely important to cure patients and prevent the spread of the epidemic in US troops and the civilian population. A diagnosis of dengue virus infection based only on clinical syndromes is not reliable, since these syndromes are non-specific. To confirm the dengue infection, a laboratory diagnosis is required. However, most current laboratory diagnostic methods that detect the whole virus, antigens and/or antibodies, or viral RNA are costly and time-consuming. More importantly, these methods require equipment in a laboratory setting and are not suitable for use in the field for US troops. Recently, a rapid diagnostic test (RDT) has been reported to simultaneously detect an antigen and an antibody of dengue virus. However, its sensitivity and specificity were very low in one clinical trial and it is non-specific to dengue virus serotypes. Therefore, development of a field-based diagnostic to allow for rapid identification of four dengue virus serotypes with high sensitivity and high specificity is essential for Soldiers exposed to the dengue virus. Reverse transcriptase PCR (RT-PCR)-based detection, which targets the dengue virus RNA, is a highly efficient diagnostic method for all of dengue virus serotypes. However, a RT-PCR reaction requires 2-3 enzymes, more than 2 oligonucleotide primers, 4-8 kinds of nucleotides, and several associated materials to amplify a >100-nucleotide-length RNA/DNA for detection. It is a costly, time-consuming, and equipment-requiring method, which is not suitable for use in the field. This proposal will develop a series of enzyme-triggered chemical chain reactions to amplify a detectable signal (proton). This proton signal has the simplest structure and is produced two copies in one rapid chemical reaction. Thus, it is much faster to amplify the proton than to amplify the RNA/DNA molecules, which requires more than 100 steps for one copy. In addition, these chemical reactions require two small molecules and will be finished at room temperature without additional equipment. These are low-cost and equipment-free reactions. Furthermore, this proton signal will generate many more copies than RNA/DNA and react with a pH-sensitive dye to produce a visual signal, which will have a higher sensitivity than traditional RT-PCR-based detection. Finally, a paper strip will be used as a platform to couple four DNA capture probes for dengue virus RNA binding and detection. The novel dengue virus detection tool on the paper strip should be easy to store, easy to carry, and easy to use in the field. Since the capture and detection probes in this novel tool are same as those used for RT-PCR based detection methods. The specificity of this method should be same as RT-PCR methods, which have more than 95% accuracy for diagnosis of four dengue virus serotypes. This low-cost, rapid-diagnostic, high-sensitivity, high-specificity, and equipment-free tool should be suitable to diagnose four dengue virus serotypes in the field for US troops. It is also suitable to be used for the civilian population to diagnose deng
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 31, 2017
- Source ID
- W81XWH1610141
Entities
People
- Shengxi Chen
Organizations
- Arizona State University
- United States Army