Laser scanning optical investigations of dengue virus infection from antibody fluorescence of human blood

Abstract

Dengue is the most important arthropod-borne viral disease of public health significance today, and the geographic distribution includes more than 100 countries worldwide. A definite diagnosis of dengue virus infection is based on clinical criteria supported by antibody tests of whole blood. In this study, we report on dengue infected whole blood diagnostics using laser scanning confocal microscopy (LSCM) over a laser excitation of 488, 543 and 633 nm wavelengths. Based on our findings, the system has potential applications in the detection and quantification of dengue virus infected cells, antigens and antibodies in blood in vitro. Analysis of about 100 infected patients shows that the primary organism (or pathogen), characteristic of dengue infection, causes a significant biochemical change in the nature of human blood in which it resides, and, due to which, fluorescence increases in dengue samples. Thus, the use of a reliable and sensitive rapid diagnostic test using LSCM can simultaneously detect the presence of anti-dengue IgG and IgM antibodies, which is a breakthrough in diagnosis and of great clinical use. The antibodies for dengue continue to be distinguishable for a couple of months after infection. This change in blood fluorescence may be a significant contribution from light scattering through antibodies produced against the dengue antigen.