A Multiplexed, Low Cost, Cellphone-Based System For Ebola And Marburg Disease Surveillance

Background: The aim of the study is to develop a low cost system for studying antibody responses to Ebola and Marburg infection for surveillance purposes. There are no serological assays that are available in common clinical practice for detection of filovirus antibody responses. Most experimental methods are capable of only measuring antibodies against one or two of the five species of Ebola and Marburg viruses that cause human disease. The developed system included a flow cell assay cartridge that captures specific antibodies with microarrayed recombinant antigens from all six species of filovirus, and a cellphone-based fluorescent reader for high-performance interpretation of test results. Methods and materials: The first phase of the project focused on the development a prototype flow cell cartridge containing Glycoproteins and Nucleoproteins from all six species of filovirus family arrayed on a nitrocellulose coated membrane. An opto-electro-mechanical hardware attachment that snaps at the back of a Motorola Nexus cellphone provided the user interface to manage the operation. The App acquired the test results and communicated with cloud service to report results remotely. The App also controlled the hardware attachment to turn on LEDs and digitally record the optically enhanced images. Results: The prototype system was validated with sera from non-human primates that received a live attenuated EBOV vaccine. The system clearly distinguished between sera that contained anti-EBOV antibodies and non-vaccinated controls. The second phase of the project improved on the prototype system and consists of a sealed single use assay cartridge, and a reader that designed to work with most cellphones through an App. The cartridge features plasma separation from a drop of blood, storage of heat-stable on-board dried secondary reagent, a mixing pathway, and a fluorescent signal chamber where the capture antigens are printed. The independent reader setup utilizes a dedicated imaging sensor for better control and transmits the image to cellphone through Bluetooth for user interface and data analysis. Conclusion: This disease-telemonitoring system will be useful in the laboratory analysis of recent or active infections, and may prevent the rapid overwhelming of medical systems and resources during EVD or MVD outbreaks.