Rapid, Near Patient Nucleic Acid Testing for Congenital Cytomegalovirus (CMV) Infection

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ABSTRACT Rapid, Near Patient Nucleic Acid Testing for Congenital Cytomegalovirus (CMV) Infection PA-14-088 (Direct to Phase II) Universal newborn hearing screening is mandated in the United States and is performed in the postpartum hospital setting. Current physiology-based hearing tests are unable to detect late-onset infantile hearing loss caused by congenital cytomegalovirus (CMV) infection. Antiviral treatment can ameliorate CMV-associated infant hearing loss if initiated quickly after birth; a complementary screening approach has therefore been suggested to identify newborns with congenital CMV infection in order to facilitate early detection and intervention and prevent CMV-related hearing loss and developmental delays. A nucleic acid test has been described to screen newborns for congenital CMV infection using saliva specimens that is more sensitive than the dried blood spots traditionally used by the newborn screening laboratories. Despite the existence of such a test, public newborn screening programs do not have the infrastructure necessary to test newborn saliva samples. Baebies' mission is to save the lives of newborns by bringing new tests to newborn screening. To address the current challenges to implementing CMV screening, Baebies developed and successfully tested a nucleic acid assay for CMV on a laboratory-based digital microfluidic platform. To bypass the limitations inherent to newborn screening laboratories and bring this assay to hospitals and birthing centers, we will add functionality to our near patient testing instrument to enable single sample molecular testing via PCR. We previously designed an on-cartridge PCR assay to test for CMV by fully integrating sample preparation and PCR on the same cartridge for the detection of CMV using digital microfluidic technology. With this assay, we are able to detect as few as 5 copies of CMV in 50 µL. Our system was challenged with 200 de-identified and archived saliva samples; these samples and the results were compared to the standard PCR assay for CMV. We successfully detected 15/17 positive CMV samples. We improved the sensitivity of the assay and again challenged our system with 130 prospectively collected saliva samples from newborns born at the University of Alabama at Birmingham (UAB); all the samples were identified correctly. In this Direct to Phase II project, we will expand upon our existing work by developing new technology including on-cartridge heaters and dried reagents that would enable our FINDER platform to perform CMV testing in a hospital or clinic setting using single use cartridges and readily obtainable saliva samples. The FINDER instrument is in the final stages of development for single sample biochemical newborn screening. Once the technology is developed, we will improve DNA extraction efficiency, further reduce time to results, and perform an analytical validation of the assay. We will then perform a small method comparison study using 250 retrospective and prospectively collected neonatal saliva samples at each of two sites (UAB and Duke University). A near patient newborn screening platform for combined biochemical and molecular testing has the ability to introduce new targeted and universal single sample tests for newborn screening.