Molecular Diagnosis of congenital Cytomegalovirus (CMV) using Loop-Mediated Isothermal Amplification (LAMP) in oral swab samples from neonates in Panama

Background: Congenital cytomegalovirus (CMVc) infection constitutes one of the leading causes of hearing loss and neurodevelopmental delay during infancy. Identification of newborns with CMVc infection facilitates the provision of beneficial interventions. However, most neonates affected by CMVc infection present with a subclinical form of the disease and go undiagnosed. Therefore, it is increasingly recommended to perform expanded neonatal CMV testing. Saliva is presented as an attractive specimen type for newborn CMV testing, since it is easier to collect than urine and presents higher sensitivity for CMV detection than dried blood samples. Methods: We evaluated the Alethia CMV assay, an isothermal loop-mediated isothermal amplification method that is rapid and easy to use for the qualitative detection of CMV DNA in samples from neonatal saliva. Neonates less than one month old were tested using the Alethia assay according to the manufacturer's guidelines. Blood samples from the patients who tested positive in the qPCR test were also studied retrospectively. Result: a total of 200 prospectively collected saliva swabs, 40 (20%) patients tested positive in the Alethia assay, and only 14 could be tested confirmatory real-time PCR, where 9 of the 40 patients tested positive in both the Alethia assay and qPCR. Overall, the Alethia assay showed 99% positive and negative concordance, respectively, for the saliva sample. Conclusion: The Alethia CMV assay is an accurate method to identify neonates with CMVc infection and, given its simplicity, seems suitable for CMV testing.