2131. Performance of Dried Blood Spot (DBS) for the Diagnosis of Congenital Cytomegalovirus (cCMV) in a Single Center: A Real-World Experience


 
 
 The newborn DBS has been used for the retrospective diagnosis as well as a screening method for cCMV. We aimed to assess the sensitivity and specificity of this test compared to traditional methods, for the diagnosis of children suspected to have cCMV in the first 21 DOL.
 
 
 
 In this single-center retrospective cohort study, all patients (N= 304) with a request for DBS testing between 2013 and 2021 were reviewed. Those with a DBS available for testing, a medical record at our institution, and at least one diagnostic test for cCMV obtained within the first 21 days of life (DOL) were included for review (N=86).
 DBS were requested from the Texas State Health Department and sent to the Center for Disease Control for testing by DNA CMV PCR.
 DBS results were compared to patients whose diagnoses were made via traditional testing with at least one accepted method (urine culture, urine PCR, blood PCR and/or saliva culture) obtained within the first 21 DOL. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated.
 
 
 
 Of the 86 patients included, 59 had a diagnosis of cCMV established by conventional testing, with 50 of them having a positive DBS and 9 a negative result. DBS had a sensitivity of 84.7%, specificity of 100 %, positive predictive value of 100 % and a negative predictive value of 75%.
 Those patients with a true positive DBS had a higher median level of viremia by CMV blood PCR (6487 IU/ml vs 471 IU/ml, p= 0.012) when compared to those with a false negative result.
 All patients with cCMV and congenital hearing loss had a positive DBS (N=15). A significant difference was noted in the median viremia levels of those patients with cCMV with congenital hearing loss vs those with cCMV without congenital hearing loss (17,547 IU/ml vs 3,175 IU/ml, p=0.012)
 Of those cCMV patients that developed late onset hearing loss (N=9), 8 had a true positive DBS and 1 had a false negative result.
 
 
 
 DBS could be useful in the diagnosis of cCMV, and its performance may be related to the level of CMV viremia at birth. DBS appears to be able to accurately identify those patients with congenital hearing loss and those who will develop late onset hearing loss. Future studies are needed to determine the best population that can be identified by this test.
 
 
 
 Ryan H. Rochat, MD, PhD, MS, Merck Sharpe & Dohme: Grant/Research Support Jerry A. Miller, MS, PhD, CPH, Merck: Grant/Research Support Gail J. Demmler-Harrison, MD, Elsevier: Book royalties|Merck: Grant/Research Support|Microgen: Advisor/Consultant|Microgen: Grant/Research Support|Moderna: Advisor/Consultant|UpToDate Wolters Kluwer Health: Royalties.
