A rational approach to identifying newborns with hearing loss caused by congenital cytomegalovirus infection by dried blood spot screening

Abstract

Objective: Congenital cytomegalovirus (cCMV) infection is the most common congenital infection, with the majority of infected newborns having no detectable signs. The aim of this study was to examine the accuracy of our newly developed DBS-based assay as an appropriate mass screening method for cCMV infection.

Methods: Between May 2011 and October 2016, newborns delivered at six hospitals in Nagano Prefecture, Japan were enrolled prospectively. We employed dried blood spot (DBS)-based assays with real-time quantitative PCR (qPCR).

Results: Prior to the clinical study, confirmation analysis was carried out using positive and negative controls. The sensitivity and specificity of this DBS-based qPCR assay for the detection of CMV DNA were 83 and 97%, respectively. During the study period, 9675 newborns were enrolled. The total recovery rate of DBS was 99.92% (9,667/9,675). From our analysis of the 9,667 samples, 47 DBS samples were found positive by the qPCR test (0.48%), and 9620 (99.5%) DBS samples were CMV-negative.

Conclusions: The risk of neural disorders associated with cCMV infection is thought likely to increase with CMV viral load in the blood. DBS screening for cCMV may be sufficient in a clinical setting, and offers a realistic and feasible option for universal mass screening.

Chinese abstract

目的：先天性巨细胞病毒（cCMV）感染是最常见的先天性感染, 大多数感染的新生儿都无可检测体征。这项研究的目的是检测我们新开发的以DBS为基础的检测方法的准确性, 这是一种合适的cCMV感染的群体筛选方法。

方法：2011年5月至2016年10月期间, 对在日本长野县的六家医院分娩的新生儿进行了前瞻性注册。我们采用了具实时定量PCR（qPCR）的以干血斑（DBS）为基础的检测方法。

结果：在临床研究之前, 用阳性和阴性对照进行了确认分析。这种用于检测CMV 染色体的基于DBS的qPCR测定法 的灵敏度和特异性分别为83％和97％。在研究期间, 有9675名新生儿参与。DBS的总回收率为99.92％（9,667/9,675）。从我们对9,667个样本的分析中, 47个DBS样本通过qPCR检测发现为阳性（0.48％）, 9620个（99.5％）DBS样本为CMV阴性。

结论：认为与cCMV感染相关的神经疾病的风险可能随着血液中CMV病毒载量的增加而增加。 DBS筛查cCMV在临床上可能足够有效, 为广泛的大规模筛查提供了一种切实可行的选择。

Keywords:

• Congenital cytomegalovirus infection
• hearing loss
• screening
• dried blood spot

Acknowledgements

We would like to thank to the following pediatricians and gynecologists for providing the DBS cards and patient/parent care: Dr. Yukihide Miyosawa (Shinshu University Hospital), Dr. Takenori Natsume, Dr. Tetsuo Kubo and Dr. Ryosuke Osada (Hokushin General Hospital), Dr. Fumio Morohashi and Dr. Kaoru Kimura (Shinonoi General Hospital), Dr. Shigeto Kato and Dr. Isao Shiozawa (Matsumoto City Hospital), Dr. Atsushi Baba and Dr. Yasushi Takagi (Suwa Red-cross Hospital), and Dr. Setsuko Nakata, Dr. Yosuke Shima and Dr. Teruyuki Yamazaki (Iida Municipal Hospital). We would also like to thank the following lab technicians for their contributions: Ms. Yurika Ito, Ms. Tomomi Tanoue, Mr. Tetsuya Yamamoto and Ms. Saori Nomura.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by a Health Labour Sciences Research Grant from the Ministry of Health, Labour and Welfare, and a Shinshu University Hospital Grant-in-Aid for Medical Research.