Automated NeuMoDx Mpox Assay Differentiates Clade I from Clade II with 99% Sensitivity
A multicenter evaluation across three US and European sites validated the NeuMoDx MPXV real-time PCR assay on 296 clinical samples, achieving 99.2% sensitivity and 96.6% specificity for lesion swabs. The fully automated assay consolidates extraction, amplification, and interpretation while differentiating MPXV clade I from clade II, a critical capability given clade I's regulated status. With analytical sensitivity of 50 copies/mL and verified inclusivity across over 5,000 genomes, the platform addresses current laboratory workflow and biosafety needs.
The original study
Multi-center evaluation of the Research Use Only NeuMoDx monkeypox virus (MPXV) fully automated real-time PCR assay.
- Authors
- Mostafa HH, Wall G, Su S-C, Hysa G, Gong L, Dadjeu UC, et al.
- Journal
- Journal of clinical microbiology
- Type
- Journal Article, Evaluation Study, Multicenter Study, Research Support, Non-U.S. Gov't
- PMID
- 38639489
Original abstract
UNLABELLED: The mpox outbreak, caused by monkeypox virus (MPXV), accelerated the development of molecular diagnostics. In this study, we detail the evaluation of the Research Use Only (RUO) NeuMoDx MPXV assay by multiple European and US sites. The assay was designed and developed by Qiagen for the NeuMoDx Molecular Systems. Primers and probes were tested for specificity and inclusivity in silico. The analytical sensitivity of the assay was determined by testing dilutions of synthetic and genomic MPXV DNA. A total of 296 clinical samples were tested by three sites; the Johns Hopkins University (US), UZ Gent (Belgium, Europe), and Hospital Universitario San Cecilio (Spain, Europe). The analytical sensitivity of the assay was 50 copies/mL for both clades I and II. The assay showed 100% in silico identity for 80 clade I and 99.98% in silico identity for 5,162 clade II genomes. Clade II primers and probes showed 100% in silico specificity; however, identity of at least one of the two sets of clade I primers and probes with variola, cowpox, camelpox, and vaccinia viruses was noticed. The clinical validation showed sensitivity of 99.21% [95% confidence interval (CI): 95.66-99.98%] and specificity of 96.64% (95% CI: 91.62-99.08%) for lesion swab samples. The NeuMoDx MPXV Test shows acceptable analytical and clinical performance. The assay improves the laboratory's workflow as it consolidates nucleic acid extraction, PCR, data analysis, and interpretation and can be interfaced. The Test Strip can differentiate clades I and II, which has important laboratory safety implications. IMPORTANCE: In this manuscript, we provide detailed in silico analysis and clinical evaluation of the assay using a large cohort of clinical samples across three academic centers in Europe and the United States. Because the assay differentiates MPXV clades I and II, this manuscript is timely due to the current need to rule out the regulated clade I by diagnostic clinical laboratories. In December 2023, and due to first report of cases of sexually transmitted clade I infections in the Democratic Republic of the Congo, when generic assays that do not differentiate the clades are used, samples are considered regulated. The assay meets the need of full automation and has a marked positive impact on the laboratory workflow.