Construction of Lentivirus-Based Reference Material for RT-PCR Detection of Middle East Respiratory Syndrome Coronavirus and Its Application in External Quality Assessment.

Nucleic acid amplification technology (NAT) has been the most used one for rapid detection of Middle East Respiratory Syndrome coronavirus (MERS-CoV) since MERS-CoV was first detected in 2012. It is important to develop stable and safe reference materials for assessing the quality of NAT kits and performing an external quality assessment (EQA) in different laboratories. In this study, the MERS-CoV RNA fragments including upE, ORF1b, and N were packed within human immunodeficiency virus type 1 (HIV-1)-like particles. The lyophilized virus-like particles (VLPs) were found to be stable at 37 °C or below and safe to be used not only as the control material for PCR detection of MERS-CoV but also as the reference material for EQA. In an EQA organized by Ningbo International Travel Healthcare Center in China, 49 participating institutions achieved 100% agreement in detecting MERS-CoV using various commercial diagnosis kits and different extraction methods. However, different Ct values reported by different sites for the same sample implied that a need exists to standardize the RNA extraction method and/or the PCR detection conditions between the laboratories.