The role of laboratory diagnostics in emerging viral infections: the example of the Middle East respiratory syndrome epidemic

Abstract

Rapidly emerging infectious disease outbreaks place a great strain on laboratories to develop and implement sensitive and specific diagnostic tests for patient management and infection control in a timely manner. Furthermore, laboratories also play a role in real-time zoonotic, environmental, and epidemiological investigations to identify the ultimate source of the epidemic, facilitating measures to eventually control the outbreak. Each assay modality has unique pros and cons; therefore, incorporation of a battery of tests using traditional culture-based, molecular and serological diagnostics into diagnostic algorithms is often required. As such, laboratories face challenges in assay development, test evaluation, and subsequent quality assurance. In this review, we describe the different testing modalities available for the ongoing Middle East respiratory syndrome (MERS) epidemic including cell culture, nucleic acid amplification, antigen detection, and antibody detection assays. Applications of such tests in both acute clinical and epidemiological investigation settings are highlighted. Using the MERS epidemic as an example, we illustrate the various challenges faced by laboratories in test development and implementation in the setting of a rapidly emerging infectious disease. Future directions in the diagnosis of MERS and other emerging infectious disease investigations are also highlighted.

Inclusion of MERS‐spike protein ELISA in algorithm to determine serologic evidence of MERS‐CoV infection

“…Our current diagnostic algorithm for identification of MERS‐CoV‐specific serum antibodies in patients with a suspected history of MERS‐CoV infection includes initial screenings by indirect ELISA using MERS‐CoV nucleocapsid (N) protein, and then confirmation with immunofluorescent staining of MERS‐infected cells, and microneutralization titration (MNt) assays . Other international groups are primarily using a combination of indirect ELISA against the spike (S) protein with confirmatory neutralization assays . S1 ELISAS have been found to correlate well with neutralizing antibodies .…”

Development and validation of different indirect ELISAs for MERS-CoV serological testing

“…Indirect ELISA based on recombinant MERS-spike (S) ectodomain protein (amino acids 1-1297) was recently included in this algorithm (Trivedi et al, 2017). Other groups have also used several other assays such as S protein microarray, IFA staining based on cells expressing recombinant full length S protein, plaque reduction neutralization test (PRNT), MERS-CoV pseudoparticle neutralization (ppNT) assay, and indirect ELISA based on S1 recombinant protein (Perera et al, 2013;Reusken et al, 2013;Zhao et al, 2013;Hemida et al, 2014;Meyer et al, 2014;Fukuma et al, 2015;Grehan et al, 2015;Müller et al, 2015;Muth et al, 2015;Park et al, 2015;Chan et al, 2017). More recently, S-based competitive ELISA (cELISA) based on neutralizing monoclonal Abs (mAbs) have been developed and shown to correlate well with neutralization assays with high sensitivity and specificity (Fukushi et al, 2017).…”

Qualitative and Quantitative Determination of MERS-CoV S1-Specific Antibodies Using ELISA

“…Prepare all solutions using deionized water and store them at room temperature or 4 C. Diligently follow all waste disposal regulations when disposing waste materials. 6. Diluent for primary and secondary antibodies: Primary and secondary antibodies should be diluted in blocking buffer (see Note 3).…”