MERS coronavirus: data gaps for laboratory preparedness

Abstract

Since the emergence of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) in 2012, many questions remain on modes of transmission and sources of virus. In outbreak situations, especially with emerging organisms causing severe human disease, it is important to understand the full spectrum of disease, and shedding kinetics in relation to infectivity and the ability to transmit the microorganism. Laboratory response capacity during the early stages of an outbreak focuses on development of virological and immunological methods for patient diagnosis, for contact tracing, and for epidemiological studies into sources, modes of transmission, identification of risk groups, and animal reservoirs. However, optimal use of this core public health laboratory capacity requires a fundamental understanding of kinetics of viral shedding and antibody response, of assay validation and of interpretation of test outcomes. We reviewed available data from MERS-CoV case reports, and compared this with data on kinetics of shedding and immune response from published literature on other human coronaviruses (hCoVs). We identify and discuss important data gaps, and biases that limit the laboratory preparedness to this novel disease. Public health management will benefit from standardised reporting of methods used, details of test outcomes by sample type, sampling date, in relation to symptoms and risk factors, along with the currently reported demographic, clinical and epidemiological findings.

Keywords: Coronavirus; Laboratory preparedness; Middle East Respiratory Syndrome Coronavirus; SARS.

Fig. 1

Top: Schematic representation of comparative profiles of SARS shedding (peak viral load) and antibodies kinetics, based on data described by , , , . At the top left of the figure, peak viral load information for HCoV-NL63 is given, based on . Bottom: schematic representation of relationship between sensitivity of molecular detection and serology in relation to time of sampling and kinetics of infection.

Fig. 2

(A) Summary of case reports with diagnostic information relevant for laboratory preparedness. (naso-pharyngeal swab or aspirate (NP); throat swab (TS); nasal swab (NS); oro-nasal swab (ORS); tracheal aspirates (TA); Sputum (SP); bronchoalveolar lavage (BAL); Stool (ST);Urine (U); serum or plasma (S/P); positive (+); negative (−); upper respiratory tract (URT); lower respiratory tract (LRT); * not present in figure; not available data (na). (B) Summary of data from published literature and reports on MERS-CoV RT-PCR positive respiratory specimens by sample type, and timing of sampling since onset of symptoms (see Ref. [29]).