Abstract
Middle East respiratory syndrome coronavirus (MERS-CoV) causes a spectrum of illness. We evaluated whether cycle threshold (C-t) values (which are inversely related to virus load) were associated with clinical severity in patients from Saudi Arabia whose nasopharyngeal specimens tested positive for this virus by real-time reverse transcription PCR. Among 102 patients, median C-t of 31.0 for the upstream of the E gene target for 41(40%) patients who died was significantly lower than the median of 33.0 for 61 survivors (p =, 0.0087). In multivariable regression analyses, risk factors for death were age >60 years, underlying illness, and decreasing C-t. Results were similar for a composite severe outcome (death and/or intensive care unit admission). More data are needed to determine whether modulation of virus load by therapeutic agents affects clinical outcomes.