Viral RNA in Blood Affects Middle East Respiratory Syndrome Coronavirus Illness Severity

The presence of viral RNA in blood is an indicator of more serious illness in patients with Middle East Respiratory Syndrome coronavirus, including fever, the need for mechanical ventilation, and death.

Although not an effective means of diagnosing Middle East Respiratory Syndrome coronavirus, RNA detected in the blood of patients can be indicative of more severe illness, according to a study published in Emerging Infectious Diseases.

So Yeon Kim, MD, of the National Medical Center in Seoul, South Korea and colleagues examined data on 21 patients in South Korea  whose MERS coronavirus diagnosis was confirmed by the Korea Centers for Disease Control and Prevention via respiratory samples.

Dr Kim and colleagues collected 21 whole blood and serum samples from study participants and extracted viral RNA using MagNA Pure LC 2.0 automated nucleic acid extractor and MagNA Pure LC total nucleic acid isolation kit manufactured by Roche Diagnostics, in Mannheim, Germany. They noted viral RNA in 6 whole blood samples and 6 in serum samples. Dr Kim and colleagues said that fever and the need for mechanical ventilation was more common in the patients whose samples had viral RNA.

Only 33% of samples contained viral RNA, so detecting the RNA was not a good means of diagnosis, the researchers explained.

“Blood viral RNA was present in a subpopulation of patients and… these patients had significantly poorer prognoses, as demonstrated by the need for more frequent mechanical ventilation and the increased risk for death,” Dr Kim and colleagues reported.

Researchers said that risk factors for more severe disease were also indicated by viral RNA in upper respiratory samples, but not lower respiratory ones.

Although viral RNA does not help in MERS coronavirus detection, it can be used as an indicator to predict those patients who will experience more severe disease.


1. Kim SY, Park SJ, Cho SY, et al. Viral RNA in blood as indicator of severe outcome in Middle East respiratory syndrome coronavirus infection. Emerg Infect Dis. 2016;22(10).