This file photo provided by the National Institute for Allergy and Infectious Diseases shows a colorized transmission of the MERS coronavirus that emerged in 2012. (Photo11: NIAID via The Canadian Press/AP)

This file photo provided by the National Institute for Allergy and Infectious Diseases shows a colorized transmission of the MERS coronavirus that emerged in 2012.
(Photo11: NIAID via The Canadian Press/AP)

Patients with Middle East respiratory syndrome (MERS) develop more severe critical illness and have higher mortality than patients with non-MERS severe acute respiratory infection (SARI), according to investigators involved with the largest study of critically ill patients with MERS. The study was presented at the ATS 2016 International Conference.

Until March 20, 2016, 1690 cases of MERS had been reported to the World Health Organization, with 80% of those cases in Saudi Arabia. The reported cases had an overall mortality of 35%. The investigators – led by Yaseen Arabi, MD, chairman, Intensive Care Department, and professor, College of Medicine, King Saud bin Abdulaziz University for Health Sciences and King Abdullah International Medical Research Center, Riyadh, Saudi Arabia – embarked on their research because few studies have examined the clinical course of critically ill patients.

They collected data from 14 hospitals in 4 cities in Saudi Arabia and compared critically ill patients with laboratory-confirmed MERS to those admitted with SARI of non-MERS etiology during a similar period.

A total of 299 MERS patients with SARI were admitted to the participating ICUs and were compared with 218 patients with SARI only. Patients with MERS were younger (median age, 58 years) compared with non-MERS patients (median age, 70 years). There were a number of chronic morbidities common in both groups, including diabetes and liver disease. Symptoms such as cough, shortness of breath, and sputum production were also similar.

“Patients with MERS were more likely to be hypoxemic and to require invasive mechanical ventilation (85% versus 73%, p = 0.001), vasopressor therapy (77% versus 55%, p = 0.001), and renal replacement therapy (47% versus 23%, p = 0.001),” the investigators wrote. Mortality was higher in MERS versus non-MERS patients (70% versus 36%, p = 0.001).

“There is a substantial overlap in clinical presentation and co-mortalities among patients with MERS and SARI of other etiologies, making diagnostic testing an essential component of SARI investigation of at-risk patients,” the authors concluded.