A Comparative Study of Clinical Presentation and Risk Factors for Adverse Outcome in Patients Hospitalised with Acute Respiratory Disease Due to MERS Coronavirus or Other Causes

Abstract

Middle East Respiratory syndrome (MERS) first emerged in Saudi Arabia in 2012 and remains a global health concern. The objective of this study was to compare the clinical features and risk factors for adverse outcome in patients with RT-PCR confirmed MERS and in those with acute respiratory disease who were MERS-CoV negative, presenting to the King Fahad Medical City (KFMC) in Riyadh between October 2012 and May 2014. The demographics, clinical and laboratory characteristics and clinical outcomes of patients with RT-PCR confirmed MERS-CoV infection was compared with those testing negative MERS-CoV PCR. Health care workers (HCW) with MERS were compared with MERS patients who were not health care workers. One hundred and fifty nine patients were eligible for inclusion. Forty eight tested positive for MERS CoV, 44 (92%) being hospital acquired infections and 23 were HCW. There were 111 MERS-CoV negative patients with acute respiratory illnesses included in this study as “negative controls”. Patient with confirmed MERS-CoV infection were not clinically distinguishable from those with negative MERS-CoV RT-PCR results although diarrhoea was commoner in MERS patients. A high level of suspicion in initiating laboratory tests for MERS-CoV is therefore indicated. Variables associated with adverse outcome were older age and diabetes as a co-morbid illness. Interestingly, co-morbid illnesses other than diabetes were not significantly associated with poor outcome. Health care workers with MERS had a markedly better clinical outcome compared to non HCW MERS patients.

Focus on Middle East respiratory syndrome coronavirus (MERS-CoV)

“…Diarrhea is significantly more frequent in patients infected with MERS-CoV than in patients with another acute, febrile respiratory conditions [45].…”

“…Moreover, hyperleukocytosis, lymphocytopenia, thrombocytopenia, hypoalbuminemia, elevated serum creatinine, LDH and CRP levels, and hypoxemia (PaO2/FiO2 < 300) have been repeated reported in MERS-CoV infected patients and are associated with severity and death [34,45].…”

“…The main challenge of MERS-CoV infection is the absence of specific clinical features for differential diagnosis with other viral respiratory diseases [37,45]. This difficulty, combined with precautionary action taken to avoid potential secondary contamination with MERS-CoV [46], can result in medical confusion and inappropriate patient management due to prolonged, difficult isolation that makes it impossible to perform the necessary complementary tests while waiting for PCR results [47].…”

“…There are no specific laboratory findings related to MERS-CoV infection. Nevertheless in patients with acute respiratory infection in MERS-endemic areas, MERS-CoV infections have been associated with normal leukocyte and/or polymorphonuclear neutrophil counts but elevated transaminases [37,45].…”

“…Imaging (chest X-ray and sometimes chest CT) has revealed infection-related features in 51-75% of cases. The lesions observed are uni-or multi-focal ground glass opacifications, of subpleural and lower lobe predominance, with sometimes bilateral bi-basal involvement or features of organizing pneumonia [34,37,42,45].…”