Middle East respiratory syndrome coronavirus: a case-control study of hospitalized patients.
BACKGROUND
There is a paucity of data regarding the differentiating characteristics of patients with laboratory-confirmed and those negative for Middle East respiratory syndrome coronavirus (MERS-CoV).


METHODS
This is a hospital-based case-control study comparing MERS-CoV-positive patients (cases) with MERS-CoV-negative controls.


RESULTS
A total of 17 case patients and 82 controls with a mean age of 60.7 years and 57 years, respectively (P = .553), were included. No statistical differences were observed in relation to sex, the presence of a fever or cough, and the presence of a single or multilobar infiltrate on chest radiography. The case patients were more likely to be overweight than the control group (mean body mass index, 32 vs 27.8; P = .035), to have diabetes mellitus (87% vs 47%; odds ratio [OR], 7.24; P = .015), and to have end-stage renal disease (33% vs 7%; OR, 7; P = .012). At the time of admission, tachypnea (27% vs 60%; OR, 0.24; P = .031) and respiratory distress (15% vs 51%; OR, 0.15; P = .012) were less frequent among case patients. MERS-CoV patients were more likely to have a normal white blood cell count than the control group (82% vs 52%; OR, 4.33; P = .029). Admission chest radiography with interstitial infiltrates was more frequent in case patients than in controls (67% vs 20%; OR, 8.13; P = .001). Case patients were more likely to be admitted to the intensive care unit (53% vs 20%; OR, 4.65; P = .025) and to have a high mortality rate (76% vs 15%; OR, 18.96; P < .001).


CONCLUSIONS
Few clinical predictors could enhance the ability to predict which patients with pneumonia would have MERS-CoV. However, further prospective analysis and matched case-control studies may shed light on other predictors of infection.
Medical Department, Saudi Aramco Medical Services Organization, Dhahran, Saudi Arabia Indiana University School of Medicine, Indianapolis.
Jaffar A
JA
Al-Tawfiq
Medical Department, Saudi Aramco Medical Services Organization, Dhahran, Saudi Arabia.
Kareem
K
Hinedi
Medical Department, Saudi Aramco Medical Services Organization, Dhahran, Saudi Arabia.
Jihad
J
Ghandour
Medical Department, Saudi Aramco Medical Services Organization, Dhahran, Saudi Arabia.
Hanan
H
Khairalla
Medical Department, Saudi Aramco Medical Services Organization, Dhahran, Saudi Arabia.
Samir
S
Musleh
Medical Department, Saudi Aramco Medical Services Organization, Dhahran, Saudi Arabia.
Alaa
A
Ujayli
World Health Organization Collaborating Center for Mass Gathering Medicine, Saudi Arabian Ministry of Health Al-Faisal University, Riyadh, Saudi Arabia.
Ziad A
ZA
Memish
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015510:Clinical Medicine / Q000379:methods*; D018352:Coronavirus Infections / Q000175:diagnosis* / Q000473:pathology* / Q000821:virology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D065207:Middle East Respiratory Syndrome Coronavirus / Q000302:isolation & purification*; D055815:Young Adult
MERS; case-control; coronavirus; radiographic characteristics