Table.

Comparison of clinical and laboratory features of MERS and SARS

		MERS7, 8, 9, 10, 13, 33, 84, 85	SARS86, 87, 88, 89, 90, 91
First cases reported		April, 2012 (Zarqa, Jordan), June, 2012 (Jeddah, Saudi Arabia)	November, 2002 (Guangdong, China)
Incubation period
	Mean (95% CI; days)	5·2 (1·9–14·7)	4·6 (3·8–5·8)
	Range (days)	2–13	2–14
	Serial interval	7·6 days	8·4 days
Basic reproduction number		<1	2–3
Patient characteristics
	Adults	98%	93%
	Children	2%	5–7%
	Age range (years)	1–94	1–91
	Average age (years)	Median 50	Mean 39·9
	Sex ratio (male:female)	64·5%:35·5%	43%:57%
Mortality
	Overall CFR	40%	9·6%
	CFR in patients with comorbidities	60%	46%
Disease progression
	Time from onset to ventilatory support	Median 7 days	Mean 11 days
	Time from onset to death	Median 11·5 days	Mean 23·7 days
Presenting symptoms
	Fever (>38°C)	98%	99–100%
	Chills or rigors	87%	15–73%
	Cough	83%	62–100%
	Dry	56%	29–75%
	Productive	44%	4–29%
	Haemoptysis	17%	0–1%
	Headache	11%	20–56%
	Myalgia	32%	45–61%
	Malaise	38%	31–45%
	Shortness of breath	72%	40–42%
	Nausea	21%	20–35%
	Vomiting	21%	20–35%
	Diarrhoea	26%	20–25%
	Sore throat	14%	13–25%
	Rhinorrhoea	6%	2–24%
Comorbidities		76%	10–30%
Laboratory results
	Chest radiography abnormalities	90–100%	94–100%
	Leucopenia (<4·0 × 109 cells per L)	14%	25–35%
	Lymphopenia (<1·5 × 109 cells per L)	32%	68–85%
	Thrombocytopenia (<140 × 109 platelets per L)	36%	40–45%
	High lactate dehydrogenase	48%	50–71%
	High alanine aminotransferase	11%	20–30%
	High aspartate aminotransferase	14%	20–30%
Factors associated with severe disease or death		Being immunocompromised, comorbidity (eg, obesity, diabetes, cardiac disease, lung disease), concomitant infection, low albumin, age ≥65 years	Old age, being male, high initial or peak lactate dehydrogenase, high neutrophil count on presentation, comorbidity, low CD4 and CD8 lymphocyte counts at presentation

CFR=case-fatality rate. MERS=Middle East respiratory syndrome. SARS=severe acute respiratory syndrome.