Are hospital MERS outbreaks just like SARS?
Comparing hospital clusters, MERS and SARS both ignite via early super-spreaders then drop below R=1 within 3–5 generations; a >100-case outbreak is about twice as likely for SARS (2% vs 1%), while MERS transmission is more heterogeneous.
Source
Transmission characteristics of MERS and SARS in the healthcare setting: a comparative study
Study at a glance
- Design
- Computational / modelling — Comparative analysis of MERS vs SARS hospital outbreak trees plus 5,000 branching-process simulations per virus
- N
- N=8607 · 973 MERS and 7,634 SARS cases for HCW fractions; trees for Korea MERS n=186, Al-Hasa n=25, Singapore SARS n=188, Toronto n=90
- Population
- Laboratory-confirmed MERS and SARS cases in published hospital clusters (Saudi Arabia, South Korea, Singapore, Toronto, and other SARS sites)
- Outcome
- Exposure mix, reproduction number by generation, transmission heterogeneity, and probability of large nosocomial outbreaks
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Compiled exposure data and transmission trees for large MERS (South Korea 186; Al-Hasa 25; Jeddah) and SARS (Singapore 188; Toronto 90) hospital clusters, compared secondary-case distributions (negative binomial R and k), and simulated 5,000 outbreaks of each virus.
What they found
Healthcare-linked MERS ranged from 43.5% (Jeddah 2014) to 100% (Al-Hasa and Korea). Korea’s index patient infected 30 others; two second-generation patients infected 80 and 23. HCWs were 13.4–13.5% of MERS vs 19–57% of SARS. Probability of >100 cases: ~2% SARS vs ~1% MERS; >186 MERS cases ~1%.
The limits
What it doesn't show
Few fully resolved trees and reporting bias toward large clusters mean R and k are imprecise; simulations do not prove which infection-control rule would have stopped Korea 2015.
Key terms
- Super-spreading
- One case generating many secondary infections; Korea’s index MERS patient infected 30 people.
- Reproduction number R
- Mean secondary cases per case; in these hospitals it fell below 1 within three to five generations.
- Dispersion parameter k
- Negative-binomial heterogeneity; smaller k means more super-spreading. MERS looked more heterogeneous than SARS.
- Nosocomial
- Acquired in a healthcare setting; a large share of MERS cases were hospital-linked.
- Branching process
- Simulation that grows an outbreak from a distribution of secondary cases; 5,000 runs per virus here.
- MERS
- Middle East respiratory syndrome coronavirus; often subcritical in the community but amplifying in hospitals.
Flashcards
Research intelligence for this paper
See its role on concept claims, tensions it is part of, placement history, and related discoveries.
Quiz yourself
Korea 2015 MERS cluster size:
Common questions
How large was the Korea cluster?
186 MERS infections linked to healthcare facilities.
Index patient’s secondary cases?
About 30.
Chance of >100 hospital cases?
About 2% for SARS vs 1% for MERS.
HCW share of MERS?
13.4% in Saudi Arabia vs 13.5% in Korea.
More on Critical care