Real-time epidemiological assessment of the May–June 2015 Korean MERS-CoV outbreak: a single traveller returning from the Middle East (with presumed camel/regional exposure, never pinned to a specific animal contact) visited four hospitals before diagnosis, seeding a nosocomial chain that grew to 186 confirmed cases and 38 deaths across 16 hospitals, with roughly 44% of cases hospital-exposed patients and most transmission attributable to a handful of superspreading events. Estimates a hospital-transmission reproduction number and shows the epidemic curve and case geography are dominated entirely by which hospitals the index and secondary cases happened to visit.
relevance_note: second historical precedent for the base-rate claim, same viral family as SARS-CoV-2 — the outbreak that became internationally visible and geographically “located” itself is a chain of Korean hospitals wholly disconnected from the true zoonotic exposure (dromedary camels, Middle East), illustrating how surveillance/contact-density venues become the recorded epicenter regardless of where spillover occurred.