title: Risk of MERS importation and onward transmission: a systematic review and analysis of cases reported to WHO.
abstract: BACKGROUND
  The continuing circulation of MERS in the Middle East makes the international dissemination of the disease a permanent threat. To inform risk assessment, we investigated the spatiotemporal pattern of MERS global dissemination and looked for factors explaining the heterogeneity observed in transmission events following importation.
  
  
  METHODS
  We reviewed imported MERS cases worldwide up to July 2015. We modelled importations in time based on air travel combined with incidence in Middle East. We used the detailed history of MERS case management after importation (time to hospitalization and isolation, number of hospitals visited,…) in logistic regression to identify risk factors for secondary transmission. We assessed changes in time to hospitalization and isolation in relation to collective and public health attention to the epidemic, measured by three indicators (Google Trends, ProMED-mail, Disease Outbreak News).
  
  
  RESULTS
  Modelled importation events were found to reproduce both the temporal and geographical structure of those observed - the Pearson correlation coefficient between predicted and observed monthly time series was large (r = 0.78, p < 10(-4)). The risk of secondary transmission following importation increased with the time to case isolation or death (OR = 1.7 p = 0.04) and more precisely with the duration of hospitalization (OR = 1.7, p = 0.02). The average daily number of secondary cases was 0.02 [0.0,0.12] in the community and 0.20 [0.03,9.0] in the hospital. Time from hospitalisation to isolation decreased in periods of high public health attention (2.33 ± 0.34 vs. 6.44 ± 0.97 days during baseline attention).
  
  
  CONCLUSIONS
  Countries at risk of importation should focus their resources on strict infection control measures for the management of potential cases in healthcare settings and on prompt MERS cases identification. Individual and collective awareness are key to substantially improve such preparedness.
authors: Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d'épidémiologie et de Santé Publique (IPLESP UMRS 1136), 75012, Paris, France. chiara.poletto@inserm.fr.
authors: Chiara
authors: C
authors: Poletto
authors: Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d'épidémiologie et de Santé Publique (IPLESP UMRS 1136), 75012, Paris, France.
authors: Pierre-Yves
authors: PY
authors: Boëlle
authors: Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d'épidémiologie et de Santé Publique (IPLESP UMRS 1136), 75012, Paris, France.|Institute for Scientific Interchange Foundation, via Alassio 11/c, 10126, Torino, Italy.
authors: Vittoria
authors: V
authors: Colizza
mesh_terms: D018352:Coronavirus Infections / Q000453:epidemiology* / Q000401:mortality / Q000635:transmission*; D004196:Disease Outbreaks; D006801:Humans; D017053:Infection Control; D008877:Middle East / Q000453:epidemiology; D008962:Models, Theoretical; D011634:Public Health; D012307:Risk Factors; D014944:World Health Organization
keywords: Epidemic preparedness; Imported cases; MERS; Secondary transmission