چکیده (انگلیسی):

MERS coronavirus cases notified in the Middle East region since the identification of the virus in 2012have displayed variations in time and across geography. Through a combined modelling approach, weestimate the rates of generation of cases along the zoonotic and human-to-human transmission routesand assess their spatiotemporal heterogeneity. We consider all cases notified to WHO from March 2012 tomid-September 2014. We use a stochastic modelling of the time series of case incidence in the Middle Eastregion to estimate time- and space-dependent zoonotic and human-to-human transmission parameters.The model also accounts for possible lack of identification of secondary transmissions among notifiedcases. This approach is combined with the analysis of imported cases out of the region to assess therate of underreporting of cases. Out of a total of 32 possible models, based on different parameterisationand scenario considered, the best-fit model is characterised by a large heterogeneity in time and acrossspace for both zoonotic and human-to-human transmission. The variation in time that occurred duringSpring 2014 led to a 17-fold and 3-fold increase in the two transmissions, respectively, bringing thereproductive rate to values above 1 during that period for all regions under study. The model suggeststhat 75% of MERS-CoV cases are secondary cases (human-to-human transmission), which is substantiallyhigher than the 34% of reported cases with an epidemiological link to another case. Overall, estimatedreporting rate is 0.26. Our findings show a higher level of spatial heterogeneity in zoonotic transmissioncompared to human-to-human, highlighting the strong environmental component of the epidemic. Sincesporadic introductions are predicted to be a small proportion of notified cases and are responsible fortriggering secondary transmissions, a more comprehensive understanding of zoonotic source and pathof transmission could be critical to limit the epidemic spread.© 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-NDlicense (http://creativecommons.org/licenses/by-nc-nd/4.0/).