Nuanced risk assessment for emerging infectious diseases

Preliminary epidemiological assessment of MERS-CoV outbreak in South Korea, May to June 2015

“…Since 12 June, when the first fourth-generation case was confirmed, 10 more potential fourth-generation cases have been reported. Because of the marked heterogeneity in transmissibility, with the vast majority of cases associated with just these three superspreading events in the nosocomial setting, it would be misleading to summarily characterise the transmissibility of the virus in this ongoing outbreak with a single average value of the reproductive number [14]. The mean serial interval was 12 to 13 days in each of four epidemiological clusters associated with Cases 1, 14, 15 and 16.…”

Assessing the risk of observing multiple generations of Middle East respiratory syndrome (MERS) cases given an imported case

“…While the assumption may be common among modelling studies, it did not allow us to account for the variable type and effectiveness of interventions, especially at later generations of cases in each cluster. Secondly, MERS outbreaks have frequently been amplified in healthcare settings [6,19,20], but we limited ourselves to accounting for individual heterogeneity in a general sense. An improvement on this point was difficult, because MERS outbreaks have been seen mostly in healthcare settings without large-scale community transmission.…”

“…generation 3 counting from the index case as generation 0) have been reported in South Korea [2]. Although the inter-human transmission potential of MERS is considered to be too low to cause large-scale epidemics [3][4][5], high variability and heterogeneity in the transmission potential have been underscored [6]. As MERS continues to spread globally, it is vital that risk assessment involves an evaluation of the potential outcomes following MERS importation events [7].…”

Emerging and Reemerging Infectious Disease Threats

“…For example, the current analyses of transmissibility for MERS Co-V suggest that it is not a likely pandemic threat because of its low reproduction number or "r nought" (R 0 ). However, different cluster sizes, demographics, geographies, and public health and healthcare infrastructures may alter the outbreak characteristics and the reproduction number (R 0 ) (Fisman et al, 2014). Capturing critical data will allow for accurate characterization within the context of the outbreak and will direct response activities such as control measures and medical surge management.…”