Epidemics on networks: Reducing disease transmission using health emergency declarations and peer communication

Azizi, Asma; Montalvo, Cesar; Espinoza, Baltazar; Kang, Yun; Castillo-Chavez, Carlos

The model captures changing disease transmission dynamics by incorporating-after a health emergency has been declared-risk information propagation, that play by assumption, over the same social network. Risk information is transmitted at different rates depending on the economic/education levels of individuals. We focus on single outbreaks, within a SusceptibleeInfectedeRecovered (SIR) framework. The dissemination of awareness (risk information) among the susceptible population, a process triggered by the declaration of a health emergency by the public health authorities, generates temporary changes on the knowledge and understanding of risk of infection, thus altering their activity and effectiveness as communicators of risk. Becoming aware of the risk of infection and inciting our ability to communicate risk, takes place at a rate modeled as a function of the economic/educational level of individuals in the network. Economic/educational levels are preassigned qualities to individuals in the network from pre-selected distributions. A susceptible individual may be a member of three sub-classes of susceptible: Unaware, S u , Aware, S a and Indifferent, S i . Unaware individuals that become aware of the risk of infection may (depending on their economic/educational level), change their state to Aware, that is, be ready to convey information, with different levels of enthusiasm, on the risks of the infection to neighbors in the network. Aware, is assumed to be a temporary state and so a transition to the Indifferent state is included. The triggers that determine or drive awareness state are a function of the disease prevalence level and not the time since start of the outbreak. The case when delays in transmitting real-time prevalence information to public health officials takes place, the most likely scenario is not considered. However, we know that it brings additional consequences (see (Velasco-Hern andez, Brauer, & Castillo-Chavez, 1996) ).