  Interaction patterns among individuals play vital roles in spreading
infectious diseases. Understanding these patterns and integrating their impact
in modeling diffusion dynamics of infectious diseases are important for
epidemiological studies. Current network-based diffusion models assume that
diseases transmit through interactions where both infected and susceptible
individuals are co-located at the same time. However, there are several
infectious diseases that can transmit when a susceptible individual visits a
location after an infected individual has left. Recently, we introduced a
diffusion model called same place different time (SPDT) transmission to capture
the indirect transmissions that happen when an infected individual leaves
before a susceptible individual's arrival along with direct transmissions. In
this paper, we demonstrate how these indirect transmission links significantly
enhance the emergence of infectious diseases simulating airborne disease
spreading on a synthetic social contact network. We denote individuals having
indirect links but no direct links during their infectious periods as hidden
spreaders. Our simulation shows that indirect links play similar roles of
direct links and a single hidden spreader can cause large outbreak in the SPDT
model which causes no infection in the current model based on direct link. Our
work opens new direction in modeling infectious diseases.
