Figure 4: The influence of reservoir host ecology on the epidemiology of rabies.

a| The ‘SEI’ model for rabies epidemiology represents transitions of hosts between individuals that are classified as susceptible (S), infected and incubating RABV (‘exposed’ (E), infected and infectious (I) and temporarily immune (T). Both intraspecific transmission and spillover infections to non-reservoir hosts arise from infectious reservoirs in the I class. The force of infection (λ) depends on the frequency of susceptible and infected and infectious individuals in the population, total population size and transmission rate. Solid arrows indicate portions of the transmission cycle that are common to all RABV reservoirs. Dashed arrows may only occur for some reservoir hosts, depending on pathbiological relationships with rabies (see Fig. 2) or human interventions such as the presence of vaccination campaigns. b| Variation in reservoir host ecology influences different phases of the transmission cycle, causing reservoir host-specific transmission dynamics and maintenance mechanisms. Maps show the geographic range of four of the best-studied RABV reservoir hosts, although RABV may be absent from some parts of each species’ range, for example because of changing viral distributions or local eradication efforts. The drivers of transmission dynamics are mapped for each reservoir host to the compartmental model in panel a, to illustrate how ecology affects transmission dynamics. The epidemiological dynamics observed in each reservoir are summarized.

Of note, spillover infections to a broad range of species occur from each reservoir; shown are the principle spillover hosts infected by each reservoir.