Figure 1. Spectrum of Disease

<b>Figure 1:</b> Representations of variation associated with coral disease exemplifying a spectrum within increasing variation or influence of one corner of the triangle. Lines illustrate the three-dimensionality of the spectrum and do not necessarily correspond with interactions among the specific circles. A) the simplistic model (original disease triangle concept), single pathogen, single host represented by aspergillosis. (B)-(D) Examples of increasing variation in pathogen and hosts, represented by (B) white band disease, (C) stony coral tissue loss disease and (D) white plague. The disease spectrum and could also be considered a way to conceptualize the most complex of the spectrum, as in (D): dysbiosis, with many hosts, highly influenced by the environment. The number of circles corresponds to the rankings of the pathogen, host and environment for that disease (Table 1, see text). Rank levels are determined by the known number of host species/pathogens/environmental drivers. Number of circles could also reflect influence of that corner on disease (in which more circles could indicate increased influence).