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We have studied a dynamical model for the role of indirect transmission in the spread of an infectious agent, inspired by a recent case of sarcoptic mange in populations of South American camelids. The disease can be transmitted either by direct contact or indirectly by means of infectious fomites left in the environment. We have explored the potential of these infectious reservoirs as triggers for emerging disease outbreaks. We have analyzed a mean-field epidemiological model for such a system and identified different types of dynamical phases, controlled by the relative levels of direct and indirect transmission. Among these, we found a new regime where the disease can emerge and persist solely through fomites. This possibility reveals a potential evolutionary pathway for parasites to enhance their fitness beyond co-evolution with their hosts. We also define an effective reproductive number that controls disease persistence. Additionally, we have explored some extensions that go beyond the well-mixed hypothesis of usual mean-field models.