The health consequences of arbovirus infections such as dengue fever (DENV), Chikungunya (CHIKV) and Zika (ZIKV) has in recent years become a public health challenge, due to failure of prevention followed by increased incidence and pronounced social inequality in occurrence and consequences. This motivates a more systematic analysis of the potential mechanisms and pathways that generate these inequalities. We present in the paper a model that delineates five possible mechanisms driving the inequality of ZIKV and congenital Zika syndrome (CZS). They include differential exposure to bad housing and sanitary conditions, differential exposure to vector density and virus, differential vulnerability to the health effects of exposure to virus, differential intrauterine susceptibility to the teratogenic effects of ZIKV infection and differential social consequences of caring for a disabled child. For each mechanism, we present empirical evidence or need for more research as well as a discussion about policy implications.