Factors affecting the emergence and prevalence of vector borne infections (VBI) and the role of vertical transmission (VT).

Vector-borne infections (VBI) are very common around the globe and they account for many devastating diseases. They are not found exclusively in the third world or tropical regions but spread to every corner of the planet. The factors driving these infections are many and interact in very complex ways. This review attempts to put into perspective the external-climate change and demographics, as well as the internal factors that drive these infections with particular attention to the role that verticle transmission (VT) plays in the prevalence and emergence of these infections. VT has been widely demonstrated, its role in the maintenance of disease in nature has been suggested, but whether this role has a positive or negative effect seems to vary from species to species. The incorporation of this mechanism of transmission into the classic cycle of infection/maintenance of disease seems to explain important aspects of the epidemiology of VBI.