and sustain the zoonotic cycle of the virus. The animal reservoir of the virus maintains a suitable virus level in the blood to allow the infection of a vector mosquito. A bridge-vector mosquito such as Aedes albopictus, which can survive in an urban area and spread to rural, semi-rural, and forest areas could carry the virus to a sylvatic environment. Zika fever: The Zika virus is caused by the single stranded RNA Flavivirus that uses the Aedes mosquito as a vector to infect other human and animal hosts. A 2015 zika virus strain isolated from a human in Brazil was used to infect pregnant rhesus macaques intravenously and intraamniotically. Both the dams and the placentas were infected with Zika positive tissue samples being recorded for up to 105 days. This confirms a reverse zoonotic transference potential between humans and non-human primates. Yellow fever: Yellow fever virus also transmitted by the bite of an infected Aedes or Haemagogus species of mosquitoes that feed off an infected animal. The historical course of the American slave trade is a prime example of introduction of a pathogen to create a completely new sylvatic cycle. Previous hypotheses of a "New World YFV" were laid to rest in a 2007 study that examined rates of nucleotide substitution and divergence to determine that yellow fever was introduced into the Americas approximately 400 years ago from West Africa. It was also around the 17th century that yellow fever was documented by Europeans complicit in slave trafficking. The actual mode of introduction could have played out in a number of scenarios whether a viremic Old World human, infected Old World mosquito, eggs laid by an Old World infected mosquito, or all three were transported to the Americas seeing that yellow fever transmission was not uncommon on sailing vessels. Amidst more recent yellow fever outbreaks in southeastern Brazil, the spillback potential was highly indicated. Molecular comparisons of non-human primate outbreak strains proved to be more closely related to human strains than strains derived from other non-human primates thus suggesting a continuing reverse zoonosis. Chikungunya: The Chikungunya virus is a single stranded RNA alphavirus typically transmitted by the Aedes mosquitoes to another animal host. There is no evidence to suggest a barrier to Chikungunya switching hosts between humans and non-human primates because it has no preferences in any given primate species. It has a high potential to spill-over or spill-back into