Zoonotic Blood-Borne Pathogens in Non-Human Primates in the Neotropical Region: A Systematic Review

Understanding which non-human primates (NHPs) act as a wild reservoir
for blood-borne pathogens will allow us to better understand the ecology of diseases and the role of
NHPs in the emergence of human diseases in Ecuador, a small country in South America that lacks
information on most of these pathogens. Methods and principal findings: A systematic review was
carried out using PRISMA guidelines from 1927 until 2019 about blood-borne pathogens present
in NHPs of the Neotropical region (i.e., South America and Middle America). Results: A total of
127 publications were found in several databases. We found in 25 genera (132 species) of NHPs a
total of 56 blood-borne pathogens in 197 records where Protozoa has the highest number of records in
neotropical NHPs (n = 128) compared to bacteria (n = 12) and viruses (n = 57). Plasmodium brasilianum
and Trypanosoma cruzi are the most recorded protozoa in NHP. The neotropical primate genus with the
highest number of blood-borne pathogens recorded is Alouatta sp. (n = 32). The use of non-invasive
samples for neotropical NHPs remains poor in a group where several species are endangered or
threatened. A combination of serological and molecular techniques is common when detecting
blood-borne pathogens. Socioecological and ecological risk factors facilitate the transmission of these
parasites. Finally, a large number of countries remain unsurveyed, such as Ecuador, which can be of
public health importance. Conclusions and significance: NHPs are potential reservoirs of a large
number of blood-borne pathogens. In Ecuador, research activities should be focused on bacteria and
viruses, where there is a gap of information for neotropical NHPs, in order to implement surveillance
programs with regular and effective monitoring protocols adapted to NHPs.