Detection of Vector Transmitted Zoonotic Pathogens in Nonhuman Primates in the Manuel Antonio National Park and Surrounding Areas of Costa Rica

Background: The Manuel Antonio National Park (MANP) and its surrounding areas in Costa Rica are home to endangered non-human primates (NHPs), including Saimiri oerstedii citrinellus and Cebus imitator, that coexist in close contact with humans and domestic animals. Such interactions may facilitate the transmission of vector-borne zoonotic diseases. This study aimed to investigate the presence of selected vector-transmitted pathogens of zoonotic relevance in NHPs from this region. Methods: Between 2021 and 2022, 40 free-ranging NHPs (19 C. imitator, 19 S. oerstedii citrinellus, 2 Alouatta palliata) were sampled in MANP and surrounding areas. Blood samples were tested for Trypanosoma spp., Plasmodium spp., Mycoplasma spp., and arboviruses including dengue virus (DENV), chikungunya virus (CHIKV), Zika virus (ZIKV), Venezuelan equine encephalitis virus (VEEV), and West Nile virus (WNV). Molecular analyses were conducted using PCR and RT-qPCR protocols, with sequencing for species confirmation. Results: Eight of 40 NHPs (20.0%) tested positive for at least one pathogen. Trypanosoma minasense was confirmed by sequencing in three C. imitator (16.7%). Plasmodium spp. was detected in one C. imitator and one A. palliata (5.0%), though species-level identification was unsuccessful. One C. imitator tested positive for CHIKV (Ct 36.8), representing the first PCR-confirmed case of CHIKV in NHPs in Central America. Two C. imitator were positive for Mycoplasma spp. (11.1%). No co-infections were observed. All animals were negative for DENV, ZIKV, VEEV, and WNV. Conclusions: This study provides the first molecular evidence of CHIKV infection in NHPs in Costa Rica and highlights the circulation of Trypanosoma spp., Plasmodium spp., and Mycoplasma spp. in wild primates from MANP. These findings emphasize the need for a One Health approach to surveillance, particularly in regions where human-wildlife interactions are frequent. Longitudinal and serological studies are recommended to assess the potential reservoir role of NHPs and their implications for public health and conservation.