Wild animals (WA) have shown to be excellent bioindicators of important zoonotic-relevant pathogens in incrementally anthropogenic environments. As a result of continuous increase of anthropogenic pressure on fragile ecosystems, the contact of human populations with WA is constantly increasing. In an increasingly globalized world, anthropogenic factors such as intensified farming with consequent agro-industrial monocultures, unsustainable natural resources exploitation such as illegal mining, indiscriminate logging, wildlife hunting/trafficking, and wildlife-meat consumption, have strengthened the human-animal interface, thus increasing the risk of bidirectional disease spillover. The WA are indirect indicators of ecosystem health since they are sentinels of some neglected anthropozoonotic ecto- and endoparasitic diseases. Therefore, it is important to know the parasite fauna occurring in Neotropical wildlife, not only to strengthen conservation plans for threatened species, but also for the generation of valuable public health information to avoid potential human infections. Since Neotropics is an extensive and highly heterogeneous region, here we selected the hinge joining key territory of Colombia because remains as a poorly investigated area for wildlife parasitology and is the second most biodiverse country of the globe. Thus, there are scarce and old dated literature reports on various infectious agents that Colombian wildlife may harbour.
Herein we presented a first nationwide approach on neglected parasite fauna occurring in Neotropical wild- and domestic animal populations closely related to human populations in different habitats or biomes in which they inhabit. Additionally, WA-associated infectious diseases emergence or re-emergence highlights the need for better understanding on the mechanisms and factors involved in eco-epidemiology of parasitoses. Consequently, sampling efforts of present doctoral research proposal covered a wide range of biological regions from the Andean to the Amazon, the Caribbean and included the vast Orinoco basin. Covering a total of 524.970 Km2, thus constituting half of the continental national territory area of Colombia. Moreover, WA and domestic animals' species as diverse as the Antillean manatee (Trichechus manatus manatus), the bush dog (Speothos venaticus), the capybara (Hydrochoerus hydrochaeris), the puma (syn. cougar) (Puma concolor), the crab-eating fox (Cerdocyon thous), the jaguar (Panthera onca), the jaguarundi (Herpailurus yagouaroundi) and the ocelot (L. pardalis). Additionally, a nationwide survey on angiotropic nematode A. vasorum was conducted including serological analyses of 955 domestic dogs (Canis familiaris) and a worldwide analysis of neglected angio-neurotropic Gurltia paralysans in wild and domestic felids were herein included and/or sampled across previously described study areas.
Globally, a total of twenty-three (23) different parasite taxa were here reported through different methodologies such as various coproparasitological examination techniques, enzyme-linked immunosorbent assays (ELISA), scanning electron microscope (SEM), and both molecular identification and thereafter phylogenetic analyses. Some of these parasites were brought back from oblivion, constitute new host records, or have enlarged previously known distribution areas in Colombia. The first of these surprising and unexpected findings was the occurrence of Spirometra sp. and Spirometra mansoni in wild felids and canids, respectively. Additionally, herein we report the occurrence of zoonotic T. cati in jaguars and ocelots during faecal examination, highlighting again the potential role of wildlife in parasite transmission to local human communities. Additionally, the occurrence of soil-borne zoonotic nematode genus Strongyloides in endemic populations of wild large rodents such as capybaras as potential wild reservoir host for strongyloidiosis of domestic animals and humans inhabiting the Orinoco basin was reported. Furthermore, in the same giant rodent species (H. hydrochaeris) abovementioned we reported for the first time the trematode Plagiorchis muris as a new host record. This zoonotic-relevant food-borne disease, known as plagiorchiosis still remains as a major worldwide public health concern. In addition, in Colombian capybaras herein we reported the presence of water-borne apicomplexan and anthropozoonotic parasites Cryptosporidium, Neobalantidium coli and Entamoeba sp.
In the same way, herein we identified the occurrence of the nematode genus Lagochilascaris which entails public health concern. Human lagochilascariosis due to Lagochilascaris minor is an extremely neglected zoonotic disease and limited to the American continent. To the best of our knowledge here we present first non-human case report of L. cf. minor in a Colombian crab-eating fox. Thus, current doctoral thesis constitutes the first report of this parasite in non-human WA of Colombia. Finally, regarding the last zoonotic parasite identified in current doctoral thesis we reported the occurrence of the neglected causative agent of dipylidiosis in wild canids. Herein we expand the geographical distribution range of Dipylidium caninum sensu lato to the Pan-Amazon and northern Andean regions and constituting the first host record of this anthropozoonotic cestode in bush dogs. Analysed bush dog cestode corresponded well to recently proposed D. caninum canine genotype which occurs at a higher frequency in canids, has a shorter prepatent period and longer lifespan than the D. caninum feline genotype.
Nowadays constant surveillance of wildlife- and domestic animal-related diseases is imperative not only for better understanding of their adverse impact on environment, human- and animal populations but also on biodiversity conservation. Despite not having clinical nor epidemiological relevance in human populations, other non-zoonotic parasites were here identified both in WA and domestic animals. One of these cases were the acanthocephalan genus Oncicola identified both in ocelots (Leopardus pardalis) and jaguars and the precise phylogenetic identification of Taenia omissa collected from a dead puma (P. concolor) and a road-killed jaguarundi. Similarly in the same hosts species above mentioned, Cystoisopora-like oocysts were identified at a higher taxa level. Moreover, herein we reported the occurrence of highly underestimated protozoan species such as Eimeria trinidadensis, the nematodes Protozoophaga obesa, the capillarid Echinocoleus hydrochoerid and the metastrongyloid lungworms A. vasorum and G. paralysans, the cestode of the genus Monoecocestus sp., and neglected trematodes Hippocrepis hippocrepis, Taxorchis schistocotyle, and Chiorchis fabaceus. For all these unattended parasites we tried to bring more attention on possible consequences for WA health and hopefully will derive in more awareness on these cryptic parasites. Free-ranging WA should be considered not only as natural reservoirs for various pathogens but also to be affected by them; the same holds true for peri-domestic and synanthropic WA within Colombian national territories. Thus, emblematic WA species here investigated can be a good way to draw attention of the importance of parasite investigations under the concept of One Health, particularly for unattended species of vertebrate and invertebrate animals. Finally, current compendium generated new insights and highlighted future perspectives to parasitological research as a still-expanding field in the Americas.
