Environmental and biological drivers of prevalence and number of eggs and oocysts of intestinal parasites in red howler monkeys from Central Amazonia

Abstract Host-parasite relationships can be directly affected by host’s biological aspects and environmental factors, which influence both the survival of infective forms incidence parasites. However, logistical difficulties in accessing samples for parasitological studies makes Amazon Forest into a poorly known region relation to dynamic parasites wild animals. Here, using 34 red howler monkeys’ donated local subsistence hunters from two habitat types (white-water flooded forest upland forest) as an opportune alternative, we detected four intestinal parasite taxa infecting this species (two nematodes – Trypanoxyuris sp. Strongyloides sp., one protozoan Entamoeba –, not-identified trematode, last just found white-water forest). was most prevalent (56.5% at 54.5% There no difference between or individual sex regarding prevalence any taxa. On other hand, strong seasonality, with increasing all river water level increased. In terms egg cyst counts, sexes (females > males, p = 0.002) (upland forest, 0.02), positive relationship (p 0.002). Although some these shared humans howlers, further investigations are necessary study taxonomy thoroughly assess potential zoonotic cross-transmission pathogens people living Amazon. study, unveiled seasonal effect parasites, that also might occur non-human primates addition, our results on periods high risk infection useful estimate future impacts climate change host-parasite dynamics.