Changing parasite landscapes in captive primates: methodological advances and findings from the Wrocław Zoo

Long-term parasitological studies of non-human primates (NHPs) kept in zoological gardens offer valuable insights into host-parasite relationships in controlled settings. Despite regular veterinary supervision and preventative measures, many surveys have shown that captive primates often harbour diverse intestinal parasites, including species of zoonotic importance. This work summarises the historical and current parasitological research conducted on primates at Wrocław Zoological Garden, Poland, and highlights changes in diagnostic techniques, parasite diversity, and infection patterns over time. Early studies, employing classical coproscopic methods such as direct smear, decantation, and flotation, reported an overall parasite prevalence of around 40%, mainly nematodes. Later investigations expanded sampling strategies, enabling assessment of anthelmintic efficacy and resistance in specific taxa. Environmental and managerial factors - including close contact with caretakers and visitors, limited enclosure space, and inadequate pest control - were identified as key contributors to transmission. Over the past twenty years, the use of molecular diagnostic tools has considerably improved detection sensitivity, particularly for intestinal protozoa that were often missed by traditional microscopy. A notable shift in the parasite community composition has been observed: helminth prevalence has decreased, while protozoan infections have become more frequent. Whether these changes are due to methodological advancements or actual alterations in parasite ecology remains uncertain. Overall, the findings indicate that enhancements in husbandry, enclosure hygiene, and veterinary care have effectively reduced helminth transmission, yet protozoan infections continue to be common. Ongoing monitoring with molecular methods, alongside comparative studies across European zoological institutions, is essential for a comprehensive understanding of the long-term dynamics of primate parasitism in captivity.