# Prevalence and characterization of gastrointestinal and ectoparasites in long-tailed macaques (Macaca fascicularis) from ecotourism regions of Aceh, Indonesia

## TL;DR

This study examines the prevalence of parasites in long-tailed macaques in ecotourism areas of Aceh, Indonesia, highlighting zoonotic risks and the need for health monitoring.

## Contribution

The study combines traditional and advanced diagnostic methods to characterize zoonotic parasites in wild macaques in ecotourism regions.

## Key findings

- Nematodes were the most prevalent parasites, with Ancylostoma spp. and Oesophagostomum spp. being common.
- Mixed infections were more frequent than single infections, and zoonotic species like Trichuris trichiura were identified.
- Combining SEM and lactophenol staining improved parasite identification accuracy.

## Abstract

Long-tailed macaques (Macaca fascicularis) serve as critical sentinels for zoonotic disease surveillance due to their ecological proximity to human populations. Understanding their parasitic burden is vital for conservation and public health, particularly in ecotourism areas where human-primate interactions are frequent. This study aimed to investigate the prevalence, diversity, and morphological characteristics of gastrointestinal (GI) and ectoparasites in M. fascicularis across four natural habitats in Aceh Province, Indonesia.

A total of 100 fecal samples were collected from wild macaques at four sites: Pulau Weh Sabang Nature Tourism Park, Kuala Langsa Mangrove Forest, Saree (Aceh Besar), and Aceh Jaya. The parasitological examination involved the centrifugation method, lactophenol staining, and scanning electron microscopy (SEM). Parasites were identified based on egg morphology and adult worm anatomy.

Of the 100 samples analyzed, 45% tested positive for GI parasites. Nematode prevalence was highest (80%), followed by protozoa (10%) and ectoparasites (10%). Identified nematodes included Ancylostoma spp. (70%), Oesophagostomum spp. (50%), Strongyloides spp. (40%), Ascaris spp. (30%), Enterobius spp. (20%), and Trichuris spp. (10%). Protozoan (Balantidium spp.) and ectoparasitic (Psoroptes spp.) infections were less common. Mixed infections were more frequent (70%) than single infections (30%). Adult worms examined through SEM and lactophenol staining were confirmed to be two nematode species: Oesophagostomum (Conoweberia) bifurcum and Trichuris trichiura, both with zoonotic potential.

The high prevalence of nematodes, particularly zoonotic species, underscores the importance of monitoring parasitic infections in M. fascicularis residing in tourist-exposed areas. This study highlights the utility of combining traditional and advanced diagnostic techniques to enhance parasite surveillance. Integrating health assessments of wild primate populations into conservation programs is recommended to mitigate zoonotic risk and support One Health objectives.