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

Abstract

Background and aim: 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.

Materials and methods: 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.

Results: 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.

Conclusion: 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.

Keywords: Aceh; Macaca fascicularis; Oesophagostomum bifurcum; Trichuris trichiura; ecotourism; gastrointestinal parasites; scanning electron microscopy; zoonosis.

Figure 1

Macaca fascicularis individuals from which fecal samples were collected.

Figure 2

Location of fascicularis feces sampling [Source : Aceh Qanun Number 19 of 2013 concerning the Aceh Regional Spatial Planning (RTRW) for 2013-2033].

Figure 3

Various types of nematode eggs, protozoa, and ectoparasites identified in fecal samples of fascicularis. (a) Balantidium spp., (b) Ascaris spp., (c) Trichuris spp., (d) Oesophagustomum spp., (e) Enterobius spp., (f) Strongyloides spp., (g) Ancylostoma spp., and (h) Psoroptes spp. mites.

Figure 4

Oesophagostomum (Conoweberia) bifurcum. (a) Anterior part, (b) cephalic portion, (c) posterior part of female, (d) posterior part of the male showing equal and similar spicules, (e) prebursal papilla, and (f and g) bursa ray (f: dorsal ray, g: lateral ray). cc=Cervical colar, dr=Dorsal ray, gub=Gubernaculum, lr=Lateral ray, pbp=Prebursa papilla, spi=Spicula, vul=Vulva.

Figure 5

Scanning electron microscopy of Oesophagostomum (Conoweberia) bifurcum. (a and b) Cephalic end, (c) internal and external leaf crown, (d) anterior part, (e) buccal tooth, (f) external corona radiata leaf and cephalic papilla, and (e) cervical papilla, and (g) cervical papilla. am=Amphid, cec=Cephalic solar, cp=Cephalic papilla, cc=Cervical colar, cv=Cervical vesicle, ecl=External leaf crown elements, ilc=External leaf crown elements.

Figure 6

Trichuris trichiura. (a) Anterior part, (b) cephalic portion, (c) middle portion of stichosome, (d) bacillary band, (e) posterior part of male showing equal and similar spicules, (f) posterior part of male showing spicule sheath, and (g) detail of the spiny spicular sheath. sp=Spicule, sps=Spicule sheath.