# Prevalence of Gastrointestinal Parasites in Wild Asian Elephants (Elephas maximus) at a National Park in Eastern Thailand

## TL;DR

This study found that wild Asian elephants in a Thai national park have high rates of gastrointestinal parasites, likely due to contact with livestock and environmental factors.

## Contribution

The study provides new baseline data on parasite prevalence in wild Asian elephants and emphasizes the need for integrated surveillance.

## Key findings

- All 135 fecal samples contained at least one parasite species, with 84.4% having mixed infections.
- Strongyle-type and Strongyloides spp. nematodes were the most common, followed by Paramphistomum spp. and Fascioloides jacksoni trematodes.

## Abstract

Wild Asian elephants (Elephas maximus) living near agricultural lands often come into contact with livestock, increasing the risk of cross-species disease transmission. This study investigated gastrointestinal parasites in wild elephants at Khao Sip Ha Chan National Park, eastern Thailand, an important area within the Eastern Forest Complex where human–elephant interactions are frequent. Fecal samples (n = 135) were collected from three wild elephant populations and examined using four standard parasitological methods—all samples contained at least one parasite species, with a high rate of mixed infections. The most common parasites were strongyle-type and Strongyloides spp. nematodes, followed by the trematodes Paramphistomum spp. and Fascioloides jacksoni. Parasite prevalence and intensity varied between populations, likely influenced by environmental factors and proximity to livestock. These results highlight the importance of long-term parasite monitoring in wild elephants and support a One Health approach to managing wildlife–livestock interfaces for conservation and disease prevention.

Protected national parks continue to face increased pressure from the expansion of human–wildlife interface zones, where habitat encroachment promotes human–wildlife contact and zoonotic disease transmission. Gastrointestinal parasites (GIPs) are a significant health issue in wild Asian elephants (Elephas maximus), affecting their fitness, survival, and potential for cross-species transmission. This study aimed to investigate the prevalence of GIPs among wild elephants at Khao Sip Ha Chan National Park in eastern Thailand. Direct smear, formalin-ethyl acetate sedimentation, flotation, and McMaster egg per gram (EPG) counting were used to examine 135 fecal samples from three populations. The findings showed that nematodes (Strongyle-type and Strongyloides spp.) and trematodes (Paramphistomum spp. and Fascioloides jacksoni) were identified. All samples were positive for at least one parasite species, and 84.4% were affected by mixed infections. The prevalence of Strongyle-type and Strongyloides spp. varied significantly among the studied populations, but Paramphistomum spp. had a moderate prevalence, and Fascioloides jacksoni had a low prevalence. The high parasite burden could be explained by environmental factors, host density, and movement patterns influencing parasite transmission, and these factors should be further investigated. These findings provide crucial baseline data and underscore the need for integrated parasite surveillance, alongside long-term conservation and future research.