Prevalence of intestinal trichomonads in captive non-human primates in China

Trichomonads are protozoan symbionts with the capacity to infect vertebrates including humans and non-human primates (NHPs), sometimes with pathogenic effects. However, their diversity and prevalence in NHPs in China are poorly understood. A total of 533 fecal samples were collected from captive NHPs in Yunnan Province, China, of which 461 samples from Macaca fascicularis and 72 from Macaca mulatta. Trichomonadidae species were identified using PCR amplification of the ITS-1/5.8S/ITS-2 sequences. The overall prevalence of trichomonads in NHPs was determined to be 11.4% (61/533), with gender, diarrhea, and region identified as potential risk factors for the infections. Sequence alignment and phylogenetic analysis identified three species of trichomonads, i.e., Trichomitopsis minor (n = 45), Pentatrichomonas hominis (n = 11), and Tetratrichomonas sp. (n = 5). To the best of our knowledge, this is the first study to report Trichomitopsis minor infection in NHPs in China. Of note, Pentatrichomonas hominis is generally recognized as a parasitic organism affecting humans. Collectively, our results suggest that NHPs are potential sources of zoonotic trichomonad infections, highlighting the importance of surveillance and control measures to protect human and animal populations.