Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 9 1 2014 03 15 125 128 EN Hai Long Li School of Basic Medicine, Dali University, Dali, China. Qian Li School of Basic Medicine, Dali University, Dali, China. Ling Dong School of Basic Medicine, Dali University, Dali, China. Juan Li Institute of Veterinary Medicine, Guangdong Academy of Agricultural Sciences, Guangzhou, China. Feng Cai Zou College of Animal Science and Technology, Yunnan Agricultural University, Kunming, China. Li Zhang School of Basic Medicine, Dali University, Dali, China. 2015 10 14   Background: Balantidium coli infects humans, primates and pigs, causing serious diarrhea and dysentery. Little information on the prevalence of B. coli in primates is available in China. This investigation was conducted to determine the prevalence of B. coli infection in bred rhesus monkeys in Guangxi Zhuang Nationality Autono-mous Region (GZNAR), southern China. Methods: A total of 120 fecal samples were collected from rhesus monkeys bred in cages in GZNAR and B. coli cysts and/or trophozoites were examined microscopi-cally after sedimentation with water in May 2013. Results: 77 (64.2%) samples were tested positive. The prevalence was 65% (39/60) and 63.3% (38/60) in female and male monkeys, respectively. 80% (48/60) cages in this nonhuman primate center were positive for B. coli. Conclusion: The present survey revealed high circulation of B. coli in bred rhesus monkeys in GZNAR, which poses potential threats to animal and human health. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/424 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/424/320