Confirmed Infection with Intestinal Schistosomiasis in Semi-Captive Wild-Born Chimpanzees on Ngamba Island, Uganda

Abstract Background: Intestinal schistosomiasis, caused by Schistosoma mansoni, is endemic to Lake Victoria, with high prevalence of the disease observed in human lakeshore communities. However, nonhuman primates have recently been overlooked as potential hosts of the disease, despite known susceptibility. Methods: Using a variety of stool, urine, and serological diagnostic methods, 39 semi-captive wild-born chimpanzees and 37 staff members at Ngamba Island Chimpanzee Sanctuary, Lake Victoria, Uganda, were examined for S. mansoni infection. Miracidia recovered from stool were DNA barcoded to investigate cross-over between humans and chimpanzees. The island was also surveyed for Biomphalaria intermediate host snails, which were examined for infection with S. mansoni. Results: Chimpanzees were unequivocally shown to be infected with intestinal schistosomiasis with a seroprevalence in excess of 90%. Three egg-positive cases were detected, although the sensitivity of the diagnostic tests varied due to earlier...