Epidemiology and Molecular Characterization of Cryptosporidium spp. in Humans, Wild Primates, and Domesticated Animals in the Greater Gombe Ecosystem, Tanzania

• Type of Material: Article
• Authors: Michelle Parsons, Emory University; Dominic Travis, University of Minnesota; Elizabeth V. Lonsdorf, Franklin and Marshall College; Iddi Lipende, The Jane Goodall Institute; Dawn M. Anthony Roellig, Centers for Disease Control and Prevention; Shadrack Kamenya, The Jane Goodall Institute; Hongwei Zhang, Henan Center for Disease Control and Prevention; Lihua Xiao, Centers for Disease Control and Prevention; Thomas Gillespie, Emory University
• Language: English
• Date: 2015-02-20
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• License: Creative Commons Creative Commons CC0 1.0 Universal
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pntd.0003529
• Title of Journal or Parent Work: PLoS Neglected Tropical Diseases
• ISSN: 1935-2727
• Volume: 9
• Issue: 2
• Start Page: e0003529
• End Page: e0003529
• Grant/Funding Information: Funding for this study comes from the Morris Animal Foundation (MAF D09ZO-041 and MAF D09ZO-634), the Emory University Global Health Institute, the Arcus Foundation, the Leo S. Guthman Foundation and the National Institutes of Health (R01 AI58715).
• Research Categories: Environmental Sciences; Health Sciences, Public Health

Abstract

Cryptosporidium is an important zoonotic parasite globally. Few studies have examined the ecology and epidemiology of this pathogen in rural tropical systems characterized by high rates of overlap among humans, domesticated animals, and wildlife. We investigated risk factors for Cryptosporidium infection and assessed cross-species transmission potential among people, non-human primates, and domestic animals in the Gombe Ecosystem, Kigoma District, Tanzania. A cross-sectional survey was designed to determine the occurrence and risk factors for Cryptosporidium infection in humans, domestic animals and wildlife living in and around Gombe National Park. Diagnostic PCR revealed Cryptosporidium infection rates of 4.3% in humans, 16.0% in non-human primates, and 9.6% in livestock. Local streams sampled were negative. DNA sequencing uncovered a complex epidemiology for Cryptosporidium in this system, with humans, baboons and a subset of chimpanzees infected with C. hominis subtype IfA12G2; another subset of chimpanzees infected with C. suis; and all positive goats and sheep infected with C. xiaoi. For humans, residence location was associated with increased risk of infection in Mwamgongo village compared to one camp (Kasekela), and there was an increased odds for infection when living in a household with another positive person. Fecal consistency and other gastrointestinal signs did not predict Cryptosporidium infection. Despite a high degree of habitat overlap between village people and livestock, our results suggest that there are distinct Cryptosporidium transmission dynamics for humans and livestock in this system. The dominance of C. hominis subtype IfA12G2 among humans and non-human primates suggest cross-species transmission. Interestingly, a subset of chimpanzees was infected with C. suis. We hypothesize that there is cross-species transmission from bush pigs (Potaochoerus larvatus) to chimpanzees in Gombe forest, since domesticated pigs are regionally absent. Our findings demonstrate a complex nature of Cryptosporidium in sympatric primates, including humans, and stress the need for further studies.