Irwin, Mitchell T.
M.A. (Master of Arts)
Department of Anthropology
Biology; Parasitology; Microbiology; Forensic anthropology
Cryptosporidium and Giardia are ubiquitous enteric protozoan pathogens that infect humans, domestic animals, and wildlife worldwide. These pathogens are known to cause gastroenteritis in their hosts, often being fatal in immunocompromised individuals. Both parasites are zoonotic and cross-species transmissions have occurred between humans, wildlife and domestic animals. Cryptosporidium and Giardia infections are reported in young children in Madagascar; however, the extent of these infections throughout the Malagasy population is relatively unknown and unstudied. The rainforest of Tsinjoarivo, Madagascar, contains areas with pristine forests as well as fragmented forests which have been created by human encroachment and deforestation. Since protozoan parasites have not been studied in Tsinjoarivo, this project provides a baseline study of Cryptosporidium and Giardia infections in a cross-species sample of lemurs, humans, domestic mammals, and invasive rats in this area. I collected fecal samples during the period May to July, 2014 from two diurnal lemur species (Propithecus diadema and Hapalemur griseus), humans, domestic mammals (cattle, pigs and dogs), and invasive rats. The fecal samples were tested for the presence of Cryptosporidium and Giardia utilizing immunofluorescence assay testing. No lemurs were found to be positive for Cryptosporidium or Giardia. I found Cryptosporidium infections in humans (10%), cattle (20%), pigs (20%), dogs (15%) and invasive rats (38%). I found Giardia infections in humans (10%), pigs (40%), dogs (29%) and invasive rats (53%). I assessed possible infection risk factors for humans using: age, sex, household size, gastrointestinal symptoms, frequency of forest entry, and contact with lemurs, domestic mammals and invasive rats. All infected human subjects were children ≤13 years old. Furthermore, all human participants reported having direct contact with domestic mammals and invasive rats within the last 30 days. Potential infection risk factors for domestic mammals were examined (age and group size) with no significant results found. I detected coinfections of both Cryptosporidium and Giardia in humans (6%), pigs (20%), dogs (15%) and invasive rats (33%). As human populations increase in Madagascar, the human-wildlife encounters also increase, making it critical to understand this interface and its health impacts to humans and animals alike. The results of this study document zoonotic health concerns at Tsinjoarivo and can assist the public health and conservation efforts by adding to our understanding of Cryptosporidium and Giardia infection risks for sympatrically living humans, wildlife and domestic animals.
Spencer, Laurie, "Prevalence and transmission of Cryptosporidium and Giardia infections amongst lemurs, humans, domestic mammals and invasive rats in Tsinjoarivo, Madagascar" (2017). Graduate Research Theses & Dissertations. 4502.
iv, 89 pages
Northern Illinois University
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