Giardia spp., ten years of parasitological data in the biggest zoo of Latin America

Giardia spp. (Diplomonadida: Hexamitidae) is an important and widely studied protozoan parasite with worldwide distribution. Nowadays have six described species, and the most important probably is Giardia duodenalis due to the zoonotical potential that some assemblages have. Many studies analysing samples from wild animals have detected Giardia in captive environment, including the zoonotic type. The aim of this study was to determine the prevalence of Giardia sp. in wild captive animals at Sao Paulo Zoo, using conventional parasitological techniques (direct smear, passive flotation with saturated sodium chloride solution and simple gravity sedimentation), from 2006 to 2016. In total, 7066 coprological exams were performed during this period with samples from mammals, birds, reptiles and amphibians. The prevalence of Giardia infections was of 1.5% (103/7066). Mammals had the higher prevalence of infections with 2% (77/3872), followed by birds with 1.1% (25/2186) and reptiles with only one positive sample (1/894). All samples from amphibians were negative. Representatives of thirteen families presented positive results for this parasite: Dromaidae, Phasianidae, Ramphastidae, Cervidae, Giraffidae, Canidae, Felidae, Herpestidae, Myrmecophagidae, Callithrichidae, Cebidae, Hylobatidae and Dipsadidae. This study presents the first report of Giardia sp. in Pavo muticus and Brachyteles arachnoides. Infections were prevalent in Cebidae and Ramphastidae species. The findings of this study highlight the importance of identifying which Giardia assemblage are involved in the infections and if they may have a zoonotic potential.