title: Individual subject meta-analysis of parameters for Giardia duodenalis shedding in animal experimental models.
abstract: Giardia duodenalis is a zoonotic protozoan parasite with public health importance worldwide. While articles about animal model infectivity have been published for G. duodenalis, the studies have used diverse protocols and parameters to evaluate the infectivity of this protozoan parasite. Hence, the objectives of this study were to (1) conduct a meta-analysis of published literature for cyst shedding and diarrhea outcomes in animal models and (2) develop recommendations to help standardize experimental dose response studies. Results showed that, for the outcome of cyst shedding in faeces, the covariates of infective stage (cyst versus trophozoite), Giardia dose, and the interactions between doses and infective stage, as well as dose and species of experimental host, were all significant (P value ≤ 0.05). This study suggests inoculation of the experimental host with cysts rather than trophozoites and administration of higher doses of Giardia will most likely result in cyst shedding. Based on the results of this meta-analysis, the infective stage (cyst versus trophozoite), parasite dose, and the interactions between dose and infective stage, as well as dose and species of experimental host, should be considered when designing experimental dose response studies that will assist in the study of zoonotic neglected tropical diseases globally.
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, One Shields Avenue, University of California, Davis, CA 95616, USA ; Escuela de Medicina Veterinaria, Facultad de Ecologia y Recursos Naturales, Universidad Andres Bello, Republica 440, 8370251 Santiago, Chile.
authors.forename: A D
authors.initials: AD
authors.lastname: Adell
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, One Shields Avenue, University of California, Davis, CA 95616, USA ; One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: W A
authors.initials: WA
authors.lastname: Miller
authors.affiliation: Department of Public Health Sciences, School of Medicine, University of California, Davis, CA 95616, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Harvey
authors.affiliation: One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: E
authors.initials: E
authors.lastname: Van Wormer
authors.affiliation: Department of Civil & Environmental Engineering, College of Engineering, University of California, Davis, CA 95616, USA ; Singapore Centre on Environmental Life Sciences Engineering (SCELSE), School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 ; School of Civil and Environmental Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551.
authors.forename: S
authors.initials: S
authors.lastname: Wuertz
authors.affiliation: Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, One Shields Avenue, University of California, Davis, CA 95616, USA ; One Health Institute, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Conrad
mesh_terms: D000818:Animals; D057138:Bacterial Shedding; D003967:Diarrhea / Q000469:parasitology*; D004195:Disease Models, Animal; D005243:Feces / Q000469:parasitology*; D016829:Giardia lamblia / Q000472:pathogenicity*; D005873:Giardiasis / Q000453:epidemiology / Q000469:parasitology* / Q000662:veterinary*; D006801:Humans; D015995:Prevalence