Förekomst av Giardia i symtomfria valpkullar

The flagellate Giardia intestinalis has been known to cause diarrhea in both man and dog. Results from epidemiological studies have indicated that transmission of the parasite from dog to man is plausible even though that route of infection has yet to be shown. Several international studies have shown that the parasite frequently occurs in asymptomatic dogs. In Sweden the prevalence of Giardia in healthy dogs is not known though. In this study, faecal samples were collected at two separate occasions from 21 litters and 21 bitches showing no symptoms from the gastrointestinal tract. The samples from each litter were pooled but the samples from the bitches were analyzed individually. All of the samples were analyzed both by immunofluorescence (Waterborne Cyst-a-Glo Kit) and an ELISA test (ProSpect Giardia Microplate Assay). 7 out of 21 (33 %) litters and 2 out of 21 (9.5 %) bitches in this study was harboring the parasite. 3 of the positive samples were sent to the Swedish Institute for Infectious Disease Control (SMI) where they were classified based on genotype in order to evaluate their zoonotic potential. All the analyzed samples belonged to genotypic group C and D that have never been shown to be able to infect humans. When comparing the two methods used in this study to detect Giardia it was evident that ELISA is a more sensitive method than immunofluorescence. The results indicate that Giardia is a common parasite in the bowel of asymptomatic Swedish puppies. This is a complicating factor as it makes it rather difficult to assess positive test results in a clinical environment.