Active substances: Azithromycin
+ free Zithromax pill.
However, at that time, they were not able to assign to these animals a maj or role in the epidemiology of waterborne giardiasis in humans.
A polymerase chain reaction PCR -based method for genotyping G.
Analysis was performed using Giardia cysts purified directly from feces. Isolates were collected from humans and dogs living in isolated Aboriginal communities in Australia where Giardia infections are highly endemic. This is the first report of the genetic characterization of Giardia from dogs and humans living in the same locality.
Groups 1 and 2 contained all of the human isolates, whereas groups 3 and 4 consisted entirely of Giardia recovered from dogs.
These results suggest that zoonotic transmission of Giardia infections between humans and dogs does not occur frequently in these communities. A genetic basis for the differences observed between the groups was supported by sequence analysis of nine in vitro cultured isolates that were placed into the same genetic groups established by enzyme electrophoresis.
Pathogen-free mice were also successfully infected with Giardia from hamsters, but Giardia cysts obtained from parakeet feces and stored for 1-3 days were unable to infect mice or canaries 1 CAIR, 1984.
Cross transmission studies in which beavers and muskrats were fed Giardia cysts from muskrats, beavers and mice were conducted by Erlandsen et al. Beavers did not become infected when inoculated with cysts of G. Summary of Cross-Species Transmission Many early Giardia transfer studies were poorly controlled, but more recent carefully controlled studies indicate that cross-species transmission of Giardia can occur.
Experimental human and animal infection studies offer increasing evidence that some lower animals, particularly fur-bearing water mammals, are capable of harboring Giardia that can also infect humans Isaac-Renton, 1994.
While Giardia that are indistinguishable from those that infect humans are widespread throughout the Animal Kingdom, current evidence remains insufficient regarding their ability to be transferred to humans.
The role in nature of these animals as a source of human infection, however, remains controversial.
Of all of these animals, existing evidence suggests that the beaver and the muskrat are the most likely candidate mammals to serve as a source or reservoir of giardiasis and possible cause of some outbreaks in humans.
Both of these aquatic mammals can be infected with isolates of Giardia from humans. However, each has also been shown to harbor strains of Giardia that are phenotypically distinct from those found in humans.
The other type maybe one acquired by the beaver from human sources, which can multiply in the beaver and in turn br transmitted via water back to humans. The argument supporting the complicity of the beaver and muskrat in human giardiasis and minimizing the role of other animals is as follows: In North America, epidemic and endemic giardiasis is frequently transmitted by contaminated water.
To deposit sufficient numbers of cysts that can infect large numbers of humans in a short time arguably is best accomplished by Giardia-mfected animals which, by nature, defecate in fresh water.
Beavers have been implicated as a possible source of contamination in several waterborne outbreaks Craun, 1990.
Studies taking this approach are in progress in British Columbia, and have strengthened the evidence that suggests a role for beaver in the spread of giardiasis to humans Isaac-Renton, 1994.
Buret et al. A study ofGiardia infection of ruminants found that cyst output and clinical signs resembled human disease and that the Giardia from infected ruminants was morphologically and antigenically similar to humans.