Quantitative risk assessment for Cryptosporidium oocysts and Giardia cysts was performed to determine the public health significance of non-potable use of tertiary treated reclaimed water. Seven reclaimed water treatment plants in the southwestern United States participated in this study. The average public exposure to oocysts and cysts was estimated, based on concentrations, recovery efficienc...

BACKGROUND Giardia spp. are flagellated protozoan parasites that infect humans and many other vertebrates worldwide. Currently seven species of Giardia are considered valid. RESULTS Here, we report a new species, Giardia cricetidarum n. sp. in hamsters. Trophozoites of G. cricetidarum n. sp. are pear-shaped with four pairs of flagella and measure on average 14 μm (range 12-18 μm) in length an...

Giardia and Cryptosporidium spp. are important enteric protozoan pathogens for humans and animals, and have been found to contaminate water as well as edible shellfish all over the world. This is the first study to simultaneously investigate the presence of Giardia and Cryptosporidium in inflowing water and harvested shellfish in a geographically closed environment (Varano Lagoon, Southern Ital...

BACKGROUND Dose-response parameters based on clinical challenges are frequently used to assess the health impact of protozoa in drinking water. We compare the risk estimates associated with Giardia in drinking water derived from the dose-response parameter published in the literature and the incidence of acute digestive conditions (ADC) measured in the framework of an epidemiological study in a...

There are several drugs available for the treatment of giardiasis in cats, including metronidazole. The purpose of this study was to determine whether metronidazole benzoate administered at a dose of 25 mg/kg, orally, twice a day for 7 days lessens or eliminates Giardia cyst shedding in cats with chronic infection. Twenty-six, adult, laboratory-reared cats were used in this study. Sixteen cats ...

Eight pairs of published PCR primers were evaluated for the specific detection of Cryptosporidium parvum and Giardia lamblia in water. Detection sensitivities ranged from 1 to 10 oocysts or cysts for purified preparations and 5 to 50 oocysts or cysts for seeded environmental water samples. Maximum sensitivity was achieved with two successive rounds of amplification and hybridization, with oligo...

We quantified mRNA abundance from 10 stages in the Giardia lamblia life cycle in vitro using Serial Analysis of Gene Expression (SAGE). 163 abundant transcripts were expressed constitutively. 71 transcripts were upregulated specifically during excystation and 42 during encystation. Nonetheless, the transcriptomes of cysts and trophozoites showed major differences. SAGE detected co-expressed clu...

The interaction of the intestinal phases of Giardia muris and Trichinella spiralis was investigated in Swiss albino mice. Intraoesophageal inoculation of G. muris cysts seven days before, or seven days after, similar inoculation of T. spiralis larvae resulted in significant reduction in the numbers of Giardia trophozoites in small bowel and Giardia cysts in stools. This effect was not observed ...

Giardia duodenalis is an intestinal protozoal parasite capable of causing both clinical and subclinical disease in a broad range of species, including humans and cats. The parasite has a ubiquitous distribution and infection occurs worldwide in nearly all mammals. Giardia infection in cats may not be associated with any clinical signs, but affected cats most commonly exhibit acute small bowel d...