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Query: UMLS:C0017536 (giardiasis)
 1,714 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Giardia lamblia has emerged as the most common intestinal parasite in the United States. This article presents a brief review of the clinically important aspects of giardiasis and evaluates the currently used therapeutic agents. Three drugs have been advocated for the treatment of giardiasis; furazolidone (Furoxone), metronidazole (Flagyl), and quinacrine (Atabrine). None of them, however, is ideal. Metronidazole and quinacrine are more effective than furazolidone, but furazolidone has the advantage of a liquid formulation that makes administration to children easier. Quinacrine is much less expensive than the other two agents but has a somewhat higher rate of side effects and a bitter taste. There is concern about the carcinogenic potential of furazolidone and metronidazole, but this has not been evaluated for quinacrine. In the balance, we conclude that quinacrine is probably the preferable drug to use in the pediatric age group because of proven effectiveness and lower cost.
Clin Pediatr (Phila) 1982 Jul
PMID:Treatment of giardiasis: literature review and recommendations. 704 42

One hundred fifty-nine children aged 24 to 61 months with 60% ascariasis prevalence and 21.5% giardiasis prevalence in rural Guatemala were studied prospectively for 1 yr. They were divided into four groups comparable for age, sex, socioeconomic status, and past growth experience as judged by slopes of height and weight on age. Each group was randomly assigned to the following 2-monthly treatment regimens: group I, placebo, group II, piperazine, group III, metronidazole; group IV, piperazine and metronidazole. Height and weight were measured every 3 months and stools were examined for parasites every 4 months. Piperazine administration decreased the prevalence of ascariasis to 33.8% at the end of the study but growth remained unaltered. Metronidazole administration decreased the prevalence of giardiasis to 2.5% at the end of the study and was accompanied by increased growth as judged by delta weight, delta % weight for age, slope of weight on age, delta height, delta % height for age and slope of height on age. It is suggested that failure of antiascaris treatment to enhance growth in this study may be because of 1) absence of severe malnutrition in the subjects, 2) adequacy of dietary protein, 3) possible low worm load, and 4) failure to eradicate ascariasis. The findings suggest that giardiasis is associated with reduced growth in preschool children.
Am J Clin Nutr 1982 Jul
PMID:Effect of periodic antiascaris and antigiardia treatment on nutritional status of preschool children. 709 Oct 37

Giardiasis is the most common parasitic infection in the United States. Variation in the numbers of cysts and/or trophozoites that are present along with the need for a skilled microscopist offer challenges in diagnosis. We compared the sediment wet preparation and permanent stained smear results (concentration in formalin-ethyl acetate and preparation of a smear prepared from a polyvinyl alcohol-preserved specimen) from 512 consecutive specimens with the results obtained by using the Merifluor Cryptosporidium/Giardia Direct Immunofluorescence Assay (DFA; Meridian Diagnostics, Inc., Cincinnati, Ohio) and the ProSpecT Giardia EZ Microplate Assay (EIA; Alexon, Inc., Sunnyvale, Calif.). The Merifluor DFA detected 33 of 33 positive specimens, and the ProSpecT EIA detected 32 of 33 positive specimens. The diagnostic sensitivities of the Merifluor DFA and the ProSpecT EIA were 100 and 97%, respectively. The specificities of the assays were 99.8%. The Merifluor DFA and the ProSpecT EIA appear to be equally sensitive, and both are more sensitive than conventional microscopy.
J Clin Microbiol 1995 Jul
PMID:Comparison of conventional stool concentration and preserved-smear methods with Merifluor Cryptosporidium/Giardia Direct Immunofluorescence Assay and ProSpecT Giardia EZ Microplate Assay for detection of Giardia lamblia. 766 78

As a result of disposal problems related to the use of mercury compounds, many laboratories have considered switching from mercuric chloride-based Schaudinn's and polyvinyl alcohol (PVA) stool preservatives to other non-mercury-based preservatives. The primary use for PVA-preserved specimens is the permanent stained smear, the most important technique in the routine ova and parasite examination for the identification and confirmation of intestinal protozoa. A comparison of organism recovery and morphology of the intestinal protozoa was undertaken with PVA containing either a zinc sulfate base or the "gold standard" mercuric chloride base. Paired positive fecal specimens (106 from 64 patients) were collected and examined microscopically by the trichrome stain technique. There were 161 instances in which organism trophozoite and/or cyst stages were identified and 3 in which human cells were identified. Morphology, clarity of nuclear and cytoplasmic detail, overall color differences, and the ease or difficulty in detecting intestinal protozoa in fecal debris, as well as the number of patients with a missed diagnosis, were assessed from the permanent stained smear. Overall organism morphology of the intestinal protozoa preserved in zinc sulfate-PVA was not always equal in nuclear and cytoplasmic detail or range of color after permanent staining to that seen with mercuric chloride-PVA. However, the same organisms were usually identified in both specimens, with the exception of situations in which organism numbers were characterized as rare (no organisms per 10 oil immersion fields at x1,000 magnification but at least one organism in the smear) [9 of 161 (5.6%)] or the organism was missed because of poor morphologic detail [12 of 161 (7.5%)]. In only six of these cases [6 of 161 (3.7%)] did the results involve pathogens. The patient diagnosis was missed in four cases of amebiasis and two cases of giardiasis; in both situations the organism numbers were rare. There were no discrepant results with Dientamoeba fragilis. Overall agreement between the two PVA-based results was 87.0% (140 of 161); when the instances of rare organisms were disregarded, the overall agreement was 92.5% (149 of 161). On the basis of these findings, zinc-PVA is viable substitute for mercuric chloride-PVA used for trichrome permanent stained smears.
J Clin Microbiol 1993 Feb
PMID:Evaluation of intestinal protozoan morphology in polyvinyl alcohol preservative: comparison of zinc sulfate- and mercuric chloride-based compounds for use in Schaudinn's fixative. 767 2

A 7-year-old boy, who had returned to the United States in June 1991 after a 3-year stay in Malawi, was evaluated in October 1991 because of hematuria. He was excreting Schistosoma haematobium eggs and was treated with praziquantel (PZQ; approximately 40 mg/kg). He may have spit up < or = 30% of this dose, and a concomitant Giardia lamblia infection might have caused malabsorption of PZQ. Because of persistent excretion of viable eggs, he was retreated with PZQ in January and May 1992. Egg excretion was first quantified 2 months following his second course of PZQ; at that time it was 35 eggs per 10 mL of urine. He excreted viable eggs at least as late as October 1992, 5 months after his third PZQ course. Experimental administration of chemotherapy to hamsters infected with the S. haematobium strain demonstrated that it was susceptible to PZQ. Repeated courses of therapy with PZQ may be necessary to cure S. haematobium infection, and both parasite and host factors should be considered if infection persists.
Clin Infect Dis 1995 Feb
PMID:Persistence of Schistosoma haematobium infection despite multiple courses of therapy with praziquantel. 774 35

Giardia lamblia, a cause of diarrheal disease throughout the world, is a protozoan parasite that thrives in the small intestine. It is shown here that wheat germ agglutinin (WGA), a naturally occurring lectin widely consumed in normal human diets, reversibly inhibits the growth of G. lamblia trophozoites in vitro, and reduces infection by G. muris in the adult mouse model of giardiasis. The inhibitory effect was dose related, not associated with cytotoxicity and reversed by N-acetyl-D-glucosamine in accordance with the known specificity of the lectin and in agreement with the presence of GlcNAc residues on the surface membrane of G. lamblia trophozoites. Cell cycle analysis revealed that parasites grown in the presence of WGA are arrested in the G2/M phase, providing an explanation for the lectin-induced inhibition of cell proliferation. Comparison of electrophoretic profiles by lectin blot analysis revealed both glycoprotein induction and suppression in growth-arrested organisms. Our findings raise the possibility that blocking trophozoite growth with naturally occurring dietary lectins may influence the course of giardiasis. In addition, the study of cell cycle arrest by WGA may provide a model to study the regulation of cell division in lower eukaryotes.
J Clin Invest 1994 Dec
PMID:Growth inhibition of the intestinal parasite Giardia lamblia by a dietary lectin is associated with arrest of the cell cycle. 798 83

In vivo, epithelial cells which line the intestine are intimately associated with lymphocytes, termed intraepithelial lymphocytes. Previous studies have demonstrated that intraepithelial lymphocytes are present in the uninflamed mucosa, and become especially prominent in various human enteropathies including coeliac disease, tropical sprue, dermatitis herpetiformis, and giardiasis. Using the intestinal crypt cell line T84, and a previously well-defined human mucosa-derived lymphocyte (MDL) line with phenotypic features similar to (but not specific for) intraepithelial lymphocytes, we describe a co-culture model to study the functional sequellae of MDL-T84 cell interactions in vitro. A co-culture method was defined which permitted reconstitution of the paracellular spaces of physiologically confluent epithelial monolayers with MDL. Such co-cultures thus mimicked the correct geometry of intraepithelial lymphocytes-epithelial cell interactions. The presence of physiologically positioned MDL brought about specific and dramatic effects on intestinal epithelial monolayer function. In a dose-dependent fashion, the presence of MDL significantly attenuated barrier function (expressed as a decrease in monolayer resistance), decreased epithelial electrogenic Cl- secretion, and modulated epithelial-neutrophil interactions. Such effects were not reproduced in monolayers similarly reconstituted with inert polystyrene beads equivalent in size to MDL. These MDL-elicited effects on epithelial function specifically required direct MDL apposition to the epithelial basolateral membrane. Furthermore, this specific form of MDL-epithelial basolateral contact released soluble factors which were able to confer the MDL-reconstituted phenotype on virgin epithelial monolayers in the absence of MDL. We have previously shown that many aspects of the MDL converted epithelial phenotype described here can be induced by IFN-gamma. While IFN-gamma, a cytokine produced by many lymphocytes including intraepithelial lymphocytes, was detectable in conditioned supernatants from co-cultures, it existed at concentrations insufficient to fully explain the physiologic effects observed here.
J Clin Invest 1994 Aug
PMID:Reconstitution of cultured intestinal epithelial monolayers with a mucosal-derived T lymphocyte cell line. Modulation of epithelial phenotype dependent on lymphocyte-basolateral membrane apposition. 804 Mar 34

Giardia lamblia is a common gastrointestinal pathogen but is not generally appreciated as a cause of severe illness. To describe the epidemiology of severe giardiasis, we reviewed data on hospital discharges from the United States and the state of Michigan and compared results for giardiasis with those for shigellosis. From 1979 to 1988, an estimated 4,600 persons were hospitalized for giardiasis annually in the United States; the incidence of giardiasis was 2.0 hospitalizations per 100,000 persons, compared with 2.4 hospitalizations per 100,000 persons for shigellosis. Rates of giardiasis were highest among children younger than 5 years old and women of childbearing age; the median length of hospital stay was 4 days (annual total, 23,238 days). Among residents of Michigan from 1983 to 1987, the average annual incidence of hospitalization was 1.4 per 100,000 persons for giardiasis, compared with 1.0 per 100,000 persons for shigellosis. Volume depletion was the most frequently listed codiagnosis (33.2%); 18.7% of children younger than 5 years old who had severe giardiasis had failure to thrive. Physicians should consider the diagnosis of giardiasis for persons with severe gastrointestinal illness.
Clin Infect Dis 1994 May
PMID:Severe giardiasis in the United States. 807 67

Giardia lamblia is a frequent cause of diarrhea throughout the United States and the world. Advances in basic biology indicate that different strains of Giardia exist, that mammals can be infected with G. lamblia-type organisms, and that secretory IgA is important to host protection. Although water remains the most common mode of transmission of Giardia, there has been an increase in the number of person-to-person cases, especially related to children in day care, as well as an increase in food-borne cases. New antigen detection assays have improved the ability to diagnose Giardia in the stool and make it unlikely that duodenal sampling will be necessary. Metronidazole has become the drug of choice for most cases of giardiasis because of its efficacy, favorable tolerance, and availability. For pregnant women who require treatment, a non-absorbable aminoglycoside, paromomycin, may be tried first and metronidazole used if initial treatment fails.
Infect Dis Clin North Am 1993 Sep
PMID:Giardiasis. Issues in diagnosis and management. 825 57

This article reviews important intestinal protozoal infections in cats. Among intestinal protozoa, Giardia and coccidia are the most important infections. Giardiasis is a common problem in catteries, especially where young kittens run free on the floor. Overcrowding and high humidity favour the survival and transmission of Giardia. Diagnosis is made by fecal examination by direct or concentration methods. Metronidazole is the drug of choice for treating giardiasis. Among the coccidial parasites, Isospora felis and Cryptosporidium sp. are the common infections. Virtually all cats become infected with Isospora felis. The pathogenicity of I. felis is controversial. Cryptosporidium parvum infection is a zoonosis. Cryptosporidium is transmitted by direct fecal-oral cycle. Cryptosporidial infections appear to be clinical in immunosuppressed cats. No drug has been found satisfactory for treatment of cryptosporidiosis.
Vet Clin North Am Small Anim Pract 1993 Jan
PMID:Intestinal protozoa infections. 842 88


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