Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “GIARDIASIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1991

An immunoenzymatic dot-ELISA for the detection of Giardia lamblia antigen in stool eluates of clinical cases of giardiasis.

A dot-ELISA technique for the detection of G. lamblia specific antigen in stool eluates of clinical cases of giardiasis was developed and evaluated employing monospecific antibodies to a G. lamblia specific coproantigen with a molecular mass of 66 kDa. The assay detected 22 (91.7%) of the 24 microscopically confirmed cases of giardiasis while none of the stool eluates from 20 patients with gastrointestinal parasites other than G. lamblia and 20 apparently healthy subjects had any detectable levels of G. lamblia-specific coproantigen. Of the 25 stool eluates from clinically suspected cases of giardiasis, 13 (52%) were found to contain G. lamblia-specific coproantigen. A 3-month-follow up of five of such cases where stool eluates has antigen detected by dot-ELISA assay, revealed the presence of G. lamblia cysts on repeated stool examinations. All the clinically suspected cases with detectable levels of G. lamblia-specific coproantigen by dot-ELISA were relieved of their clinical symptoms following metronidazole therapy. Single stool eluate examination by dot-ELISA was found to be sufficient to confirm the diagnosis. The dot-ELISA is an easy, rapid, sensitive and specific procedure for confirming the diagnosis of suspected cases of giardiasis. It should be a valuable diagnostic aid under field conditions as well as in the laboratory.

Animals↗
PubMedDate not supplied

Intestinal amoebiasis and giardiasis in southern Indian infants and children.

The role of Entamoeba histolytica and Giardia lamblia as causative agents of paediatric diarrhoea was studied in a southern Indian population. Relationship between infant feeding practices, co-existing malnutrition and the occurrence of intestinal amoebiasis and giardiasis was also examined. The subjects were 361 paediatric patients with acute diarrhoea and 70 hospitalized control children without diarrhoea. Faecal samples from cases and controls were examined for the protozoal pathogens using faecal preservatives, permanent staining and formalin-ether concentration. Bacteriological studies were conducted on 244 of the 361 cases. A high prevalence of invasive amoebiasis was seen in the 0-6 month (12.5%) and 7-12 month (20.3%) age groups. Giardiasis was uncommon under 6 months (2.1%) but occurred in 8-10% of all other age groups. Invasive amoebiasis occurred mainly in children on weaning foods (45.9%) but also [corrected] in exclusively breast-fed children (13.5%). Giardiasis was not seen in exclusively breast-fed infants, but commonly occurred in older children on normal diets. There was no association between amoebiasis or giardiasis and malnutrition.

Age Factors↗
PubMed1989

Zoonotic aspects of giardiasis: a review.

Several studies suggested that some water-borne epidemics of giardiasis in the U.S.A. were of zoonotic origin. Also, cats and dogs were suspected of being sources of giardiasis for man. These observations have been partly supported by experimental cross-transmissions. However, there are also some indications that zoonotic giardiasis may not be common. The host-specificity of Giardia spp. is still controversial. To date, morphological characteristics can only differentiate three very basic types of Giardia: G. intestinalis, G. muris and G. agilis. Host-specific and morphometric criteria resulted in the description of more than 40 species of Giardia; many of them probably invalid. Only a few subtle antigenic differences among G. intestinalis (lamblia) strains have been observed. The comparison of isoenzymes and DNA banding patterns revealed 3 basic groups, not necessarily related to host origin. Further biochemical, immunological, genetic and cross-transmission studies in host and parasite populations are needed to better understand host-specificity of various Giardia isolates. At the present time one may only conclude that although mammals and man do not seem to possess their own unique species of Giardia, in reality the major methods of transmission of giardiasis probably remain basically host-specific.

Animals↗
PubMed1977

Prepatency of giardiasis.

Recently acquired giardiasis was suspected in 199 patients because of typical symptoms following a trip to a known endemic area. In 130 cases giardiasis was confirmed by stool examination, although most of the samples obtained less than 3 wk after probable infection were negative for Giardia lamblia. Prepatency was documented in 35 patients who, after one or more negative stool examinations, started to excrete Giardia. The median prepatent period was 14 days, and in most cases the prepatent period was less than 3 wk. The median incubation time of giardiasis was 8 days, and in two-thirds of the cases the symptoms had continued for over a week before the parasite became detectable in faeces. A practical conclusion was that, in suspected cases of giardiasis with negative stool findings during the first 3 wk after possible exposure to Giardia, examination of repeated faecal samples is still effective in confirming the diagnosis.

Disease Outbreaks↗
PubMed2004

Determinants of the geographical distribution of endemic giardiasis in Ontario, Canada: a spatial modelling approach.

Giardiasis surveillance data as well as drinking water, socioeconomic and land-use data were used in spatial regression models to investigate determinants of the geographic distribution of endemic giardiasis in southern Ontario. Higher giardiasis rates were observed in areas using surface water [rate ratio (RR) 2.36, 95 % CI 1.38-4.05] and in rural areas (RR 1.79, 95 % CI 1.32-2.37). Lower rates were observed in areas using filtered water (RR 0.55, 95 % CI 0.42-0.94) and in those with high median income (RR 0.62, 95 % CI 0.42-0.92). Chlorination of drinking water, cattle density and intensity of manure application on farmland were not significant determinants. The study shows that waterborne transmission plays an important role in giardiasis distribution in southern Ontario and that well-collected routine surveillance data could be useful for investigation of disease determinants and identification of high-risk communities. This information is useful in guiding decisions on control strategies.

Animals↗
PubMed2005

Under-notification of giardiasis in Auckland, New Zealand: a capture-recapture estimation.

Estimation of the degree of undercount is important for disease surveillance. Capture-recapture techniques are now being used to evaluate the completeness of disease ascertainment. This study estimated the level of under-notification of giardiasis in the Auckland adult population using a capture-recapture method. Two independent datasets of giardiasis cases > or = 15 years were generated from the 1998-1999 Auckland Giardiasis Study (AGS) case database and cases notified to Auckland Regional Public Health Services (ARPHS) for the same period of time. Cases were matched and under-notification was estimated using a two-sample capture-recapture method. During the 12-month period, 199 cases participated in the AGS and 413 cases were notified to ARPHS. The capture-recapture calculation indicated that only 49% of cases were notified. Under-notification by a factor of 2 obscures the true burden of giardiasis. Socio-economic conditions and water quality may influence disease notification inversely. Capture-recapture techniques are useful in evaluating the completeness of surveillance.

Adolescent↗
PubMed1997

Giardiasis in HIV: a possible role in patients with severe immune deficiency.

We report the epidemiological, clinical and therapeutic characteristics of giardiasis in a population of HIV-infected patients with diarrhoic syndrome. During the period between 1988 and 1995, 720 HIV-patients with diarrhoic syndrome were evaluated. Fecal specimens were submitted to parasitological examination according to the Ritchie formalin-ethil acetate centrifugal sedimentation method and stained with iodine. Samples also underwent modified Ziehl-Neelsen staining and standard bacteriologic testing. Cystis of G. intestinalis were identified in stool sample of 25 patients. Two patients were classified as in stage A2 and 23 in C3. Mean CD4 values of patients with giardiasis (26.9 cells/mmc) were compared with those of 65 patients from whom, during the study, was isolated Cryptosporidium parvum (63.12, cells/mmc): the difference resulted highly significant (p < 0.001). Among the patients with full-blown AIDS, giardiasis occurred following a single previous AIDS-defining event in 13 inividuals, in seven and in five subjects giardiasis was the 3rd and, respectively, the 4th relevant AIDS-defining condition. Death occurred within the following 2 months in nine patients and within 6, 12 and 24 months in seven, six and two patients, respectively; at present only three AIDS patients are still alive. In general, G. intestinalis in HIV+, is not considered a major cause of enteritis; nevertheless, in our experience enteritis due to G intestinalis is a frequent event among AIDS patients, especially in the most advanced stage of disease, irrespectively of the risk factor. The increase in mean survival of AIDS patients will probably lead to a progressive emergence of this pathogen which could determine a severe diarroic syndrome with hydro-electrolytic impairments.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Giardiasis: nutritional implications.

The debate about the pathogenicity of Giardia lamblia in man has ended, and th issues regarding the prevalence of clinical and subclinical infections and their nutritonal impact have become the foremost considerations. Giardiasis can produce steatorrhea, maldigestion, and malabsorption of carbohydrates and of vitamins A and B12. The mechanisms of the absorptive dysfunction are not clear, but morphological abnormalities of the intestinal mucosa and/or bacterial overgrowth might play a role. Severe clinical giardiasis can cause "failure to thrive" in young children, but the impact, if any, of subclinical giardiasis on growth in general populations is not well defined. Protein-energy malnutrition appears to predispose to giardial infection, perhaps because of the accompanying hypochlorhydria, immunosuppression, and altered gastrointestinal flora. The lack of a sensitive and noninvasive diagnostic test for human giardial infection limits the investigation of the nutritional correlates of giardiasis.

Animals↗
PubMed1979

Malabsorption of water miscible vitamin A in children with giardiasis and ascariasis.

Vitamin A absorption was studied using a water-miscible oral preparation of vitamin A in 19 children ages 1 1/2 to 9 years old with giardiasis and/or ascariasis, both before and after their eradication with appropriate therapy, and in three children without parasites. Marked impairment of vitamin A absorption was noted when administered in a water miscible form in children with 1) combined infection with Giardia lamblia and Ascaris lumbricoides, 2) giardiasis alone, and 3) in a proportion of children with ascariasis alone. In children with both giardiasis and ascarasis eradication of the infections promptly lead to a significant improvement in vitamin A absorption and restored it to normal. Children with giardiasis alone also showed improved vitamin A absorption after therapy. In children with ascariasis alone successful therpay did not lead to a statistically significant improvement.

Ascariasis↗
PubMed1987

Malabsorption of oral antibiotics in humans and rats with giardiasis.

We observed unexplained treatment failures in 13 patients with serious infections and apparent incidental giardiasis. Antibiotic concentrations were assayed in the serum from patients before initiating anti-Giardia therapy and again 2 to 3 weeks after therapy. The peak serum concentrations of antibiotics were higher after treatment for giardiasis. The rat model of giardiasis was used to examine the hypothesis that oral antibiotics are malabsorbed during Giardia lamblia infection. Twenty-eight-day-old Sprague-Dawley rats were fed amoxicillin (50 mg/kg/dose), ampicillin (50 mg/kg/dose), cefaclor (50 mg/kg/dose), cephalexin (50 mg/kg/dose), erythromycin (50 mg/kg/dose), penicillin V (50 mg/kg/dose) or sulfamethoxazole (20 mg/kg/dose) and sera were assayed for antibiotics at 1, 2, 4, 6 and 12 hours after therapy. The same rats were fed 10(5) G. lamblia cysts on 4 consecutive days. On Day 7 of infection the rats were fed the same antibiotic and sera were assayed for antibiotics at 1, 2, 4, 6 and 12 hours after therapy. The mean peak serum concentrations for all drugs except sulfamethoxazole were significantly higher in the rats before infection with G. lamblia. These data suggest that oral antibiotic therapy maybe compromised by decreased absorption in the presence of giardiasis.

Administration, Oral↗
PubMed1988

Depressed humoral immune responses to surface antigens of Giardia lamblia in persistent giardiasis.

The specific anti-plasma membrane- or surface-specific serum antibodies to Mr 82,000 antigen of Giardia lamblia trophozoites in cases of persistent and nonpersistent giardiasis in a pediatric population indicated significantly low concentrations of these antibodies in patients with persistent giardiasis. There was an insignificant difference in the amount of antibodies to whole trophozoite extract in persistent and nonpersistent giardiasis or asymptomatic carriers. The acute/nonpersistent cases had predominantly IgM class antigiardial antibodies, whereas persistent and asymptomatic carriers had antigiardial antibodies of the IgG class. The inability of persistent cases of giardiasis to clear infection appears to be related to low concentrations of antiplasma membrane/anti-Mr 82,000 antigiardial antibodies.

Animals↗
PubMed1991

Enzyme-linked immunosorbent assay for copro-diagnosis of giardiasis and characterisation of a specific Giardia lamblia antigen in stools.

An enzyme-linked immunosorbent assay (ELISA) has been evaluated for copro-diagnosis of giardiasis with anti-trophozoite antibody to capture specific Giardia lamblia stool antigen (GLSA), which was then detected by specific antibody conjugated with horseradish peroxidase. GLSA was demonstrated in stool eluates from all the 24 confirmed cases of giardiasis. None of the stool eluates from apparently healthy subjects or from patients carrying intestinal parasites other than G. lamblia had GLSA. Of the 25 microscopy-negative clinically suspected cases of giardiasis, 17 (68%) patients had GLSA in their stool eluates; these patients responded to anti-giardial therapy. The specific antigen was isolated and affinity-purified by the use of specific antibody; it had a Mr of 66 Kda, and its immunoreactivity was lost after treatment with heat or trypsin but unaltered by metaperiodate. ELISA seems to be a sensitive and specific method for copro-diagnosis of giardiasis, especially in highly suspected cases.

Animals↗
PubMed2004

Celiac disease diagnosis in patients with giardiasis: high value of antitransglutaminase antibodies.

OBJECTIVES: The main objective of this study is to assess the presence of celiac disease (CD) in patients with giardiasis and to evaluate the tools for diagnosis of CD in these patients. METHODS: A total of 40 patients with giardiasis were evaluated. Celiac disease was confirmed or discarded by intestinal biopsy and serological markers. Antigliadin antibodies were determined by ELISA and antitransglutaminase antibodies by one-step immunochromatographic assay and ELISA. RESULTS: Out of the 40 patients with giardiasis 37 showed normal intestinal mucosa. In this group, IgA antibodies to gliadin were positive in 7 patients, yielding a specificity of 82%. All of them were negative for transglutaminase antibodies by the immunochromatographic assay and by ELISA (specificity of 100%). The remaining 3 patients showed a subtotal intestinal villous atrophy consistent with CD, however, only two presented IgA antibodies to transglutaminase and gliadin. CONCLUSIONS: Due to its low specificity antigliadin antibodies are not useful for the screening of CD in patients with giardiasis. On the other hand, antitransglutaminase antibodies are highly specific and sensitive. One-step immunochromatographic assay is an easy and economic alternative. The findings of villous atrophy must be supported by other markers of CD to achieve the diagnosis of CD in these patients.

Adolescent↗
PubMed1990

[Studies on the giardiasis as the zoonosis].

To obtain basic data on the route of Giardia infection as zoonosis, we examined feces from 80 dogs and 16 cats for Giardia cysts and evaluated the detection rates. In addition, familial infection was studied in 3 family members of the patient with giardiasis. Giardia cysts were detected in 10 of the 80 dogs (12.5%) but none of the cats. Of the 10 dogs from which Giardia cysts were isolated, 6 had been maintained by the breeders. Tow other dogs were for examination in the research institutions. None of the family members of the patient with giardiasis had this infection. Since the detection rates of Giardia cysts in the dogs and cats were low, the possibility that human infection is acquired from dogs or cats seemed to be low. However, some of patients with giardiasis we encountered had never been abroad. This fact together with the presence of Giardia cysts in the dogs despite the low detection rates suggest that attention should be paid to the possible association between human giardiasis and pets since the number of people keeping pets is increasing.

Animals↗
PubMed1976

Serum antibodies and jejunal histology in giardiasis associated with malabsorption.

An immunofluorescent test, using Giardia lamblia cysts as antigen, gave positive results in 32/36 cases of giardiasis with malabsorption, 0/2 cases of giardiasis without malabsorption, and 0/17 control patients without giardiasis or malabsorption. The test was positive in 10/34 patients with malabsorption in whom G. lamblia could not be detected by stool examination or biopsy; some of these cases were presumed to be cryptic giardiasis. There was a crude correlation between antibody titre and the severity of the histological lesion in the jejunum. The finding of a reliable source of antigen remains a problem.

Antibodies↗
PubMed2005

Immunopathology of giardiasis: the role of lymphocytes in intestinal epithelial injury and malfunction.

T lymphocyte-mediated pathogenesis is common to a variety of enteropathies, including giardiasis, cryptosporidiosis, bacterial enteritis, celiac's disease, food anaphylaxis, and Crohn's disease. In giardiasis as well as in these other disorders, a diffuse loss of microvillous brush border, combined or not with villus atrophy, is responsible for disaccharidase insufficiencies and malabsorption of electrolytes, nutrients, and water, which ultimately cause diarrheal symptoms. Other mucosal changes may include crypt hyperplasia and increased infiltration of intra-epithelial lymphocytes. Recent studies using models of giardiasis have shed new light on the immune regulation of these abnormalities. Indeed, experiments using an athymic mouse model of infection have found that these epithelial injuries were T cell-dependent. Findings from further research indicate that that the loss of brush border surface area, reduced disaccharidase activities, and increase crypt-villus ratios are mediated by CD8+ T cells, whereas both CD8+ and CD4+ small mesenteric lymph node T cells regulate the influx of intra-epithelial lymphocytes. Future investigations need to characterize the CD8+ T cell signaling cascades that ultimately lead to epithelial injury and malfunction in giardiasis and other malabsorptive disorders of the intestine.

Animals↗
PubMed1988

Epidemic giardiasis caused by a contaminated public water supply.

In the period November 1, 1985 to January 31, 1986, 703 cases of giardiasis were reported in Pittsfield, Massachusetts (population 50,265). The community obtained its water from two main reservoirs (A and B) and an auxiliary reservoir (C). Potable water was chlorinated but not filtered. The incidence of illness peaked approximately two weeks after the city began obtaining a major portion of its water from reservoir C, which had not been used for three years. The attack rate of giardiasis for residents of areas supplied by reservoir C was 14.3/1000, compared with 7.0/1000 in areas that received no water from reservoir C. A case-control study showed that persons with giardiasis were more likely to be older and to have drunk more municipal water than household controls. A community telephone survey indicated that over 3,800 people could have had diarrhea that might have been caused by Giardia, and 95 per cent of households were either using alternate sources of drinking water or boiling municipal water. Environmental studies identified Giardia cysts in the water of reservoir C. Cysts were also detected in the two other reservoirs supplying the city, but at lower concentrations. This investigation highlights the risk of giardiasis associated with unfiltered surface water systems.

Adult↗
PubMed1997

Giardiasis: a histologic analysis of 567 cases.

BACKGROUND: The histopathology of the upper and lower gastrointestinal tract of patients with giardiasis as shown by endoscopy with biopsy is ill-defined. We therefore report on 567 cases observed in our institution. METHODS: A retrospective analysis of all cases with giardiasis observed between 1988 and 1994 was performed. RESULTS: On histologic slides trophozoites were found in duodenal (82.5%) and jejunal (2.1%) mucosa and also in gastric antral (8.7%) and ileal mucosa (12.1%) but rarely in the colon (0.4%). An entirely normal light-microscopic appearance of the duodenal mucosa was found in 462 cases (96.3%). Mild villous shortening and mild inflammation of the lamina propria were observed in duodenal mucosa in 18 subjects (3.7%). In jejunal, ileal, gastric, and colonic mucosa, no Giardia-specific histologic changes were identified. There was a clear male predominance with 347 (61.2%) males and 220 (38.8%) females. Mean age, which was comparable in males and females, was 49.5 +/- 17 years (range, 3-95 years). In 252 Giardia-positive cases gastric biopsy specimens were available, and showed Helicobacter pylori-associated gastritis in 57.8%, reactive gastritis in 10.3%, normal mucosa in 12.9%, chronic atrophic gastritis of the body in 2.9%, and other forms of gastritis in 16.1%. CONCLUSIONS: This study shows that the histology of the small-bowel mucosa is inconspicuous in most subjects with giardiasis. A search for the parasite must therefore be made in all biopsy samples obtained from this area. Furthermore, giardiasis was not associated with a particular gastric disease, such as chronic atrophic gastritis of the body.

Adolescent↗