Giardia Intestinalis Infection Research Articles

The anthelmintic effects of probiotics against Giardia intestinalis infection: A narrative review

The anthelmintic effects of probiotics against Giardia intestinalis infection: A narrative review

Giardia intestinalis - atypical symptoms of infection in the daily practice of various specialists

Giardia intestinalis infection is the most common parasitic infection in the world. The parasite's reservoir is mainly humans and many species of mammals. Giardiasis is a parasitic disease of the duodenum and small intestine. Infection spreads easily through the oral-fecal route. Its most frequent symptom is chronic diarrhea, but it can also be asymptomatic. This article analyzes atypical symptoms of Giardia Intestinalis infection based on available studies in the PubMed database. Observations have shown that giardiasis can manifest in various types of dermatoses such as urticaria, angioedema, atopic dermatitis, erythema nodosum, or Wells syndrome. A relationship between Giardia Intestinalis infection and various allergic syndromes, manifesting as chronic urticaria or angioedema, has also been observed, as well as an increased occurrence of food allergies due to increased exposure to antigens. Studies have also shown that giardiasis can cause polyneuropathy, avitaminosis, and malabsorption syndrome. Even years after infection, chronic fatigue syndrome can still be observed

Conserved Candidate Antigens and Nanoparticles to Develop Vaccine against Giardia intestinalis.

Giardia intestinalis (Giardia lambia, Giardia duodenalis) infections in humans may be asymptomatic or symptomatic and associated with diarrhea (without blood), abdominal cramps, bloating, flatulence, and weight loss. The protozoan Giardia is the third most common cause of diarrhea and death in children under five, preceded only by rotavirus and by Cryptosporidium parvum and C. hominis infections. Antimicrobial drugs, particularly 5-nitroimidazole (5-NIs), are used to treat giardiasis in humans. Immunologically naive or immunocompromised host are more vulnerable to Giardia infection, whereas a degree of resistance to this protozoan is present in humans living in endemic areas. This suggests that vaccination may be a potential and appropriate means to control this parasitic disease outbreak and protect the human population. This review discusses Giardia antigens related to vaccine development. Additionally, based on the latest development of nanoparticle technology, a combination of methods for future research and development is proposed for the design of the next generation of powerful immunogens and an effective vaccine against Giardia.

The Pathogenesis of Giardia Intestinalis

Giardia intestinalis infection leads to intestinal cell damage and loss of the brush border of the intestinal epithelium, resulting in shortened microvilli and impaired epithelial barrier function. Watery diarrhoea, diarrhoea, nausea, abdominal pain, vomiting, and weight loss are all symptoms of this pathological alteration. Most infections are asymptomatic. Malnutrition absorption is the most common symptom of Giardia intestinalis infection. To treat Giardia intestinalis, several medications with good efficacy are employed, but the dose regimen is not always ideal, and the evolution of drug resistance is beginning to cast doubt on their clinical worth. In addition, some of these drugs can produce side effects that cause discomfort and make it difficult for patients to adhere to treatment. Giardia intestinalis is an important zoonotic parasite that causes diarrhoea in humans and many mammals. In recent years, its pathogenesis, including structural proteins and excretion of Giardia intestinalis, surface antigen variants, and the role of Giardia intestinalis in the small intestine, has been extensively studied. This article discusses this issue and lists the risks of Giardia intestinalis to the human intestine and the various diseases it can cause.

Sparse Evidence for Giardia intestinalis, Cryptosporidium spp. and Microsporidia Infections in Humans, Domesticated Animals and Wild Nonhuman Primates Sharing a Farm-Forest Mosaic Landscape in Western Uganda.

Zoonotic pathogen transmission is considered a leading threat to the survival of non-human primates and public health in shared landscapes. Giardia spp., Cryptosporidium spp. and Microsporidia are unicellular parasites spread by the fecal-oral route by environmentally resistant stages and can infect humans, livestock, and wildlife including non-human primates. Using immunoassay diagnostic kits and amplification/sequencing of the region of the triosephosphate isomerase, small ribosomal subunit rRNA and the internal transcribed spacer genes, we investigated Giardia, Cryptosporidium, and microsporidia infections, respectively, among humans, domesticated animals (livestock, poultry, and dogs), and wild nonhuman primates (eastern chimpanzees and black and white colobus monkeys) in Bulindi, Uganda, an area of remarkably high human–animal contact and spatial overlap. We analyzed 137 fecal samples and revealed the presence of G. intestinalis assemblage B in two human isolates, G. intestinalis assemblage E in one cow isolate, and Encephalitozoon cuniculi genotype II in two humans and one goat isolate. None of the chimpanzee and colobus monkey samples were positive for any of the screened parasites. Regular distribution of antiparasitic treatment in both humans and domestic animals in Bulindi could have reduced the occurrence of the screened parasites and decreased potential circulation of these pathogens among host species.

Pre-and post-treatment evaluation of intestinal inflammation in Giardia and Blastocystis infected children: a community-based study.

Giardia intestinalis and Blastocystis hominis cause frequent infections in children in developing countries. However, the role of intestinal inflammation in their pathogenesis is still poorly understood. Faecal calprotectin (FC) level is used as an indicator of intestinal inflammation and neutrophil migration in the intestinal tract. The present study aimed to evaluate intestinal inflammation by measuring FC level among children infected with either G. intestinalis or B. hominis before and after treatment. Stool samples were collected from 282 children inhabiting a rural area in Egypt and examined microscopically for intestinal parasites. FC level was estimated in a group of children infected with G. intestinalis (n = 12) or B. hominis (n = 12) before and 3weeks after receiving nitazoxanide (200mg twice daily for 3days) and compared to a control group (n = 18) of parasite-free children. Cases of mixed infection were excluded. Nitazoxanide cure rate was 83% in both infections with a remarkable reduction of infection intensity in uncured children. The difference in FC levels between infected children and controls was not statistically significant. Also, the difference between the pre- and post-treatment estimations was not statistically significant. Elevated levels were observed before treatment in three children (two infected with G. intestinalis and one with B. hominis) who displayed normal post-treatment levels. Although G. intestinalis and B. hominis infections appear to cause no remarkable intestinal inflammation, they may induce abnormally elevated FC levels in a subset of children.

DNA-based detection of Leptospira wolffii, Giardia intestinalis and Toxoplasma gondii in environmental feces of wild animals in Korea.

Leptospira, Giardia intestinalis and Toxoplasma gondii infections are reported in humans and animals worldwide, but molecular surveillance of these pathogens in Korean wildlife is still limited. Here, we examined the prevalence of these pathogens in environmental feces of Eurasian otters, leopard cats and raccoon dogs using nested PCR followed by DNA sequencing. G. intestinalis was detected in all of three animals, while T. gondii was detected only in leopard cats. Leptospira wolffii was detected in raccoon dog and Eurasian otter. Our results suggest that these animals can act as a reservoir of these zoonotic pathogens. Consistent monitoring of these pathogens in wildlife is needed to prevent from their infections in humans and livestock in Korea.

Giardiasis notifications are associated with socioeconomic status in Sydney, Australia: a spatial analysis

ObjectiveIn developed countries prolonged symptoms due to, or following, Giardia intestinalis infection can have a significant impact on the quality of life. In this research, we investigate the presence of a socioeconomic status (SES) gradient in the reporting of giardiasis in South West Sydney Local Health District (SWSLHD), New South Wales (NSW), Australia, across geographic scales. MethodsWe used a large database, spatial‐cluster analysis and a linear model. ResultsFirstly, we found one spatial cluster of giardiasis in one of the most advantaged neighbourhoods of SWSLHD. Secondly, rates of giardiasis notifications were significantly and consistently lower in SWSLHD compared to an unnamed advantaged Local Health District and NSW over multiple years. Finally, we found an overall significant positive dose–response relationship between counts of giardiasis and area‐level SES. ConclusionsLower reporting in disadvantaged areas may represent true differences in incidence across SES groups or may result from differential use of health services and reporting. Implications for public healthIf the disparities result from differential use of health services, research should be directed toward identifying barriers and facilitators of use. If disparities result from a true difference in incidence, then the behavioural mediators between SES and giardiasis should be identified and addressed.

Companion animals as a potential source of Giardia intestinalis infection in humans in the Czech Republic – A pilot study

Giardia intestinalis is a common enteric single-celled parasite infecting both humans and animals. Its eight morphologically identical but genetically distinct groups called assemblages differ from each other in host range. While assemblages A and B infect a wide range of hosts, including humans, the other assemblages (C to H) limit their host preferences to particular animal groups only. In companion animals as Giardia hosts, genotyping data have previously shown various results depending on pet species, location, environmental or breeding conditions, and the study design. To strengthen available epidemiological data from developed countries and to evaluate the role of pets in Giardia zoonotic transmission, we investigated Giardia-positive stool samples of three pet species (54 dogs, 18 cats, and 18 chinchillas) by a sequence-based analysis of three Giardia genes (β-giardin, glutamate dehydrogenase and triose phosphate isomerase). In dog samples, we confirmed assemblage C (21/54), assemblage D (32/54), and one case of a mixed infection C + D (1/54). In cats, we found assemblage F (16/18) and assemblage A, specifically sub-assemblage AI (2/18). All Giardia samples from chinchillas were characterised as assemblage B, specifically sub-assemblage BIV (18/18). These results indicate that in the Czech Republic, pet dogs may not represent a source of Giardia infection for humans because of the presence of only canid-specific genotypes C and D. In contrast, other pets, namely, chinchillas and, to a lesser extent, cats, may pose a potential risk of Giardia transmission to owners or breeders because they can host zoonotic Giardia genotypes.

Giardiasis: Characteristics, Pathogenesis and New Insights About Treatment.

Giardia intestinalis infection causes enterocytes damage and loss of brush border of the epithelial cells of the intestine that leads to shortening of microvilli and altered epithelial barrier function. This pathology results in aqueous diarrhoea, steatorrhea, nausea, abdominal pain, vomiting and weight loss. However, most infections are asymptomatic. The main consequence of Giardia colonization is nutrients malabsorption. Several families of drugs with good efficacy are used for Giardia treatment, but sometime dosing regimens are suboptimal and emerging resistance begins to question their clinical value. Moreover, some of these drugs can cause side effects that result in patient discomfort and low adherence to the treatment. This paper reviews the drugs currently used for the treatment against Giardia: the mechanism of action, the efficacy, the normal dosing, side effects and in vitro and clinical studies. In addition, new therapies against Giardia such as those based on phytochemicals, Lactobacillus and nanotechnology are collected in this paper, trying to find the ideal treatment for this disease with maximum efficacy and minimum adverse effects.

Evaluation of Giardia Intestinalis Infection by Antigen Detection and Microscopy in Stool Samples of School Going Children in Rural Areas of Hapur District, UP, India

Evaluation of Giardia Intestinalis Infection by Antigen Detection and Microscopy in Stool Samples of School Going Children in Rural Areas of Hapur District, UP, India

Enteric Infections in Young Children are Associated with Environmental Enteropathy and Impaired Growth.

To investigate the relationship between faecal contamination in child play spaces, enteric infections, environmental enteropathy (EE) and impaired growth among young children. A prospective cohort study was conducted of 203 children 6-30months of age in rural Bangladesh. Stool samples were analysed by quantitative PCR for Shigella, Enterotoxigenic Escherichia coli (ETEC), Campylobacter jejuni, Giardia intestinalis and Cryptosporidium spp. Four faecal markers of intestinal inflammation were also measured: alpha-1-antitrypsin, myeloperoxidase, neopterin and calprotectin. Child growth was measured at baseline and 9months after enrolment. E.coli was measured in soil in child play spaces. Forty-seven percent of study children had three or more enteric pathogens in their stool. Thirty five percent (71/203) of children had Shigella, 30% (61/203) had ETEC, 73% (148/203) had C.jejuni, 79% (160/203) had Giardia intestinalis and none had Cryptosporidium. Children with ETEC had significantly higher calprotectin concentrations (Coefficient: 1.35, 95% Confidence Interval [CI]: 1.005, 1.82). Children with Shigella had a significantly higher odds of being stunted at our 9-month follow-up (OR: 2.01, 95% CI: 1.02, 3.93). Children with Giardia intestinalis had significantly higher E.coli counts in the soil collected from their play spaces (OR: 1.23, 95% CI: 1.02, 1.48). Enteric infections were significantly associated with EE and impaired growth in rural Bangladesh. These findings provide further evidence to support the hypothesis that contaminated soil in child play spaces can lead to enteric infections, many of which are likely subclinical, resulting in EE and impaired growth in young children.

Giardia intestinalis infection associated with malnutrition in children living in northeastern Brazil.

The present study aimed to determine the prevalence and factors associated with Giardia intestinalis infection, verifying its impact on the nutritional status of children in northeastern Brazil. A cross-sectional study was conducted to obtain parasitological, sociodemographic, and anthropometric data in two municipalities in the states of Piauí and Ceará, northeastern Brazil. Prevalence of giardiasis was 55/511 (10.8%). G. intestinalis was more frequent in people living in poverty (30/209 [14.4%], p = 0.041), performing open evacuation (26/173 [15%], p = 0.034), and drinking rainwater stored in cisterns (9/56 [16.1%], p = 0.005). The proportion of stunting and being underweight in children infected with G. intestinalis was significantly higher than that in uninfected children (5/23 [21.7%] vs. 10/179 [5.6%], p = 0.017, OR = 4.69, 95% confidence interval [CI] = 1.44-15.25 and 5/23 [21.7%] vs. 13/179 [7.3%], p = 0.038, OR = 3.54, 95% CI = 1.13-11.09, respectively). Infection with G. intestinalis remained significantly associated with stunting and being underweight after adjustment for poverty, municipality, sex, and age in a logistic regression multivariate model. In rural areas in northeastern Brazil, giardiasis has acquired great public health importance in the soil-transmitted helminths control era, impacting the nutritional status of children and requiring new approaches to diagnosis and treatment and translational research that could generate applicable solutions at the community level.

Hookworm infection is associated with decreased CD4+ T cell counts in HIV-infected adult Ugandans.

Most studies evaluating epidemiologic relationships between helminths and HIV have been conducted in the pre-ART era, and evidence of the impact of helminth infections on HIV disease progression remains conflicting. Less is known about helminth infection and clinical outcomes in HIV-infected adults receiving antiretroviral therapy (ART). We sampled HIV-infected adults for eight gastrointestinal parasites and correlated parasitic infection with demographic predictors, and clinical and immunologic outcomes. Contrasting with previous studies, we measured parasitic infection with a quantitative, highly sensitive and specific polymerase chain reaction (PCR) method. This cohort study enrolled HIV-infected Ugandans from August-September 2013 in Mbale, Uganda and collected stool and blood samples at enrollment. Real-time PCR quantified stool: Ascaris lumbricoides, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Trichuris trichiura, Cryptosporidium spp., Entamoeba histolytica, and Giardia intestinalis infection. Generalized linear models assessed relationships between parasitic infection and clinical or demographic data. 35% of participants (71/202) tested positive for ≥1 helminth, mainly N. americanus (55/199, 28%), and 4.5% (9/202) were infected with ≥2 stool parasites. Participants with hookworm infection had lower average CD4+ cell counts (-94 cells/mcL, 95%CI: -141, -48 cells/mcL; p<0.001) after adjustment for sex, CD4+ nadir at clinic entry, and time on ART. The high prevalence of parasitic infection and correlation with decreased CD4+ concentrations highlight the need to re-examine the effects of invasive helminth co-infection in rural, HIV-infected populations in the era of widely available ART. Elucidating the relationship between hookworm infection and immune recovery could provide opportunities for health optimization, e.g. integrated deworming, in these vulnerable populations.

Detection of Giardia intestinalis infections in Polish soldiers deployed to Afghanistan.

Members of the Polish Military Contingent (PMC) have been stationed in Afghanistan since 2002. They typically serve in areas characterised by low standards of sanitation which often leads to the development of food- and waterborne diseases. The aim of the study was to evaluate the prevalence of Giardia intestinalis infections among Polish soldiers deployed to Afghanistan. The research study was conducted as part of a programme for prevention of parasitic diseases of the gastrointestinal tract run by the Polish Armed Forces. The study was carried out in August 2011; it involved 630 asymptomatic Polish soldiers serving in the Forward Operational Base (FOB) Ghazni in eastern Afghanistan. Stool specimens obtained from members of the PMC were first tested in FOB Ghazni (detection of Giardia intestinalis by Rida Quick Giardia immunochromatographic tests and Ridascreen Giardia immunoenzymatic tests - single samples). Next, the same biological material and two other faecal specimens fixed in 10% formalin were transported to the Military Institute of Medicine in Poland, where they were tested for Giardia intestinalis under light microscopy (direct smear, decantation in distilled water). Parasitological tests performed under light microscopy showed that 2.7% (17/630) of the study group were infected with Giardia intestinalis. Some of these results were confirmed by immunochromatographic tests (6/630). In contrast, immunoenzymatic tests (ELISA) demonstrated a significantly higher detection rate reaching 18.1% (114/630). Immunoenzymatic tests confirmed all the positive results given by light microscopy and by immunochromatographic tests. The prevalence rate of Giardia intestinalis infections in Polish soldiers deployed to Afghanistan was found to be high. Microscopic methods exhibit low sensitivity and therefore may result in the underestimation of the true parasite prevalence. Immunoenzymatic tests (ELISA) showing a much higher sensitivity in comparison to light microscopy and immunochromatographic tests ought to be applied in screening for intestinal protozoan infections in areas characterised by harsh environmental conditions.

Anti-giardia activity and acute toxicity of a methanol extract of Senna racemosa bark

Ethnopharmacological relevanceSenna racemosa (Mill.) H.S. Irwin & Barneby (syn. Cassia racemosa Mill.) is a plant used in traditional Mayamedicinal practices to treat diarrhea. A methanol extract of S. racemosa bark has been shown to have in vitro activity against Giardia intestinalis. No studies of its efficacy and toxicity in in vivo models have been done. The present study objective was to analyze the activity of this methanol extract of S. racemosa bark against Giardia intestinalis trophozoites in experimentally infected mice, and evaluate its toxicological effects in rats. Material and methodsS. racemosa was collected in Merida, Yucatan, Mexico (21°58′N, 89°36′W) in June 2005. The bark methanol extract was obtained and high performance liquid chromatography (HPLC-DAD) was used to generate a constituent profile. In vivo anti-giardia activity was assayed with an experimental model of G. intestinalis infection in neonatal CD-1 mice. Nine doses ranging from 0.25–15mg extract/kg body weight were tested to determine the dose required to kill 50% of the trophozoites (ED50). An acute toxicity assay was run in which one of four single doses (200, 1000, 2000 and3000mg/kg body weight) was orally administered to adult Wistar rats. Animal weight, death rates, toxic effects and behavioral parameters were observed over a 14-d period. They were then euthanized and a necropsy performed. ResultsThe S. racemosa bark extract inhibited growth of G. intestinalis (ED50=1.14mg/Kg) in neonatal CD-1 mice. No toxic or lethal effects were observed even at the highest dosage (3000mg/Kg), and neither were signs of toxicity observed in internal organs. The active compounds chrysophanol and physcion were present in the extract at a 1.76 ratio. ConclusionsThe results strongly support traditional use of S. racemosa bark for treatment of diarrhea caused by Giardia intestinalis infection.

Positive correlation of HIV infection with Giardia intestinalis assemblage B but not with assemblage A in asymptomatic Kenyan children

A cross-sectional molecular epidemiological study of Giardia intestinalis infection was conducted among asymptomatic Kenyan children with (n = 123) and without (n = 111) HIV infection. G. intestinalis assemblage B infection was positively correlated with HIV infection [HIV (+), 18.7% vs. HIV (-), 11.7%; P = 0.013], whereas assemblage A infection was not [HIV (+), 4.1% vs. HIV (-), 6.3%; P = 0.510]. Thus, HIV infection is a risk factor for G. intestinalis assemblage B infection but not for assemblage A infection.

Prevalence of Canine Giardiasis in the Daejeon and Chungnam Area

A total number of 100 fecal samples were examined for the presence of Giardia intestinalis infection in dogs using a Giardia ELISA kit (SNAP ® test, IDEXX Laboratories, Inc., Westbrook, ME). 49 males and 51 females were examined for a G. intestinalis infection in Daejeon and Chungnam area of South Korea. The overall positive rate of G. intestinalis infection was 12.00%. G. intestinalis infection resulted to be more prevalent in males (12.24%) than in females (11.76%), and in symptomatic dogs (18.18%) than in asymptomatic dogs (11.54%). There were no significant differences between the two groups. 19.60% being found in the 2 analysis revealed a significantly higher prevalence (p < 0.05) in the < 2-year-old group than in the other, and a significantly higher prevalence in dogs kept in a shared kennel (36.00%, p < 0.001). This study is the first survey of G. intestinalis infection prevalence in South Korea according to life style (particularly between dogs kept in a shared kennel and that of dogs kept separately) using an ELISA kit, and this study is expected to provide a useful reference for clinicians and breeders.

Asymptomatic Giardia intestinalis infection and Roux-en-Y gastric bypass

Giardiasis is one of the most common parasitic infections of the human intestine worldwide, and ranges from 3-7% in western countries to 100% in some populations [1]. Giardia Intestinalis (i.e Duodenalis or Lamblia) is a flagellated, binucleated protozoan parasite that infects the upper intestinal tract in many mammalian hosts. Giardiasis can present with a broad range of clinical manifestations, from being asymptomatic to acute or chronic nonspecific gastro-intestinal symptoms associated with malnutrition [2]. However little is known regarding Giardiasis in human obesity. [...]

Myocarditis in association with giardia intestinalis infection

A 33 year old man presented with a one day history of central chest discomfort of heavy character occurring at rest. The discomfort was not pleuritic and there was no associated dyspnoea. He had been unwell for seven days prior with frequent small volume loose stools, steatorrhea, and offensive flatus. This was accompanied by nausea and abdominal distension.