Diagnosis Of Giardiasis Research Articles

Systematic Review of Diagnostic Approaches for Human Giardiasis: Unveiling Optimal Strategies.

Giardiasis, caused by the protozoan Giardia intestinalis, affects around 400 million people worldwide, emphasizing the critical need for accurate diagnosis to enhance human health, especially in children. Prolonged giardiasis in childhood can lead to intellectual deficits and other complications. A variety of diagnostic tools, including microscopic, immunological, and molecular methods, are available for detecting G. intestinalis infection. Choosing the most suitable method can be challenging due to the abundance of options. This systematic review assesses the reliability and applicability of these diagnostic modalities. Utilizing the Dimensions and Wordart platforms for data analysis, we focus on relevant literature addressing diagnostic methods for human giardiasis. Microscopic techniques, particularly Ritchie's method, emerge as the primary choice, followed by enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). PCR's limited use is attributed to its high cost and infrastructure challenges in developing nations. In conclusion, our analysis supports microscopic methods as the gold standard for giardiasis diagnosis. However, in cases where symptoms persist despite a negative diagnosis, employing more sensitive diagnostic approaches is advisable.

Detection of IgG Anti-Giardia duodenalis Antibodies in Sera by Indirect Immunofluorescence and Western Blotting Assays.

Serological assays are alternative laboratory tools for the diagnosis of parasitic infections. The aim of this work was to evaluate the performance of the indirect fluorescent antibody test (IFAT) and Western blotting (WB) for the detection of IgG anti-Giardia antibodies in human sera. Sera from individuals infected with Giardia duodenalis, other parasites or non-parasitized were selected for serological assays. Ninety-seven sera were tested by IFAT at 1:20 and 1:40 dilutions and of these, 40 samples were also analyzed by WB. The sensitivity and specificity of the IFAT was 97% and 46.9% at 1:20 sera dilution, and 39.4% and 59.4% at 1:40 sera dilution. The low molecular weight polypeptides fractions of 25kDa, 27-31kDa and 45-55kDa were the most frequently identified by the sera of individuals infected with G. duodenalis, along with low cross-reactivity, presenting an individual sensitivity of 42.8%, 50.0% and 57.1%, and specificity of 83.3%, 83.3% and 91.7%, respectively. The highest overall sensitivity of WB (85.7%) was based on the immunoreactivity of sera with at least one of those proteins. The concordance between the detection of G. duodenalis in feces by microscopy and the WB results was considered substantial (Kappa = 0.61). Constant exposure to Giardia infection throughout a lifetime can maintain high levels of specific antibodies in serum, even without active infection. Moreover, proteins found in intestinal amoebas may hinder the serological diagnosis of giardiasis in endemic areas due to cross-reactivity, which can be partially solved using Giardia low molecular weight proteins.

Disease Biomarkers of Giardiasis.

Giardiasis is a common, treatable intestinal disease that adversely affects underprivileged communities living in unsanitary conditions. Giardiasis causes a wide spectrum of gastrointestinal diseases in those infected, ranging from subclinical disease that can manifest as irritable bowel syndrome with persistent abdominal symptoms. Importantly, giardiasis has been identified as a predictor of malnutrition among young children in rural areas and as a cause of waterborne mass epidemics endangering not only humans but also animals in a broad clinical, social, and economic spectrum. While the diagnosis of giardiasis is heavily dependent on the presence of cysts and/or trophozoites detected using microscopy, the intermittent cyst excretion, low infection intensity, and low sensitivity method m4akes fecal examination unrewarding, thus urging the need for an improved diagnostic method for giardiasis. Proteins are key compounds in biosynthesis, cells, tissues, and organ signaling, carrying important information related to biological and pathogenic processes, as well as pharmacological responses to therapeutic intervention, and are therefore important indicators for determining disease onset, progression, and drug treatment effectiveness. In connection with this, proteins could serve as promising biomarkers for antigen-antibody detection, as well as vaccine candidates. This article is aimed at providing a comprehensive overview of proteins, serological, molecular, inflammatory, volatile, and hormonal biomarkers associated with giardiasis and their potential for diagnostics and therapeutics.

THE ROLE OF PROBIOTICS IN THE TREATMENT OF INTESTINAL DYSBIOSIS IN PATIENTS WITH LAMBLIOSIS AND ASCARIDOSIS

Parasitic diseases remain an important problem today. Recently, many cases of combined invasion have been registered. Mixed invasion by Giardia and roundworms is the most common in Ukraine. The clinical picture of the disease is characterized by damage to various organs and systems, but most often in patients the manifestations relate to the primary site of parasitism of pathogens - the gastrointestinal tract, which is often accompanied by disruption of the intestinal microflora. The aim was to study the effect of probiotics containing bicarbonate saccharomycetes in the complex therapy of patients with giardiasis, ascariasis, and combined invasion. We examined 90 patients with giardiasis, ascariasis, and combined invasion, divided into 3 groups, depending on the type of invasion, each of which is divided into two subgroups, depending on the treatment (basic treatment and with the addition of probiotics). It was administered orally 1 capsule 2 times a day for 14 days. 1 capsule contains 250 mg of saccharomycetes and excipients. The control group consisted of 20 healthy individuals. The state of the intestinal microflora was determined using a classical microbiological study of feces to determine the population level of the microflora according to VA Znamensky. The research was performed twice: before treatment and 14 days after treatment. The diagnosis of giardiasis and ascariasis was confirmed by detection of the pathogen in the feces by parasitoscopy of feces. When studying the state of the intestinal microflora, it was found that all patients had the following changes before treatment. The content of bifidobacteria, lactobacilli, enterococci and the total content of E. coli was reduced. At the same time, there was an increase in the content of peptococci, bacteroids, Escherichia coli with weakly enzymatic properties, haemolytic Escherichia coli, fungi of the genus Candida and staphylococci. After the basic treatment, some positive changes were observed in all groups of patients, but the content of autochthonous flora still decreased, the presence of pathogenic bacteria (staphylococci) and fungal flora was noted. The content of bifidobacteria was slightly reduced. The quantitative composition of lactobacilli was higher than before treatment. Patients had a reduced amount of bacteroids, total Escherichia coli, although its content was higher than before treatment. An elevated level of Escherichia coli with weak enzymatic properties was noted. Hemolytic Escherichia coli was present, as well as the number of enterococci. Fungi of the genus Candida were available also. In the 3b group of patients there were more significant signs of improvement in the microflora.
 After the inclusion in the treatment complex of probiotics containing saccharomycetes of billard, according to the results of bacteriological research, there was a significant positive dynamic of the intestinal microflora. The content of bifidobacteria was significantly higher compared to the other two groups. The quantitative composition of lactobacilli was slightly reduced. The amount of bacteroids was normalized. The total content of Escherichia coli increased, there was a decrease in the content of Escherichia coli with weak enzymatic properties. In addition, the presence of haemolytic Escherichia coli was detected in only one patient. Almost complete normalization of the level of enterococci was observed. From the fungal flora, the level of fungi of the genus Candida was minimal, comparing similar results of other groups.

Laboratory techniques for diagnosing Giardia parasite in dogs in Mosul City, Iraq

The results of the current study showed that the different techniques of microscopic examination recorded the highest rate of infection and diagnosis of Giardia in dogs with significant differences at the level of probability p<0.05 It reached 73.4%, followed by the rapid test technique and indirect enzyme linked immunosorbent assay (ELISA) with a rate of 14.2% and 12.2% respectively. With regard to determining the sensitivity and specificity of the rapid test and microscopic examination, a sensitivity of 19% and a specificity of 100% were recorded. The results, using the indirect ELISA showed an infection rate of 12.2% of the total samples. The results showed that the number of positive samples with this technique amounted to 12 samples positive for Giardia lamblia out of the total samples positive for microscopic examination. To confirm the diagnosis of giardiasis, the results using the direct immunofluorescence technique using acridine orange fluorochrome showed the appearance of a glowing brilliance, as the cysts appeared oval green glowing and the trophozoites appeared glowing green pear.

Частота, предиктори та критерії діагностики лямбліозу в дітей

Актуальність. Поширеність лямбліозу серед дітей становить 355 випадків на 100 тис. дитячого населення, при цьому 80 % випадків інвазії припадає на дітей, молодших 14 років. Актуальність високої поширеності протозойної патології у дітей зумовлена тим, що її прояви часто маскуються під різні патологічні стани. Мета. Вивчення частоти, предикторів і критеріїв діагностики лямбліозу в дітей. Матеріали та методи. Дизайн дослідження — контрольоване рандомізоване. У дослідження включені діти, хворі на лямбліоз (n = 55), віком від 3 до 17 років. Група порівняння становила 30 практично здорових дітей. Обстеження хворих і набір матеріалу проводили на базі поліклінічного та гастроентерологічного відділень КМУ «Чернівецька обласна дитяча клінічна лікарня» впродовж 2014–2016 років. Лабораторні та інструментальні дослідження проводилися в українсько-німецькій лабораторії «Букінтермед» та лабораторії дитячого гастроентерологічного центру «Дігест». Використані непрямі (серологічний метод, макроскопія слизової оболонки ДПК при ендоскопічному дослідженні, непрямі ознаки лямбліозу в дуоденобіоптатах) та прямі (мікроскопія калу, дуоденального вмісту, виявлення вегетативних форм лямблій у дуоденобіоптатах під час гістологічного дослідження) методи дослідження. Проводилося анкетування батьків. Відмінності вважалися статистично вірогідними при досягнутому рівні значущості р ≤ 0,05. Результати. Позитивний результат отримано у 29 із 565 обстежених на лямблії осіб (5,1 %). Найчастіше потребували дообстеження на наявність лямблій діти, хворі на хронічну патологію верхніх відділів шлунково-кишкового тракту та гепатобіліарної системи, з алергічними реакціями, дисбіозом кишечника та стійкою еозинофілією крові. Діти, хворі на лямбліоз, вірогідно частіше хворіли на супутню патологію, ніж діти групи порівняння (р < 0,05). У 41,4 % випадків діти проживали в умовах, що не відповідали задовільним, не завжди дотримувалися правил гігієни. Нами встановлені несприятливі фактори антенатального (стан здоров’я матері під час вагітності, перебіг вагітності, наявність професійних шкідливостей), інтранатального (передчасні пологи, стимуляція пологової діяльності та кесарів розтин, пологова травма й асфіксія у дітей) та постнатального (тривалість грудного вигодовування, супутня патологія) періодів. Усі гістологічні ознаки можуть бути використані як імовірні критерії лямбліозу в дітей, однак із найбільшою вірогідністю можна використовувати таку ознаку, як наявність ділянок десквамації епітелію ворсинок з одночасним переважанням в інфільтраті еозинофілів і тучних клітин. Висновки. Частота лямбліозу у дітей і підлітків дорівнює 5,1 %. Встановлені нами анамнестичні фактори (соціальні, гігієнічні, медико-біологічні) можна розглядати як предиктори розвитку лямбліозу в дітей. У клініці лямбліозу домінує ураження травного тракту — у 96,3 % дітей. Для підвищення точності діагностики лямбліозу в дітей необхідно використовувати комплекс прямих і непрямих методів діагностики.

Evaluation of serum 25-hydroxy vitamin d3 levels in goat kids naturally infected with giardia duodenalis

The aim of this study was to determine 25-hydroxy vitamin D3 levels in diarrhoeic goat kids. For this purpose, blood sample witdrawn from 10 diarrhoeic goat kids (Group I) and 10 healthy goat kids (Group II). Diagnosis of giardiasis was performed with multiple methods including microscopic examination and rapid test kits. Mean 25-hydroxy vitamin D3 levels were determined as 33,37 ng/ml in diarrhoetic goat kids and 86,78 ng/ml in control and that is found to statistically significant (p<0.001). Consequently, it was convinced that giardiasis-related intestinal malabsorption may cause severe reduction in vitamin D levels and vitamin D supplement should be administered proper and sufficient doses due to anti-microbial effect with anti-giardial medication in treatment regime.

EVALUATION OF POINT OF CARE TEST FOR DIAGNOSIS OF HUMAN GIARDIASIS

Background: Giardia is a unicellular flagellated parasite infecting wide range of vertebrate hosts, including humans. Infection is usually transmitted through ingestion of cyst stage. Infection occurs worldwide, but particularly affects populations in the developing countries. Giardiasis is usually asymptomatic but, mild to moderate self-limiting diarrhea commonly occurs. In other cases, diarrhea may be severe, prolonged or even life threatening. Aim of the work: The aim of this study was to assess the value and reliability of the immunochromatographic Giardia strip test (RIDAQUICK)* in a routine diagnostic setting as a point of care test for diagnosis of Giardiasis. The results will be compared to those obtained using conventional microscopy and the ELISA test “reference method” (RIDASCREEN)*. Patients and Methods: This cross sectional study was conducted on 30 random stool samples recruited from symptomatic infants and children (<10 years old) of both genders (15 males and 15 females) complaining of gastrointestinal symptoms as diarrhoea, abdominal pain and flatulence. The studied patients were either admitted to inpatient ward of the pediatric hospitals of Ain ShamsUniversity or referred from the outpatient clinic. The samples were processed in the Central Microbiology Laboratory, Clinical Pathology Department, Ain Shams University Hospitals from January 2018 till December 2018. All stool samples were subjected to the following: Macroscopic examination of stool samples by naked eye, microscopic examination by conventional methods (Direct wet mount and iodine mount using ordinary light microscopy), immunochromatographic (ICT) Giardia strips and enzyme linked immunosorbent assay (ELISA). Results: Concerning the diagnostic yield of the used diagnostic methods microscopy and ICT compared with ELISA. ICT as diagnostic test was more efficient test than microscopy with higher accuracy (93%) to detect Giardia in all study individuals. Kappa agreement showed that there was 0.85 (almost perfect agreement between ICT with ELISA findings) and 0.66 (Substantial agreement between microscopy and ELISA). Conclusion: The use Giardia Antigen detection by ICT was found sensitive and specific for the detection of G. lamblia. They are rapid to perform and do not require experienced staff or special technical equipment, results are obtained within 9–10 min per test.

Epidemiological study of Giardia duodenalis infection in companion dogs from the metropolitan area of São Paulo Brazil.

Giardia duodenalis is a zoonotic pathogen associated with gastrointestinal disease that has a direct life cycle, with cysts eliminated in the faeces of an infected host being ingested by a susceptible host. In Brazil, studies of chronically infected adult dogs estimated a prevalence of 10%-20%. Diagnosis of giardiasis, as a cause of diarrhoea is important for the global One-Health guidelines when controlling cyst dissemination in the environment. We investigated the prevalence of G.duodenalis in the pet dog population of the metropolitan area of Sao Paulo, compared the efficacy of direct tests available to the veterinary clinical practice and attempted to identify possible risk factors associated with the parasite. Ten veterinary practices distributed throughout the municipality randomly performed the rapid SNAP ELISA test on canine faecal samples, and dog owners provided information specific to the animal via a questionnaire. The samples were also analysed using sucrose and zinc sulphate flotation techniques. Sensitivity and specificity of the tests were used to calculate required number of samples and true prevalence. Significance, agreement among tests, and odds ratio (OR) were assessed with a confidence interval (CI) of 95%. The prevalence of G.duodenalis in dogs (n=265) was 6.9% (CI 3.47-11.21). Positive tests were significantly more frequent in animals younger than 1year, with an OR for G.duodenalis occurrence nearly 7-fold that of older dogs. Direct diagnosis tests showed high agreement (96.1%, κ=0.729; p<.0001) showing that the combined techniques provide a highly accurate diagnosis. Results indicated that the control of the pathogen has been improving in the pet dog population in metropolitan Sao Paulo, but management tools including diagnosis, immunization, and treatment, especially in puppies, must be continued in order to advance towards continuous decrease of the disease.

Combined Mini-Parasep SF and Nanogold Immunoassay Show Potential in Stool Antigen Immunodetection for Giardiasis Diagnosis

Covalent loading or directional binding of biomolecules on gold nanoparticles (AuNPs) could lead to better results than simple direct adsorption for an enhanced ELISA application. The use of Mini-Parasep solvent-free (SF) without ether or ethyl acetate for the clean and efficient concentration of protozoa cysts, it is a single-use device for in vitro diagnostic use only. In this work, we used Mini-Parasep SF for the detection of giardia cysts in comparison to direct smear and Merthiolate-Iodine Formaldehyde Concentration (MIFC) technique in addition to its use in antigen detection by AuNPs biomolecule loading using rabbit polyclonal antibodies (pAb) against purified Giardia antigen (PGA). As a result, Mini-Parasep SF was the most effective method for Giardia cyst detection and regarding optimization of Mini-Parasep antigen detection, our data showed increased sensitivity and specificity of nano-sandwich ELISA to 92% and 94% respectively and increased positive predictive value (PPV) and negative predictive value (NPV) to 88.64% and 95.91% respectively. In conclusion, this research provides that Mini-Parasep SF concentrator enhanced Giardia cyst detection and improved antigen preparation for AuNPs sandwich ELISA in giardiasis diagnosis. The advantages of this method are the short assay time and the raised accuracy of antigen detection providing concentrated samples without the risk of solvent use and being a disposable Mini-Parasep it helps in giardia antigen purification as well as raising the sensitivity and specificity of ELISA through binding AuNPs.

Comparative Analysis of Parasitological, Immunodiagnostic and Histopathological Methods in the Diagnosis of Human Giardiasis

Giardiasis/lambliosis is a disease caused by the presence of a protozoan Giardia lamblia (G. lamblia) in the upper portions of the human digestive tract (DT). This cosmopolitan parasite is present particularly in children, but in all other age groups and socioeconomic conditions as well. The studies undertaken in the Ni�ava District (southeastern Serbia) have demonstrated a high prevalence of infection caused by G. lamblia species using conventional microscopy of three stool samples with or without concentration technique (6.24%), i.e. using the immunoenzymatic method to confirm the presence of G. lamblia antigen in the stool (6.59%). The use of invasive methods in the diagnosis of giardiasis is warranted in individual selected cases, when the significance of the parasite should be assessed regarding its involvement in the pathogenetic mechanisms of damage to the digestive tract mucosa.

EVALUATION OF NANO-GRAPHENE BASED SANDWICH AND DOT-ELISA AS PROMISING TECHNIQUES FOR DIAGNOSIS OF HUMAN INTESTINAL GIARDIASIS

Giardia intestinalis nowadays is recognized as the most common parasitological cause of diarrhea, with 280 million infections per year. Microscopic examination of faecal samples has the advantage of low cost and the ability to simultaneously identify other parasitic infections. However, analysis of single stool sample and the skill of the microscopist can affect the accuracy of detection. As an attempt to improve the sensitivity of laboratory diagnosis of giardiasis, the present study aimed to evaluate the diagnostic performance of different parasitological techniques (Mini Parasep, MIFC and direct smear) and to evaluate a novel antigen capture immunoassays based on IgG polyclonal antibody conjugated with nanoparticles (Nano graphene based Sandwich ELISA and Dot-ELISA) for detection of Giardia antigen in stool samples. A total of 96 human stool samples were collected and classified into three groups according to stool examination results, (GI), 61 Giardia infected patients, (GII), 20 samples collected from patients infected with other parasites and (G III), 15 healthy individuals (negative control). In the current study, Giardia antigen detection was carried out by several steps including preparation of Giardia antigen, production, purification and labeling of rabbit anti-Giardia IgG polyclonalantibodies. The Mini Parasep was the best followed by MIFC and direct smear. The study demonstrated that Nano Sandwich ELISA was higher than Traditional Sandwich ELISA regarding sensitivity, PPV, NPV and diagnostic accuracy with statistically significant difference between them, while specificity in Traditional Sandwich ELISA was higher than Nano Sandwich ELISA. Dot ELISA and Nano Dot ELISA had the same sensitivity, while Dot ELISA was higher than Nano DotELISA regarding specificity, PPV, NPV and diagnostic accuracy without significant difference. This means that the use of graphene nanoparticles improved the diagnostic testing of human giardiasis.

The results of the diagnosis of giardiasis in children with the use of the method of microscopy, enzyme immunoassay, polymerase chain reaction.

Giardiasis in children remains an urgent problem, the importance of which is determined by the endemicity for many countries and regions, polymorphism of the clinic, which causes difficulties in clinical diagnosis of this pathology. The report presents the results of the diagnostic significance of methods of laboratory diagnostics giardiase: microscopy of native and stained with Lugol solution preparation fecal enzyme-linked immunoassay (ELISA) for the presence of antibodies of class IgM and IgG antibodies to the antigens of Giardia in the serum and antigen of G. Lamblia in feces, polymerase chain reaction (PCR) - detection of Giardia DNA in feces obtained during the examination of 160 patients with giardiasis children aged 3 to 14 years. The results of our study suggest that the most informative methods of diagnosis of giardiasis in children is coproscopy (specificity - 96.2%, sensitivity - 98.1%), PCR coprofiltrate. (specificity - 85%, sensitivity 82.5%), determination of antigen in feces by ELISA (specificity - 87,5%, sensitivity - 60%). With high specificity of the blood ELISA method (90%), the sensitivity of the method is only 27.5%. It should be recognized that the «gold standard» diagnosis of giardiasis remains microscopy of native and stained with a solution of Lugol preparation of feces with a three - time study at intervals of 2-3 days.

Characteristics of Giardiasis and Enterobiаsis in children of Astrakhan region

Purpose: assessment of the clinical and epidemiological situation of current invasions in children of the Astrakhan region. 315 outpatient cards of children were analyzed in 2016. The diagnosis of Giardiasis was made to 151 children, the diagnosis of Enterobiasis — 164. The age of all observed children ranged from 9 months to 17 years. The largest part was made up of children aged 3 to 14 years of age — 80.3%, among them enterobiasis was identified — in 46.7%, giardiasis — in 33.6% of cases. Most of the children — 90.5% were from organized groups (they attended preschool institutions or school). The reasons for the examination of all children were varied. Some children — 63.5% went to the doctor with complaints or clinical symptoms. Another part of the children — 33% of the diagnosis was made as a result of preventive examinations. In most cases — 78.7% various bad habits were identified. Thus, geophagy (the habit of eating the earth) was noted in 33.3% of children, and onigophagy (the habit of biting the nails) in 24.8%. In 21.3% of cases, bad habits were absent. Contact with pets was established in 22.9% of children. According to the ultrasound, most children with giardiasis (83.8%) had pathology (reactive changes of the pancreas, liver, gallbladder dyskinesia, etc.) In case of giardiasis niferator, albendazole was administered. In case of enterobiasis albendazole, pyrantel, and mebendazole were administered in age dosages. After antiparasitic treatment, in 91.4% of cases, the clinical symptoms of the disease completely disappeared, with giardiasis — in 85.4%, with enterobiasis — in 97% of cases. In 1.3% of children with giardiasis, after several courses of antiparasitic drugs, Giardia was found in feces in the absence of complaints and clinical symptoms, indicating a possible Giardia carrier parasite in children.

EVALUATION OF POINT OF CARE TEST FOR DIAGNOSIS OF HUMAN GIARDIASIS

Background: Giardia is a unicellular flagellated parasite infecting wide range of vertebrate hosts, including humans. Infection is usually transmitted through ingestion of cyst stage. Infection occurs worldwide, but particularly affects populations in the developing countries. Giardiasis is usually asymptomatic but, mild to moderate self-limiting diarrhea commonly occurs. In other cases, diarrhea may be severe, prolonged or even life threatening. Aim of the work: The aim of this study was to assess the value and reliability of the immunochromatographic Giardia strip test (RIDAQUICK)* in a routine diagnostic setting as a point of care test for diagnosis of Giardiasis. The results will be compared to those obtained using conventional microscopy and the ELISA test “reference method” (RIDASCREEN)*. Patients and Methods: This cross sectional study was conducted on 30 random stool samples recruited from symptomatic infants and children (<10 years old) of both genders (15 males and 15 females) complaining of gastrointestinal symptoms as diarrhoea, abdominal pain and flatulence. The studied patients were either admitted to inpatient ward of the pediatric hospitals of Ain ShamsUniversity or referred from the outpatient clinic. The samples were processed in the Central Microbiology Laboratory, Clinical Pathology Department, Ain Shams University Hospitals from January 2018 till December 2018. All stool samples were subjected to the following: Macroscopic examination of stool samples by naked eye, microscopic examination by conventional methods (Direct wet mount and iodine mount using ordinary light microscopy), immunochromatographic (ICT) Giardia strips and enzyme linked immunosorbent assay (ELISA). Results: Concerning the diagnostic yield of the used diagnostic methods microscopy and ICT compared with ELISA. ICT as diagnostic test was more efficient test than microscopy with higher accuracy (93%) to detect Giardia in all study individuals. Kappa agreement showed that there was 0.85 (almost perfect agreement between ICT with ELISA findings) and 0.66 (Substantial agreement between microscopy and ELISA). Conclusion: The use Giardia Antigen detection by ICT was found sensitive and specific for the detection of G. lamblia. They are rapid to perform and do not require experienced staff or special technical equipment, results are obtained within 9–10 min per test.

Retrospective and Comparative Study of Giardia sp. Prevalence in Dogs, Cats, and Small Ruminants in Endemic Areas in Different Brazilian States

Background: Giardia, an intestinal parasite of asexual reproduction, is an important etiologic agent of diarrhea in animals and humans, transmitted by orofecal route. The disease caused by this agent, giardiasis, is endemic in the world and representing an important public health problem. The aim of the present study was do a retrospective study to determine the prevalence of Giardia sp. in fecal samples from dogs, cats, sheep and goats (small ruminants) evaluated at FMVZ Unesp, Botucatu, SP. In addition, this study presents a review of the literature on the prevalence of this protozoan in dogs, cats and small ruminants in different states of Brazil, according to the environmental of these animals.Materials, Methods &amp; Results: During 2011 to 2017, 2,698 fecal samples of dogs, 359 fecal samples of cats and 320 fecal samples of goats and sheep were analyzed. A total of 18.9% of the dogs, 24.8% of the cats, and 6.6% of the goats and sheep were positive for Giardia sp. Only previous studies that used the zinc sulphate centrifugal flotation (Faust technique) were included for comparation of prevalence. The prevalence of Giardia sp. in samples of centrifugation-fluctuation in zinc sulfate was similar in dogs, higher in cats and lower for small ruminants when compared to previous investigations. 4.4% and 6.7% of the positive samples from dogs and cats, respectively, were associated with some co-infection. Co-infections by Cystoisospora spp., Ancylostoma spp. and/ or Toxocara spp. were the most common for dogs and cats.Discussion: This study reveals the presence of Giardia sp. in different animal species in an endemic área. The results are similar to the prevalence previous reported in dogs, and higher in cats using the same diagnostic technique (Faust technique). Co-infections by Cystoisospora spp., Ancylostoma spp. and/ or Toxocara spp. were the most common for dogs and cats, as well-known in previous studies. Investigations with household, shelter and stray dogs found a significantly lower occurrence of Giardia sp. in the group of household dogs. However, for cats these comparisons should made with caution. Despite having a owner, some of these cats have free access to the streets, so they might be more expose to the sources of infection. There are few previous reports of the presence of Giardia sp. in goats and sheep, which presented much higher prevalence when compared with this study. This variation in prevalance of Giardia sp. in small ruminants can occur due to differences inherent to each region in Brazil, as well as the presence of risck factors regarding animal age, type of raising of the animals, hygienic-sanitary and management conditions, and the presence of domestic animals inside sheep and goat installations, which can potentially favor the mechanical transmission of cysts our reservoirs of this parasite. Therefore, due to regional variations in this parasite prevalence, this information is more value in regional areas, reaffirming the importance of this kind of studies in brazilian states and cities. The intermittent elimination of cysts in feces, the low number of cysts in the samples and asymptomatic infections are relevant points to the diagnosis of giardiasis, making it a challenge. The technique of centrifugation-flotation technique in zinc sulfate gives the best results when compared to other techniques available for the diagnosis of Giardia infections, justifying the choice of this technique by this study. These evidences associated to molecular diagnoses are necessary to determine the real role of these animals in the epidemiology and zoonotic transmission, due to the close contact with humans. This may be considering as a start for further investigations of Giardia sp. at municipality of Botucatu.

Cytopreparation of duodenal biopsy fixative improves detection rate of giardia in clinically suspected cases.

Giardia intestinalis is a flagellated protozoan, frequently documented as an agent for enteric illness worldwide. Laboratory procedures for diagnosis include stool examination, antigenic detection assays and, at times, mucosal biopsy. We hypothesised that the formalin fixative used as a preservative for mucosal biopsy can be a good diagnostic sample for detecting surface mucosal and luminal infective agents such as giardia. The aim of the study was to find out the utility of processing the remaining formalin fixative as a complementary diagnostic method for detecting giardia. This study included 200 cases of duodenal biopsies sampled over 6months. The biopsies were picked up using clean forceps and the remaining fixative was processed using standard cytospin protocol. The cytospin preparation and formalin-fixed paraffin-embedded tissue sections were examined by two pathologists independently blinded to each others findings. On cytology, trophozoites of giardia were detected in 23 out of 200 cases (11.50%). The cytomorphology of pear-shaped organism with paired flagella and nuclei is very diagnostic. One case also showed presence of cryptosporidium spores. No other intestinal parasite was seen. Out of the 23 positive cytology samples, only 12 (6%) corresponding formalin-fixed paraffin-embedded tissue sections showed presence of giardia. Concurrent examination of duodenal biopsy and the formalin fixative cytopreparation in cases with high index of clinical suspicion of giardiasis proved to be a useful adjunct to biopsy diagnosis of giardiasis, which was statistically significant (P<.0001). This approach adds negligible cost and effort but with good diagnostic yield. We recommend that the formalin cytopreparation be used as a complementary technique to biopsy for cases suspected of intestinal parasitic infection.

Giardia lamblia infection: review of current diagnostic strategies.

Giardiasis has a global distribution and it is a common cause of diarrhea in both children and adults and is transmitted via the fecal-oral route through direct or indirect ingestion of cysts. The laboratory diagnosis of Giardia spp. is mainly based on demonstration of microscopic cyst or trophozoite in stool samples but several immunological-based assays and molecular methods are also available for giardiasis diagnosis. The aim of this study was to conduct a review of the applied methods in medical laboratory and to highlight pitfalls and challenges of them for diagnosis of giardiasis. In this article we have evaluated the Giardia diagnostic methods with a broad review of literature, electronic databases and books. The search has covered the articles and some textbooks that have published up to 2018. It has been concluded that traditional microscopy combination with stool concentration method should still be held in the routine medical laboratory due to economical and high sensitivity and immunological-based assay and molecular methods which are recommended to use as a complementary test to the traditional technique.

Assessment of the diagnostic performance of four methods for the detection of Giardia duodenalis in fecal samples from human, canine and feline carriers

Enteric parasitic diseases including giardiasis are of public health concern. Different methods are available for the diagnosis of this parasitic infection in fecal samples such as the identification of protozoan cysts and trophozoites by light microscopy, detection of specific antigens by ELISA, and amplification of DNA fragments by PCR. The present study aimed at assessing the performance of four laboratory tests for the detection of Giardia duodenalis in fecal specimens from three different host species with a previous diagnosis of giardiasis; canine, feline and human patients provided new stool samples to be retested for Giardia before initiating treatment with antiprotozoal drugs. For this purpose, triplicate fecal specimens from 54 humans, 24 dogs and 18 cats living in the city of Niterói, RJ, southeast Brazil, were analysed by light microscopy, ELISA, immunochromatography, and nested PCR. The centrifugal-flotation method detected Giardia cysts in 89.6% (86/96) of the fecal samples. The protozoan parasite was detected via immunochromatography in 87.5% (84/96) of these samples. Giardia was detected by ELISA in 69.8% (67/96) of the stool specimens from carriers with a previous diagnosis of Giardia infection. Giardia was detected by PCR in only 39.6% (38/96) of the fecal specimens. Based on these findings, we suggest that, among the four assays that were used in this study, the zinc sulphate flotation technique (Faust et al., 1939) is the best diagnostic assay in terms of sensitivity and specificity to detect G. duodenalis on serially collected samples from dogs, cats and humans.

Comparison of ELISA, nested PCR and sequencing and a novel qPCR for detection of Giardia isolates from Jordan

Little is known about the prevalence of Giardia duodenalis in human patients in Jordan and all previous studies have used direct microscopy, which lacks sensitivity. The present study developed a novel quantitative PCR (qPCR) assay at the β-giardin (bg) locus and evaluated its use as a frontline test for the diagnosis of giardiasis in comparison with a commercially available ELISA using nested PCR and sequencing of the glutamate dehydrogenase (gdh) locus (gdh nPCR) as the gold standard. A total of 96 human faecal samples were collected from 96 patients suffering from diarrhoea from 5 regions of Jordan and were screened using the ELISA and qPCR. The analytical specificity of the bg qPCR assay revealed no cross-reactions with other genera and detected all the Giardia isolates tested. Analytical sensitivity was 1 Giardia cyst per μl of DNA extract. The overall prevalence of Giardia was 64.6%. The clinical sensitivity and specificity of the bg qPCR was 89.9% and 82.9% respectively compared to 76.5 and 68.0% for the ELISA. This study is the first to compare three different methods (ELISA, bg qPCR, nested PCR and sequencing at the gdh locus) to diagnose Jordanian patients suffering from giardiasis and to analyze their demographic data.