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Introduction: Inflammation associated with Helicobacter pylori (H. pylori) infection is linked to the development of a gastric precancerous lesion. Helminth infections could influence the pro-inflam matory response to such infection from LTCD4+ Th1 to a less harmful LTCD4+ Th2 response. Ob jective: To characterize the polarization of the LTCD4+ Th2 immune response in co-infected pa tients with H. pylori and helminths from low-risk areas for developing gastric cancer., Patients and Method: We analyzed 63 patients infected by H. pylori (40 adults and 23 children). Through the Multiplex Analysis technology (xMAP), we determined the serum profiles of the interleukins asso ciated with the polarization of the immune response of LTCD4+ Th1 (IL-1Β, INF-γ, TNF-α) as well as the LTCD4+ Th2 (IL-4, IL-10, and IL-13). The ratio between helminths co-infection status in H. pylori-infected patients and the polarization of the immune response mediated by LTCD4+ Th1 and LTCD4+ Th2 was assessed using a Mixed Effects Logistic Regression Model., Results: The frequency of helminths was similar between adults (15%) and children (17%). The polarization of the immu ne response was more prevalent in LTCD4+ Th1. Serum values of interleukins associated with the immune response polarization of LTCD4+ Th1 (IL-1Β, INF-γ, and TNF-α) and LTCD4+ Th2 (IL-4, IL-10, and IL-13) were independent of helminths infection status., Conclusion: The prevalence of in testinal parasitic infection was high and the immune response polarization was mainly LTCD4 + Th1.

Infections causes by parasites of the gastrointestinal tract are a global public health problem. In industrialised countries, their particular epidemiological (low general prevalence of enteroparasites), economic (high labour costs) and clinical characteristics (constant increase in the number of samples and diagnostic determinations to be performed) have led molecular techniques to progressively replace conventional microscopy as the first-line diagnostic method of these pathogens in modern clinical laboratories. PCR-based techniques, particularly those developed for the simultaneous detection of the various agents that can cause the same infectious disease (syndromic diagnosis), already represent a cost-effective option that allow process automisation, workflow optimisation, and comparison of results among different laboratories, and facilitate accreditation of diagnostic procedures. This review clearly and concisely discusses the current situation of the molecular diagnosis of the main species of intestinal parasites in humans, particularly the enteric protozoans causing diarrhoea (Cryptosporidium spp., Giardia duodenalis, Entamoeba histolytica), the most important members the Microsporidia phyla (Enterocytozoon bieneusi) and Stramenopiles phyla (Blastocystis sp.), as well as the helminths transmitted by soil (Ancylostoma spp., Ascaris lumbricoides, Necator americanus, Strongyloides stercoralis and Trichuris trichiura) and food (Anisakis spp., Clonorchis sinensis, Fasciola spp., Taenia solium, and Trichinella spiralis). Special attention is paid to the description of available techniques and formats, to their diagnostic benefits and the most widely used genetic markers for their detection, both in clinical laboratories and genotyping in referral and research centres., (Copyright © 2020. Publicado por Elsevier España, S.L.U.)

Infections caused by Strongyloides stercoralis and other soil-transmitted worms such as hookworms (Necator americanus and Ancylostoma duodenale) represent a major problem worldwide, especially in developing areas. They are difficult to suspect clinically since they produce non-specific and often overlapping signs and symptoms. Likewise, their long prepatent periods hamper the detection of parasitic structures. Microscopic diagnosis is still the most commonly used tool in healthcare laboratories but it is still far from being the ideal technique to detect these infections due to its low sensitivity. In addition, these nematodes have strong morphologic similarities and consequently microbiological diagnosis remains a challenge. Serology has made progress in the diagnosis of S. stercoralis infection but this option is not yet available for hookworms. Molecular biology techniques have been shown to slightly increase this lack of sensitivity, but as with other parasitic infections, they are not currently available for use in clinical microbiology laboratories. Supplement information: This article is part of a supplement entitled «SEIMC External Quality Control Programme. Year 2016», which is sponsored by Roche, Vircell Microbiologists, Abbott Molecular and Francisco Soria Melguizo, S.A. © 2019 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosasy Microbiología Clínica. All rights reserved., (Copyright © 2019 Elsevier España, S.L.U. All rights reserved.)

Introduction: The diagnosis of intestinal parasitic infections depends on the parasite load, the specific gravity density of the parasite eggs, oocysts or cysts, and the density and viscosity of flotation or sedimentation medium where faeces are processed., Objective: To evaluate the concordance between zinc sulphate flotation and centrifugal sedimentation in the recovery of parasites in faecal samples of children., Materials and Methods: Faecal samples of 330 children from day care centers were evaluated by zinc sulphate flotation and centrifugal sedimentation techniques. The frequencies of detection of parasites by each method were determined and the agreement between the diagnostic techniques was evaluated using the kappa index, with 95% confidence intervals., Results: The faecal flotation in zinc sulphate diagnosed significantly more cases of Trichuris trichiura infection when compared to centrifugal sedimentation (39/330; 11.8% vs. 13/330; 3.9%, p<0.001), with low diagnostic concordance between methods (kappa=0.264; 95% CI: 0.102-0.427). Moreover, all positive samples for Enterobius vermicularis eggs (n=5) and Strongyloides stercoralis larvae (n=3) were diagnosed only by zinc sulphate. No statistical differences were observed between methods for protozoa identification., Conclusions: The results showed that centrifugal flotation in zinc sulphate solution was significantly more likely to detect light helminths eggs such as those of T. trichiura and E. vermicularis in faeces than the centrifugal sedimentation process.

Millions of people in in rural areas and deprived tropical and subtropical regions are infected by soil-transmitted helminths: Ascaris lumbricoides, Trichuris trichiura, hookworms (Ancylostoma duodenale and Necator americanus), and Strongyloides stercoralis. Large migratory flows have made their worldwide distribution easier. Besides being debilitating and producing a significant mortality, they cause high morbidity, leading to physical and intellectual impairment in millions of children who live in poverty. Along with the use of benzimidazoles (albendazole and mebendazole), large-scale international campaigns for treatment and prevention have decreased the number of affected individuals. However, re-infestations and benzimidazole-resistance are frequent, so there needs to be awareness about the importance and consequences of these neglected parasites., (Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.)

Introduction: Soil-transmitted helminth infections are considered a public health problem in developing countries. The diagnostic tests, both for individual parient diagnosis as for population studies should be evaluated in terms of validity and reliability., Objective: To compare the direct examination, the modified Ritchie-Frick method, a Kato-Katz designed by a Brazilian group and one designed by the WHO, for the diagnosis of soil-transmitted helminthes., Materials and Methods: A diagnostic test reliability study was performed. The same stool sample was analyzed by the same observer using four diagnostic tests. 204 samples were obtained, 194 of those fulfilled the inclusion criteria and were analyzed. The observers did not know the participants' identity neither the other tests results. For the analysis the Kato-Katz (WHO) was considered as the gold standard. For the reliability assessment percent agreement, positive percent agreement, Kappa statistic, and intraclass correlation were performed., Results: The Brazilian Kato-Katz showed a good performance with high sensitivity and specificity for T. trichiura and Hookworm with values of 0.97 and 0.96 respectively, and a high specificity with mild sensitivity for A. lumbricoides (0.95 and 0.79) meanwhile the direct examination and the Ritche-Frick method showed a performance between mild and poor. The differences were higher for hookworm and Trichiuris trichiura than for Ascaris lumbricoides., Conclusion: The Brazilian Kato Katz test could be implemented, but further studies are needed to correlate its operative capacity with its feasibility, availability and cost.

Imported parasitosis represents an increasingly frequent diagnostic challenge for microbiology laboratories. A surge in immigration and international travel has led to a rise in the number of imported cases of parasitosis, and this trend is expected to continue in the future. The present article addresses this challenge by reviewing recommended diagnostic approaches and tests. Currently, microscopy is always recommended when analysing blood samples for parasites. If malaria is suspected, rapid antigen testing (including at least HRP2 antigen) should also be performed. The work-up for suspected leishmaniasis should include serology, culture, and in selected cases detection of antigen in urine. In suspected Chagas disease, two different serological tests should be performed. PCR for blood protozoa is highly sensitive, although it cannot be used to rule out Chagas disease, since this condition may be present without parasitemia. Accurate diagnosis of intestinal amebiasis usually requires PCR or antigen detection tests. In helminthiasis, traditional microscopy may need to be complemented with other tests, such as agar plate culture for strongyloidiasis, Og4C3 antigen detection for bancroftian filariasis, and antibody detection test for filariasis and schistosomiasis., (Copyright © 2010 Elsevier España, S.L. All rights reserved.)

Intestinal parasites are highly prevalent in tropical areas and developing countries, but are also common in industrialised countries as well. Traditionally, their diagnosis has been made by microscopic examinations of the faeces of the patient. These have been shown to have poor sensitivity, require serial samples, are very time-consuming and require a specialised technique. In the last few years, advances in the molecular biology of these parasites and research into the specific immune response of the patient, has made it possible to develop more efficient detection systems that help the clinician, allow treatments to be followed up and make it easier to carry out epidemiological studies. Among these systems are the methods for detecting faecal antigens, which, in general, have good specificity and sensitivity; properties which make them a useful tool in microbiology laboratories., (2010 Elsevier España S.L. All rights reserved.)

In recent years, there has been an increase in cases of imported helminthiasis in Spain because of two complementary causes: immigration and international travel. Although the prevalence of helminthiasis is high in the immigrant population, the risk of transmission to the Spanish population is low. In this review, we provide clues to aid in the diagnosis of the helminthiasis, highlighting the geographic characteristics, clinical findings and analytical results of the most frequent types. The low sensitivity of the classic parasitological diagnostic test, mainly in tissue helminthiasis, is described. In addition, the advantages and limitations of the common serological methods for detecting related circulating antigens and antibodies are presented. Certain molecular methods used in the diagnosis of imported helminthiasis and the best strategies for screening of this condition are discussed.

Background: Strongyloides stercoralis is a world wide distributed small intestinal nematode parasite. In immunocompetent individuals S stercoralis can produce asymptomatic infections or a moderate clinical picture of diarrhea, some cases become chronic. In immunocompromised patients, a disseminated disease may appear, sometimes fatal. In Chile, there is little epidemiological information about S stercoralis infections and appropriate diagnostic techniques are usually not used., Aim: To evaluate the yield of an ELISA test for the diagnosis of strongyloidiasis in Chilean patients., Material and Methods: Ten serum samples from patients with S stercoralis infections confirmed by a positive stool examination, 66 samples from individuals with other infections by tissue helminthes (24 toxocariasis, 15 trichinellosis, 11 hydatidosis, 12 fascioliasis and 4 cysticercosis), 13 samples from subjects with autoimmune diseases and 49 samples from apparently healthy individuals with a normal eosinophil count, were studied. ELISA antigen was prepared using a filariform larval extract obtained from a murine species of Strongyloides, maintained in laboratory animals., Results: Using 0.33 optical density units as a cut off value, 9 of 10 sera of S stercoralis infected individuals, had a positive ELISA test. No cross reactions were observed with sera of patients with other helminthic infections, autoimmune diseases or in healthy individuals. Thus, specificity, positive and negative predictive values were 100%., Conclusions: The results obtained are similar with those found by other investigators. ELISA test for strongyloidiasis is a useful tool for the diagnosis of clinical cases and for seroepidemiological studies of this nematode infection in Chile.

The aims of this work were: 1.--to determine the intestinal helminth prevalence in children who live and attend primary schools in Santa Fe city. 2.--to characterize the socio-cultural and sanitary aspects of the children studied and consequently to group them in three supposed strata (hypo, meso and hyperendemic). The study was carried out during 1998. Considering the following variables: kind of streets, sewers and water supplies, parents' educational levels, satisfied or unsatisfied basic needs, the city was divided in three strata, according to the intestinal helminthic prevalence expected: 1--hypoendemic (< 25%), 2--mesoendemic (25-75%) and 3--hyperendemic (> 75%). Schools with children of both sexes, and ages between 5 and 13 who belonged to each one of the supposed strata, were identified. A direct parasitic examination and a Kato Katz technique were performed on a stool specimen of each selected child. An epidemiological survey was answered by the children's parents. The prevalence of helminths and geohelminths, with 95% confidence intervals, were respectively: total sample (n = 163). 36.2% and 34.4%; stratum 1 (n1 = 60) 0% and 0%; stratum 2 (n2 = 70) 41% (29.9-52.9) y 38.6% (27.2-50.0) and stratum 3 (n3 = 33) 91% (81.1-100) and 87.9% (76.6-99.2). The above-mentioned variables, related to the socio-cultural and sanitary aspects, allowed to identify three well defined strata: hypoendemic, mesoendemic and hyperendemic, according to the different helminth prevalence detected among pupils who attend primary level school in Santa Fe city.

To determine the prevalence and epidemiological parameters of intestinal parasites in schoolchildren, a faecal analysis was performed in 349 individuals of both sexes, between 5 and 16 years of age. The methodology used included, a fresh test, formol-ether technique and faecal egg counts by the Kato-Katz method. Eighty three per cent of the children presented enteroparasites, with a high prevalence of polyparasitism (71.6%). There was not significative difference between parasitoses, sex and age. However, it was observed an increase of helminthiasis and protozooses in children between 7 and 10 years of age. The principal enteroparasites founded were: Trichuris trichiura (41.8%), Ascaris lumbricoides (35.2%), Blastocystis hominis (48.1%) and Endolimax nana (22.9%). When the intensity of infestation was studied by the faecal egg counts, it was observed that the highest percentage of children with T. trichiura had light infestations (84.3%), while 45.9% of the children with A. lumbricoides had severe infestations. The Abundance, Mean Intensity and Aggregation Coefficient (k) values show an over-dispersed spatial disposition of both helminths, where only few children harbour heavy burdens and eliminate a large quantity of eggs. This aggregation was higher for T. trichiura (k = 0.298) than for A. lumbricoides (k = 1.138).

By means of Kato-Katz technique 113,254 coprological samples of the human population belonging to 100 counties from Venezuela were analyzed. It was determined the following prevalences: Ascaris lumbricoides 26.8%, Trichuris trichiura 32.7% and hookworm 5.6%. It was found a strong correlation between A. lumbricoides and T. trichiura infection (p < 0.001), a significant correlation between T. trichiura and hookworm (p < 0.5) and no correlation between A. lumbricoides and hookworm.

Five hundred and eleven samples of feces were examined by several coproparasitological techniques: Kato-Katz, Willis, Ritchie and direct wet mount. It was found that Kato-Katz was the most reliable technique for the diagnosis of Trichuris trichiura, Necator americanus, and Ascaris lumbricoides, demonstrating the largest number of cases. Willis, Ritchie and direct wet mount were effective in that order. Taking into account that Kato-Katz is a quantitative method, it should be recommended in the diagnosis of soil-transmitted helminthiasis.

This review of internal parasitic diseases discusses methods of immune diagnosis, immune mechanisms of the host, and immunoprophylaxis against both protozoan and metazoan parasites of livestock. The limiting factors for immunodiagnosis are specificity and whether the host animals respond sufficiently to produce detectable serological responses. Because the array of antigens is so complex, the method of choice for helminths is to use excretory/secretory products of the parasite as antigens for microplate ELISA. Similarly, for protozoa, immunodiagnosis is facilitated by using a few, selected, immunodominant antigens rather than extracts of whole parasite. However, serodiagnosis does not always identify parasitised animals especially in the young, malnourished or sick host. Similarly, parasites may themselves modulate the response of the host and remain serologically undetectable. The production of recombinant, pure, parasite proteins is already facilitating diagnostic serology for several parasite species and, using recombinant DNA probes, it is now possible to distinguish inter- and intra-species differences. The central role of inflammatory cytokines, the regulatory proteins produced by activated T helper cells, in modulating both protective and potentially damaging inflammatory responses is discussed. Finally, the genetic control of the immune response and its relevance to immunoprophylaxis is considered. Several interesting developments in the production of sub-unit vaccines and the potential methods of delivery are appraised.