Immunodiagnostic Techniques Research Articles

Methods for the Diagnosis of Grapevine Viral Infections: A Review

The yielding capacity of grapevine growth and the quality of the resulting product heavily depend on the health of the cultivated plants. The phytopathogens affecting the vineyards can cause a significant reduction in the yield and quality of the product. For this reason, it is extremely important to use diagnostic methods that make it possible to identify the pathogens, and to choose the correct method of plant protection. This review considers the main viral grapevine pathogens, and the existing methods of their diagnosis. The limitations of conventional diagnostic methods that are based either on the visual assessment of symptoms, or on bio-testing, are analyzed. A major focus is placed on two intensively developed approaches of diagnosis, molecular genetic and immunochemical methods. Applications of amplification techniques and DNA chips are presented, as well as opportunities for next-generation sequencing. A reduction of assay duration and labor intensity in combination with the assay shifts from specialized laboratories toward the places of sampling are considered as the main factors influencing the development of immunodiagnostic techniques. The potential place of diagnostic tests in vine-growing practices, and the requirements for their most efficient applications for early disease diagnosis is also discussed.

Cell-free expression, purification and immunoreactivity assessment of recombinant Fasciola hepatica saposin-like protein-2.

Cell free protein synthesis has become a powerful method for the high-throughput production of proteins that are difficult to express in living cells. The protein SAP2 of Fasciola hepatica (FhSAP2), which has demonstrated to be both, an excellent vaccine candidate against experimental fascioliasis and a good antigen for serodiagnosis of human chronic fascioliasis, is a typical example of a molecule that is difficult to produce. This is mainly due to its tendency to get over-expressed in inclusion bodies by prokaryotes. FhSAP2 expressed in an Escherichia coli-based expression system is poorly glycosylated, insoluble and often undergoes improper folding leading it to reduced immunogenicity. In this work, FhSAP2 was expressed in vitro using the eukaryote cell free system, TNT T7 Quick coupled transcription/translation, that has been designed for the expression of PCR-generated DNA templates. FhSAP2 was expressed in micro-volumes and purified by an affinity chromatography method, which gave a protein yield of 500µg/ml as determined by bicinchoninic acid assay method. Circular dichroism, Western blotting and enzyme-linked immunosorbent assay analysis were used to confirm the secondary structure, purity and integrity of protein. Results demonstrate that FhSAP2 can be expressed in a cell-free system retaining its main conformational and antigenic properties. The protein purified could be used in immunization experiments and immunodiagnostic techniques.

Usefulness of the early molecular diagnosis of Q fever and rickettsial diseases in patients with fever of intermediate duration

Most cases of fever of intermediate duration (FDI) in Spain are associated with infectious diseases (mainly Q fever and rickettsia infections). In clinical practice, the causal diagnosis of these entities is based on immunodiagnostic techniques, which are of little help in the early stages. Therefore, the aim of this study was to evaluate the usefulness of molecular techniques for the early diagnosis of Q fever and rickettsia diseases in patients with FDI. A PCR method was used to detect the presence of genetic material of Coxiella burnetii and Rickettsia spp. in blood specimens from 271 patients with FDI. The specificity of both techniques is high, allowing diagnosis in cases undiagnosed by specific antibodies detection. These data suggest that the use of molecular techniques, with proper selection of the study specimen, and using appropriate primers is a useful tool in the early diagnosis of the main causes of FDI, especially if serology is negative or inconclusive.

Isolation, production, and characterization of a new single chain anti-idiotypic antibody against benzo[a]pyrene

ABSTRACTPolycyclic aromatic hydrocarbons are chemical carcinogens which could induce the development of human cancers. Anti-idiotypic antibodies against benzo[a]pyrene (BP) are perspective for human cancer immunoprophylaxis and tumor immunodiagnostic techniques. The purpose of this study was to isolate anti-idiotypic antibodies against BP from human lymphocytes naïve phage library. The anti-idiotypic antibody, named B5, was selected. Analysis of the nucleotide and amino acid sequences B5 showed no similarity to known protein databases antibodies. B5 bound idiotypic antibodies against BP in direct and competitive ELISA. It was suggested that the B5 carried an immunological image of BP and bound the idiotypic antibodies against BP.Abbreviations: scFv: single-chain variable fragment; Ab1: idiotypic antibodies; Ab2: anti-idiotypic antibodies; CBD: cellulose binding domain; BSA: bovine serum albumin; PBS: phosphate buffer; BP-BSA: benzo[a]pyrene-BSA conjugate; Cr-BSA: chrysene-BSA conjugate; Py-BSA: pyrene-BSA conjugate; Ac-BSA: anthracene-BSA conjugate; Ba-BSA: benz[a]anthracene-BSA conjugate; PAH: polycyclic aromatic hydrocarbons; pSh: mouse idiotypic single-chain variable fragment against benzo[a]pyrene; T72: human idiotypic single-chain variable fragment against benzo[a]pyrene.

Performance validation of western blot for anti-HIV antibody detection in blood samples collected on filter paper (DBS)

ABSTRACT Introduction: For conducting field studies on human immunodeficiency virus (HIV) serodiagnosis, the use of samples collected on filter paper [dried blood spot (DBS)] is profitable owing to the simplicity in handling and delivering them. Because of these characteristics, the use of DBS is recommended for studies in which the goal is to increase the population access to diagnostic testing, including HIV infection screening. For HIV diagnosis, the conventional strategy firstly uses an enzyme immunoassay as screening test, and the positive sample is confirmed on a complementary assay, as western blotting (WB). Objective: This study aimed at evaluating the analytical performance of WB assay for analyzing DSB samples. Method: One hundred eighteen blood samples collected in filter paper were analyzed by a modified WB. These samples derived from the SampaCentro Study, and they were HIV-antibody-positive in a screening test. In order to assess the reliability of these results, the assay performance was previously certified by employing the sample panel (reference panel) of Instituto Adolfo Lutz (IAL), which consisted of whole blood and plasma paired samples. Results: All of the DBS samples [100% (118/118)] showed the band pattern compatible with the criterion for HIV positivity established by the Ministry of Health. To validate the WB testing, the reciprocal relationship between antibody reactivity of DBS samples and of the respective plasma samples was investigated. Conclusion: WB optimization allowed the achievement of accurate results, and the easy DBS sample collection, transportation and storage will support the use of this immunodiagnostic technique for conducting HIV/acquired immunodeficiency syndrome (Aids) epidemiological surveys.

Immunodiagnosis of Human Fascioliasis: An Update of Concepts and Performances of the Serological Assays.

Human Fascioliasis (HF) is a foodborne neglected parasitic disease caused by Fasciola hepatica and Fasciola gigantica. New epidemiological data suggest that the endemic areas of the disease are expanding and HF is being reported from areas where it was previously not observed. Diagnosis of HF is challenging. Performances of parasitological approaches, based on the detection of parasite's egg in the stool, are not satisfactory. Currently serological methods for the diagnosis of HF are mainly based on detection of anti-Fasciola antibodies in serum. Although, there have been some improvement in the development of immunological diagnostic tests for the diagnosis of HF, yet these tests suffer from insufficiency in sensitivity or/and specificity. Detection of antigens, rather than antibodies, seems to be a suitable approach in the diagnosis of HF. Antigen can be detected in sera or stool of the fascioliasis patients. Circulating antigen in serum disappears within a short time and most of the circulating antigens are in immune complex forms which are not freely available to be detected. Therefore, antigenemia might not be an appropriate method for the diagnosis of HF. Detection of antigen in stool (coproantigens) seems to be a suitable alternative method for the diagnosis of HF. Recent data provided convincing evidence that detection of coproantigen improved and simplified the diagnosis of HF. The present review highlights the new achievements in designing and improvement of diagnostic approaches for the immunodiagnosis of HF. Moreover, current status of the available immunodiagnostic techniques for the diagnosis of HF, their strengths and weaknesses has been discussed.

Utilidad del diagnóstico molecular precoz de fiebre Q y rickettsiosis en pacientes con fiebre de duración intermedia

Most cases of fever of intermediate duration (FDI) in Spain are associated with infectious diseases (mainly Q fever and rickettsia infections). In clinical practice, the causal diagnosis of these entities is based on immunodiagnostic techniques, which are of little help in the early stages. Therefore, the aim of this study was to evaluate the usefulness of molecular techniques for the early diagnosis of Q fever and rickettsia diseases in patients with FDI. A PCR method was used to detect the presence of genetic material of Coxiella burnetii and Rickettsia spp. in blood specimens from 271 patients with FDI. The specificity of both techniques is high, allowing diagnosis in cases undiagnosed by specific antibodies detection. These data suggest that the use of molecular techniques, with proper selection of the study specimen, and using appropriate primers is a useful tool in the early diagnosis of the main causes of FDI, especially if serology is negative or inconclusive.

THE PROCESS OF Leishmania INFECTION - DISEASE AND NEW PERSPECTIVES OF PALEOPARASITOLOGY.

Species of the genus Leishmania (Kinetoplastida, Trypanosomatidae) are causative agents of leishmaniasis, a complex disease with variable clinical spectrum and epidemiological diversity, constituting, in some countries, a serious public health problem. The origin and evolution of leishmaniasis has been under discussion regarding some clinical and parasitological aspects. After the introduction of paleoparasitology, molecular methods and immunodiagnostic techniques have been applied allowing the recovery of parasite remains, as well as the diagnosis of past infections in humans and other hosts. The dating of archaeological samples has allowed the parasitological analysis in time and space. This manuscript presents the state of the art of leishmaniasis and prospects related to paleoparasitology studies and their contribution to the evolutionary and phylogenetic clarification of parasites belonging to the genus Leishmania, and the leishmaniasis caused by them.

Intestinal Obstruction by Ascaris lumbricoides in a 12-year-Old Boy: A Case Report in Pakistan

Background: Ascariasis is a severe parasitic disease widely prevalent in remote parts of Pakistan due to poor sanitation, and improper water supply system. Objective: The aim of this study is to describe an unusual clinical course of severe intestinal ascariasis in a boy of 12 years old in Khyber Pakhtunkhwa, Pakistan. Methods: Multi-disciplinary clinical and laboratory examinations, including physiological and immunodiagnostic techniques, socioeconomic status and imaging, have been performed during hospitalization. Results: A case of severe intestinal ascariasis was diagnosed at an age of 12 years old. The patient felt headache, abdominal pain and vomiting. Pre operation diagnosis was included: erythrocytes below and leucocytes were above the normal range. Blood, pressure, temperature and serum amylase were normal. Three days after his admission to the hospital, 03 kilograms roundworms were evidenced from the small intestine in a surgical trauma of the patient. Based on their morphological characterization the parasites were identified as Ascaris lumbricoides. Conclusions: Ascariasis should always be taken into consideration in a differential diagnosis of irregular spaceoccupying lesions located in the intestine, especially in patients who live in endemic areas and their epidemiological history indicates potential risk factors for the infection. In children appendicitis is more frequently recognized than in old age, and a clinical prognosis can be no less severe than in young patients. Early diagnosis of A. lumbricoides infection in humans provides the choice of proper and optimal treatment for saving or significantly extending a patient’s life.

Immunodiagnosis Tools for Parasitic Diseases

Regarding harmful agents in livestock, parasites play an important role moreover it also effect 1/4th of the human populace by various zoonotic diseases (e.g. Toxplasma, Cryptosporidium, Trypanosomiasis, etc.). In livestock the parasites successful invade host immune responses, so early diagnosis of parasitic agents by various immunodiagnostic techniques is very important. Numerous immunological/serological techniques have been emerged such as the complement fixation test (CFT), immunodiffusion (ID), indirect haemagglutination (IHA), indirect immunofluorescent antibody test (IFA), various forms of enzyme-linked immunosorbent assay (ELISA) [Sandwich ELISA, indirect and direct ELISA, competitive ELISA, falcon assay screening test ELISA (FAST-ELISA), dot-ELISA, rapid antigen detection system (RDTS), and luciferase immune precipitation system (LIPS)] and radioimmunoassay (RIA). They targets different components of parasite, moreover they can detect disease before the emergence of clinical sign. These tests are used for many important parasitic diseases like Echinococcus multilocularis, Wuchereria bancrofti, Taenia solium and parasite causing Babesiosis, Toxoplasmosis, Visceral leishmaniasis, Human African Trypanosomiasis in both man and animals. Moreover now a day’s nano and biosensor technology has also been used for improvising the diagnostic aspect. This current mini-review is an attempt to consolidate some information of different serological based test for early diagnosis of main parasitic disease.

Indirect Heamagglutination as an Immunodiagnostic Technique for Cystic Echinococcosis in Iraqi Patients

Objective: The aim is to determine the effectiveness of indirect Haemagglutination (IHA) as diagnostic techniques for Cystic Echinococcosis in Iraqi and the possible correlation of age and gender in disease occurrence. Material and Methods: IHA technique using sensitized sheep red blood cells coated with an Echinococcus granulosus antigen. A chi square, Pearson correlation used for analysis of categorical variables. Results: Patients presented with clinical manifestation of hydatidosis (202) selectively enrolled in this study. The mean age was 31.64±8.98 years. The minimum age was 18 years and the maximum age was 70 years. Males represent 50%, with the mean age of 33.50±7. 8 years. The rest of patients were females with a mean age of 29.78±9. 6 years. Positive cases represent 19.3%, and the 80.7% were negative. The number of positive cases was higher among females (22.8%) compared with males (15.8%) with no significant difference (p= 0.212) or correlation between gender and IHA results (p = 0.214) .The majority of patients had a the rage of 24-30 years, 31-36 years and 18-23 years. Among males, a higher number of positive cases at 31-36 years followed by 24-30 years and 49-54 years. Among females, a higher number of positive cases with 24-30 years of age was followed by those with 37-42 years of age and 18-23 years of age. There was a significant difference (p= 0.001) between age groups according to gender without a significant correlation between the age group and IHA results according to gender (p= 0.268). Conclusion: The IHA is considered as rapid, reliable and adequate technique that makes it possible to process a large number of samples simultaneously. It does not require highly trained technical personnel. Females appear to be more susceptible to CE than males especially in younger age groups.

Taenia solium porcine cysticercosis in Madagascar: Comparison of immuno-diagnostic techniques and estimation of the prevalence in pork carcasses traded in Antananarivo city

Taenia solium cysticercosis was reported in official veterinary and medical statistics to be highly prevalent in pigs and humans in Madagascar, but few estimates are available for pigs. This study aimed to estimate the seroprevalence of porcine cysticercosis among pigs slaughtered in Antananarivo abattoirs. Firstly, the diagnostic performance of two antigen-ELISA techniques (B158B60 Ag-ELISA and HP10 Ag-ELISA) and an immunoblotting method were compared with meat inspection procedures on a sample of pigs suspected to be infected with (group 1; n=250) or free of (group 2; n=250) T. solium based on direct veterinary inspection in Madagascar. Sensitivity and specificity of the antigen ELISAs were then estimated using a Bayesian approach for detection of porcine cysticercosis in the absence of a gold standard. Then, a third set of pig sera (group 3, n=250) was randomly collected in Antananarivo slaughterhouses and tested to estimate the overall prevalence of T. solium contamination in pork meat traded in Antananarivo.The antigen ELISAs showed a high sensitivity (>84%), but the B158B60 Ag-ELISA appeared to be more specific than the HP10 Ag-ELISA (model 1: 95% vs 74%; model 2: 87% vs 71%). The overall prevalence of porcine cysticercosis in Antananarivo slaughterhouses was estimated at 2.3% (95% credibility interval [95%CrI]: 0.09–9.1%) to 2.6% (95%CrI: 0.1–10.3%) depending on the model and priors used. Since the sample used in this study is not representative of the national pig population, village-based surveys and longitudinal monitoring at slaughter are needed to better estimate the overall prevalence, geographical patterns and main risk factors for T. solium contamination, in order to improve control policies.

Serum vitamin D levels in patients with atopic asthma

BackgroundIt must be obvious that no one factor should be held accountable for the etiology of allergic diseases, asthma or acute asthma exacerbations. Operating on a genetic basis many factors must play a role. It has been postulated that vitamin D deficiency, as a result of industrialization and Westernized lifestyles that have led to sun-avoidance behaviors and more time indoors, has a role in the development of asthma and allergies (Green, 2010) [1]. ObjectiveTo assess the relationship between serum vitamin D levels and severity of asthma in patients with atopic asthma. Patients and methodsThe study was carried out on 30 patients with atopic asthma, divided into three groups according to severity of airway obstruction, and ten healthy control subjects. Serum 25-hydroxyvitamin D3 [25(OH) D], a vitamin D metabolite, was measured using an immunodiagnostic ELISA technique. Results86% of all asthmatic patients were vitamin D insufficient, as defined by a level ⩽30ng/ml 25(OH) Vit D. Mean vitamin D levels were the lowest in patients with severe asthma. ConclusionVitamin D insufficiency is common in patients with atopic asthma that is correlated with its degree of severity.

Unusual Occurrence of Advanced Alveolar Echinococcosis in Young Patients from Poland

Background: Human alveolar echinococcosis is a severe parasitic disease of a progressive and neoplasm mimicking development, which has begun an emerging infection in Poland and some parts of Europe. Due to the very slow development after primary infection in human beings, in most cases alveolar echinococcosis is usually diagnosed in patients older than 40 years old. Advanced cases of E. multilocularis infection are sporadically reported in younger patients. Objective: The aim of this study is to describe an unusual clinical course of severe liver alveolar echinococcosis in young Polish patients which is sporadically observed in other endemic countries. Methods: Multi-disciplinary clinical and laboratory examinations, including epidemiological interview, imaging, histopathological and immunodiagnostic techniques have been performed during hospitalization in a reference university centre. Results: We present three exceptionally rare cases of alveolar echinococcosis with final diagnosis established at an age under 30 years old. Thought a medical diagnosis recognised at a young age, only one of those patients could undergo a radical surgical resection of the parasitic mass located in the liver. Two other cases received longterm chemotherapy with albendazole due to an advanced and non-operative parasitic process with distant and contiguous metastases to the lungs and omentum. A possibility of a more intensive invasion with local E. multilocularis strains of a higher pathogenicity or acquired in very early infancy has been discussed. Conclusions: 1. Alveolar echinococcosis should always be taken into consideration in a differential diagnosis of irregular space-occupying lesions located in the liver, especially in patients who live in endemic areas and their epidemiological history indicates potential risk factors for the infection. 2. In young patients alveolar echinococcosis is actually more frequently recognised than previously expected, and a clinical prognosis can be no less severe than in elderly patients. 3. Early diagnosis of E. multilocularis infection in humans facilitates the choice of proper and optimal treatment for saving or significantly extending a patient’s life.

Strongyloides stercoralis and Relatives: Recent Advances in General and Molecular Biology

Human strongyloidiasis is a threat to global health, presenting significant challenges in diagnosis and clinical management. The imperative to incorporate strongyoidiasis more fully into control programs for soil-transmitted helminths is increasingly recognized. The unique life cycles of S. stercoralis and congeneric species contain both free-living and parasitic generations, and transcriptomic methods have recently identified genes of potential importance to parasitism in these parasites. Proteomics recently revealed stage-specific secreted proteins that appear crucial to the host-parasite interaction. A comprehensive genome sequencing project for Strongyloides spp. is now nearing completion. Recent technical advances in transgenesis for S. stercoralis and S. ratti, including the first establishment of stable transgenic lines, promise to advance functional evaluations of genes expressed in conjunction with crucial life cycle events. Studies employing these methods recently bolstered the hypothesis that S. stercoralis uses cellular signaling pathways homologous to three that regulate dauer larval development in Caenorhabditis elegans to regulate morphogenesis and development of its infective third-stage larva. The free-living generation of Strongyloides makes classical genetics formally possible. Recent advances, such as a genetic map of S. ratti and a molecular genetic and karyotypic analysis of sex determination in S. papillosus, will greatly facilitate this approach. Advanced methods for study of chemosensation in C. elegans were recently applied to discover numerous host attractant molecules that mediate host finding and contact by infective third-stage larvae of Strongyloides spp. Finally, nucleic acid-based diagnostic methods have recently come to the fore as alternatives to parasitological and immunodiagnostic techniques.

Nickel nanoparticle-doped paper as a bioactive scaffold for targeted and robust immobilization of functional proteins.

Cellulose-based materials are widely used in analytical chemistry as platforms for chromatographic and immunodiagnostic techniques. Due to its countless advantages (e.g., mechanical properties, three-dimensional structure, large surface to volume area, biocompatibility and biodegradability, and high industrial availability), paper has been rediscovered as a valuable substrate for sensors. Polymeric materials such as cellulosic paper present high protein capture ability, resulting in a large increase of detection signal and improved assay sensitivity. However, cellulose is a rather nonreactive material for direct chemical coupling. Aiming at developing an efficient method for controlled conjugation of cellulose-based materials with proteins, we devised and fabricated a hybrid scaffold based on the adsorption and in situ self-assembly of surface-oxidized Ni nanoparticles on filter paper, which serve as "docking sites" for the selective immobilization of proteins containing polyhistidine tags (His-tag). We demonstrate that the interaction between the nickel substrate and the His-tagged protein G is remarkably resilient toward chemicals at concentrations that quickly disrupt standard Ni-NTA and Ni-IDA complexes, so that this system can be used for applications in which a robust attachment is desired. The bioconjugation with His-tagged protein G allowed the binding of anti-Salmonella antibodies that mediated the immuno-capture of live and motile Salmonella bacteria. The versatility and biocompatibility of the nickel substrate were further demonstrated by enzymatic reactions.

Field comparison of circulating antibody assays versus circulating antigen assays for the detection of schistosomiasis japonica in endemic areas of China

BackgroundSchistosomiasis remains a serious public health problem in affected countries, and routine, highly sensitive and cost-effective diagnostic methods are lacking. We evaluated two immunodiagnostic techniques for the detection of Schistosoma japonicum infections: circulating antibody and circulating antigen assays.MethodsA total of 1864 individuals (between 6 and 72 years old) residing in five administrative villages in Hubei province were screened by serum examination with an indirect hemagglutination assay (IHA). The positive individuals (titer ≥20 in IHA) were reconfirmed by stool examination with the Kato-Katz method (three slides from a single stool specimen). Samples of good serum quality and a volume above 0.5 ml were selected for further testing with two immunodiagnostic antibody (DDIA and ELISA) and two antigen (ELISA) assays.ResultsThe average antibody positive rate in the five villages was 12.7%, while the average parasitological prevalence was 1.50%; 25 of the 28 egg-positive samples were also circulating antigen-positive. Significant differences were observed between the prevalence according to the Kato-Katz method and all three immunodiagnostic antibody assays (P-value <0.0001). Similar differences were observed between the Kato-Katz method and the two immunodiagnostic antigen assays (P-value <0.0001) and between the antigen and antibody assays (P-value <0.0001).ConclusionBoth circulating antibody and circulating antigen assays had acceptable performance characteristics. Immunodiagnostic techniques to detect circulating antigens have potential to be deployed for schistosomiasis japonica screening in the endemic areas.

Capillary-driven surface-enhanced Raman scattering (SERS)-based microfluidic chip for abrin detection

Herein, we firstly demonstrate the design and the proof-of-concept use of a capillary-driven surface-enhanced Raman scattering (SERS)-based microfluidic chip for abrin detection. The micropillar array substrate was etched and coated with a gold film by microelectromechanical systems (MEMS) process to integrate into a lateral flow test strip. The detection of abrin solutions of various concentrations was performed by the as-prepared microfluidic chip. It was shown that the correlation between the abrin concentration and SERS signal was found to be linear within the range of 0.1 ng/mL to 1 μg/mL with a limit of detection of 0.1 ng/mL. Our microfluidic chip design enhanced the operability of SERS-based immunodiagnostic techniques, significantly reducing the complication and cost of preparation as compared to previous SERS-based works. Meanwhile, this design proved the superiority to conventional lateral flow test strips in respect of both sensitivity and quantitation and showed great potential in the diagnosis and treatment for abrin poisoning as well as on-site screening of abrin-spiked materials.

Detección de coproantígenos para el diagnóstico de echinococosis canina en la zona fronteriza de La Quiaca-Villazón

Cystic Echinococcosis is a major public health issue. Immunodiagnostic techniques based on the identification of parasite antigens in dog dry faeces have been developed as alternatives for the surveillance of canine Echinococcosis. The environmental conditions favouring the parasite cycle were met in the border of La Quiaca-Villazón, given the presence of definitive (dog) and intermediate hosts (sheep and goats). The most important activity in La Puna is sheep and goat rearing; slaughtering is carried out almost exclusively in the field by sheep's owners, and preventive health measures do not apply. The aim of this study was to determine the presence of dogs parasitized by Echinococcus granulosus in this border region. A hundred and sixty eight (168) stool specimens were collected during 2006. La Quiaca samples were taken from the following selected areas: the semirural area of Barrios, the rural areas of Santa Catalina, Yavi Chico, El Portillo, Pumahuasi and Cara Cara and the urban area of La Quiaca; selected urban areas in Villazón and the semi-rural area of Ojo de Agua, Lampaya and Matancillas. The samples were analyzed by copro-ELISA -Western blot test. The cities of San Francisco and Barrios had a prevalence of 14.3% and 6.7%, respectively. A prevalence of 3.4% was observed in the urban area of Villazón, which indicates that dogs become infected in the rural areas and bring the risk into the city. Lampaya showed a prevalence of 30%. These findings suggest the need to implement strategies for the control of hydatidosis, both in urban and rural areas to avoid the increase and spread of Echinococcosis in the region.

Pilot field trial of the EG95 vaccine against ovine cystic echinococcosis in Rio Negro, Argentina: Early impact and preliminary data

Cystic echinococcosis is endemic in the Rio Negro province of Argentina. After 30 years of control using praziquantel in dogs the transmission rate to humans and sheep has decreased significantly, however transmission persists. The objective of the study is to assess the impact of the inclusion of the EG95 vaccine for sheep in the control programme, including analysis of the vaccine's operative feasibility in field conditions. The vaccine was applied in an area comprising four communities of native people including 79 farms with 3146 lambs and 311 dogs in total. Seventy one farms were designated as control areas where no vaccinations were undertaken while vaccinations of lambs undertaken on 91 farms. Lambs received two vaccinations with the EG95 vaccine followed by a single booster injection when the animals were 1–1.5 years of age. Farm locations were defined using GPS coordinates for the houses. Evidence for Echinococcus granulosus transmission was monitored by coproantigen ELISA on samples of dog faeces, by E. granulosus-specific PCR using soil samples, and anti-E. granulosus antibody assessments in sera from 2 to 4 teeth lambs, purgation of dogs to detect E. granulosus worms and necropsy on adult sheep. Before the vaccine was introduced, 26.2% of sheep with 2–4 teeth were positive using ELISA/WB, the prevalence decreased to 7.8% at the third year following use of the vaccine. Necropsy of animals older than 6 years (not vaccinated) showed that 66.1% of animals were infected with E. granulosus. In dogs, 4% was found positive for E. granulosus using arecoline purgation and 24.7% of the farms were infected using coproELISA/WB. During the first year of vaccination 2721 lambs received the first vaccine dose and 2448 received a booster. In the second year 2138 lambs were initially vaccinated and 1745 received a booster, and 1308 animals received the third dose. During the third year 1110 lambs received the first dose from which 539 received a booster and 723 animals received the third dose. An analysis of advantages and limitations of the diagnostic techniques used and the ability of the geospatial analysis to detect risk area are included. Based in the immunodiagnostic techniques, the EG95 vaccine has been able to prevent the infection in animals up to 3 years old. Also, the difficulties in the field for the correct vaccine administration and the social features and habits that may impact on echinococcosis control are included in the analysis.