Comparison and evaluation of analytic and diagnostic performances of four commercial kits for the detection of antibodies against Echinococcus granulosus and multilocularis in human sera

Crucial role of biosensors in the detection of helminth biomarkers in public health programmes

Helminthiases are highly prevalent but neglected infections that affect more than 1·5 billion people worldwide. Considering the worldwide prevalence of helminthiases, WHO has declared them a public health concern since 2001, necessitating rigorous control and elimination efforts. However, only a few reliable point-of-care diagnostic tests are available for assessing the effectiveness of public health interventions targeting helminthiases, thus increasing the risk of suboptimal outcomes, misallocation of resources, and emergence of drug-resistant helminths. This Review provides an introduction on helminthiases and strategies to achieve control, elimination, interruption in transmission, and eradication of these infections. The Review then comprehensively details the existent biosensors that can be used to detect these infections in human samples, focusing on their target biomarkers, the bioreceptors used, and the sensing readouts. The Review concludes with an in-depth discussion on the persistent challenges related to helminthiases, aiming to encourage the development of much-needed diagnostics specific to these neglected infections.

Unusual cholesterol crystal formation in a rare clinical case report of splenic echinococcal cyst in a patient from Sardinia, Italy

Cystic echinococcosis (CE) is a zoonotic disease caused by Echinococcus granulosus sensu lato, the metacestode of a tapeworm parasite of high medical importance. Infection of the parasite leads to the development of echinococcal cysts, and the spleen is a rarely infected organ. A 46-year-old woman who was born and who resides in Sardinia, Italy, was referred to the Echinococcosis outpatient clinic at the University Hospital of Sassari (Sardinia, Italy) for a pain in the left flank. She used to live in the countryside, in contact with several animals, and for 2 years, she had been working in a family garden, growing vegetables as a hobby. Ultrasounds and X-ray were performed, which evidenced a rounded formation in the upper third of the spleen, while a CT scan confirmed a parasitological cyst. Immunological examinations on serum samples did not detect specific antibodies against Echinococcus spp. Following surgical exportation, the whole spleen with the cystic lesion was delivered to the World Organisation for Animal Health (WOAH) and the National Reference Laboratory for Echinococcosis for further laboratory analyses. Moreover, characterization of the cyst fluid resulted dense and shiny. Observation under a light microscope at ×400 magnification revealed the formation of rectangular crystals and aggregates attributable to cholesterol molecules. Subsequently, through parasitological investigation, molecular biology investigations confirmed E. granulosus sensu stricto G1. We describe cholesterol crystals in a splenic echinococcal cyst for the first time. There is no clear explanation of how the cholesterol crystals formed in this case, but this was attributed to multifactorial causes, including atherosclerosis, chronic inflammation, parasite metabolism, and host responses.

Evaluation of the In-Vitro Effects of Albendazole, Mebendazole, and Praziquantel Nanocapsules against Protoscolices of Hydatid Cyst

Cystic echinococcosis still remains a serious health and economic problem worldwide. The etiologic agent is Echinococcus granulosus sensu lato, giving origin to a fluid-filled cystic lesion. Therapy faces several challenges. Nanodrugs have shown promise as chemotherapeutics against hydatid cysts. The present study evaluated a highly safe lipid nano-polymeric capsule for its superior efficacy and ability to overcome drug resistance. Nanocapsule drugs were formulated into six groups: Albendazole, mebendazole, praziquantel, albendazole + mebendazole, albendazole + praziquantel, and praziquantel + mebendazole. The protoscolicidal effects of these six groups were assessed at 10, 60, and 120 min in three concentrations (1, 0.5, and 0.25 mg/mL). Drug formulations were evaluated via zeta potential, droplet size, solubility, particle size analyzer (PSA), and scanning electron microscopy. According to the PSA results, the mean size of the albendazole nanocapsules was 193.01 nm, mebendazole was 170.40 nm, and praziquantel was 180.44 nm. Albendazole + mebendazole showed the greatest protoscolicidal activity at a concentration of 1 mg/mL after 120 min. In contrast, each drug's 0.25 mg/mL single-dose times showed the least protoscolicidal activity after 120 min. With the right application of nanotechnology, it is possible to produce safe and effective drugs, such as the polymeric combination of albendazole and mebendazole, which has promising implications.

Advances in Detecting Cystic Echinococcosis in Intermediate Hosts and New Diagnostic Tools: A Literature Review

Cystic echinococcosis (CE) is a zoonotic disease affecting humans and animals. Despite a lack of clarity about many details of parasite-intermediate host interactions, the nature of the immune responses triggered by hydatid infection has revealed new perspectives. This study discusses the latest advances in elucidating the immunologic mechanism of echinococcosis and its detection and potential approaches to enhance serodiagnosis accuracy. Moreover, nanobiosensors have been evaluated according to their potential to improve treatment efficiency and aid in an early diagnosis of cystic echinococcosis. The serum of an intermediate host can diagnose CE by analyzing antibodies induced by Echinococcus granulosus. Among the most notable features of this method are its noninvasive ability and high sensitivity, both of which make it an excellent tool for clinical diagnosis. Several serological tests, including ELISAs and immunoblotting, can detect these antibodies to assess the disease's state and determine the treatment outcome. A thorough understanding of what cross-reactivity means and the stage of the disease are crucial to interpreting serological results. Nanobiosensors have also proven better than conventional biosensors in detecting hydatid cysts. Additionally, they are highly sensitive and versatile when detecting specific biomarkers, improving diagnostic accuracy. These immunomodulatory molecules, induced by E. granulosus, are a good candidate for diagnosing cystic echinococcosis because they alter intermediate host immune responses. Hydatid cyst detection is also enhanced through nanobiosensors, which provide better accuracy.

Investigation of patients with new infection of echinococcal cyst in Sardinia, Italy

Cystic Echinococcosis (CE) is a zoonotic disease caused by the larval stage of a tapeworm of Taeniidae family, genus Echinococcus and species Echinococcus granulosus sensu lato (s.l.). CE is a worldwide public health problem and is highly incident in all Mediterranean areas. Following clinical, image techniques and serological investigations all 83 subjects involved in the study were diagnosed for CE. General and clinical data were entered into a database and evaluated. The 43.37% were female and 56.63% male, mean age was 50.71 while the range most represented (22.7%) was between 61->70 years. The purposes of our survey were to investigate these 83 patients enrolled in the study and to deeply examine 20 (24.10%) patients that developed a new echinococcal cyst. Moreover, the causes at the basis of the onset of a new cyst were analysed, together with a possible correlation with different treatments related to primary infection corresponding to surgery (n=7), albendazole (n=6), PAIR (n=3) and watch and wait (n=4). A possible link with medical treatments of the primary infection was observed in the subjects who underwent surgery or PAIR and a likely correlation attributable to high environmental contamination in subjects managed with drugs or watch and wait was detected. Moreover, our analysis evidenced that patients with a new infection presented a more severe diagnosis along with a major mortality rate. Finally, these data may have an important contribution for an epidemiological point of view concerning the percentage of CE in a specific geographical endemic area, such as Sardinia.

Immunohistochemistry as a Reliable Tool for the Diagnosis of Cystic Echinococcosis in Patients from Sardinia, Italy-A Confirmatory Study

Cystic Echinococcosis (CE) is a zoonotic disease caused by the larval stage of the tapeworm Echinococcus granulosus sensu lato (s.l.). This study aims to investigate the use of two monoclonal antibodies (mAbEmG3 and mAbEm2G11) by immunohistochemistry (IHC) to confirm the diagnosis of CE in human patients, in particular in those cases in which other techniques fail to provide a correct or conclusive diagnosis. For this purpose, a survey on 13 patients was performed. These subjects were referred to Sardinian hospitals (Italy) from 2017 to 2022 and were suspected to be affected by CE. Our findings from these 13 patients showed the detection of E. granulosus sensu stricto by IHC in 12 of 13 echinococcal cysts, as one sample was of a non-parasitological origin. The results confirmed that IHC, by means of the mAbEmG3 and mAbEm2G11, is a reliable diagnostic tool that showed a very high performances when tested on strain of E. granulosus s.l. from Sardinia.

Head-to-Head Comparison of Nine Assays for the Detection of Anti-Echinococcus Antibodies: A Retrospective Evaluation

Background

Echinococcosis is a neglected tropical disease that is severely underdiagnosed in resource-limited settings. In developed countries, diagnosing echinococcosis is challenging, and reliable serological assays are urgently needed. In the Central European Alps, EM is more common than EG; however, data on the diagnostic performance of assays for EM cases are scarce. We evaluated the suitability of nine antibody assays for routine diagnostics.

Methods

Nine commercially available serological assays for detecting anti-Echinococcus antibodies were compared head-to-head using samples collected from 50 patients with echinococcosis and 50 age- and sex-matched control subjects. The assays are Anti-Echinococcus ELISA (IgG) (Euroimmun), Echinococcus IgG ELISA (DRG), Echinococcus IgG ELISA (IBL International), Echinococcus Western Blot IgG (LDBIO Diagnostics), EUROLINE WB (Euroimmun), Hydatidosis ELISA IgG (VirCell), Hydatidosis VIRCLIA IgG Monotest (VirCell), Ridascreen Echinococcus IgG (R-Biopharm), and Virapid Hydatidosis (VirCell). The cases were ranked according to the WHO-Informal Working Group on Echinococcosis (WHO-IWGE) criteria as confirmed, probable, or possible.

Results

The performance of the assays varied greatly, with overall sensitivities ranging between 50% and 88% and specificities between 62% and 100%. We observed a trend toward better performance with cases classified as "confirmed" using the WHO-IWGE criteria. Combined analysis with sequential screening and confirmatory testing resulted in a maximum sensitivity of 84% and specificity of 100%. Differentiation between EG and EM infections is clinically relevant but was found to be unreliable.

Conclusions

Echinococcus serological assays are highly variable in terms of sensitivity and specificity. Knowledge of the pre-test probability in the patient cohort is required to choose a suitable assay. A combined approach with screening and confirmatory assays may be the best diagnostic strategy in many situations.

Serological Comparison of Native Antigen ELISAs with Rapid ICT Test Kits for the Diagnosis of Human Alveolar and Cystic Echinococcosis in China

BACKGROUND

The aim of this study was to compare the diagnostic performance of native antigen ELISAs and ADAMU-AE/CE commercial ICT test kits in subjects either exposed to Echinococcus infection or with clinically diagnosed alveolar (AE) or cystic (CE) echinococcosis.

METHODS

A total of 370 subjects with a previous clinical confirmation of CE or AE from northwestern China were recruited. Serum samples were also obtained from 3923 children/teenagers during a community survey. All sera were tested using native antigen ELISAs. The ADAMU-AE/CE test kits were subsequently used for the serology of the 370 clinically confirmed individuals and of 251 children/teenagers that were ELISA antibody-positive for both Echinococcus species but ultrasound-negative during baseline survey. An analysis of the association between the serological tests and ultrasound classification was carried out amongst 89 AE and 164 CE cases. A Kappa consistency analysis was undertaken to compare the diagnostic performance of the native antigen ELISAs and the ADAMU kits and the ultrasound imaging results. The χ² test was also used for a comparison of the different seropositivity rates between the groups.

FINDINGS

There was poor consistency (Kappa = 0.26 and 0.28 for AE and CE respectively) between the native antigen ELISAs and the ADAMU kits for the diagnosis of AE and CE among the cases and the surveyed children/teenagers, but a relatively good consistency (Kappa = 0.63) between the ADAMU-AE kit and ultrasound observations for the AE cases. Additionally, of the 251 teenagers co-positive for both AE and CE antibodies by the native antigen ELISAs, only one was found positive by the ADAMU-AE kit, verified as a new AE case on subsequent ultrasound follow-up. The remainder (N = 250) were negative by serology using the ADAMU-AE/CE kits and by ultrasound examination. The two native antigen ELISAs did not discriminate well between cases of clinically diagnosed AE and CE. In contrast, ADAMU-AE and ADAMU-CE commercial ICT test kits readily differentiated cases of AE from CE with specificities of 99% for AE and 100% for CE.

CONCLUSIONS

The ADAMU-AE/CE kits proved reliable, accurate, and amenable diagnostic tools in the clinical setting for confirmation of suspected AE/CE cases. The native antigen ELISAs tests can provide useful information on the level of human exposure to Echinococcus infection.

Genetic Characterization of Echinococcus granulosus sensu stricto Isolated from Human Cysts from Sardinia, Italy

This study involved 20 patients affected by cystic echinococcosis (CE) who were referred to different hospitals of Sardinia (Italy) from 2017 to 2022. By means of a multidisciplinary approach, diagnosis was confirmed for CE in 18 patients and for different aetiologies in two subjects. Moreover, serology was positive for 15 subjects. Since multiple CE cysts were found in five patients, a total of 27 lesions were collected; however, only one for each patient was investigated for genetic characterization of E. granulosus s.s. DNA isolates. Our results included 15 fertile cysts that underwent DNA extraction and amplification by three different PCRs targeting nuclear (calreticulin) and mitochondrial genes (cox1 and nad5). DNA was sequenced, and by neighbour-joining phylogenetic trees we determined 10 G1 and five G3 genotypes previously reported in Sardinia. These sequences were used to construct a network, along with those circulating in Mediterranean areas. The haplotype network calculated on cox1 evidenced seven different haplotypes of the 15 isolates, with SAR2 the most represented, carried by seven cysts, and SAR17 never described in the Mediterranean area. Meanwhile, the nad5 sequences showed the most common haplotype as nd5SAR7, as well as two new haplotypes not previously described, nd5SAR13, isolated from a Sardinian patient, and nd5SAR14, isolated from a Romanian patient.

Environmental Influence on the Occurrence of Multi-Organ Cystic Echinococcosis Infection in a Patient from Sardinia, Italy

An uncommon clinical case of an adult woman who was referred to the hospital with severe symptoms attributable to cystic echinococcosis (CE) is described in this report. According to a questionnaire, the subject was exposed to a high risk of infection since she was employed on a farm about 20 years before diagnosis. She lived close to several animal species and handled vegetables in inadequate hygienic conditions. Medical and laboratory investigations confirmed the presence of massive echinococcal cystic lesions in each lung and in the liver. Given the peculiarity of the case, pharmacological and surgical treatments were the only conceivable option. The association of pharmacological treatment, surgery, and interventional radiology procedure represented a reliable and effective way to handle a complex case of human hydatidosis. A multi-disciplinary approach was mandatory, resulting in a clear and conclusive diagnosis of CE caused by the zoonotic parasite E. granulosus sensu stricto of the G1 genotype.

Evaluation of a novel Echinococcus granulosus recombinant fusion B-EpC1 antigen for the diagnosis of human cystic echinococcosis using indirect ELISA in comparison with a commercial diagnostic ELISA kit

Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by the metacestode of Echinococcus granulosus sensu lato (s.l.). A large proportion of the patients are asymptomatic at the early and late stages of the disease. CE diagnosis is mainly based on imaging techniques. Laboratory diagnosis including antibody-antigen (recombinant or fusion recombinant) can be used for the diagnosis and follow up of CE and alveolar echinococcosis (AE), but need optimization and standardization. This study aimed to evaluate the efficacy of a recombinant B-EpC1 (rB-EpC1) fusion antigen comprising B1, B2, B4, and EpC1 antigens of E. granulosus using indirect ELISA in comparison with a commercial ELISA kit for the serodiagnosis of CE. The recombinant protein was expressed in the expression host, E. coli BL21, and purified. This recombinant antigen was then evaluated by indirect ELISA and compared to the commercial CE diagnostic kit (Vircell, Spain). The study samples included 124 human sera consisting of 62 sera of patients with CE, and 62 sera of individuals without clinical evidences of CE and specific anti-CE antibodies in routine indirect ELISA. The diagnostic sensitivity and specificity of the indirect rB-EpC1-ELISA test for detection of specific anti-hydatid cyst antibodies in human CE were 95.2% and 96.8%, respectively. Also, the diagnostic sensitivity and specificity of the commercial ELISA test were 96.8% in this study. Initial evaluation of the recombinant fusion antigen (B-EpC1) was promising for the detection of CE by ELISA in clinical settings. Standardization and evaluation of recombinant fusion protein require further studies.