Ultrasound-Based Prevalence of Cystic Echinococcosis in the Samarkand Region of Uzbekistan: Results from a Field Survey.

Cystic echinococcosis (CE) is a zoonosis caused by Echinococcus granulosus. Uzbekistan is endemic for CE, but estimates of disease burden are lacking. We present findings from a cross-sectional, ultrasound-based survey evaluating the prevalence of human CE in the Samarkand region, Uzbekistan. The survey was conducted between September and October 2019 in the Payariq district, Samarkand. Study villages were selected based on sheep breeding and reported human CE. Residents aged 5-90 years were invited to receive a free abdominal ultrasound examination. The WHO Informal Working Group on Echinococcosis classification was used for cyst staging. Information regarding CE diagnosis and treatment was collected. Of 2,057 screened subjects, 498 (24.2%) were male. Twelve (0.58%) had detectable abdominal CE cysts. In total, five active/transitional (N = 1 CE1, N = 1 CE2, N = 3 CE3b) and 10 inactive cysts (N = 8 CE4, N = 2 CE5) were identified. Two participants had cystic lesions with no pathognomonic features of CE and were given a 1-month course of albendazole for diagnostic purposes. Twenty-three additional individuals reported previous surgery for CE in the liver (65.2%), lungs (21.6%), spleen (4.4%), liver and lungs (4.4%), and brain (4.4%). Our findings confirm the presence of CE in the Samarkand region, Uzbekistan. Additional studies are needed to assess the burden of human CE in the country. All patients with a history of CE reported surgery, even though most cysts found during the current study were inactive. Therefore, it appears there is a lack of awareness by the local medical community of the currently accepted stage-specific management of CE.

Circulating Small RNA Profiling of Patients with Alveolar and Cystic Echinococcosis.

Alveolar (AE) and cystic (CE) echinococcosis are two parasitic diseases caused by the tapeworms Echinococcus multilocularis and E. granulosus sensu lato (s. l.), respectively. Currently, AE and CE are mainly diagnosed by means of imaging techniques, serology, and clinical and epidemiological data. However, no viability markers that indicate parasite state during infection are available. Extracellular small RNAs (sRNAs) are short non-coding RNAs that can be secreted by cells through association with extracellular vesicles, proteins, or lipoproteins. Circulating sRNAs can show altered expression in pathological states; hence, they are intensively studied as biomarkers for several diseases. Here, we profiled the sRNA transcriptomes of AE and CE patients to identify novel biomarkers to aid in medical decisions when current diagnostic procedures are inconclusive. For this, endogenous and parasitic sRNAs were analyzed by sRNA sequencing in serum from disease negative, positive, and treated patients and patients harboring a non-parasitic lesion. Consequently, 20 differentially expressed sRNAs associated with AE, CE, and/or non-parasitic lesion were identified. Our results represent an in-depth characterization of the effect E. multilocularis and E. granulosus s. l. exert on the extracellular sRNA landscape in human infections and provide a set of novel candidate biomarkers for both AE and CE detection.

Bacterial and Fungal Occurrence in Hydatid Cysts from Livestock in Central Iran.

Echinococcus granulosus sensu lato causes Cystic echinococcosis. This study investigated the bacterial and fungal species in the liver and lung hydatid cysts obtained from sheep, goats, cattle, and camels slaughtered in Yazd abattoir, Central Iran. In this study, 84 hydatid cysts were obtained from 20 sheep, 13 goats, 25 cattle, and 26 camels. The fertility and viability rates were assessed using light microscopy and eosin staining, respectively. The aspirated hydatid cysts were cultured to detect the presence of any bacteria and fungi. Bacterial isolates were identified by biochemical tests. DNA was also extracted from germinal layers, and then genotyping was carried out targeting the cox 1 gene. The statistical analysis was performed by SPSS version 16.0. This study showed that 22.62% (19/84) of hydatid cysts had bacterial occurrence, and none of the samples had fungal species. Among the fertile cysts, 52.6% had bacterial occurrence, of which 40% were viable. Most bacteria detected in hydatid cysts included Staphylococcus saprophyticus, Escherichia coli, and S. epidermidis. Hydatid cysts with bacterial occurrence were identified as G1-G3, G5, and G6/G7. The bacterial species occurrence in hydatid cysts had no significant relationship with fertility and viability (P > 0.05), without any significant relation with viability (P > 0.05), animal species (P > 0.05), involved organ in animals (P > 0.05), and hydatid cyst genotypes (P > 0.05). It should also be mentioned that this is the first study to assess the relationship between hydatid cyst genotyping and the occurrence of fungal and bacterial species.

Conservative Management of Liver Echinococcal Cysts in Pregnant Women: One Center's Experience in Pavia, Italy.

Human cystic echinococcosis (CE) in pregnancy is rarely reported, with approximately one case of CE for every 20,000 to 30,000 pregnant women in endemic areas. Little information on its management is available. We report our experience with a watch-and-wait approach in this group of patients. We retrieved clinical data from pregnant patients with hepatic CE seen at our clinic from 1989 to 2021. All patients had at least one hepatic CE cyst and received no treatment during pregnancy. Ultrasound was used to monitor cyst evolution; outcome and complications of pregnancy and echinococcal infection were evaluated. Twelve patients with 15 pregnancies were included in this study. At the time of pregnancy, nine patients had a single cyst and two patients had multiple hepatic CE cysts. Cysts were in stage CE3a, CE3b, CE4, and CE5, according to the WHO Informal Working Group on Echinococcosis classification. All cysts except one remained stable in stage and size during and after pregnancy. In one patient with a history of multiple treatments with albendazole and with a CE4 cyst at the start of pregnancy, reactivation of the cyst during pregnancy was observed. All pregnancies except three had eutocic delivery. Cesarean sections were performed for reasons unrelated to CE. In our experience, "watch and wait" in pregnant women with uncomplicated transitional and inactive CE of the liver was a safe option in a small cohort of patients. Pooled data from other referral centers, including cases with CE1 and CE2 cysts, are needed to confirm the safety of this approach.

Ultrasound-based evaluation of the prevalence of abdominal cystic echinococcosis in the Turkestan region of Kazakhstan.

BACKGROUND: Human cystic echinococcosis (CE) is a zoonotic disease caused by Echinococcus granulosus sensu lato. CE is known to be endemic in some parts of Central Asia. We present findings from an ultrasound-based survey to estimate the prevalence of CE in the Turkestan oblast of Kazakhstan. METHODS: In October 2019, six villages were chosen based on records from a national surveillance dataset. Inhabitants aged 5-90 y were invited to undergo a free abdominal ultrasound to screen for CE cysts. All identified cysts were staged according to the WHO-endorsed classification for CE cysts. RESULTS: A total of 2252 individuals underwent ultrasound screening. Twenty-two (0.98%) individuals had CE, with a combined total of 33 cysts: 25 (75.7%) inactive (14 CE4, 11 CE5) and 8 (24.3%) active/transitional (2 CE1, 1 CE2, 3 CE3a, 2 CE3b). One patient had a postsurgical cavity. Sixty-eight patients (3.0%) reported CE prior to surgical treatment. In 25 (36.8%) previously diagnosed patients, albendazole prophylaxis was not used. CONCLUSIONS: CE is endemic in the study region, with ongoing transmission. The number of surgically treated CE patients suggests an underestimation of the disease burden by the current surveillance system. Further studies on local CE epidemiology and the implementation of expert treatment recommendations are needed.

Prospective collection of clinical data on cystic echinococcosis: experience with the European Registry of Cystic Echinococcosis in Pavia, Italy.

BACKGROUND: Cystic echinococcosis (CE) is a chronic, complex and neglected infection that may cause serious disease in humans. Given its peculiar epidemiologic and clinical features, collection of clinical data is challenging. Notification systems, when available, fail to record important clinical features, available data are mostly retrospectively collected and no prospectively enrolled uniform surveillance systems exist. The European Register of Cystic Echinococcosis database (ERCE) is the first systematic attempt to address these issues. METHODS: Here, we describe the demographics and clinical characteristics of 436 patients who accessed the CE clinic at the University of Pavia-San Matteo Hospital Foundation, in Pavia, Italy, from March 2012 to February 2020. RESULTS: Overall, 436 patients, consisting of 204 (46.8%) males and 232 (53.2%) females were enrolled; the mean age at enrollment was 50 (range 4-88) y. Of the 436 patients, 248 (56.9%) were born in Italy while 188 (43.1%) were foreign-born. In total, 638 CE cysts were counted, most of them in the CE4 (230; 36.1%) and CE3b (131; 20.5%) stages. CONCLUSIONS: This is the largest cohort of CE patients with detailed clinical and demographic data published to date. We strongly encourage colleagues caring for CE patients in the European Union to join the ERCE.

Trends in the Surgical Incidence of Cystic Echinococcosis in Uzbekistan from 2011 to 2018.

Cystic echinococcosis (CE) is a zoonosis with a cosmopolitan distribution caused by Echinococcus granulosus sensu lato tapeworms. Although Uzbekistan and other countries in Central Asia are considered endemic, estimates of disease burden are lacking. We present data regarding surgically managed cases of CE obtained from Uzbekistan's national disease surveillance registry. These data are from medical centers in Uzbekistan authorized to treat the disease and reported to the Uzbek Center for Sanitation and Epidemiology from the period 2011 to 2018. Information included patient age class (children 14 years or younger versus adults 15 years and older), but no data regarding cyst location. Incidence rates were calculated using data from the national population registry, and the Cuzick nonparametric test for trends was used to test for differences in the incidence over time at the country and regional levels. A total of 7,309 CE cases were reported. Of these, 857 (11.73%) involved pediatric patients. The mean incidence rates were 4.4 per 100,000 population in 2011 and 2.3 per 100,000 population in 2018 (P = 0.016). One region (Republic of Karalpakistan) showed a nonstatistically significant increase (P = 0.824). All other regions except three showed a statistically significant decrease. We present data showing a decrease in the overall incidence of surgically treated CE in Uzbekistan from 2011 to 2018. However, the presence of cases involving children suggests ongoing parasite transmission. The absence of clinical information (starting with cyst stage and localization) needs to be addressed to improve the national surveillance system. Field studies are also needed to further explore the epidemiology of CE in the country.

Accuracy of an experimental whole-blood test for detecting reactivation of echinococcal cysts.

BACKGROUND: Cystic echinococcosis (CE) is a complex disease for which clear understanding of clinical manifestations is needed to avoid misdiagnosis, inappropriate treatment, and severe complications. We evaluated the accuracy of a whole-blood stimulation test based on Interleukin (IL)-4 detection in response to Antigen B (AgB) of Echinococcus granulosus sensu lato to discriminate cyst viability and detect cyst reactivation in patients with hepatic CE. METHODOLOGY/PRINCIPAL FINDINGS: Thirty patients with CE3b cysts and 37 patients with spontaneously-inactivated CE4-CE5 cysts were recruited (T0). After enrollment, 5 patients with CE3b cysts received albendazole, resulting in cyst solidification (CE4) in 4/5. Within a two-year follow-up, the whole-blood test was repeated at two time-points, in ≥14 (T1) and in ≥4 (T2) patients per group. IL-4 and a panel of other soluble factors were measured in the stimulated plasma. Baseline IL-4 levels were significantly higher in patients with CE3b compared to those with CE4 cysts (p = 0.006). Test accuracy for CE3b diagnosis had a sensitivity of 33-60% and a specificity of 76-95%, depending on the cut-off applied. Overall, IL-4 levels did not change significantly over time in either group; however, patients within the CE3b group showed a significant decrease of IL-1ra, IL-6, IL-8, G-CSF, IFN-γ, IP-10, MCP-1, MIP-1α, FGF at T1 compared to T0 (p≤0.042). CONCLUSIONS/SIGNIFICANCE: Whole-blood IL-4-response to AgB is significantly higher in patients with active compared to inactive CE but apparently not modulated over time after treatment. On the contrary, the levels of IL-1ra, IL-6, IL-8, G-CSF, IFN-γ, IP-10, MCP-1, MIP-1α, FGF significantly decreased in active CE during follow-up. Additional studies are needed to understand whether these findings might have a clinical significance for patients' follow-up.

Field Performance of a Rapid Diagnostic Test for the Serodiagnosis of Abdominal Cystic Echinococcosis in the Peruvian Highlands.

We evaluated the performance of a commercial rapid diagnostic test (RDT) in a field setting for the diagnosis of abdominal cystic echinococcosis (CE) using sera collected during an ultrasound population screening in a highly endemic region of the Peruvian Andes. Abdominal CE was investigated by ultrasonography. Sera collected from individuals with abdominal CE (cases) and age- and gender-matched volunteers with no abdominal CE (controls) were tested independently in two laboratories (Peru and Italy) using the VIRapid® HYDATIDOSIS RDT and RIDASCREEN® Echinococcus IgG enzyme-linked immunosorbent assay. Performance indexes of single and serially combined tests were calculated and applied to hypothetical screening and clinical scenarios. Test concordance was also evaluated. Prevalence of abdominal CE was 6.00% (33 of 546) by ultrasound. Serum was obtained from 33 cases and 81 controls. The VIRapid test showed similar sensitivity (76% versus 74%) and lower specificity (79% versus 96%) than results obtained in a hospital setting. RDTs showed better performance when excluding subjects reporting surgery for CE and if weak bands were considered negative. Concordance between tests was moderate to very good. In hypothetical screening scenarios, ultrasound alone or confirmed by RDTs provided more reliable prevalence figures than serology alone, which overestimated it by 5 to 20 times. In a simulation of case diagnosis with pre-test probability of CE of 50%, positive and negative post-test probabilities of the VIRapid test were 78% and 22%, respectively. The application of the VIRapid test alone would not be reliable for the assessment of population prevalence of CE, but could help clinical decision making in resource-limited settings.

Extracellular non-coding RNA signatures of the metacestode stage of Echinococcus multilocularis.

Extracellular RNAs (ex-RNAs) are secreted by cells through different means that may involve association with proteins, lipoproteins or extracellular vesicles (EV). In the context of parasitism, ex-RNAs represent new and exciting communication intermediaries with promising potential as novel biomarkers. In the last years, it was shown that helminth parasites secrete ex-RNAs, however, most work mainly focused on RNA secretion mediated by EV. Ex-RNA study is of special interest in those helminth infections that still lack biomarkers for early and/or follow-up diagnosis, such as echinococcosis, a neglected zoonotic disease caused by cestodes of the genus Echinococcus. In this work, we have characterised the ex-RNA profile secreted by in vitro grown metacestodes of Echinococcus multilocularis, the casuative agent of alveolar echinococcosis. We have used high throughput RNA-sequencing together with RT-qPCR to characterise the ex-RNA profile secreted towards the extra- and intra-parasite milieus in EV-enriched and EV-depleted fractions. We show that a polarized secretion of small RNAs takes place, with microRNAs mainly secreted to the extra-parasite milieu and rRNA- and tRNA-derived sequences mostly secreted to the intra-parasite milieu. In addition, we show by nanoparticle tracking analyses that viable metacestodes secrete EV mainly into the metacestode inner vesicular fluid (MVF); however, the number of nanoparticles in culture medium and MVF increases > 10-fold when metacestodes show signs of tegument impairment. Interestingly, we confirm the presence of host miRNAs in the intra-parasite milieu, implying their internalization and transport through the tegument towards the MVF. Finally, our assessment of the detection of Echinococcus miRNAs in patient samples by RT-qPCR yielded negative results suggesting the tested miRNAs may not be good biomarkers for this disease. A comprehensive study of the secretion mechanisms throughout the life cycle of these parasites will help to understand parasite interaction with the host and also, improve current diagnostic tools.

Evaluation of the sensitivity and specificity of GST-tagged recombinant antigens 2B2t, Ag5t and DIPOL in ELISA for the diagnosis and follow up of patients with cystic echinococcosis.

Cystic echinococcosis (CE) is a neglected zoonotic disease caused by Echinococcus granulosus sensu lato. Diagnosis and monitoring of CE rely primarily on imaging while serology is used as a confirmatory test. However, imaging is not always conclusive and currently available serological assays have suboptimal sensitivity and specificity, lack standardization, and are not useful for patients´ follow-up. Seroassays for CE are usually based on hydatid fluid (HF), a complex, variable antigenic mixture, and cross-reactivity exists especially with alveolar echinococcosis. Recombinant proteins based on immunogenic antigens most abundant in HF, such as AgB1, AgB2 and Ag5, have been used to overcome these limitations. None of them so far showed potential to replace HF; however, their performance have been largely tested on a limited number of samples, and comparison of different antigens using the same cohort has been rarely performed. The combination of several immunogenic epitopes in a single recombinant protein could enhance test sensitivity. For the diagnosis and follow-up of patients with CE, we compared the performance of the crude HF, previously described recombinant 2B2t antigen, and GST-tagged version of 2B2t, and novel designed recombinants (GST-Ag5t and the GST-DIPOL chimera containing AgB1, AgBB2 and Ag5 epitopes) by IgG-ELISA format. Samples belong to a retrospective cohort of 253 well-characterized patients with CE, previously described for the evaluation of the 2B2t antigen, 92 patients with alveolar echinococcosis, and 82 healthy donors. The reference standard for CE diagnosis was the presence of a CE lesion as diagnosed by ultrasonography. The highest sensitivity was obtained with HF [86.7%, 95% confidence interval (CI): 81.2-91.0], followed by GST-2B2t (70.0%, 95% CI: 63.1-76.2), 2B2t (65.5%, 95% CI: 58.5-72.0), GST-Ag5t (64.5%, 95% CI: 57.5-71.1) and GST-DIPOL (63.1%, 95% CI: 56.0-69.7). The GST-2B2t had the best specificity (95.8%, 95% CI: 88.3-99.1) and the lowest cross-reactivity (38.7%, 95% CI: 27.6-50.6). Good response to treatment also correlated to negative test results in the GST-2B2t ELISA. While none of the tested recombinant antigen appears suitable to replace HF for the diagnosis of CE, GST-2B2t should be further explored as a confirmation test, based on its high specificity and low cross-reactivity, and for the follow-up after treatment in those patients with positive serology for this antigen.

Evidence of Low Prevalence of Cystic Echinococcosis in the Catanzaro Province, Calabria Region, Italy.

Cystic echinococcosis (CE) is one of the neglected tropical diseases recognized by the WHO. Echinococcus granulosus sensu lato affects more than 1 million people worldwide and is responsible for high costs in the healthcare system. A clear knowledge of the prevalence of CE and its clinical characteristics could have an important impact on the approach to its diagnosis and to the public health planning of treatment and control interventions. We performed a prevalence study in four municipalities of Catanzaro Province, South Italy. This area is considered to be at high risk of CE because of ovine breeding. We screened by abdominal ultrasound 2,426 volunteers, four of whom had abdominal CE. Given the need for prevention and control programs for CE in endemic areas of Italy, a detailed mapping of prevalence of CE, to complement data obtained through hospital discharge records, appears imperative.

Incidence Rates of Surgically Managed Cystic Echinococcosis in Kazakhstan, 2007-2016.

Cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of the cestode Echinococcus granulosus. The parasite typically infects dogs and ungulates, with humans acting as dead-end hosts. Information on the epidemiology of CE is lacking from Central Asia, including from Kazakhstan where CE cases are reported centrally. This study presents data from the Kazakhstan Scientific and Practical Center for Sanitary and Epidemiological Evaluation and Monitoring on CE patients treated surgically, with a diagnosis confirmed by pathology. Evaluation of data from 2007 to 2016 indicated that the CE incidence rate decreased during this time period in most areas of Kazakhstan (country-level incidence rate of 5.6 versus 4.7 cases/100,000 population in 2007 and 2016, respectively). Cystic echinococcosis had a higher incidence in southern Kazakhstan, with an incidence rate between 7.0 and 10.5 cases per 100,000 population, whereas northern regions had rates less than 4.0 cases per 100,000 population. Moreover, despite the overall decrease, CE incidence continues to increase in the south. Cystic echinococcosis surveillance is needed, particularly in the south, to help inform policymakers and orient disease control efforts.

Diagnostic Performances of Commercial ELISA, Indirect Hemagglutination, and Western Blot in Differentiation of Hepatic Echinococcal and Non-Echinococcal Lesions: A Retrospective Analysis of Data from a Single Referral Centre.

The diagnosis of cystic echinococcosis (CE) is based on imaging. Serology supports imaging in suspected cases, but no consensus exists on the algorithm to apply when imaging is inconclusive. We performed a retrospective analysis of serology results of patients with untreated hepatic CE and non-CE lesions, seen from 2005 to 2017, to evaluate their accuracy in the differential diagnosis of hepatic CE. Serology results of three seroassays for echinococcosis (ELISA RIDASCREEN, indirect hemagglutination (IHA) Cellognost, and Western blot LDBIO) and clinical characteristics of eligible patients were retrieved. Patients were grouped as having active or inactive CE and liquid or solid non-CE lesions. Sensitivity, specificity, and diagnostic accuracy were compared between scenarios encompassing different test combinations. Eligible patients included 104 patients with CE and 257 with non-CE lesions. Sensitivity and diagnostic accuracy of Western blot (WB) were significantly higher than those of the following: 1) IHA or ELISA alone, 2) IHA+ELISA interpreted as positive if both or either tests positive, and 3) IHA+ELISA confirmed by WB if discordant. The best performances were obtained when WB was applied on discordant or concordant negative IHA+ELISA. Analyses performed within "active CE (n = 52) versus liquid non-CE (n = 245)" and "inactive CE (n = 52) versus solid non-CE (n = 12)" groups showed similar results. Specificity was high for all tests (0.99-1.00) and did not differ between test combination scenarios. WB may be the best test to apply in a one-test approach. Two first-level tests confirmed by WB seem to provide the best diagnostic accuracy. Further studies should be performed in different settings, especially where lower test specificity is likely.

Inefficient and abortive classical complement pathway activation by the calcium inositol hexakisphosphate component of the Echinococcus granulosus laminated layer.

Persistent extracellular tissue-dwelling pathogens face the challenge of antibody-dependent activation of the classical complement pathway (CCP). A prime example of this situation is the larva of the cestode Echinococcus granulosus sensu lato, causing cystic echinococcosis. This tissue-dwelling, bladder-like larva is bounded by a cellular layer protected by the outermost acellular "laminated layer" (LL), to which host antibodies bind. The LL is made up of a mucin meshwork and interspersed nano-deposits of calcium inositol hexakisphosphate (calcium InsP6). We previously reported that calcium InsP6 bound C1q, apparently initiating CCP activation. The present work dissects CCP activation on the LL. Most of the C1 binding activity in the LL corresponded to calcium InsP6, and this binding was enhanced by partial proteolysis of the mucin meshwork. The remaining C1 binding activity was attributable to host antibodies, which included CCP-activating IgG isotypes. Calcium InsP6 made only a weak contribution to early CCP activation on the LL, suggesting inefficient C1 complex activation as reported for other polyanions. CCP activation on calcium InsP6 gave rise to a dominant population of C3b deposited onto calcium InsP6 itself that appeared to be quickly inactivated. Apparently as a result of inefficient initiation plus C3b inactivation, calcium InsP6 made no net contribution to C5 activation. We propose that the LL protects the underlying parasite cells from CCP activation through the combined effects of inefficient permeation of C1 through the mucins and C1 retention on calcium InsP6. This mechanism does not result in C5 activation, which is known to drive parasite-damaging inflammation.

Role of microRNAs in host defense against Echinococcus granulosus infection: a preliminary assessment.

Cystic echinococcosis (CE) is a neglected helminthic zoonosis caused by the larval stage of the tapeworm Echinococcus granulosus s.l. MicroRNAs (miRNAs) are regulators of gene expression that have been linked with the pathogenesis of several human diseases, but little exists in the available literature about miRNAs in CE. Here, we investigate the expression profiles of 84 microRNAs relevant to the function of lymphocytes and other immune cells during CE infection in the peripheral blood of patients with cysts in active and inactive stages. We applied the microRNA PCR array technology to blood samples from 20 patients with a single hepatic CE cyst in either the active (CE3b) or inactive (CE4-CE5) stage. Our results show a significant upregulation of eight miRNAs (let-7g-5p, let-7a-5p, miR- 26a-5p, miR- 26b-5p, miR- 195-5p, miR- 16-5p, miR- 30c-5p, and miR- 223-3p) in patients with active cysts compared to those with inactive cysts. The high expression of these miRNAs in patients with active cysts suggests their role in a specific host immune response against the infection. Further work in this direction may help shed light on the pathogenesis of human CE.

Correction to: Role of microRNAs in host defense against Echinococcus granulosus infection: a preliminary assessment.

The published article unfortunately contained mistake. After replacing the image from colored version to black and white, the Fig. 1 caption, unfortunately, was left unupdated.

Cystic Echinococcosis of the Bone in Kazakhstan.

Cystic echinococcosis (CE) is a parasitic zoonosis caused by E. granulosus primarily affecting the liver and lungs. CE of the bone is by far the most debilitating form of the disease and is very difficult to manage as it mimics malignant tumors. We reviewed bone CE cases admitted to a reference oncological hospital in Kazakhstan from January 2010 to February 2017. Among eight patients, the mean age was 33.5 years, and the male/female ratio was 1 : 3. Patients were examined by X-ray (8/8), CT (7/8), and MRI (3/8). CE was in the spine (2 cases), pelvis (3 cases), and long bones (humerus, tibia, and femur; one case for each). All patients were treated surgically. No perioperative albendazole was administered. No patient received albendazole afterwards. The mean hospital stay was 25 days. Interventions are urgently needed to assess the burden of CE in Kazakhstan and to inform clinicians of the existence of the disease.

Evaluation of the recombinant antigens B2t and 2B2t, compared with hydatid fluid, in IgG-ELISA and immunostrips for the diagnosis and follow up of CE patients.

Cystic echinococcosis (CE) is one of the most widespread helminthic zoonoses and is caused by the tapeworm Echinococcus granulosus complex. CE diagnosis and monitoring primarily rely on imaging techniques, complemented by serology. This is usually approached by the detection of IgG antibodies against hydatid fluid (HF), but the use of this heterogeneous antigenic mixture results in a variable percentage of false positive and negative results, and has shown to be useless for follow-up due to the long persistence of anti-HF antibodies in cured patients. To improve test performances and standardization, a number of recombinant antigens mainly derived from HF have been described, among them the B2t and 2B2t antigens. The performance of these antigens in the diagnosis and follow up of patients with CE has been so far evaluated on a limited number of samples. Here, we evaluated the performances of tests based on B2t and 2B2t recombinant antigens compared to HF in IgG-ELISA and immunochromatography (IC) for the diagnosis and follow-up of patients with CE in a retrospective cohort study. A total of 721 serum samples were collected: 587 from 253 patients with CE diagnosed by ultrasonography (US), 42 from patients with alveolar echinococcosis and 92 from healthy donors from Salamanca (Spain). The highest overall sensitivity was obtained with HF in ELISA (85.5%), followed by IC containing HF and 2B2t-HF (83.0% and 78.2%, respectively). The lowest sensitivity was obtained with B2t and 2B2t in ELISA (51.8%). The highest specificity was obtained with IC containing 2B2t-HF (100%), and the lowest with HF-ELISA (78.0%). The lowest cross-reactivity with sera from patients with alveolar echinococcosis was detected with the recombinant antigens in ELISA (9.5% - 16.7%) and the highest with the HF-IC (64.3%). The results of B2t and 2B2t-ELISA were influenced by cyst stage, as classified by US according to the WHO-Informal Working Group on Echinococcosis (WHO-IWGE), with low sensitivity for inactive (CE4 and CE5) cysts, and by the drug treatment, with higher sensitivity in patients after drug treatment compared with patients not subjected to drug treatment. The two recombinant antigens in ELISA provided promising results for monitoring patients in follow-up, although their use is limited to patients with positive serology against them at the beginning of the follow-up. Potential biological reasons behind the low sensitivity of the recombinant antigens and possible strategies to enhance the performance of CE serology are discussed.