The differential diagnosis of hepatic cystic echinococcosis (CE) may be challenging. When imaging is insufficient, serology can be applied, but no consensus diagnostic algorithm exists. We evaluated the performances of nine serological tests commercialized in Europe for the diagnosis of “echinococcosis”. We performed a diagnostic accuracy study using a panel of sera from patients with hepatic CE (n = 45 “liquid” content stages, n = 25 “solid” content stages) and non-CE focal liver lesions (n = 54 with “liquid” content, n = 11 with “solid” content). The diagnosis and staging of CE were based on ultrasound (gold standard). Nine commercial seroassays (5 ELISA, 2 WB, 1 Chemiluminescence Immunoassay [CLIA] and 1 Immunochromatographic test [ICT]) were the index tests. Sensitivity (Se) ranged from 43 to 94% and from 31 to 87%, and specificity (Sp) from 68 to 100% and from 94 to 100%, when borderline results were considered positive or negative, respectively. Three seroassays (2 ELISA, 1 WB) were excluded from further analyses due to poor performances. When tests were combined, Sp was 98–100%. The best results were obtained using the WB-LDBIO alone (Se 83%) or as a third test after two non-WB tests (Se 67–86%). A validated WB or two non-WB tests, read with stringent criteria (borderline = negative and considered positive only if concordant positive), possibly confirmed by the WB, appear sensible approaches.

Background: Strongyloidiasis, a nematode infection which is mainly caused by Strongyloides stercoralis in humans, can lead to a fatal syndrome in immunocompromised individuals. Its diagnosis is challenging due to the absence of a diagnostic gold standard. The infection is highly prevalent in migrants from endemic countries in tropical and subtropical areas, and a rapid diagnostic test would be helpful for screening purposes. The aim of this study was to estimate the accuracy of a novel immunochromatographic test (ICT) for the diagnosis of S. stercoralis infection. Methods: A single-centre diagnostic accuracy study was undertaken using well-characterized frozen sera available from the biobank of a referral hospital for parasitic diseases in Italy. The included sera were from migrants from sub-Saharan Africa, and matching results were available for agar plate culture and/or polymerase chain reaction for S. stercoralis; moreover, the results of both a commercial enzyme-linked immunosorbent assay test and an in-house immunofluorescence test for strongyloidiasis were made available. Laboratory staff who read the ICT results were blinded as regards the results of the other tests. Two readers independently read the ICT, and a third one was involved when results were discrepant. The accuracy of the ICT was assessed both against the results of the panel of faecal tests and by latent class analysis (LCA). Results: Agreement between the readers was excellent [Cohen’s κ = 92.7%, 95% confidence interval (CI) 88.3–97.1%]. When assessed against the results of the faecal tests, the sensitivity and specificity of the ICT were 82.4% (95% CI 75.7–89.0%) and 73.8% (95% CI 66.8–80.9%), respectively. According to the LCA, the sensitivity and specificity were 86.3% (95% CI 80.1–92.5%) and 73.9% (95% CI 67.0–80.8%), respectively. Conclusions: The results of the ICT demonstrated ease of interpretation. The accuracy proved good, though the sensitivity might be further improved for screening purposes. Graphical

Background: Currently approved vaccines are highly effective in protecting against hospitalization and severe COVID-19 infections. How pre-existing immunity responds to new variants with mutated antigens is crucial information for elucidating the functional interplay between antibodies and B and T cell responses during infection with new SARS-CoV-2 variants. Methods: In this study, we monitored the dynamics and persistence of the immune response versus different SARS-CoV-2 variants of concern that emerged during the pandemic period (2021–2022) in a cohort of vaccinated healthcare workers, who experienced breakthrough infection in the Pre-Delta, Delta, and Omicron waves. We evaluated both the humoral and cell-mediated responses after infection. We also evaluated the anti-SARS-CoV-2 antibodies levels produced by infection in comparison with those produced after vaccination. Results: Our results highlighted that the immune response against the Delta VOC mainly involved an adaptive humoral and switched memory B cells component, even 3 months after the last vaccine dose, conversely showing a high percentage of depleted adaptive T cells. Omicron infections triggered a consistent production of non-vaccine-associated anti-N antibodies, probably to balance the spike epitope immune escape mechanisms. Conclusion: Our results suggest a direct dependence between the VOC and different humoral and B and T cell balances in the post-infection period, despite the administration of a different number of vaccine doses and the elapsed time since the last vaccination.

Background: The potential of schistosomiasis to spread across borders, coupled with the considerable delay by which infected travellers and migrants are diagnosed in Europe, calls for better surveillance of the distribution of this disease. This study explored the geographical origin and genetic profiles of Schistosoma infections imported into Europe and diagnosed in a network of 11 European centres specialized in traveller and migrant health. Methods: Genetic profiles were obtained from DNA extracted from concentrated Schistosoma eggs or Schistosoma -positive samples (faeces, urine, biopsy) collected during routine diagnostic procedures. The species-specific cytochrome oxidase sub-unit 1 ( cox1 ) diagnostic region and the standard complete internal transcribed spacer (ITS) 1 + ITS2 (ITS1 + 2) ribosomal DNA region were amplified and sequenced, together with a partial region of 18S ribosomal DNA in selected cases. Prevalences of the different genetic profiles within the whole patient cohort and by country/geographical area of possible infection were analysed. A phylogenetic analysis was performed using the larger cox1 (~ 956 base pairs) sequences dataset. Results: A total of 94 samples were available for analysis, 36 from patients with a diagnosis of intestinal schistosomiasis and 58 with urinary schistosomiasis, all acquired in a sub-Saharan African country. Mitochondrial (mt) cox1 , nuclear ITS1 + 2 and/or 18S (mt/nuclear) genotypes were successfully obtained from 51/94 (54%) samples; while for 43/94 (46%) samples, only a partial mt genotype was obtained. Infections with Schistosoma haematobium and Schistosoma mansoni were identified in the majority of cases (66/94; 70%), while mixed Schistosoma spp. genetic profiles, which were identified in 30% (28/94) of the samples, were almost exclusively (27/28; 96%) associated with cases of urinary schistosomiasis. Among the urinary infections, almost half (27/58; 47%) could be identified as having a mixed genetic profile. These mostly (26/28; 93%) included genetic traits of S. haematobium and Schistosoma bovis , and all were from patients probably infected in West Africa. Conclusions: Infections with S. haematobium and S. mansoni represent the majority of cases of schistosomiasis currently being diagnosed in Europe; however, mixed Schistosoma genetic profiles (mostly S. haematobium/S. bovis ) were identified in at least 30% of samples. Our results call for a coordinated effort encompassing prompt diagnosis and treatment of Schistosoma infections, together with monitoring of the possible introduction of species of Schistosoma and establishment of their autochthonous transmission under suitable conditions in Europe.

Background/Objectives: Strongyloides stercoralis is a soil-transmitted helminth that can cause severe disease in immunocompromised individuals. In non-endemic clinical settings, recommended diagnostic strategies rely on serology alone or in combination with a sensitive fecal test, maximizing sensitivity to avoid missed infections. The S. stercoralis VirClia^® IgG monotest (Vircell, Spain) is a novel automated chemiluminescent immunoassay (CLIA) that detects IgG antibodies against the recombinant NIE and SsIR antigens. This study evaluated its diagnostic accuracy (sensitivity and specificity) in a non-endemic clinical setting. Methods: In this monocentric retrospective study, 245 serum samples from the Tropica Biobank of a referral centre for parasitic diseases in Italy were analyzed. Samples originated from individuals from Africa (n = 85), America (n = 31), Asia (n = 53), and Europe (n = 76). Diagnostic accuracy was estimated using Bayesian latent class analysis based on a model including five routinely used diagnostic tests. Results: The S. stercoralis VirClia^® IgG monotest showed a sensitivity of 95.0% (95% credible interval [CrI]: 90.1–98.2%) and a specificity of 90.8% (95% CrI: 85.1–96.0%) for the tested population. Conclusions: In immunocompetent individuals with a risk of previous exposure to S. stercoralis, the S. stercoralis VirClia^® IgG monotest showed high diagnostic accuracy. Its high sensitivity supports current recommendations favouring highly sensitive serological assays for screening and diagnosis in non-endemic clinical settings.

Background/Objectives: The diagnosis of infection with Strogyloides stercoralis, recently targeted for control by the World Health Organization, (WHO), is challenging. Specific coproparasitological methods (agar plate culture [APC], Baermann sedimentation), recommended by the WHO for public health use, are labor-intensive and require bulky disposable materials as well as experienced microscopists. We explored the sensitivity of an alternative stool culture method using recyclable glass beads, followed by microscopy and PCR in comparison to routine APC and PCR performed on uncultured stool. Methods: We conducted a diagnostic sensitivity study on samples from patients with positive serology for strongyloidiasis who submitted stool specimens to our laboratory between January 2023 and December 2025 for parasitological confirmation. Samples were processed by routine APC and PCR on fresh stool, as well as experimental culture on bead-based plates (BPC), PCR on APC- and BPC-cultured stool, and PCR on stool incubated directly in the collection container. Results: Twenty-six of 110 samples (23.6%) tested positive in at least one technique. Within this subset, the most sensitive techniques were the APC and PCR after APC (both 84.62%); PCR on fresh stool was the least sensitive (42.31%) (p = 0.002). The sensitivity of BPC (65.38%) was lower than that of APC, although not statistically significantly. Comparable sensitivity was observed between microscopy and PCR after APC or BPC. PCR after incubation in the container showed a sensitivity of 57.69%. Agreement ranged from 50 to 84.6%. Conclusions: Alternative culture methods with more field-friendly implementation features could be interesting alternatives to standard methods. Further studies evaluating their performance and applicability in public health and clinical contexts are warranted.